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Let me introduce you to Rebecca (not a real name). She is an engineer, more precisely a vehicle engineer: someone, an expert, who has been trained to develop and build cars.

Today is a very exciting day for Rebecca. After a long search and many disappointing refusals, she has finally landed her dream job: she is going to work as senior engineer in one of the worlds leading car manufacturers! Specifically, she has been hired to develop next-generation vehicles: energy-efficient cars, self-driving trucks, you name it. The stakes are high, but Rebecca is ambitious and confident in her skills. After all, her qualifications are flawless and she has done several internships in top-notch companies in her field. In short, she is more than ready to tackle this challenge and start turning her dream designs into real vehicles. She has been preparing all her live for this moment. She cannot wait to meet her new colleagues during her induction day, it will be a moment for sure to remember, she thinks.

After reporting at the company’s reception, she is brought to the manager’s office. We will call him Branden (again not a real name, for privacy reasons, we cannot afford lawsuits). Branden tells Rebecca how delighted they are that she accepted their offer, that the company sees a great potential in her, and that they will help her as much as possible to develop her exciting designs. After some polite small talk about not very interesting generalities, Rebecca asks Branden the questions that were burning inside her but that she never had the courage to ask when she was interviewed for the job. What follows is an abridged version of that conversion between Rebecca (B) and her manager Branden (B).

The above story, you would agree, sounds a bit ridiculous: a car company that hires a stellar engineer but then does not provide the means for her to do any of her core work! Well, replace a car company with a university and welcome to Academia. Believe it or not, the situation that early career scientists (e.g. recently hired Assistant Professors) face, is, with some caveats, similar to the story of our unfortunate Rebecca. In a nutshell, you are hired to carry out research but are not given the means to do this research. For this you have to apply for research funding, a competitive and time-consuming system where success is more often than not the exception. And who survives in these academic Hunger Games? The fittest, the luckiest, or the more persistent? This will be the content of the next post …

Disclaimer: the following post is going to be a rather dry one about some recent controversies concerning the funding of the higher education system in The Netherlands. Moreover, it is probably going to be incomplete and not fully accurate, both since the discussion is quite complex and also since my understanding of the overall situation (as well as my Dutch skills) is still somewhat limited. In any case, this ongoing argument is something that most likely will directly shape the near and long term future of the Dutch universities and research institutions, so it is definitely worth trying to understand a bit what is going on.

Let me start with a quick overview of the Dutch higher education system, summarised by the numbers below. The overall yearly budget of the national universities is around EUR6.8G, with most of it (EUR3.8G) coming from directly from the government (the so-called Rijksbijdragen), followed by European (think of ERC for example) and private funding (EUR1.9G) and then in smaller proportion by the NWO, the Dutch Organisation for Scientific Research, and by the student tuition fees (collegegeld). With these means, in 2016 more than 260K students were being educated in one of the Dutch higher education programs by around 25000 academics (where here the tally includes also PhD students and junior teachers). Interestingly, following a similar trend as in other countries, the number of support, management, and policy personnel is now comparable to that of the actual academics.

All this mess about the infamous Van Rijn commission and recommendations has to do with the way the Dutch higher education system is being financed by the government, and a number of proposed changes in this model. As with most other European countries (England excluded of course), also in the Netherlands higher education is reasonably affordable, being heavily subsidised by the state. As show in the map below, The Netherlands falls into the middle category of European countries, with the average yearly tuition rates for EU students being around EUR2K. This of course does not mean that higher education is cheaper here than say in the UK, but rather that a bigger chunk of the cost is financed indirectly via the taxpayers as compared to the upfront costs paid by the students (in terms of the tuition fees).

A very remarkable feature of the lowlands is that, despite being a relatively small country, The Netherlands has an outstanding university system, both in terms of education and of research. For example, according to the THE World University Rankings (insert here all required caveats/rants about rankings before moving on), The Netherlands has 13 universities in the top 500, to be compared with the 21 of France and the 8 of Spain, countries with a significantly larger population. One can also take a look at many other estimators, such as number of scientific papers and their impact, the number of grants from the European Research Council secured by PIs hosted by Dutch institutions, patents, and one could go on for a long time. All these complementary measures tell a consistent story: the Dutch higher education system appears to be in outstanding shape and world-leading science is being carried out at its universities and research institutes.

Or it this not the case? Actually, there are number of signals that suggest that the situation is far less rosy, and that the position of the Dutch higher education system might be under strong pressure. One reason for this has to do with the way Dutch universities receive their funding for education from the government, the so-called first money stream. In the current system, this source of income depends heavily on the number of students that enrol in a given education program (say a bachelor or a master program) in any given year. This choice of financing model leads to several challenges. First of all, faculties and departments are faced with a significant uncertainty concerning their funding even on a year by year basis: if the number of students decreases in some programs suddenly then might find themselves in red numbers, while if the opposite situation happens they might turn out to be understaffed and have to quickly hire new instructors and teachers, or even have to look for new lecture rooms. The bottom line is that in such situation long term and strategic planning is clearly difficult due to these potentially sudden variations of income. This often leads to an increase in the relative fraction of scientific personnel in temporary contracts, which allows universities to adjust more easily to changes in supply and demand in the education market. Whether this increase in temporary positions as opposed to permanent staff is desirable is a topic for another discussion, but it seems to be that it is a natural consequence of the current financing model.

Another problem associated to this funding model of Dutch higher education system is that it creates incentives to dump programs with low influx of students and focus on those with high influx. This has lead to the termination of programs with an insufficient number of students, such as the recent example bachelor program in Dutch language at the VU Amsterdam, which created a certain outrage in the media (but again, there is limited wiggle room to tackle this kind of problems within the current funding model). There are also concerns that this system creates perverse incentives to emphasise quantity instead of quality, and boost as much as possible the number of students at any cost. While it is of course important to take into account the preferences of the students (at the end of the dat, it is their own lives which will be affected by such choices) it might seem to be unwise that these choices completely determine which programs are on offer. One can always make strong cases for higher education programs that might be less attractive but are equally important for the society in the long term, and that deserved to be sustained rather than cancelled at the earliest opportunity.

As far as I understand, at some point the current government realised that the job market required many more graduates with hard natural sciences and engineering degrees that the universities were producing. Moreover, the recent increase in the number of students in these disciplines had lead to a structural underfunding of these programs, specially for the technical universities such as TU Delftt and TU Eindhoven. With this motivation, the Dutch government wanted to increase the funding of the hard natural sciences (which for some obscure reason are known as the Beta-disciplines in Dutch) as well as the engineering degrees. So they installed the so-called Van Rijn commission with the task of finding a way to improve the funding of the beta and technical programs, and here comes the catch, in a budget neutral way. While the devil is in the details, one does not need to be a rocket scientist to figure out that this can only happen if part of the funding which is currently allocated to the social sciences and the humanities, and the medical disciplines (again in the Dutch jargon known as the alpha and gamma disciplines respective) to the exact sciences and the engineering programs. And indeed this is one of the main recommendations of the Van Rijn commission, which has been in most part assumed by the Ministry of Education, Culture, and Science (OCW). While there are many positive aspects of Van Rijn, such us proposing a more stable model less depending on student influx and reducing the competition for research funding in favour of an increase in structural resources, this redistribution both between universities and between disciplines is my far the most controversial measure.

And while there is a war going on about the numbers (where the government claims that the universities are going to receive actually more money as compared to the current situation and with everyone else claiming the contrary) some projections are extremely disturbing: if implemented, the recommendations of the Van Rijn commission could lead in the next few years to a “redistribution” of teaching and scientific personnel from the alpha/gamma/medical disciplines to the beta/technical ones of rather staggering size: up to 2000 FTE (full time equivalent), which for a country as the Netherlands would be rather devastating. Of course here redistribution is just the jargon that human resources people like to use to soften the blow, but in plain language this simply means that these 2000 FTE will either be fired or their temporary contracts will not be renewed, in order to hire their counterparts in the beta/technical programs. Fun fact: in the Dutch higher education system there is no such thing as being tenure, and even full professors or other scientific staff with permanent contract can be fired if the university management deems it necessary.

In the table below, one can find a summary of the assessment by the Dutch Association of Universities (VSNU) about the impact of the the implementation of the measures of the Van Rijn commission would have on their short-term financing. While general universities would loose up EUR10K each in terms of structural funds, the technical universities, in particular TU Delft, would strongly benefit from the redistribution. See here for a more extensive discussion of the financial consequences of the implementation of the recommendations of the Van Rijn commission. The universities of Groningen, Maastricht, and Rotterdam would be the ones most severely affected by these cuts.

De VSNU heeft de tabel die maandag in het debat #VanRijn werd uitgedeeld, aangevuld met alle relevante cijfers. Zie https://t.co/BFuSDGFMRV pic.twitter.com/NCv1Aabhmj

— Universiteiten van Nederland (@tweetsunl) July 3, 2019

If, as it seems to be the case, the government is going to move forward implementing the recommendations from the Van Rijn commission, the general universities will face an almost unsolvable dilemma: or they decides to avoid any redistribution between faculties, making even more severe the under-financing problem of the scientific disciplines, or they redistribute funding and personnel from alpha, gamma, and medical programs to the Beta ones, dealing a very serious blow on otherwise very succesful education programs and compromising their long-term viability. My own university, the VU Amsterdam, has already announced that they will not implement any redistribution in 2020, but at some point in the future some kind of action will need to be taken, an “impossible balancing act” to implement: current estimates imply that due to Van Rijn by 2022 around 120 FTE will need to be “redistributed” from the beta, gamma, and medical disciplines to the beta ones within the VU, where again redistribution means either not renewing the contracts of temporary staff or of directly terminating the contracts of permanent scientific personnel.

“Divide and conquer” is not a sustainable strategy for the future of higher education. It’s a bad idea, plain and simple. Invest in the future! @VUamsterdam @CarelStolker @Rianneletschert @eppobruins https://t.co/pkrnXnGq67

— Vinod Subramaniam (@vinsub) July 1, 2019

Perhaps the most mind-blowing aspect of this situation is that The Netherlands is not a poor country with a struggling economy which simply does not afford to invest in higher education. On the contrary, it is a rich country with a booming economy. Indeed, in 2018 the overall budget surplus was of 11 billion euros, that is, around three times the total government contribution to the whole higher education system (see figures above). So there does not seem to be any reasonable financial or budgetary reason to impose this dramatic austerity, other than the deliberate political will of reducing the size of the alpha and gamma sectors in higher education. I might be very well be missing something important here (Dutch politics are almost incomprehensible for the outsider, with a multitude of small parties and a complicated “polder” model for negotiating among them), but it seems to be rather short-sighted in addition to unnecessary.

Perhaps a key aspect of the whole discussion that politicians might be missing is that investing on education in general, and higher education in particular, is quite different that say building a highway. There you can build one part, stop if you run out of money, and then finish when money comes back, easy peasy, and get the job done. But building a strong, competitive higher education ecosystem takes decades to consolidate but it can be destructed very easily, as the sad example of Spain shows, still reeling from the savage cuts that took place after the economic crisis in 2008. Or perhaps they realise that this is the case, and then everything is done on purpose? The Netherlands is already one of the most effective countries in Europe in terms of research productivity (ratio of output to investment) but further squeezing this lemon might end up cracking the system.

To me, as someone who has just recently joined the Dutch system, the whole discussion seems almost surreal: why a wealthy country would like to unnecessarily damage its highly competitive higher education and scientific ecosystem? In a very competitive world, with powerful emerging economies playing each time a more important role in the global stage, reducing the support for a crucial pillar of the future of a country and its economy such as higher education is really difficult to understand.

Despite the title, I have never seen a single Game of Thrones episode. I read the first of the books though some time ago, and while the book was interesting and catchy, everyone there was very but very bad and miserable, so I was not really motivated to proceed further. This said, I remember that Tyrion Lannister seemed at a first glance a character that might last a couple of chapters at most, specially given the low survival rate on the GoT universe. But apparently, at least from the Twitter spoilers, he was remarkably still around in the last episodes of the series. So all in all, his strategy was reasonably succesful: starting as an underdog, he became one of the dominant figures of the storyline, which is no small feat taking into account that terrible fire-breathing dragons were also involved. So Tyrion Lannister seemed to me to be a not too bad analogy to discuss some interesting recent developments about the future collider saga, namely the fact that the Compact Linear Collider (CLIC), which for a long time seemed not to be topping the bookies’ predictions , now appears to slowly but surely be gaining traction within the community. I will try to explain in this post why this might be the case.

What is CLIC? A nice summary of this future collider project can be found in the talk that Aidan Robson gave at the Nikhef Colloquium recently. CLIC would be a high-luminosity, multi-TeV electron–positron collider to be built at the CERN site which would operate in three phases. The first one, CLIC-1, would have a center of mass energy of 380 GeV and would focus on precision studies of the Higgs boson and the top quark, which are sensitive to potential new physics beyond the Standard Model (SM) via quantum corrections. Such program is to common to other proposed lepton colliders such as the International Linear Collider (ILC), the FCC-ee or the Chinese CepC. The key difference of CLIC is that it can be be upgraded to CLIC-2 (operating at 1.5 TeV) and then CLIC-3 (at 3 TeV), being thus the only lepton collider over the table that can reach the multi-TeV region. This offers significant advantages, both in terms of guaranteed deliverables (such as the measurement of the Higgs potential) as well as a marked increase in the reach for direct and indirect physics beyond the SM. Moreover, this upgrade program could be adjusted to other center of mass energies after stage-1, provided there is a good scientific motivation for that.

Indeed, one of the main physics goals of any future particle collider beyond the high-luminosity LHC should be the precise measurement of the Higgs self-coupling. The strength of the self-interactions of the Higgs boson plays a crucial role in the mechanism that drives electroweak symmetry breaking, and might be related to cosmological phenomena such as the matter-antimatter asymmetry or the phase transitions in the early universe. Some researchers are even proposing that the Higgs boson itself was the responsible for inflation. In this respect, the high-energy stages of CLIC offer the potential of measuring the Higgs self-coupling with a precision of a few percent . Lower energy lepton colliders, in particular the circular FCC-ee and CepC, would not be able to directly access this self-coupling via Higgs pair production though still they could be sensitive to it via quantum corrections to single Higgs production, emphasising the need for a global approach. Note that only for center of mass energies above 500 GeV is a lepton collider able to produce pairs of Higgs bosons at an appreciable rate.

CLIC would also be able to extend the HL-LHC reach for searches of new particles and interactions. In the context of such searches for potential new physics beyond the SM, it should be emphasised again that the distinction between direct (where one explicitly produces new heavy particles) and indirect (where quantum effects modify the properties of known particles) constraints is rather arbitrary. Indeed, with both types of searches one is being sensitive to kinematic regions never explored before, which is the main point of a search. To illustrate the potential of indirect searches at lepton colliders such as CLIC, in the figure below I show the expected bounds on the Wilson coefficients of specific dimension-6 operators of the Standard Model Effective Field Theory (the SMEFT) from future colliders, compared to the reach of the HL-LHC. Note from the right y-axis that these bounds can be interpreted as probing energies as high as 50 TeV, depending on the operator, which is much higher that the actual center of mass energy (3 TeV in stage-3 of CLIC). Here the SMEFT is the lower-energy effective theory of any ultraviolet completion of the Standard Model, and is written as a tower of higher-dimensional operators, , with $\latex \Lambda$ is the scale of new physics where the effective theory approximation breaks down. This way, with precision measurements of “SM” processes, either at proton-proton or at lepton-colliders, we can thus be sensitive to energy scales way above those of which that probed by direct searches. For these kind of studies the very clean environment of electron-positron collisions, with a high signal to background ratio, is very beneficial.

Ok, so far so good. Now about the challenges: despite the very attractive scientific prospects, the main difficulties to be overcome by CLIC (partly shared with any other future collider proposal) are the costs and the energy footprint. In the table below I show an overview of the (approximate) costs of power consumption for different proposals for future colliders, as summarised in the documents for the European Strategy for Particle Physics update. Assuming that very rough conversion factor that 1 ILCU = 1 CHF = 1 $ hold, then one sees that the costs for the various Higgs factories (ILC, CLIC-1, CEPC) are similar, with the exception of FCC-ee, which would be around a factor 2 more expensive. Note however that the FCC-ee cost includes also the costs of digging the 100 km tunnel.  If the FCC-hh is built afterwards, then its costing would be a further CHF17K, but if FCC-hh is built standalone. one needs to add the CHF7K for the tunnel. This implies that the costings for the FCC-ee and the FCC-hh become more attractive once they are considered as a joint facility, rather than as two single experiments, since then the tunnel digging costs are shared between the two of them. In other words, assuming that the FCC-hh is built afterwards (and this is a big if), then the costings of FCC-ee become comparable to those of CLIC stage-1, ILC250, and CepC.

Let me also emphasise however that the total costs of these facilities needs to the factored out by its total operation time: this is not a on-off payment but rather a long-term investment in cutting edge fundamental science and technology, with quantifiable returns on investment also in terms of spin-offs, education, and outreach. Another interesting number in this comparison is the power consumption required by these facilities: between stage-1 and stage-3, the power consumption of CLIC would increase by more than a factor 3, where its energy footprint would become comparable to that of the FCC-hh, the 100 TeV future hadron collider.

What is then the gist of the matter? Why, given that its physics potential is comparable or superior to that of other electron-positron high-energy colliders (in particular thanks to its higher in center of mass energy) and that the costs are not particularly worse, CLIC might seem to be the underdog in the future collider wars? One reason has to do with the long-term scientific strategy that CERN will select for its future. Certainly, there is a strong motivation for CERN to plan ahead such that there is a new collider operating on site once the HL-LHC program is completed around 2035. The question, of course, is what type of collider should that be. For example, the advocates of the circular project, FCC-ee, advocate strongly that this project could indeed start by 2035 (provided the construction of the 100 km tunnel starts around 2025) and moreover that it would naturally pave the way towards the 100 TeV hadron collider since the tunnel would already be in place (in the same way as LEP paved the way to the LHC, the argument follows). Most certainly CERN is not going to build two lepton colliders, so if one decides to follow this option (as opposed to say moving directly to a higher energy proton collider), then the choice would be between CLIC and FCC-ee. In this case, the main argument in favour of the FCC-ee as opposed to CLIC is that it facilitates the eventual construction of a 100 TeV (or higher) hadron collider. So CLIC advocates need to (scientifically) fight not only with the FCC-ee aficionados but also with those of the 100 TeV hadron collider.

This is, however, only a small part of the story, since also the role played by the Asian community will be crucial. In particular, whether or not the Japanese keep pushing the ILC project, in principle with the support of CERN (under active discussion now) and the Chinese move forward with their Higgs factory project CepC (increasingly likely) will affect any decision that CERN takes in this respect. It is clear that the chances of CLIC would increase if the ILC does not move forward, for example, specially since ILC is unlikely to be realised without CERN’s support. Note, in any case, that CLIC, in particular due to its unique reach into the multi-TeV regime, has from many points of view a complementary physics program to that of the Higgs factories. It is therefore a complicated discussion with many actors involved.

The question of the timescales is also of paramount importance in this discussion: as mentioned above, ideally one would like the next collider to start operation as soon as HL-LHC is completed (if built on the CERN site) or as soon as possible if it is built in some other location, in Asia for example. According to the timeline below, both CLIC and the ILC could start operation as soon as 2034, with CepC even a few years earlier. FCC-ee would start shortly afterwards, but with as many attractive features as it has, it would also delay the start of the CERN’s 100 TeV hadron collider by up to around 2060 at the earliest. Even by the standards of high energy physics, this is perhaps planning far too long in the future: I will be lucky to be around to see the first 100 TeV collisions, though perhaps I will have uploaded my brain to the cloud by then ;). This is thus another important factor to take into account in the discussion for future colliders: is it wise to plan ahead that far in the future? Maybe, I don’t have the answer for this question. In this context, another of the selling points of CLIC is that its energy can be adjusted to tailor to any new developments on our field, for example, hints or even discoveries of new physics that might be provided by the HL-LHC or evidence for heavy dark matter particles. In this case these new insights could be use to tune the center of mass energy of CLIC after the initial (Higgs and top factory) stage to ensure a maximal scientific return.

What are then the next steps? If CERN wants to have a new particle collider operative by the time the HL-LHC program is completed, a decision about start digging tunnels (or replacing and producing magnets) needs to be made by 2025 at the latest. This means that the recommendations that will be provided by the current EPPSU, to be presented by 2020, will not be definitive but will anyway be very important to inform the 2025 decision. For example, a recommendation to invest in further R&D for the CLIC accelerator technologies could be understood as a sign that this machine could be the future of CERN. It is not written in stone that the high-energy frontier can only be reached by hadron collisions, and perhaps plasma wakefield acceleration or muon colliders will be the next big breakthrough in particle physics. In the meantime, we want a collider with a bullet-proof physics case, that combines guaranteed deliverables with a wide exploration potential and that is based on demonstrated reliable accelerator technologies. We also want to avoid duplications and overlaps and we should combine global efforts in HEP in an optimal way. The Strategy Group in charge of writing these recommendations has a challenging task in front of them, so we should all stay tuned for developments!

Correction: I fixed a mistake in the FCC tunnel costings, thanks to Aidan Robson for pointing this to me!

Some relatives of mine have always been obsessed with the details of my work schedule. They were not really interested in the actual content of my research, but kept asking every time we met at what time I was expected to start working in the mornings, when was I allowed to leave work in the afternoon, how many days of holiday did I have per year, and so on. They were not alone: many of my friends, while I was pursuing my PhD, were also puzzled about what exactly I was doing at the university and how I spent my time there during the day.

So what actually do researchers all day round? How do they distribute their time? What on Earth does actually doing science really mean? Actually, we are pretty busy people, trying carry out at more or less the same time an ever-growing number of activities. To begin with, a researcher, specially if she is embedded into a university, is expected not only to carry out research, write papers, and request and secure external funding, she also has to teach, organise courses, supervise bachelor, master, and PhD thesis students, recruit teaching assistants, contribute to management tasks at the department, faculty, and university level, participate in selection committees of all sorts (hiring, promotion, evaluation, accreditation, curriculum), and one could go on more and more. On top of all this, one needs to add academic travels, participating in workshops and conferences, attending seminars, colloquia, and all kinds of related events. Moreover, note that several of these tasks can be considered on their own full-time jobs. It is thus natural to ask how at all is it possible to juggle all these responsibilities in a minimally efficient way? It would seem almost a mathematical impossibility to fit all of them within a 40-hour week ….

These already tricky boundary conditions are rendered even more stressing by the intrinsic inefficiency of some of the core activities that constitute the everyday life of researchers. A prime example of this is applying for research funding. It is very difficult to be able to carry out your research program without first securing external financial support (and in some countries, like in The Netherlands, literally impossible since all grants are to some extent personal). In addition, one of the most important criteria for the stabilisation of tenure trackers and early career researchers is their demonstrated ability to attract external funding. All this would be very reasonable, if not for the fact that the plummeting success rates imply that most of the sizeable amount of effort that researchers invest in writing grant applications is demonstrably wasted time.

The same considerations apply to other facets of academia. For many of my colleagues, it is not the large workload that represents the most challenging aspect of their job, but rather it is the futility of many parts of it. In other words, it is not the hard work itself, but the pointlessness of some (or many) of our core activities, which is the source of endless frustration. Meetings, needless to say, fall also straight on in this category. It is not uncommon that I have back-to-back meetings the whole day, and I consider myself as someone with a relatively light teaching and management load. While some meetings are useful and productive, and thus necessary, some others are utterly irrelevant – nothing sinks your heart as having to sit through a 2-hour meeting with the certainty that this is time lost forever. Moreover, (many) academics are the kind of people that enjoy listening to themselves, so meetings often become a succession of incoherent interventions rather than a truly productive conversation.

We don’t have an agenda for today’s meeting, only updates. Which means we’ll explain to the chairs who weren’t here last week what we explained to you then.

— Associate Deans (@ass_deans) June 4, 2019

Given the many pressures of academia, and the limited time available, it is not surprising that one often hears or reads the statement that science cannot be considered as a regular nine-to-five job, and that committed researchers, if they really want to strive for excellence and be successful in their careers, should be able to sustain a workload of say 70 or 80 hours per week during extended period of times. In addition, they should also be able to endure endless travels, attend conferences all over the world for networking and to publicise their results, and accept all possible requests of service and committee memberships that they receive, without forgetting various other important duties such as for example being editors and referees of journals and academic publications. Needless to say again, the same people expect that scientists should also of course check their emails at all times, and reply immediately even late at night or during weekends and holidays. Is it therefore true that only those scientists so devoted to their work that they would deserve the appropriate label of workaholics will attain success and reach the pinnacles of Academia?

On the one hand, It cannot be denied that being successful in academia in general, and in scientific research in particular, requires to work very hard, to be focused and well organised, and to some extent also to make sacrifices in your personal life. On the other hand, it is a demonstrably false statement that success can only be achieved by systematic working overtime evenings, weekends, and even holidays. Sure, there are times when an extra push is required, for example to meet a deadline, or to finalise a publication, but as a general rule keeping a healthy balance between your work and personal life will in the long term make you a more effective (and thus succesful) scientist, and, even more importantly, a happier person. Moreover, while everyone is free to manage their time as they find more appropriate, those PIs (principal investigators) that impose this workaholism viewpoint to the junior members of their groups and expect nothing else from them than complete devotion with immediate replies to their email requests even on weekends and holidays, in addition to violating labor law, are deliberately putting them in a dangerous situation and making them likely to experience burn-out or be affected by the mental health issues that ravage academia.

Though deriving conclusions based on a N=1 sample is not very scientific, I have been basically working “office hours” my whole scientific life and I think I can be reasonably happy with the end result. This means in particular I have never worked on weekends and very seldom on evenings, unless there are deadlines that, procrastinators as we are, we struggle to meet at the last minute. And I don’t think for a minute that I would have been more succesful, productive, and happier had I worked overtime systematically, most likely the opposite would be true (not that I had much choice with childcare duties since the end of my PhD!). This said, this does not mean that I switch off my brain to science while I am outside the office, since I fear that I am well past this point. For example, I start putting together grant proposals or papers when doing household chores: in particular I strongly recommend vacuuming for pumping your imagination in case you need a catchy title for your proposal, in my experience this has worked pretty well 😉

Ok, all this is very nice, but still one has to manage a rather heavy workload. So how does this work in practice? Again speaking from my experience, I would say that they key point is not working more, but in working better and being more efficient and selective. Scientific research is not quite the same as say building a pyramid, where if you spend twice the time you will (hopefully) get twice the job done. There are many cases in which working more leads to diminishing return, and there is plenty of scientific evidence that productivity drops after working a given amount of hours. You simply cannot be productive for 12 hours in a row, no matter how you put it, at least in a systematic way. So with the risk of sounding like a dubious self-help guru, here you have some tips that can help in this respect.

• Be very selective: attend only the really important seminars and conferences, and drop everything else. Try to ensure as much quality time as possible to write and carry out research, and if this involves not attending every single seminar or colloquia scheduled in your department, then so be it.
• Say no to things. You don’t need to accept every possible invitation to give a talk abroad, to write an invited chapter or to participate in the organisation of that conference. All these things are important but also time consuming, so prioritise what are the most relevant opportunities and politely decline everything else.
• Cluster you days in coherent groups of activities. For example, one can have days where all the meetings in the week are scheduled, including student supervision, or the days where one focuses only on writing papers or preparing lectures. You can have “teaching days”, “management days”, “research days”, and likewise, and in those days focus only on that activity and postpone everything else.
• Do not check email compulsively. Check email maybe every hour or two hours, and only answer the really urgent ones. You can then answer the less urgent emails at a later stage. A very succesful physicists whom I know very well never checks his email during the week and only checks it and replies on Fridays (of course this person has an administrative assistant so please do not take him as example, but you see my point).
• Choose carefully your research projects and collaborators. Toxic, inefficient, or absent collaborators can delay significantly the completion of a project and the production of scientific results, subtracting that much-needed time from other urgent tasks.
• Never be afraid of dumping projects if at some point you see that it is leading nowhere. Cut your losses and move on, never get stuck just trying to finish something for the sake of it.

Many more could be said, but you get the idea. Work hard, but also work smart. Be selective and focus on what is important. And never postpone “real life” because of science, since then it might be difficult (or even impossible) to recover the lost time.

When discussing about the various options concerning the future of particle physics, in particular in the context of the Update of the European Strategy for Particle Physics, the Higgs boson plays certainly a most important role. The Higgs is truly a unique beast, whose mysterious properties we have just started to unveil. Therefore, also motivated by some recent discussions on Twitter, I though it would be appropriate to write something about why moving forward with the ongoing charting of the Higgs boson sector should be the cornerstone for any future development in particle physics, and in particular why such study is immensely more important for our fundamental understanding of Nature, and represents a much higher goal than a mere bureaucratic rubber-stamping of the Standard Model.

#LHC & most importantly its successor(s) (@FCC_study @CLIC_study @LCNewsLine) could be seen as spectroscopes to explore #ZeptoSpace rather than potential new particles factories. The #HiggsBoson as the 1st elementary scalar quantum field discovered is a new precision probe indeed https://t.co/ZmUMHAlf4A

— A Quantum of Obstinacy (@bardot_cedric) June 2, 2019

Let me try to motivate why the Higgs boson is a particle like no one humankind has ever encountered before. To begin with, the Higgs boson is the first and only elementary scalar particle ever found. In quantum theory, all elementary particles carry a quantum number known as spin, which can be understood as some form of intrinsic angular momentum (picture a ball spinning around some axis, but now this ball is point-like, with a vanishing radius). Before the LHC discovery of the Higgs boson in 2012, we had found either spin-1/2 particles (such as the quarks and the electrons) or spin-1 particles (such as the photon), but never spin-0 particles. And the implications of this seemingly innocuous property are actually vast: while spin-1/2 and spin-1 particles have masses that are protected from large quantum corrections due to symmetry principles, spin-0 particles such as the Higgs boson do not, implying that in principle they can be sensitive to extremely high scales. This delicate sensitivity, called sometimes the hierarchy problem, is not a conceptual limitation of the theory, but it represents a rather dramatic breakdown of the extremely successful principle of separation of scales. This principle tells us, in a nutshell, that for example we don’t need to know about the existence of the strong force to describe the chemistry of molecules, since the two phenomena act at well-separated energies and distances. Unless there are new particles around, currently unknown, the Higgs boson mass actually depends on the physics that take place at very large energies, which is quite weird and unexpected.

Another facet of the unique character of the Higgs boson stems from the fact that it also drives the only fundamental interaction which is not determined by the gauge principle. Putting gravity aside (that can also be written in the form of a gauge theory), the three fundamental interactions (the electromagnetic, strong, and weak forces) follow the same basic principles, and their behaviour is fixed by tight symmetry principles. The Yukawa couplings between the Higgs boson and the quarks and charged leptons thus represents a rather startlingly different type of fundamental force, which deserves intense scrutiny. It is worth mentioning here that, while the ATLAS and CMS measurements have demonstrated that the Higgs boson is the responsible for the mass of the heavier fermions (the bottom and top quarks, and the tau lepton), we still have no evidence that this is also the case for the lighter muon and charm quark, let alone for the up and down quarks and the electron that constitute the nucleon and thus the overwhelming majority of all visible mass in the Universe! For all we know, the humble electron could receive its mass from a completely different mechanism that the one in the Standard Model. Thus trying to pin down the interplay between the Higgs mechanism and the masses of the lighter fermions is also a topic of utmost importance for our understanding of elementary particles and their interactions.

Indeed, as opposed to the gauge sector of the Standard Model, whose properties are exquisitely determined by elegant symmetry principles, the Higgs sector is truly a “model”, more than a theory. In its current formulation, it is a combination of ad hoc ingredients and minimality, not following any symmetry principle, and leads to a large number of free parameters to be extracted from the experimental data. It is simple and it seems to work, but we really don’t have an understanding of why this is the case in terms of deeper principles. So conceptually this situation is very unsatisfactory. We are thus still a long way to elucidate the mystery of electroweak symmetry breaking, in other words, the underlying reason of why elementary particles acquire any mass at all rather than being massless. This is why it has been argued that the Higgs sector of the Standard Model is likely to be an effective description of a more sophisticated theory at high energies, in the same way as how the Landau phenomenological model of superconductivity was eventually replaced by the more fundamental BCS theory.

Another of the major unknowns of the Higgs sector, and actually of the Standard Model itself, is given by the strength (or even the very existence) of the self-interactions of the Higgs boson. Given that the self-coupling of a fundamental scalar particle represents a truly new type of force, different from anything we’ve found before, the quest for the Higgs self-interactions is one the central goals of the LHC program. Moreover, a measurement of the Higgs self-coupling would provide crucial information on the electroweak symmetry breaking mechanism, probe the underlying strength of the Higgs interactions at high energies, such as testing the composite nature of the Higgs boson, and might be related to the matter-antimatter asymmetry of the Universe in the context of electroweak baryogenesis scenarios. A precise determination of the Higgs boson self-interaction would be, almost by itself, a strong enough justification for a future collider.

The Higgs self-coupling can be probed in two different ways, as shown schematically below. On the one hand, one can access via double Higgs production, where a pair of Higgs bosons is produced simultaneously. On the other hand, the Higgs self-coupling can also be accessed indirectly via virtual corrections to single Higgs production. In this latter case, one needs to measure very precisely differential distributions of single-Higgs production and compare them with theory calculations that include these higher order effects to constrain the Higgs self-interactions. These two pathways to probe the Higgs self-coupling are complementary: one is more direct but is less frequent, while the other is indirect but benefits from a higher abundance of events.

For all these various reasons, elucidating the properties of the Higgs boson offers an ideal probe to search for novel particles and interactions that might lie beyond the Standard Model. In addition, the Higgs could very well act as a portal to address some of the biggest mysteries in particle physics and cosmology such as the explanation of the tiny neutrino masses, the nature of dark matter, or the origin of the matter-antimatter asymmetry in the Universe. The Higgs is indeed a unique probe of the zeptouniverse, the microscope with the highest resolution conceivable so far. Thus the detailed understanding of its various properties should be one of the drivers for both short- and long-term efforts in high-energy physics.

It is also worth emphasising that we do not aim to measure more precisely the properties of the Higgs boson just for the sake of it, to know what number occupies the fifth decimal place in some coupling. The key observation in this respect is that in quantum field theory, the mathematical language that describes elementary particles, precision often gives you indirect access to energies and distances far beyond those that you can probe directly at particle colliders. This feature is nicely illustrated in this summary plot below, produced in the context of the ESPPU, that highlights how, when interpreted in the effective field theory context, the measurements of the Higgs boson properties and couplings at future colliders can provide access up to and above 50 TeV in specific scenarios (recall that the LHC center-of-mass energy is currently 13 TeV). In other words, the precision characterisation of the Higgs boson properties provides an extremely powerful microscope that allows us to study the fundamental laws of Nature at very small distances and extreme energies.

Of course you don’t need to only take my word for the crucial importance of the Higgs boson in modern particle physics: you can watch how a selected group of notorious particle physicists play and sing it! The video below is the of the theme songs of the biannual Physics at TeV Colliders workshop, which gathers LHC physicists in an iconic venue in Les Houches in the French Alps, to discuss recent progress in collider physics and work in collaborative projects. You can even find the whole lyrics here. It’s all about that Higgs, ’bout that Higgs, ….

Universities, the temples of higher education, are supposed to deliver excellent, flawless teaching. University professors should always be, at least according to PR leaflets and websites, inspiring, motivated teachers, and devoted mentors that guide their students through the fascinating adventure of learning. However, while there are of course a large number of outstanding university professors who truly drive their students’ learning, there are many others that struggle when put in front of a classroom. How can this be the case? Who teachers the teachers? This is a bit of a chicken-and-egg question, but it is worth asking ourselves what kind of extensive training and preparation do university professors undergo before they start teaching.

Upon a brief moment of reflection, it should be not too difficult to realise that there exist several reasons for why university professors are not necessarily that good at what should be one of the core duties of their job. First of all, few university staff are recruited solely on the basis of their pedagogical skills. In most cases, there are other factors that carry much more weight in the selection and hiring procedure, such as their research productivity and impact, and even more important lately, their demonstrated ability and potential to attract external funding (assuming that any such a thing is real). So, when looking for a job in academia, early career scholars and scientists have all incentives to boost their research portfolio, and little to devote their limited time to teaching, even less to investigate, pursue, and implement new educational approaches.

Moreover when hired, for instance at the Assistant Professor level, most scientists have had only a rather reduced exposure to teaching. Perhaps they have taken care of small-group tutorials, or have been in charge of supervisions, but few have experienced the burden of coordinating and teaching a large bachelor course with say more than one hundred students. Indeed, unbeknown to many people, teaching involves much (but really, like a lot) more than the mere time spent in the lecture room with the chalk in hand. It also requires setting up a bunch of detailed documents such as the syllabi and the study guides, determine and produce the evaluation and assessment methods, prepare material including lecture notes, handouts and slides, and all this checking that the various university regulations (and there are a lot of these) have been religiously obeyed. Then one has the marking, addressing the students’ questions and doubts, being available for office time and the like. In a nutshell, it is not a walk in the park, and in most cases the only way to prepare for the job by talking to your peers, trial and error, and of course by actually doing it.

A second reason why excellence in teaching is not as frequent in our universities as one might naively think has to do with the fact that, for all the many devoted and enthusiastic teachers around, there are also many professors who simply don’t care much about the students in front of them in the classroom. For many scientists, teaching is a disruption from their really important activities such as doing experiments, writing papers, and requesting (and securing) funding, while students represent a nuisance that should be avoided as much as possible. At most, they can be tolerated as an eventual source of personnel for their labs, but that is as far as it gets. The fact that many university departments reward their more successful staff with significant teaching reductions is a further sign highlighting the underlying priorities.

A third possible reason of why even highly successful researchers can become rather lousy teachers arises from the fact that, for an activity that is supposed to represent an integral part of our job, we receive surprisingly little training on how to become a good instructor. Mostly, we are supposed to learn the trade by imitation, and we tend to spend much less time thinking about what works and what not in education as compared to what we do in our research activities. Even between those of us that devote our efforts to the hard sciences there is often little interest to investigate what actually works and what not, at the quantitative level, from the pedagogical and educational perspective.

Such position can be inefficient or even dangerous for several reasons. First of all, it often assumes that all students are more or less like ourselves, and that we should teach them using the same methodology as that of our own favourite teachers. But this is far from being the case: the fact that I would definitely enjoy a heavy lecture with lengthy mathematical derivations does not necessarily mean that my students will also benefit, even less enjoy, from a similar type of lecture (and this is as it should be!). There exist many different types of learners, and focusing on a single type based on our own preferences is definitely a pedagogical bias that we should strive to avoid. Statistically speaking, our students are very different from ourselves, and this should be seen as an opportunity rather than as a drawback. Moreover, there exist a large degree of variation in interest, skills, and receptivity in our student population, and tailoring our teaching methods to a specific subset of this population (perhaps to the one that we consider to be composed by the ideal students) is not only rather pedagogically inefficient, it is also unfair with the rest of our students. As access to higher education widens up and our students become more and more diverse, we should be more careful in considering who do we have in front of us and what are the strategies that could work best to assist them in their learning, as opposed to those that we, subjectively, believe to be the best ones.

Ok, then you might ask, perhaps we should start teaching some teachers how to do their job better?  Well, the good news is that more often than not one does not need to implement burdensome measures or to motivate our staff to undergo extensive training: there are many simple, cost-effective measures that can lead to significant improvements in student learning. The first is perhaps really obvious, but one can never underestimate its vital importance: talking a lot. Talk to the students to check how the course is going, what works and what not, what are the points they find more challenging and where do they struggle. In my experience, student feedback represents a useful resource to improve the courses, and one should not wait until it is too late to gather it. Talk also to fellow teachers and instructors, gather statistics about their experiences, their ideas, what has been successful for them. Everyone enjoys doing their job better, and stubborn as academics can be, when presented with ideas that work they are the first to take them on board. And talk also with the management, with people that have a broad view of the local education ecosystem, with program and education directors. Be of course also critical with the input that you receive from them, but also be open to learn new things that eventually will make you a better teacher.

A second low-cost measure to improve students’ learning is to find the most efficient methods to communicate knowledge. For example, one of my little personal crusades is to reduce the use (and abuse) of slides and powerpoints in the classroom, especially for foundational courses. While using slides might be justified in some contexts, for example in large classrooms, I strongly believe that nothing beats a good old blackboard (whiteboards are also fine though!). Sure, you will cover less material, but this is fine: the main goal of a lecture is that the students learn something, as opposed to everything. Moreover, using blackboards naturally slows you down, so for students is easier to follow, take notes, and in general feel more engaged with the lecture. Well, many people often object, but I do have a horrible handwriting, or I don’t know how to draw graphs, or I am messy with the blackboard. Again, this is fine: just provide handouts or lecture notes, all the relevant information will still be available, and the most important process of all, which is the knowledge transfer between the teacher and the students, will have happened anyway. Someone once told me that in some countries the use of slides is banned for bachelor courses. While being perhaps too extreme (every course, instructor, and students are different so flexibility is important) I believe that such a measure goes into the right direction.

Of course, at the end of the day there is no substitute for passion. All pedagogical theories and technological support pale in front of a motivated, engaging teacher who loves to communicate knowledge and to educate students. But supplementing this passion with a few of mostly common-sense tips can go a very long way in significantly improving the teaching and learning experience in our universities, both for the instructors and for the students.

Since I am still exploring the potentialities of the blog, I will try next to summarise one of my recent research publications, which addresses the rather non-trivial point of whether or not possible new physics beyond the Standard Model can be confounded by effects of the strong interaction. Let’s see how this works out!

At hadron colliders such as the Large Hadron Collider (LHC), one accelerates protons up to almost the speed of light and then makes them collide. By reconstructing the debris of such very energetic collisions, we can have access to the laws of nature at the smallest of the distances, well below the atomic or the nuclear radius. Since protons are not fundamental particles, the LHC is more of a Large Quark and Gluon Collider (LQGC), though it is unlikely that this acronym will catch up. Therefore, to be able to make predictions about what will happen at the LHC, for example how many Higgs bosons will be produced within a year, it is not enough to know the energy of the colliding protons: we also need to determine how this energy is distributed among the proton’s constituents, namely the quarks and gluons.

The information about the energy distribution of the quark and gluons in the proton is encoded by quantities called the Parton Distribution Functions (PDFs), see here for a rather extensive recent review. We cannot compute these PDFs from first principles, at least with current technology, so we need to extract them from experimental data using a global QCD analysis – basically a big fitting machinery where the parameters that define the PDFs are adjusted to maximise the agreement with the input experimental data.

A recent development in this context has been the availability of LHC measurements themselves to constrain the PDFs. For example, one can use the production of top quark pairs to obtain information on the gluon content of the proton. As you can see from the Feynman diagram below, the production of top quark pairs provides direct information on the gluon content of the proton. The same holds for many other processes, for example, the production of a lepton-antilepton pair, the so call Drell-Yan process, allows us to separate the quark and antiquark content, and disentangle different quark flavours among them.

As the LHC accumulates more and more data, these PDF-sensitive measurements start to probe higher and higher scales, well above the Higgs boson mass. While in our determination of the PDFs we always assume that the Standard Model calculations are valid everywhere, if new physics Beyond the Standard Model are present within the LHC reach (perhaps in the form of subtle deviations with respect the SM predictions) there is the real risk that they would be “fitted away” into the PDFs. In other words, you would be missing out a unique opportunity to identify deviations with respect to the Standard Model since you have reabsorbed them into the PDFs!

One possible way to eliminate this risk is by determining simultaneously the PDFs together with this possible New Physics effects. So in our paper we performed the first join extraction of the PDF parameters and of the coefficients of the Standard Model Effective Field Theory (SMEFT). The SMEFT is a powerful theoretical framework that encodes in a model-independent way the effects of any new physics scenario at high energies that reduces to the SM at low energies. The question we want to address is to which extent these SMEFT effects can be reabsorbed into the PDFs. In other words, is new physics hiding in plain sight and we are just fooling ourselves since we are fitting it away into our QCD parameters?

One first check is to perform a sampling of the SMEFT parameter space and run PDF fits for a number of benchmark points. Does the fit quality improve once these additional New Physics parameters are added? The answer is that it does, though not dramatically. As you can see below, the fit quality (quantified by the ) improves at the post-fit level, that is, once the PDFs are readjusted to match the change in underlying theory as compared to the SM assumption. The effect is not dramatic but noticeable, showing that yes, indeed, partially new physics effects can be absorbed into the PDFs.

If this is the case, how we can tell SM effects from possible new physics ones? One can exploit kinematical differences between effects that arise from the strong interaction (one of the three fundamental forces that compose the Standard Model) and those related to physics beyond the SM. They key aspect here is the different dependence on the energy of these effects. In the case of the strong force, as we go towards higher energies we expect differences that scale as , while in the case of SMEFT corrections, they scale as . In the previous equations, is the typical mass scale of the strong interactions (basically one third of the proton mass) while is the (unknown) energy scale where new physics beyond the SM appear. And indeed, if one plots the fit quality as a function of the energy of the process, one observes a very different trend in the case of the Standard Model (feeble dependence with the energy) and in the SMEFT case (strong sensitivity to changes in the energy). Such trend would be the smoking gun to disentangle QCD and new physics effects within the global fit.

To summarise, in this work we have successfully demonstrated how one can disentangle possible BSM effects within the global PDF analysis. The next step will be to carry out a more extensive interpretation of LHC measurements as well as to explore a basis as wide as possible in the SMEFT parameter space.

Disclaimer: I write a first version of this article as part of my guest blogging in the Particle Physics People blog at Interactions.org. Given the intense discussions about the future of high energy physics that are taking place in the last months, including the update of the European Strategy, I though it would be nice to extend a bit this entry and post it this time in my new blog. Hopefully this will also allow testing the comments functionalities!

It is a well known fact within the community that high energy Physics finds itself at a crossroads. Paradoxically, the main reason for this state of affairs is none other than the extreme success of both our theoretical framework and our experimental programs. Indeed, our current understanding of elementary particles, as encapsulated by the Standard Model, has so far been confirmed with exquisite precision by countless experiments, except for a handful of anomalies that might or might not lead to something deeper. Even then, there are plenty enough urgent fundamental questions that are so far left unanswered! Indeed, while the discovery of the Higgs boson in 2012 by the ATLAS and CMS collaborations implies that there are no obvious targets of where the next layer of complexity in our understanding of physical reality can be identified, we should not be idle and keep pushing our efforts towards addressing these pressing questions.

To begin with, the Standard Model (SM) does not provide a candidate for dark matter, the mysterious non-luminous form of matter five times more abundant than normal matter and whose existence we infer from astronomical observations. It does not provide either a microscopic mechanism for the dark energy accelerating the expansion of the universe. Neither does the SM explain how the observed asymmetry between matter and antimatter was generated in the early universe, nor the fact that neutrinos have non-zero masses. While some of these puzzles have different levels of relevance (for example, it is not complicated to augment the Standard Model to include neutrino masses), all of them are truly fundamental questions which we should work hard to answer if our goal is to understand Nature at its deepest levels.

In addition to these ’observational’ conundrums, the SM also contains several puzzles of a more theoretical nature. To begin with, we still don’t know for sure if the scalar boson observed at the LHC is really the SM Higgs boson, or if it is instead a more complicated creature. For example, it could very well be that the Higgs is a composite particle itself, in the same way as how protons are not fundamental but rather composed by quarks and gluons. In addition, in the SM the mass of the Higgs boson is not protected by any symmetry, and for this reason it will tend to grow up to the highest energies at which the theory is valid. In this respect, we do not really understand the unbearable lightness of the Higgs particle. We also have no clue whatsoever of the origin of the flavour structure in the SM, for instance why there are three generations and not 27, and what mechanism determines the observed values of the masses of the SM particles. Moreover, the Higgs boson interactions are mediated by a force completely different from any of the forces we know (such as electromagnetism, drive by the gauge principle) so if there are any hidden sectors beyond the SM the Higgs offers a unique portal to access therm. So there is definitely no lack of fascinating problems to be tackled! Whether these theoretical puzzles are real conceptual issues or not is hotly debated within the community. For example, perhaps the flavour puzzle is merely a consequence of anthropic selection, as speculative as the latter is. In any case is clear that there is still a lot to learn about fundamental physics at the higher energies and smallest distances.

Going even deeper into the foundations of high-energy physics, we don’t know how to marry the two most arguably successful physical theories ever formulated, quantum mechanics and general relativity. Indeed, the ongoing quest for quantum gravity has turned out to be a formidable challenge attacked without success by some of the most brilliant physicists of the last decades. The fact that the experimental signatures of quantum gravity are in most cases orders of magnitude beyond our foreseeable experimental reach does for sure not help in this context. Quantum gravity has been so far the playground of mostly theoretical speculations, though there are hopes that its effects can be probed experimentally in the near future either from cosmological observations or from ultra-high precision measurements of quantum systems. Formulating a theory of quantum gravity would be a massive breakthrough, comparable or even more important than the formulation of quantum mechanics and general relativity themselves.

I encourage the interested reader to take an interactive look at the various mysteries of the Standard Model and the various “Theories of Everything” that have been proposed in this infographic by Quanta Magazine.

In addition, particle physics is much, but really much, broader than just searching for new theories beyond the Standard Model or trying to formulate the theory of quantum gravity. Particle physics is also about achieving an improved understanding of pressing questions within the strong interaction, including how the masses and spin of the hadrons are generated in terms of its constituents, whether or not heavy quarks are part of the proton wave function, the possible onset of extreme dynamical regimes of gluon-dominated matter, or pinning down the properties of the Quark-Gluon Plasma, the hot and dense medium created in the collisions between heavy ions. Anyone who reduces high energy physics to model building is deliberately misleading, and leaving out crucial (and thriving) areas of our field.

One of the main hopes to unravel the next layer of the physical reality is that the thorough exploration of the Higgs boson properties can shed some light on the SM mysteries. For instance, we are now only starting to scratch the surface of the Higgs particle, and current and future measurements at the LHC will tell us more about its underlying nature. Indeed, one of the main goals of the High-Luminosity upgrade of the LHC (HL-LHC), which will deliver up to a factor 10 more collisions, is the accurate profiling of the properties of the Higgs boson, where any deviation with respect to the tightly fixed properties of the SM would represent a “smoking gun” for new physics beyond it. Crucial in this context is the measurement of its self-coupling: not only we have never observed a fundamental scalar particle interacting with itself, it could play a role to explain the matter-antimatter asymmetry in the universe by means of electroweak baryogenesis.

While the HEP community is certainly together in its support for the full exploitation of the physics potential of the HL-LHC as a major priority, it’s less clear what should come next. Should we build yet a bigger particle collider? A different type of collider? Perhaps the key is in the intensity, high-precision frontier? Should we focus on completely different types of experiments, perhaps more weighted towards astrophysics and cosmology? Something else that no one has even thought of before?

In this context, one particularly attractive proposal goes under the name of Future Circular Collider (FCC). The FCC would be a gargantuan particle collider with a radius of around 100 kilometers, dwarfing the already pretty huge LHC. This collider could accelerate protons up to the extreme energies of 100 TeV, about 7 times more powerful than those available at the LHC. In addition, this machine could also accommodate the collisions between electrons and positrons at high energy and luminosity, which would make extremely high precision characterization of SM particles possible, such as the Higgs boson, the W and Z gauge bosons, and the top quarks. Similar machines are under active study by the Chinese HEP community. Another proposal for the next collider is the International Linear Collider (ILC), a high energy linear accelerator of electrons and positrons, to be hosted by Japan.

While it would be amazing if we had machines like those at our disposal, they will come with a hefty price tag, and it is obviously not a decision that can be taken lightly, and the science case in each option must the weighted carefully. One particularly challenging aspect of the current situation for high-energy physics is that there is no machine that can guarantee discoveries, such as new particles or novel fundamental interactions. This was not the case in the past: at the LHC for instance there was a “no-lose” theorem guaranteeing that it would either discover the Higgs boson or instead an altogether novel force of nature. It is worth emphasizing that this is true also for many other fields, such as cosmology, where there is no current or planned experiment that can lead to guaranteed breakthroughs such as evidence for inflation or pinning down the nature of dark energy. The pros and cons of the various proposals for future collider are now being discussed in detail within the community, see for example the recent EPPSU open meeting in Granada.

The bottom line of all this lengthy disquisition is that future progress in HEP should be driven by exploration, rather than by theoretical prejudice, see also Nima Arkani-Hamed’s reflections. For many years (better said, decades) HEP was driven by theoretical efforts, with experiments successfully confirming prediction after prediction. But now our field is experiencing a U-turn, where we should think outside the box and be ready for the unexpected. A nice example of the latter is provided by the recent anomalous in the b-quark sector presented by LHCb. These anomalies seem to indicate the violation of one of the cornerstones of the Standard Model, namely the symmetry telling us that leptons of different families (say muons and electrons) interact with other particles in exactly the same way. Only time will tell the fate of these anomalies, but if confirmed they would represent an arguably more important discovery than that of the Higgs itself!

With the same motivation, and in order to make sure that no stone is left unturned, it is healthy for our field to develop a varied program of experiments that are not limited to high-energy colliders. For instance, CERN has recently set up a Working Group focusing on the potential of ’Physics Beyond Colliders’ (PBC). The idea underlying this approach is that high-precision measurements of specific properties of known particles can reveal the presence of new, heavy particles beyond the direct reach of future colliders. This is possible by means of quantum effects, where heavy virtual particles pop up from the vacuum for a fleeting moment, leaving a measurable imprint in the SM particles.

A prime example of this precision program is shown above: the muon storage ring at Fermilab. There the “muon g-2” experiment aims to measure with exquisite precision the internal magnet of the muons, its so-called magnetic moment. The hope is to resolve a long-standing discrepancy between similar measurements and the SM predictions, which could unveil new physics beyond the SM.

Can we now summarise what the best option is for the future of HEP? Well, not really, this is precisely the million dollar question! Every member of the HEP community, including several popular bloggers within the field, has something important to say there. I think that irrespective of the exact path that our field chooses for the next years, the future is certainly bright for particle physics and everyone should certainly stay tuned for news from the high-energy frontier!

This will hopefully become soon a full fledged personal website and blog, so stay tuned! In the meantime you can contact me via email or find me on Twitter. Some information about myself as well as my contact coordinates can be found here. A brief snapshot of my research interests is also provided, as well as a list of selected talks at seminars, conferences, and workshops.