Tag Archives: Higgs

A Few Items of Interest

I was sent or came across a few interesting links that relate to things covered on this blog and/or of general scientific interest.

It was announced yesterday that the European Physical Society 2013 High Energy Physics Prize was awarded to the collaboration of experimental physicists that operate the ATLAS and CMS experiments that discovered a type of Higgs particle, with special mention to Michel Della Negra, Peter Jenni, and Tejinder Virdee, for their pioneering role in the development of ATLAS and CMS.  Jenni and Virdee are both at the LHCP conference in Barcelona, which I’m also attending, and it has been a great pleasure for all of us here to be able to congratulate them in person .

One thing that came up a couple of times regarding weather forecasting (for instance, in forecasting the path of Hurricane Sandy) is that the European weather forecasters are doing a much better job of predicting storms a week in advance than U.S. forecasters are.  And I was surprised to learn that one of the the main reasons is simple: U.S. forecasters have less computing power than their European counterparts, which sounds (and is) ridiculous.  The new director of the U.S. National Weather Service, Louis Uccellini, has been successful in his goal of improving this situation, as reported here[Thanks to two readers for pointing me to this article.]

One of the possible interpretations of the new class of high-energy neutrinos reported by IceCube (see yesterday’s post) is that they come from the slow decay of a small fraction of the universe’s dark matter particles, assuming those particles have a mass of a couple of million GeV/c². [That's much heavier than the types of dark matter particles that most people are currently looking for, in searches that I discussed in a recent article.]  I didn’t immediately mention this possibility (which is rather obvious to an expert) because I wanted a couple of days to think about it before generating a stampede or press articles.  But, not surprisingly, people who were paying more attention to what IceCube has been up to had recently written a paper on this subject[Here's an older, related paper, but at much lower energy; maybe there are other similar papers that I don't know about?]  At the time these authors wrote this paper, only the two highest energy neutrinos — which have energies that, within the uncertainties of the measurements, might be equal (see Figure 2 of yesterday’s post) — were publicly known.  In their paper, they predicted that (just as any expert would guess) in addition to a spike of neutrinos, all at about 1.1 million GeV, one would also find a population of lower-energy neutrinos, similar to those new neutrinos that IceCube has just announced. So yes, among many possibilities, it appears that it is possible that the new neutrinos are from decaying dark matter.  If more data reveals that there really is a spike of neutrinos with energy around 1.1 million GeV, and the currently-observed gap between the million-GeV neutrinos and the lower-energy ones barely fills in at all, then this will be extremely strong evidence in favor of this idea… though it will be another few years before the evidence could become convincing.  Conversely, if IceCube observes any neutrinos near but significantly above 1.1 million GeV, that would show there isn’t really a spike, disfavoring this particular version of the idea.

Regarding yesterday’s post, it was pointed out to me that when I wrote “The only previous example of neutrinos being used in astrophysics occurred with the discovery of neutrinos from the relatively nearby supernova, visible with the naked eye, that occurred in 1987,” I should also have noted that neutrinos were and are used to understand the interior of the sun (and vice versa).  And you could even perhaps say that atmospheric neutrinos have been used to understand cosmic rays (and vice versa.)

In sad news, in the “all-good-things-must-come-to-an-end” category, the Kepler spacecraft, which has brought us an unprecedented slew of discoveries of planets orbiting other stars, may have reached the end of the line (see for example here), at least as far as its main goals.  It’s been known for some time that its ability to orient itself precisely was in increasing peril, and it appears that it has now been lost.  Though this has occurred earlier than hoped, Kepler survived longer than its core mission was scheduled to do, and its pioneering achievements, in convincing scientists that small rocky planets not unlike our own are very common, will remain in the history books forever.  Simultaneous congratulations and condolences to the Kepler team, and good luck in getting as much as possible out of a more limited Kepler.

Opening of LHCP Conference

Greetings from Barcelona, where the LHCP 2013 conference is underway. I wanted to mention a couple of the opening remarks made by CERN’s Sergio Bertolucci and Mirko Pojer, both of whom spoke about the near-term and medium-term future of the Large Hadron Collider [LHC]. Continue reading

Higgs Workshop in Princeton

Today I’m attending the first day of a short workshop of particle theorists and experimentalists at the Princeton Center for Theoretical Science, a sort of “Where are we now and where are we going?” meeting. It’s entitled “Higgs Physics After Discovery”, but discussion will surely range more widely.

What, indeed, are the big questions facing particle physics in the short-term, meaning the next few months? Well, here are a few key ones:

  • A Higgs particle of some type has been discovered by the ATLAS and CMS experiments at the Large Hadron Collider [LHC] (with some contributions from the Tevatron experiments DZero and CDF); is it the simplest possible type of Higgs particle (the “Standard Model Higgs“) or is it more complex? What data analysis can be done on the LHC’s data from 2011-2012 to shed more light on this question?
  • More generally, from the LHC’s huge data set from 2011-2012 — specifically, from the data analysis that has been done so far — what precisely have we learned? (It’s increasingly important to go beyond the rougher estimates that were appropriate last year when the data was still pouring in.) What types of new phenomena have been excluded, and to what extent?
  • What other types of data analysis should be done on the 2011-2012 data, in order to look for other new phenomena that could still be lurking there? (There’s still a lot to be done on this question!) And what types of work should theoretical particle physicists do to help the experimentalists address this issue?
  • Several experiments from the Tevatron and the LHC, notably the LHCb experiment, have learned that newly measured decays of  certain mesons (hadrons with equal numbers of quarks and anti-quarks) that contain heavy quarks are roughly consistent with the Standard Model (the equations we use to describe the known elementary particles and forces, and a simplest type of Higgs field and Higgs particle.) How do these findings constrain the possibility of other new phenomena?
  • Looking ahead to 2015, when the LHC will begin running again at a higher energy per proton-proton collision, what preparations need to be made? Especially, what needs to be done to refine the triggering systems at ATLAS, CMS and LHCb, so that the maximum information can be extracted from the new data, and no important information is unnecessarily discarded?
  • Which, if any, of the multiple (but mostly mutually inconsistent) experimental hints of dark matter should be taken seriously? Which possibilities do the various dark matter experiments, and the LHC’s data, actually exclude or favor?

That might be it for the very near term. There are lots of other questions in the medium- to long-term, among which is the big question of what types of experiments should be done over the next 10 – 20 years. One challenge is that the LHC’s data hasn’t yet given us a clear target other than the Higgs particle itself. An obvious possible experiment to do is to study the Higgs in more detail, using an electron/anti-electron collider — historically this has been a successful strategy that has been used on almost every new apparently-elementary particle. But there are a lot of other possibilities, including raising the LHC’s collisions to even higher energy than we’ll see in 2015, using more powerful magnets currently under development.

If there are other near-term questions I’ve forgotten about, I’m sure I’ll be reminded at the workshop, and I’ll add them in.

Cosmic Conflation: The Higgs, The Inflaton, and Spin

Over the past week or so, there has been unnecessary confusion created about whether or not there’s some relationship between (a) the Higgs particle, recently discovered at the Large Hadron Collider, and (b) the Big Bang, perhaps specifically having to do with the period of “Cosmic Inflation” which is believed by many scientists to explain why the universe is so uniform, relatively speaking. This blurring of the lines between logically separate subjects — let’s call it “Cosmic Conflation” — makes it harder for the public to understand the science, and I don’t think it serves society well.

For the current round of confusion, we may thank professor Michio Kaku, and before him professor Leon Lederman (who may or may not have invented the term “God Particle” but blames it on his publisher), helpfully carried into the wider world by various reporters, as Sean Carroll observed here.

[Aside: in this post I'll be writing about the Higgs field and the Higgs particle. To learn about the relationship between the field and the particle, you can click here, here, here, or here (listed from shortest to most detailed).]

Let’s start with the bottom line. At the present time, there is no established connection, direct or indirect, between (a) the Higgs field and its particle, on the one hand, and (b) cosmic inflation and the Big Bang on the other hand. Period. Any such connection is highly speculative — not crazy to think about, but without current support from data. Yes, the Higgs field, responsible for the mass of many elementary particles, and without which you and I wouldn’t be here, is a spin-zero field (which means the Higgs particle has zero spin). And yes, the “inflaton field” (the name given to the hypothetical field that, by giving the universe a lot of extra “dark energy” in the early universe, is supposed to have caused the universe to expand at a spectacular rate) is also probably a spin-zero field (in which case the inflaton particle also has zero spin). Well, fish and whales both have tails, and both swim in the sea; yet that doesn’t make them closely related. Continue reading

Why the Higgs Matters, In A Few Sentences

One of the big challenges facing journalists writing about science is to summarize a scientific subject accurately, clearly and succinctly. Sometimes one of the three requirements is sacrificed, and sadly, it is often the first one.

So here is my latest (but surely not last) attempt at an accurate, succinct, and maybe even clear summary of why the Higgs business matters so much.

`True’ Statements about the Higgs

True means “as true as anything compressed into four sentences can possibly be” — i.e., very close to true.  For those who want to know where I’m cutting important corners, a list of caveats will follow at the end of the article.

  • Our very existence depends upon the Higgs field, which pervades the universe and gives elementary particles, including electrons, their masses.  Without mass, electrons could not form atoms, the building blocks of our bodies and of all ordinary matter.
  • Last July’s discovery of the Higgs particle is exciting because it confirms that the Higgs field really exists.  Scientists hope to learn much more about this still-mysterious field through further study of the Higgs particle.

Is that so bad? These lines are almost 100% accurate… I’m sure an experienced journalist can cut and adjust and amend them to make them sound better and more exciting, but are they really too long and unclear to be useable?

Some False Statements about the Higgs Continue reading

Why, Professor Kaku? Why?

Professor Michio Kaku, of City College (part of the City University of New York), is well-known for his work on string theory in the 1960s and 1970s, and best known today for his outreach efforts through his books and his appearances on radio and television.  His most recent appearance was a couple of days ago, in an interview on CBS television, which made its way into this CBS news article about the importance of the Higgs particle.

Unfortunately, what that CBS news article says about “why the Higgs particle matters” is completely wrong.  Why?  Because it’s based on what Professor Kaku said about the Higgs particle, and what he said is wrong.  Worse, he presumably knew that it was wrong.  (If he didn’t, that’s also pretty bad.) It seems that Professor Kaku feels it necessary, in order to engage the imagination of the public, to make spectacular distortions of the physics behind the Higgs field and the Higgs particle, even to the point of suggesting the Higgs particle triggered the Big Bang.

In doing this, Professor Kaku sows confusion among journalists and the public, and undermines the efforts of serious particle physicists to explain and convey, both vividly and accurately, the science and the excitement of our time.  And on what grounds does he justify this?  Doesn’t the taxpaying public deserve the truth?  Isn’t the truth already exciting enough? And what will the public think of science if, in this information era, the promulgation of falsehoods and near-falsehoods on national media is unanswered by complaints from other scientists?

I’m so frustrated with Professor Kaku’s unfortunate remarks that rather than write more today, I’ll simply direct you to Sean Carroll’s blog — Sean’s response was much more measured and polite than mine would be if I spoke my mind.  For now I’ll just conclude by suggesting that Professor Kaku has some serious explaining to do — to his scientific colleagues, to the science journalist that he misled, and to the public.

(Perhaps you will ask me the same question: “Why DOES the Higgs particle matter?”  Here’s my own article from July giving the answer; it’s short and condensed, but it’s not false, as my colleagues will attest!  For a longer explanation with more details and fewer shortcuts, you can try Sean Carroll’s book or Lisa Randall’s book, or  you can poke around on my website for various related articles; there’s the Higgs FAQ, the story of the Higgs discovery, an article on why the Higgs is not related to gravity, or if you’re really ambitious you can try this set of articles [which requires you first read this set] which is suitable for people who once took a little first-year college physics.)