Of Particular Significance

Blog – Of Particular Significance

I’ve decided to write a new set of articles explaining why it takes time, potentially a long time, to discover the Higgs particle.  First article is done: why even to find a Standard Model Higgs particle (the simplest possible type of Higgs particle that might be present in nature) has taken quite a while, if the Higgs particle is relatively lightweight.  Coming soon: various exotic Higgs particles that would take several more years to discover.  

If you’ve missed my two posts from the weekend you may want to read them:

  1. Saturday: The media is providing misleading reports on the Higgs particle search, not always properly distinguishing between the Standard Model Higgs particle (the simplest type of Higgs particle that might be present in nature) and Higgs particles in general.  There’s a very big difference.
  2. Sunday: Although the search for the Standard Model Higgs particle is at least half over, it could take a very long time (as much as 10 years) to confirm that there are no Higgs particles of any type in nature.

I’m also recommending:  (more…)

Picture of POSTED BY Matt Strassler

POSTED BY Matt Strassler

ON December 5, 2011

After yesterday’s post concerning the media reporting on the Higgs search, a lot of people have been asking me this:  “Given that the Standard Model Higgs particle (the simplest possible Higgs particle) will be found or ruled out in the coming few months, why will it take as long as ten years to be sure nature sports no Higgs particle or particles of any type?”  (more…)

Picture of POSTED BY Matt Strassler

POSTED BY Matt Strassler

ON December 4, 2011

As we approach the December 13 news conference to update the search for the Standard Model Higgs particle (the simplest possible Higgs particle) we are starting to see lots of news stories about it.  And they’re all wonderfully misleading.

I love this quote from the BBC: “But there is an even more intriguing possibility: that [the Higgs particle] may not exist at all, at least in its simplest form.”

This is a lot like saying: “Maybe the earth has no trees at all, at least not maple trees.”  Or “Maybe children on earth do not play games at all, at least not football.”  Or “Maybe Picasso did not paint any pictures at all, at least not the Mona Lisa.”

If the simplest form of the Higgs particle does not exist in nature, that will surprise no one in the field.  There are hundreds of serious scientific papers, written by experts over the past 40 years, suggesting other forms of the Higgs particle (or particles).  Every novel idea (supersymmetry, extra dimensions, little Higgs, etc.) has a more complicated story than the Standard Model Higgs particle.  Most particle physicists are hoping for precisely this situation.  Exotic Higgs particles generally would take a little longer to find than the Standard Model version of the Higgs — but they’re still Higgs particles, just as oak trees are trees and basketball is a game.

We will not know if the Higgs particle does “not exist at all” for ten years.  Let me say that again.  It will take ten more years to sweep the floor clean and assure ourselves that there is no Higgs particle, of some exotic form, hidden in Large Hadron Collider data.  See this post for more info.

So when I see a figure caption on a BBC article stating “the Higgs search is approaching its endgame at Cern”, all I can say is, “you’ve got to be kidding.”  This is not the beginning of the end; it is the end of the beginning.

Picture of POSTED BY Matt Strassler

POSTED BY Matt Strassler

ON December 3, 2011

After a day and a half of intense discussions and exchanges of information, the Intensity Frontier workshop meeting is coming to an end today. I already mentioned on Wednesday that particle physicists are currently summarizing their efforts as roughly divided into three research directions:

  • The Energy Frontier: Try to make new heavy particles or other high-energy phenomena using very high-energy high-collision-rate accelerators (such as the Large Hadron Collider)
  • The Cosmic Frontier: Let the Universe itself, through its natural particle production mechanisms, teach us something (through properties of “dark energy” or dark matter or through cosmic rays, etc.)
  • The Intensity Frontier: Search for rare new phenomena or difficult-to-produce new particles using medium-energy ultra-high-collision-rate accelerators, or some other low-energy ultra-high-rate mechanism.

Each frontier has its advantages; the energy frontier probes new particles and forces very directly, allowing for detailed study, whereas the intensity frontier is indirectly sensitive to much higher energies and/or much weaker forces, though it often provides fewer details. Meanwhile, at the cosmic frontier we rely purely upon what the universe has to offer, which has the obvious benefit that what the universe provides comes for free, and the disadvantage that what it provides is limited and out of our control. (more…)

Picture of POSTED BY Matt Strassler

POSTED BY Matt Strassler

ON December 2, 2011

Particle physicists in the United States, aiming to organize their thinking and make it easier to explain their views to each other and to the outside world, meet every few years in workshops to consider the future of the field.  (Something like this is done in a number of other scientific fields as well.) Right now, particle physics is commonly described as pursuing three general research directions:

  • The Energy Frontier: Try to make new heavy particles or other high-energy phenomena using very high-energy high-collision-rate accelerators (such as the Large Hadron Collider)
  • The Cosmic Frontier: Let the Universe itself, through its natural particle production mechanisms, teach us something (through properties of “dark energy” or dark matter or through cosmic rays, etc.)
  • The Intensity Frontier: Search for rare new phenomena or difficult-to-produce new particles using medium-energy ultra-high-collision-rate accelerators, or some other low-energy ultra-high-rate mechanism.

With the U.S. currently out of the business of the Energy Frontier (the Tevatron having closed and there being no plans for future accelerators here) the Department of Energy has recently asked the U.S. particle physics community to hold a large workshop on the Intensity Frontier, to bring its goals into focus.

A meeting associated with this effort is going on today through Friday, in Washington D.C.  (more…)

Picture of POSTED BY Matt Strassler

POSTED BY Matt Strassler

ON November 30, 2011

Some of you may remember that a few months back there were widespread reports in the media — and various blog posts, including even ones by particle physicists such as University of California-Davis’s John Conway on Cosmic Variance — giving the impression that the 2011 summer’s results from the ATLAS and CMS experiments at the Large Hadron Collider (LHC) had all but ruled out a particular speculative idea called “supersymmetry”. (Here are links to my description of supersymmetry and the classic strategy people use to look for it, as well as the assumptions that underlie that strategy and what happens when you relax them.) I complained loudly back then that this was a terribly premature conclusion — that only the most popular version of supersymmetry had been excluded by the data at that time, and that there were still many types of searches that would need to be carried out before such a broad conclusion could be drawn. And I wasn’t the theoretical particle physicist to say so.

Well, a few months on, I’m glad to say that the experimentalists at ATLAS and CMS have collectively come to the conclusion that indeed there is a great deal of work left to do. This was reflected in several talks on supersymmetry searches at the HCP conference in Paris two weeks ago, including the final talk, given by Giacomo Polesello of ATLAS. (more…)

Picture of POSTED BY Matt Strassler

POSTED BY Matt Strassler

ON November 29, 2011

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