Tag Archives: ExoticDecays

Performance Sunday NYC

Posts are limited this week and next — partly because a draft of a document about “exotic” Higgs particle decays (which I wrote about here,  here,  here,  here and  here), relevant to how the Large Hadron Collider experiments ATLAS and CMS might collect their data in 2012 (in particular, how they might trigger on such decays), needs to get done right away. (Data’s already coming in! we’re later than I’d like.)   And it really has to get done now since I’m traveling next week with limited internet.

Meantime, a reminder in case you missed it: For those of you in the New York City area: I’ll be joined by the wonderfully talented singer-songwriter-pianist Andrea Wittgens in giving a physics/music joint performance/presentation at the storied Cornelia Street Cafe, Sunday May 13th at 6 p.m., as part of their Entertaining Science series.  It’s entitled Rhapsody for Piano and Universe, and intended for the general public.  The place is pretty small, so get reservations in advance by calling 212.989.9319.

One more heads-up: again in NYC, June 16th, I’ll be giving a lecture:

THE EINSTEIN OBSESSION: SCIENCE, MYTH AND PUBLIC PERCEPTION

June 16th, 2pm

Jefferson Market Library, 425 6th Ave. West Village, NYC

Free and open to the public!

Who hasn’t heard of Einstein? We all know Einstein failed eighth grade math. (Although he didn’t.)  We know he showed energy is the same thing as mass (or was it “matter”?), that he’s the father of the atomic bomb, that he was an old man with frizzy hair, and that he was a patent clerk whose theory was that everything is relative and that nothing can move faster than light.  This messy assortment of half-truths and misconceptions permeates our culture and affects public perceptions of science, at many different levels.  In this talk we’ll consider how our culture’s obsession with Einstein impacts efforts to convey science to the public.

SEARCH Workshop Panel Discussion on LHC Posted Online

The final panel discussion at the Maryland SEARCH workshop — six theoretical particle physicists talking about the 2011 experimental results from the Large Hadron Collider [LHC] and looking ahead to the 2012 data — has finally been posted online, along with the rest of the presentations at the workshop. I wrote about the workshop, which took place in mid-March, here and here.  In the latter post, I wrote:

The workshop concluded with a panel discussion — the only point during the entire workshop when theorists were formally asked to say something. The panel consisted of Michael Peskin (senior statesman [and my Ph.D. advisor] famous for many reasons, including fundamental work on the implications of highly precise measurements ), Nima Arkani-Hamed (junior statesman, and famous for helping develop several revolutionary new ways of approaching the hierarchy problem),  Riccardo Rattazzi (also famous for conceptual advances in dealing with the hierarchy problem), Gavin Salam (famous for his work advancing the applications of the theory of quarks and gluons, including revolutionary methods for dealing with jets), and myself (famous for talking too much… though come to think of it, that was true of the whole panel, except Gavin.) And Raman Sundrum, one of the organizers (and famous for his collaboration with Lisa Randall in introducing “warped” extra dimensions, and also anomaly-mediated supersymmetry breaking [which was competitive with a paper by Rattazzi and his colleagues]) informally participated too. Continue reading

Why a Lightweight Higgs is a Sensitive Creature — Part 2

[Note added:  It is official --- as expected, at this year's Chamonix workshop, where the Large Hadron Collider's [LHC's] future is planned out each year, it was decided that the LHC’s energy will be increased by 14% next year (from 3.5 TeV energy per proton and 7 TeV energy per collision in 2010-2011 to 4 TeV per proton and 8 per collision.) Also the time between collisions will remain at 50 nanoseconds.  I’ll have some things to say about the pros and cons of this decision, in particular the challenges for the experiments, over the next few days.]

On Monday last week, I gave you half the explanation as to why a lightweight Higgs particle is a sensitive creature, one that is easily altered by new phenomena — by particles and/or forces that we might not yet know about.  It all had to do with an analogy between a violin string (or a guitar string or a xylophone key) and the properties of the Higgs particle.   Today, on the same webpage as the first half, I have provided the second half of the story. (If you have already read the first half, just look for the boldface words “The Diverse Modes of a Higgs’ Demise”, which separate last week’s prose from the new stuff.)  I’ve also added, for particle physicists and for those laypersons who want to go a little deeper, a short quantitative discussion of my main points.

Also: I will have the honor to be interviewed on Wednesday at 5 p.m. Eastern time, at

http://www.blogtalkradio.com/virtuallyspeaking/2012/02/15/matt-strassler-tom-levenson-virtually-speaking-science

which you can listen to either live or later.  My interviewer, Tom Levenson, is an eminent science journalist who has written fascinating and surprising books on Einstein and on Newton, among others, won awards for his work on television (e.g. NOVA), has a great blog (and also posts here), and is a professor of science writing at MIT.  In short, he’s a bright and interesting dude whom you should consider following on Twitter, or in whatever way floats your boat in the ocean of social media.  For this reason I suspect that the conversation is going to be a lot deeper and more interesting than the average interview, with the interviewer making at least as many interesting comments about the topic as the interviewee.

Exotic Decays of the Higgs: A High Priority for 2012

2012 may well turn out to be The Year of The Higgs.  Right now we have very little knowledge about this particle, but that may change dramatically over the year. As I described in my previous post, we’re coming toward the end of Phase 1 of the Higgs search (where the ATLAS and CMS experiments at the Large Hadron Collider [LHC] search for the simplest possible form of the Higgs particle, the Standard Model Higgs, or SM Higgs for short.) And we’re also starting up Phase 2 of the Higgs search. As discussed in my Cosmic Variance guest post, and in more detail in my most recent post, if a particle resembling the SM Higgs is found, Phase 2 involves checking its details and determining as well as possible whether it is or isn’t precisely what is predicted by the Standard Model. If no such particle is found, Phase 2 involves searching widely for the many other types of Higgs particles that nature might or might not possess. Fortunately, despite these apparently divergent aims, the two possible branches of Phase 2 involve asking some of the same experimental questions (see Figure 3 of the most recent post), and so we can start on Phase 2 before even finishing Phase 1. And that is happening now.

One of the things that has to be done in Phase 2 is to search for decays of the Higgs particle that are not among the decays predicted to occur in the Standard Model.  ["Decay" = "a disintegration of one particle into two or more". Click here for an introduction.]  Such “exotic” decays are thought of as particularly plausible, because a lightweight Higgs (below about 150 GeV/c2 or so) is a very sensitive creature. It is very easy for new particles and/or forces to alter the Higgs’ properties, perhaps causing changes in how (or how often) it is produced, and to what (and with what probability) it may decay.  As shown in a large number of papers, written by  quite a variety of particle physics theorists, there are many, many types of possible exotic decays, and they can arise for many reasons.  If you’re curious what kind of exotic decays might occur, I gave a few examples in my now somewhat out-of-date analysis of what the summer’s Higgs searches imply. The basic logic of how unusual Higgs decays might arise is still correct in the cases described, but there are many, many more possibilities too. I’ll have to write a long article about the options in the coming month or so. Continue reading