tag:blogger.com,1999:blog-2846514233477399562.post8357772218663641728..comments2024-01-08T09:37:04.406+01:00Comments on RÉSONAANCES: Diphoton updateJesterhttp://www.blogger.com/profile/08947218566941608850noreply@blogger.comBlogger72125tag:blogger.com,1999:blog-2846514233477399562.post-88631394415644424062016-04-20T13:36:55.407+01:002016-04-20T13:36:55.407+01:00I am not refusing what you said my question is tha...I am not refusing what you said my question is that did i get better with new analysis?? And to answer this question you shouldn't look at the local values but you need take into account global values also......mymathdonehttps://www.facebook.com/mymathdonecom/noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-74368762203982096042016-04-05T23:29:46.800+01:002016-04-05T23:29:46.800+01:00@Maurice: Global values are always a bit arbitrary...@Maurice: Global values are always a bit arbitrary. Take the search range, for example: do the experiments search for a peak in the range of 500 GeV to 1.5 TeV (where a graviton-like signal would make some sort of sense), or in the range of 200 GeV to 6 TeV (where a peak could appear in general)?<br /><br />Do you just search for narrow resonances, or do you search for broader ones as well (and if yes, up to which width)?<br /><br />Those choices are completely arbitrary, but they will have a strong influence on medium-sized global significances.mfbnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-53459315606905072822016-04-05T12:59:31.884+01:002016-04-05T12:59:31.884+01:00@Anonymous: A new state as composite particle has ...@Anonymous: A new state as composite particle has been discussed in the blog already. Yes, it is possible. Mesons are an example for non-elementary bosons, and something meson-like is indeed a candidate for this particle (if it is a particle).mfbnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-79345412032227284072016-04-05T11:57:26.814+01:002016-04-05T11:57:26.814+01:00@mfb
I am not denying what u wrote. But the quest...@mfb <br />I am not denying what u wrote. But the question Adam's post addresses is different, it is: "did it get better with the new analysis or worse?" And to answer this question u shouldn't just<br />stare at the local values, you have to take into account how the background changed, too.<br />Therefore clearly you have to consider the global values here, and they got worse...Mauricehttps://www.blogger.com/profile/16375058316648610565noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-28942375579678453372016-04-04T16:39:01.326+01:002016-04-04T16:39:01.326+01:00Jester, these are all big and bigger ifs, but supp...Jester, these are all big and bigger ifs, but suppose (fingers crossed) there's indeed a new force and possibly more in store at higher energies. So we keep finding new force carrier bosons but the number of fundamental fermions remains the same: three generations each of leptons, neutrinos and quarks. Would such a pattern, if the trend continues cause at some point a real tension with supersymmetry - or are there reasons why most fermions would end up with very large masses while bosons spread over lower energy spectrum?RBShttps://www.blogger.com/profile/05190152376766693948noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-77439372449839211442016-04-04T00:02:06.839+01:002016-04-04T00:02:06.839+01:00If this di photon signal is real,could this be a c...If this di photon signal is real,could this be a composite particle? Can you have a Boson made of more fundamental particles, the Higgs appears not to be. Could this be another scalar Boson? Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-33911524891000436272016-04-03T17:39:07.253+01:002016-04-03T17:39:07.253+01:00Both experiments see the strongest fluctuation at ...Both experiments see the strongest fluctuation at nearly the same (and compatible) masses. You cannot just look at global significances, that would ignore this point completely. We probably won't get an official combination as waiting for more data is better, but you can have a look at the unofficial combinations: the combined global significance exceeds the local significances of the individual experiments.mfbnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-77874018776118093202016-04-01T11:18:23.337+01:002016-04-01T11:18:23.337+01:00Adam you're day-dreaming ;-).
"In summar...Adam you're day-dreaming ;-).<br /><br />"In summary, the diphoton excess survived the first test. After adding more data and improving the analysis techniques the significance slightly increases rather than decreases, as expected for a real particle." <br /><br />No they didn't! What counts is clearly the global significance, right?! The global significance remained the same for ATLAS and decreased for CMS, as expected for a random fluctuation.<br /><br />"The signal is now a bit more solid: both experiments have a similar amount of diphoton data and they both claim a similar significance of the 750 GeV bump."<br /><br />No they don't. Wile ATLAS claims a moderate global significance of 2 \sigma, CMS now claims a global "significance" of 1 \sigma (down from 1.2 \sigma). Haha.Mauricehttps://www.blogger.com/profile/16375058316648610565noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-65319895392893678952016-03-30T23:34:10.589+01:002016-03-30T23:34:10.589+01:00"340 is close to 375", seriously? That i..."340 is close to 375", seriously? That is several standard deviations away. ATLAS 13 TeV has some excess at 340 and absolutely nothing at 375. CMS 8 TeV has some excess at 375 and a deficit at 340 GeV. Clear evidence of ... what?mfbnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-81645105548083292772016-03-30T04:42:57.930+01:002016-03-30T04:42:57.930+01:00andrew, also note that a comment on that article p...andrew, also note that a comment on that article pointed out that 375 is 3 x 125. So we may have a resonance at 3x Higgs and another at 6x (and possibly another at 12x). Can that mean something or are we numerologists at this point?Anonymoushttps://www.blogger.com/profile/09702349560231225588noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-29285290652489766492016-03-30T03:51:38.965+01:002016-03-30T03:51:38.965+01:00"Any thoughts on Motl's suggestion of a Z..."Any thoughts on Motl's suggestion of a Zy bump at 350 GeV in ATLAS and CMS data"<br /><br />Motl sees a bump that will probably reveal supersymmetry about twice a week. Executive summary: he's full of it.Rastus Odinga Odingahttps://www.blogger.com/profile/09615544434035028500noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-37412451909822383482016-03-28T22:01:48.681+01:002016-03-28T22:01:48.681+01:00Any thoughts on Motl's suggestion of a Zy bump...Any thoughts on Motl's suggestion of a Zy bump at 350 GeV in ATLAS and CMS data, albeit not very pronounced.<br /><br />http://motls.blogspot.com/2016/03/z-gamma-excess-near-375-gev-in-new-and.htmlandrewhttps://www.blogger.com/profile/08172964121659914379noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-10737577580186615612016-03-24T22:55:52.679+01:002016-03-24T22:55:52.679+01:00@Global significance: They added more data and cha...@Global significance: They added more data and changed the analysis a bit, which could give more ways to look elsewhere.<br /><br />@20:1 bet: It just goes in the wrong direction. If it is a new particle, wine for celebration won't be an issue, and if it is not a new particle, you even lose some wine. Related xkcd comic: https://xkcd.com/955/<br /><br />@Anon, multiple resonances: Depends on the resonances and their decay modes. Different spin and different spin-sensitive decay modes would make it relatively easy (different decay modes then show different angular distributions). Different decay modes and different width could work as well. Different spin and the same decay modes would give a notable effect with a larger statistics, probably the run 2 dataset or something like that. Same spin, width and decay modes: uh oh. Some theory model might be first, if it predicts various properties of the observed resonance(s) properly.mfbnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-33387532162003035902016-03-23T15:17:08.325+01:002016-03-23T15:17:08.325+01:00If there are multiple resonances there, how long w...If there are multiple resonances there, how long would it take the get enough data to distinguish them? Is the next year likely to be enough?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-10075550868318919722016-03-23T14:58:02.013+01:002016-03-23T14:58:02.013+01:00"Probably the two numbers 1.7 and 1.6 were ob..."Probably the two numbers 1.7 and 1.6 were obtained using different methods."<br /><br />could it be they got more data that is more 'spiky'? If that's the case it'd be more 'likely' to have a bump somewhere, reducing the global number? Otherwise this makes no sense... Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-58048588377653113182016-03-23T10:42:48.769+01:002016-03-23T10:42:48.769+01:00Xezlec, this is indeed hard to understand. Probabl...Xezlec, this is indeed hard to understand. Probably the two numbers 1.7 and 1.6 were obtained using different methods. <br /><br />Anon, 20:1 is fair, but what would I do with all these wine bottles? If vodka is on the table then I could take the bet. Jesterhttps://www.blogger.com/profile/08947218566941608850noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-26555229314597929142016-03-23T02:55:57.767+01:002016-03-23T02:55:57.767+01:00Thanks Chris (re pentaquark).Thanks Chris (re pentaquark).Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-20026471724306576552016-03-23T02:31:23.821+01:002016-03-23T02:31:23.821+01:00Is 20:1 a fair bet?
http://www.science20.com/a_q...Is 20:1 a fair bet? <br /><br />http://www.science20.com/a_quantum_diaries_survivor/want_to_bet_201_that_the_750_gev_resonance_is_real-168606<br />Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-43173378983071622142016-03-23T01:23:29.975+01:002016-03-23T01:23:29.975+01:00So according to Pauline Gagnon on Quantum Diaries,...So according to Pauline Gagnon on Quantum Diaries, for the combined run-1 and run-2 data, the CMS global significance actually went *down* with this update (from 1.7 to 1.6 sigma), even as the combined local significance went up. How is that possible?Anonymoushttps://www.blogger.com/profile/09702349560231225588noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-57481776628589036072016-03-22T12:38:29.542+01:002016-03-22T12:38:29.542+01:00@Anonymous: If that excess is a particle, then it ...@Anonymous: If that excess is a particle, then it is certainly an unexpected one. The 13 TeV analyses were focused on 1.5+ TeV, with maybe a few signal events over a background of nearly zero. It is hard to tune cuts to things you do not even expect.<br /><br />@Jester: well, I don't know what exactly you heard as rumor, but in general selection and forward direction don't have a 1:1 correlation.mfbnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-65725116119590887192016-03-22T00:53:34.300+01:002016-03-22T00:53:34.300+01:00mfb, I agree, the secret ATLAS analysis could be j...mfb, I agree, the secret ATLAS analysis could be just riding a random fluke (like the 115 GeV Wuon resonance in ATLAS that appeared after relaxing photon quality cuts). Concerning CMS, what I wrote is based on public data: if the BSM signal were indeed strongly peaked forward, one would expect a larger signal in their EBEE category, as compared to the signal in the EBEB category.<br /><br />Anon, the cuts are chosen to maximize sensitivity to a simulated monte carlo signal, not to the one in the real data. Jesterhttps://www.blogger.com/profile/08947218566941608850noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-5456086227747590482016-03-22T00:43:01.130+01:002016-03-22T00:43:01.130+01:00It's not surprising, but it's suspicious. ...It's not surprising, but it's suspicious. <br />Looser cuts do not necessarily reduce the significance. But, usually, in data analyses, the cut levels are chosen in order to maximize significance. If their loose-cut analysis gives a higher significance, then why did they set up tighter cuts at default? <br />Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-67034986585293682312016-03-22T00:10:39.931+01:002016-03-22T00:10:39.931+01:00Addendum: A higher significance with looser cuts (...Addendum: A higher significance with looser cuts (IF ATLAS has this, which is a big IF) is not unusual. If you know exactly what you are looking for, you tune the selection to give the highest expected significance - both loosening and tightening would then decrease the expected significance. The actual significance still has some statistical fluctuations, so it can be a bit higher in either direction. If you do not know in advance what exactly you are expecting, you'll rarely hit exactly the right spot for whatever pops up (if there is something). Maybe the signal is very clean and tighter cuts are better, maybe the signal has some messy other stuff going on and looser cuts are better.mfbnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-10910852251221704392016-03-21T23:57:16.854+01:002016-03-21T23:57:16.854+01:00Wait... rumors are now discussed as if they would ...Wait... rumors are now discussed as if they would be actual science. Okay, whatever. But taking the absense of very specific rumors as evidence that CMS does not see something? Come on.mfbnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-47169365918483107992016-03-21T20:49:11.064+01:002016-03-21T20:49:11.064+01:00The fact that the "loose cuts" ATLAS ana...The fact that the "loose cuts" ATLAS analysis boosts the significance of the excess may be caused by a high-degree of directionality in the photon beam. This, in turn, would suggest beam coherence, which is typical for radiation emitted by confined cavities (like quantum dots). This explanation stands only if CMS sees the same effect with a similar magnitude.Ervin Goldfainhttps://www.blogger.com/profile/07585008304556273617noreply@blogger.com