tag:blogger.com,1999:blog-2846514233477399562.post7513511654308347168..comments2024-01-08T09:37:04.406+01:00Comments on RÉSONAANCES: Game of Thrones: 750 GeV edition Jesterhttp://www.blogger.com/profile/08947218566941608850noreply@blogger.comBlogger141125tag:blogger.com,1999:blog-2846514233477399562.post-57413427915458679412016-08-24T15:22:26.819+01:002016-08-24T15:22:26.819+01:00"Our whole problem is to make the mistakes as...<i>"Our whole problem is to make the mistakes as fast as possible- my part- and recognize them -your part"</i> (John Archibald Wheeler in "A septet of Sibyls: aids in the search for truth")<br /><br />Thank you Jester to help the BSM community to do both with such a nice spirit (o_~)cbhttps://www.blogger.com/profile/03349828290008437401noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-26724045244628350132016-08-10T11:47:37.931+01:002016-08-10T11:47:37.931+01:00From the November 1974 revolution with love ;-)
&...From the November 1974 revolution with love ;-)<br /><br />"During the next one year, more than <b>seven hundred papers</b> were written related to th{e J/Psi} discovery which was a record in physics (if not in entire science) at that time. Subsequently, this record was broken after the discovery of high Tc super-conductivity" (arxiv.org/abs/hep-ph/9910468)cbhttps://www.blogger.com/profile/03349828290008437401noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-67283840693787307592016-08-05T14:46:56.216+01:002016-08-05T14:46:56.216+01:00Sooo...who do you think will lead the Olympic meda...Sooo...who do you think will lead the Olympic medal count?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-66297660579063712792016-08-05T00:32:16.480+01:002016-08-05T00:32:16.480+01:00I really had high hopes for this, ah well.
Don'...I really had high hopes for this, ah well.<br />Don't give up people.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-86675467797791773802016-08-04T20:02:14.471+01:002016-08-04T20:02:14.471+01:00Looks like 750 GeV is dead. https://cds.cern.ch/re...Looks like 750 GeV is dead. https://cds.cern.ch/record/2205245gazebo_dudehttps://www.blogger.com/profile/17654801760491245661noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-36993098624822202632016-07-28T05:24:36.697+01:002016-07-28T05:24:36.697+01:00I guess there is something but not enough to claim...I guess there is something but not enough to claim discovery. We likely must wait some time more.Anonymoushttps://www.blogger.com/profile/08848888888372644117noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-57612513112483283222016-07-27T22:45:52.403+01:002016-07-27T22:45:52.403+01:00http://indico.cern.ch/event/432527/sessions/95227/...http://indico.cern.ch/event/432527/sessions/95227/#20160805<br /><br />There are a few theory talks about the diphoton excess at ICHEP scheduled after the first ATLAS and CMS talks, including one from Jack Gunion. Are we supposed to believe that these people will talk about something that's been denounced just 10 mins before their talks? :)W9GFOnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-29923066345399136302016-07-26T21:47:02.910+01:002016-07-26T21:47:02.910+01:00@RBS: Without any glue, it is quite clear that fit...@RBS: Without any glue, it is quite clear that fitting a background at 125GeV is something different than at 750GeV. 1st can be done simple fitting below and behind the hump. Doing for the later one could be an issue, because it is more an extrapolation, there is not much data after the signal region.<br />@anonymus: As far as I'm unterstand there could be a fake signals by jets interpretated as Photons, this has nothing to do with how sophisticated your statistical analysis is, has it? If the purity of the di photon signal is decreasing with higher energies, your background would be higher than extrapolated from lower energies. There seems to be not enough data about purity to exclude that this is not the case.<br />If this lowers the significances by 0.5, 1 or 2 sigma, who cares? It lowers the significanes, that is the message for me!sciingnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-35447602692935681152016-07-25T20:33:50.565+01:002016-07-25T20:33:50.565+01:00@Anonymous 23 July 2016 at 07:50: Interesting poin...@Anonymous 23 July 2016 at 07:50: Interesting points about the statistical analysis, didn't check that before. Well... we'll know more in 1.5 weeks.<br /><br />@RBS: The Higgs is at a much lower mass and with a huge amount of events. The experiments just fit a polynomial to it - something that doesn't work at 750 GeV (maybe with >100/fb, but not this year). Also, you could not detect an unaccounted 1 sigma deviation with just two data points (ATLAS, CMS).mfbnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-69682755386692413382016-07-25T11:02:02.242+01:002016-07-25T11:02:02.242+01:00I think Anonymous (23 July 2016 at 07:50) is missi...I think Anonymous (23 July 2016 at 07:50) is missing the main point. <br /><br />> ATLAS and CMS fitted functional forms to the whole diphoton spectrum (with no signal regions, sidebands or extrapolation), once without a signal, and once with a signal. <br /><br />The issue seems to be that the parameters of the functional form are determined where most of the data is (at low diphoton masses). Can ATLAS and CMS really claim to capture potential mis-modeling of fakes or higher-orders at large diphoton masses (= where the signal is)? The paper shows that there are issues. <br /><br />Or look at the binned purity of the diphoton sample. How can ATLAS and CMS claim to have such small errors at high diphoton masses? Did you see how much the errors (and central values in case of CMS) changed going from conf note to preprint?<br /><br />>ven with the limited publicly available data, they could have done much more.<br /><br />Of course! But the paper seems to be making a physics point. It would be really interesting to discuss this rather than to nitpick on the statistics crap. <br />Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-10427699790027518192016-07-25T04:20:59.418+01:002016-07-25T04:20:59.418+01:00I think by now everyone *knows* 750 is dead... ove...I think by now everyone *knows* 750 is dead... overheard several times from various members of the collaboration(s), RIP. Long live ambulance chasing! :)Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-88678104327882026802016-07-24T02:31:23.002+01:002016-07-24T02:31:23.002+01:00As recently as LHCP in June, CERN were advising th...As recently as LHCP in June, CERN were advising that any discovery level announcement 'has to be' at an on-site seminar, i.e. at CERN. However, there isn't time to organize one of those before ICHEP. Maybe they have changed their policy on this in the month and will surprise us, but sadly that seems less likely than the other option which is that nothing has been discovered. still there is always the possibility that they have one or more signals are 'tantalizing' but below discovery threshold. That seems unlikely in the particular case of 750GeV though, given the scale-up factor for 13TeV data collection since March when the last public discussion took place.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-39567255300570026692016-07-23T23:46:28.894+01:002016-07-23T23:46:28.894+01:00@mfb: regarding photon background, so we have 8TeV...@mfb: regarding photon background, so we have 8TeV results that confirmed Higgs with great consistency with SM; if there were a systematic error in estimating the background, wouldn't it mean that in the 8TeV run we would also see fewer background events and so higher significance (by the same 1-2 sigma?) than in the channels not affected by the error? Yet nothing like this was reported afaik. So how can it be that we only see it now, if the same approach was used to simulate the background in both experiments?RBShttps://www.blogger.com/profile/05190152376766693948noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-40799498150712591512016-07-23T07:50:17.201+01:002016-07-23T07:50:17.201+01:00@mfb I can't judge their expertise about calcu...@mfb I can't judge their expertise about calculating backgrounds, but they misunderstand statistical issues and the experimental analysis. Their method III of estimating backgrounds describes extrapolating a functional form from sidebands into a signal region. We're told that it was the approach used by ATLAS and CMS. It wasn't. ATLAS and CMS fitted functional forms to the whole diphoton spectrum (with no signal regions, sidebands or extrapolation), once without a signal, and once with a signal. <br /><br />Their statistical analysis is extremely crude. They don't calculate a log likehood ratio hypothesis test etc; they find the p-value by finding the probability of observing n >= n_observed in the bin with the biggest excess, assuming background only and Poisson statistics, in a goodness of fit test. Even with the limited publicly available data, they could have done much more.<br /><br />Unsurprisingly, they can't reproduce anything like the official numbers for the significances. But we're then told that although their absolute significances aren't reliable, the delta significances are. This is strange - given the relationship (normal cdf) between sigma and p-value, it's extremely hard to believe significances could be affected by a systematic shift, such that delta significances were correct. I suppose sign (delta significance) could be correct. <br /><br />The physics might be great, but the stats is shaky (they also say weird things about the LEE). Do you agree?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-68981476827323712802016-07-22T20:09:30.920+01:002016-07-22T20:09:30.920+01:00Officially it is/was blinded until a few days befo...Officially it is/was blinded until a few days before th ICHEP, I guess the famous 15th July.<br />http://www.quantumdiaries.org/2016/06/17/enough-data-to-explore-the-unknown/<br /><br />BTW: The rumor was posted on 21th June, so it must be based on the few data until mid of june, less than 3/fb. 2nd filter failed.sciingnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-61587115700311944802016-07-22T13:34:57.917+01:002016-07-22T13:34:57.917+01:00@Anon it's more credit than I rightfully deser...@Anon it's more credit than I rightfully deserve but for the final answer we'd have to go all the way to the Planck scale and then...RBShttps://www.blogger.com/profile/05190152376766693948noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-13913590585108848062016-07-22T12:21:51.764+01:002016-07-22T12:21:51.764+01:00There is a new theory paper discussing a possible ...There is a new theory paper discussing a possible underestimate of jet+photon background in the relevant mass range which could influence the background fit. Didn't read it fully yet, but the authors seem to know what they are talking about: http://arxiv.org/abs/1607.06440<br />If their estimates are accurate, the significances could be overestimated a bit (0.3-1 sigma) - the excess is still interesting, but it makes a statistical fluctuation more likely.<br /><br /><br />@sciing: In analyses like this (where you don't want to wait for the dataset of the full year) unblinding is typically done once the analysis method is fixed and relevant data has been taken - this could have been done quite early. mfbnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-86041261847733899782016-07-22T06:50:14.446+01:002016-07-22T06:50:14.446+01:00How could there be thrustable rumors if the data w...How could there be thrustable rumors if the data was blinded? Sorry, but this rumor did not even pass my "does it make any sense" filter at stage 1.sciingnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-31791126399659093492016-07-21T15:53:58.568+01:002016-07-21T15:53:58.568+01:00RBS, your description of the scientific procedure ...RBS, your description of the scientific procedure is impressive. Extraordinary claims require extraordinary evidence. Perhaps this is the quite time what people need to finish everything? In a week or two, I suppose that we should know the answer, no? Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-88009095632133028472016-07-20T16:26:38.654+01:002016-07-20T16:26:38.654+01:00@Anon why guess when we can compare it e.g. with t...@Anon why guess when we can compare it e.g. with the Higgs discovery. There was the first report that raised the excitement then the discovery announcement at the seminar in CERN. But I don't recall any significant buzz in between, at least weeks rather than days in advance. The results have to be collected, data processed, reviewed and approved by both teams. This takes time and I simply don't see any obvious shortcuts to the destination answer.RBShttps://www.blogger.com/profile/05190152376766693948noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-55198325334616049662016-07-20T09:24:02.057+01:002016-07-20T09:24:02.057+01:00@RBS 17 July
I think it is clear, since said anom...@RBS 17 July <br />I think it is clear, since said anomaly, which would have completely upended physics, must have been safely disovered by now if it were true, but I perceive no 'buzz'' of any kind.<br /> Also, the rumour from reliable sources that it is dead has been well known for a full month and yet nobody (even anonymously) claiming inside knowledge has sought to challenge that. Not even a troll has bothered to do so, as far as I can tell. As for the theory papers at ICHEP 2016, I suppose anyone has the right to submit a theory paper for consideration, but how sheepish they might feel when presenting it is another matter altogether. <br />Also, there has been no attempt by CERN to prepare the ground for any earth-shattering news, even though they are sitting on mountains of data and analysing the gamma gamma data has probably been their highest priority.<br />The ever-reliable Dorigo seems to maintain his 'hunch' that their is no new physics within reach at LHC, ever, even though he would be happier than anyone if that turned out not to be the case. This thing is done, I'm afraid to say.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-56021726704599179882016-07-19T14:10:46.716+01:002016-07-19T14:10:46.716+01:00Hi Jester,
Will your SUSY bet with Lubos get deci...Hi Jester,<br /><br />Will your SUSY bet with Lubos get decided with the upcoming LHC results? 15 fb^-1 data in CMS plus 15 fb^-1 data in Atlas amounts to 30 fb^-1 from LHC.....<br />Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-71904621518817470062016-07-18T03:43:25.106+01:002016-07-18T03:43:25.106+01:00Today in hep-ph there is a paper containing the im...Today in hep-ph there is a paper containing the immortal sentence,<br /><br />"The anomaly has led to an excessive number of publications, so we feel that adding one more, and hopefully useful publication can be justified somehow."<br /><br />What fun, eh?Rastus Odinga Odingahttps://www.blogger.com/profile/09615544434035028500noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-18060744692452778282016-07-17T17:54:30.840+01:002016-07-17T17:54:30.840+01:00I'm not sure how is it clear? OK, show 2015 gr...I'm not sure how is it clear? OK, show 2015 graph with tantalizing hint; show 2016 with nothing there. Maybe you can spend 15+5 min on that, double that for Atlas and CMS. But 6 (six) theory talks, about nothing? <br />Of course they could have put it as #1 with big letters. But that would mean rising stakes high - even higher than the last time with three weeks to go. To me, nothing is clear yet. I guess it will all be clear on the 5th at the end of sessions 3 and 4.RBShttps://www.blogger.com/profile/05190152376766693948noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-22794236614387752082016-07-15T15:59:50.838+01:002016-07-15T15:59:50.838+01:00ICHEP abstracts appeared online in timetable. Long...ICHEP abstracts appeared online in timetable. Long live supersymmetry ?ICHEPhttp://ichep2016.org/noreply@blogger.com