tag:blogger.com,1999:blog-2846514233477399562.post6407127749104330517..comments2024-01-08T09:37:04.406+01:00Comments on RÉSONAANCES: Weekend plot: SUSY limits rehashedJesterhttp://www.blogger.com/profile/08947218566941608850noreply@blogger.comBlogger8125tag:blogger.com,1999:blog-2846514233477399562.post-24976124328556209872015-09-05T13:20:04.534+01:002015-09-05T13:20:04.534+01:00For reference: https://cds.cern.ch/record/2048626/...For reference: https://cds.cern.ch/record/2048626/<br />ATLAS has 200/pb and CMS has more than 65/pb as well (I guess they can even use their magnet-off data as the calorimeters don't care much). If that is not a fluctuation, more events should come soon.mfbnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-78723995650516286982015-09-04T00:36:03.897+01:002015-09-04T00:36:03.897+01:00Way too early. It takes more than 1 event to make ...Way too early. It takes more than 1 event to make a resonance :)Jesterhttps://www.blogger.com/profile/08947218566941608850noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-41056567755280035942015-09-03T21:47:54.256+01:002015-09-03T21:47:54.256+01:00Jester,
What is your take on the 3 TeV di-electro...Jester,<br /><br />What is your take on the 3 TeV di-electron event at CMS? Is this a glimpse of the Z' resonance or is it way too early to hope?<br /><br />Cheers,<br /><br />ErvinErvin Goldfainhttps://www.blogger.com/profile/07585008304556273617noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-35539477431265110482015-09-01T21:50:35.272+01:002015-09-01T21:50:35.272+01:00The performance is significantly below expectation...The performance is significantly below expectations. A few months ago the predictions were in the range of 10-12/fb, then they got lowered in multiple steps, the most recent prediction is 3/fb - a factor 4 lower.<br /><br />In terms of physics reach, see this older blog post: http://resonaances.blogspot.de/2015/05/how-long-until-its-interesting.html<br /><br />The Higgs analyses might be able to make small improvements by combining old and new data, but there won't be new things. The 13 TeV production cross-section will certainly get some measurement, but with large uncertainties (no point in counting sigmas - we know it exists and it won't disappear with higher energy).<br /><br />SUSY: Some analyses will be able to improve the limits significantly, some won't.<br /><br />Extra dimensions: even the data collected so far (0.2/fb) is sufficient to improve the limits significantly. Or discover something...<br /><br />Anyway, the problems seen this year all seem solvable - the 2016 data should easily beat the run 1 data everywhere.mfbnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-71863217076004900992015-09-01T19:40:56.890+01:002015-09-01T19:40:56.890+01:00Drew and Jester. TY for this insight. For me it is...Drew and Jester. TY for this insight. For me it is nothing less than intoxicating, that a layman like me (i drive trains for a living), can be informed like this.<br />Without the hangover!<br /><br />Michel Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-37745542273903834592015-09-01T14:29:05.859+01:002015-09-01T14:29:05.859+01:00Thanks a lot Drew. Michel, we had very high expect...Thanks a lot Drew. Michel, we had very high expectations after the glorious year 2012 where everything was running smoothly and the LHC collected more data than expected. In this respect, the beginning of run-2 is a slight disappointment. But all the problems so far are small hiccups that will not matter in the long run. Jesterhttps://www.blogger.com/profile/08947218566941608850noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-82272860866944310732015-09-01T00:59:46.563+01:002015-09-01T00:59:46.563+01:00Michael:
Yes and no.
Yes
* The Run1 start up (...Michael:<br /><br />Yes and no. <br /><br /><b>Yes</b><br /><br />* The Run1 start up (2008) had a catastrophic incident which delayed the start for much longer than delays of this year.<br /><br />* Also, the machine protection committee were very cautious during the intensity ramp-up. It was only in 2012 that serious (exponential: as much data was collected in a day, as had been collected all year before) luminosity was recorded on a daily basis.<br /><br /><b>No</b><br />Run2 started with some hindering problems in place (though some were only discovered during commissioning):<br /><br />* <a href="http://indico.cern.ch/event/389857/session/1/contribution/0/attachments/779709/1069143/LHC-status-LHCC-June15.pdf" rel="nofollow">The ULO sitting at 15R8. (slide 27)</a>. This problem seems to have been mitigated (by steering around it), but it may crop up again as larger bunch trains are used.<br /><br />* <a href="http://indico.cern.ch/event/389857/session/1/contribution/0/attachments/779709/1069143/LHC-status-LHCC-June15.pdf" rel="nofollow">In 2013, the TDIs were discovered to not be manufactured to spec. (slide 6)</a> This limits the total number of bunches down from ~ 2808 to 2500 or so. Not a problem yet.<br /><br />* <a href="http://indico.cern.ch/event/389857/session/1/contribution/0/attachments/779709/1069143/LHC-status-LHCC-June15.pdf" rel="nofollow">Scrubbing with "doublet" beams was more challenging than anticipated. (slide 31)</a> This means that it has been necessary to scrub for slightly longer with 25ns beams, and that the overall result still isn't as helpful.<br /><br />* Some <a href="https://indico.cern.ch/event/308246/session/1/contribution/18/attachments/588453/809914/QPS_R2E_Reliability_Workshopv2_Steckert.pdf" rel="nofollow">~ 1200 electronics boards</a> installed during LS1 to monitor quench protection equipment have proven to not be as radiation hard as expected. This has been the source of many beam dumps that otherwise would not have happened. Luckily, they are all being replaced <b>this week</b> during the technical stop.<br /><br />* There were a few circuits with ground fault problems that had to be fixed. This removed almost two weeks from the physics budget of the year.<br /><br /><br />Remember that various equipment is aging (cryo, electronics, communications, access) will have a higher probability of failing as time goes on.<br /><br />In short, I think Run2 is going about as well as could be expected. It's likely that data production this year will be a few factors of two below the original expectation.<br /><br />Cheers,<br />-DrewD Dayhttps://www.blogger.com/profile/18162884948703952910noreply@blogger.comtag:blogger.com,1999:blog-2846514233477399562.post-21559057357996958992015-09-01T00:14:47.112+01:002015-09-01T00:14:47.112+01:00Hi Jester.
I check Op-Vistars almost every day. N...Hi Jester.<br /><br />I check Op-Vistars almost every day. Noticed that there were a lot of problems. Even a lightning strike. <br />Did Run 1 also have these start up problems?<br /><br />Regards,<br /><br />MichelAnonymousnoreply@blogger.com