Page 6 of 7

Re: 2012 Events Discussion

Posted: Sun Jun 17, 2012 12:47 pm
by DCWhitworth
Looks like another highly successful record breaking week. 1.01 fb-1 so far plus the latest just dumped fill which is probably going to be about 200 pb-1 plus whatever they can fit in the rest of today.

:clap:

Re: 2012 Events Discussion

Posted: Mon Jun 18, 2012 9:49 pm
by Harbles
The Meeting notes for today are entertaining.
http://lhc-commissioning.web.cern.ch/lh ... eting.pptx

1.3 fb-1 for the week, yay!
Workers opened a door in the middle of a run to change some sealing (plombage) causing a dump. (boo)
Vacuum spikes and overheating on the injectors causing some concerns, apparently some mods will be made next week during the TS and possibly more changes at the next TS.
One of the main things slowing progress is waiting for the kickers to cool after injection.
With both main experiments just over 6.5 fb-1 for the year they are about half way to the goal of 13.3 fb-1 to ensure both experiments have enough data to independently verify the Higgs Per Steve Myers talk at the 110th LHCC posted above.
Now high Beta* runs for a couple of days, Some MD and then TS for a week.

Re: 2012 Events Discussion

Posted: Tue Jun 19, 2012 3:56 am
by Xymox
:) fb-1 are good... I keep trying to picture a inverse very tiny barn.. Like upside down cows..

Gotta love records...

Amazing how far we have come. Remember when we were happy with a 1x1 bunch ? hahahaha...

Gotta love the picture of the security team opening the door that caused the dump... hehehe...

Re: 2012 Events Discussion

Posted: Wed Jun 20, 2012 9:19 am
by DCWhitworth
Yeah, I remember us (and CERN !) celebrating the first inverse nano-barn.

I had an amusing conversation with a friend recently.

Me - I've been looking at the latest LHC Machine Status Report. They're pretty much saying "She canna take any more Captain !"

Friend - Yeah but they're not going to say "I canna change the laws of physics !" are they !

:D

Re: 2012 Events Discussion

Posted: Sat Jun 23, 2012 3:51 am
by Harbles
Hmm. As if one has to 'Hype' the 'Potential' discovery of the 'God Particle'.

" Geneva, 22 June 2012. CERN1 will hold a scientific seminar at 9:00CEST on 4 July to deliver the latest update in the search for the Higgs boson. At this seminar, coming on the eve of this year’s major particle physics conference, ICHEP, in Melbourne, the ATLAS and CMS experiments will deliver the preliminary results of their 2012 data analysis. "

http://press.web.cern.ch/press/PressRel ... 6.12E.html

But as Steve Myers said in his talk of last week they are still about 7 fb-1 short of having enough Data for both experiments to have a 5 sigma result.
Hmmm.

Re: 2012 Events Discussion

Posted: Tue Jul 10, 2012 12:44 pm
by Harbles
So the Hype was deserved it appears. ;)
I've heard talk of changing the 2012/2013 schedule to add a few more months of data gathering before Long Stop one.
Has anyone seen a revised schedule yet?

Re: 2012 Events Discussion

Posted: Tue Jul 10, 2012 6:45 pm
by DCWhitworth
Harbles wrote:So the Hype was deserved it appears. ;)
I've heard talk of changing the 2012/2013 schedule to add a few more months of data gathering before Long Stop one.
Has anyone seen a revised schedule yet?
In his last machine status report presentation, Steve Myers said they had the option to postpone LS1 by up to two months if more data was required.

I guess the question would be what data would they be after ? Presumably they'd have enough data through planned running to move the 'Higgs' well beyond 5 sigma so what else ?

Re: 2012 Events Discussion

Posted: Wed Jul 11, 2012 5:57 am
by Kasuha
DCWhitworth wrote:I guess the question would be what data would they be after ? Presumably they'd have enough data through planned running to move the 'Higgs' well beyond 5 sigma so what else ?
They still don't know the properties of the new particle. Out of five decay channels which apply for higgs at this mass only two were conclusive enough to claim a discovery, the remaining three are still way below discovery thresholds. And gamma channel appears to be significantly above what should be observed if it is SM higgs - so there is still more data needed to figure out real properties of the new particle.

Plus of course, data is data. They could try to find whatever new physics they please in them in the upcoming two years when LHC will be shut down.

Re: 2012 Events Discussion

Posted: Wed Jul 11, 2012 7:50 pm
by pcatom
The decision has been taken to extend the run to beyond Christmas with the likely scenario to continue p-p until Christmas and delay the p-Pb run until January (exact arrangement still under discussion). Last beams will be on 11th Feb 2013.

The main reason for the extension is technical, and not Physics driven (although i'm sure the experiments will welcome any extra data.

Re: 2012 Events Discussion

Posted: Sat Jul 14, 2012 11:48 am
by gilgamorph
The main reason for the extension is technical, and not Physics driven
Does this mean there is some reason that they couldn't begin implementing the improvements planned for LS1 until later next year?

Re: 2012 Events Discussion

Posted: Sat Jul 14, 2012 12:16 pm
by chriwi
Are theese really tecnical resons or maybe rather financial reasons , that some contributors of money like to delay the payments because of the euro-crisis?

Re: 2012 Events Discussion

Posted: Sat Jul 14, 2012 10:30 pm
by Kasuha
The only "really technical" reason preventing switching LHC off that comes on my mind is that they may have problems with obtaining a safe storage for all the helium which is now cooling the LHC.
But that's just my speculation so I wonder what these technical reasons really are.

Re: 2012 Events Discussion

Posted: Sun Jul 15, 2012 7:56 am
by pcatom
... Mainly having more time to get ready!

Re: 2012 Events Discussion

Posted: Sun Jul 15, 2012 7:17 pm
by jmc2000
pcatom wrote:... Mainly having more time to get ready!
Does this mean there's no chance of it being turned on even in late 2014?

Re: 2012 Events Discussion

Posted: Sat Aug 11, 2012 6:19 pm
by PhilG
If I understood the latest news correctly CMS lost the current in its solenoid and temperature went up to 70K. It will take 5 days to get back to normal so they will not be doing physics runs much until it is sorted.

If anyone knows more please fill us in.