Last night the Large Hadron Collider clocked up another record luminosity using 624 bunches per beam. In ATLAS the peak luminosity was measured at 737/μb/s while CMS saw about 10% less at 660/μb/s. In theory they should be seeing about the same amount. Paul Collier (head of the beams department at CERN) has said that they suspect the ATLAS figure is too high. A more accurate measurement will be made after the next technical stop in two weeks time when a Van der Meer scan will be run through. Meanwhile I will quote the lower CMS numbers and will be updating the figure in the viXra Log banner above.
An important date coming up in the LHC calendar is the 6th June when the “Physics at LHC 2011” conference starts. The experiment teams will be keen to show results using as much data as possible collected before that date. That will be challenging given the rate at which data will then be accumulating and the need to get about 3000 physicists in each collaboration to sign off on any results before they are presented.
A few weeks ago I said the LHC should be able to deliver 200/pb before the conference. In fact they have already surpassed that figure for 2011 and can add last years 40/pb as well to make nearly 240/pb. I will also be tracking this number above. Two weeks ago I upped the estimate to 500/pb for the conference but even that is looking a little unambitious now. According to the plan there are about 30 days left for physics before the 6th June and they can now easily collect about 30/pb each day. My new estimate is at least 1000/pb which is 1/fb in time for the conference assuming they don’t lose too many days to machine development or faults. Recall that 1/fb is the official target for the whole of 2011! It may sound like their original expectations were a bit low but really this amazing result is due to the exceptional early performance of the collider when compared with previous models.
The 6th June also marks the point when commissioning of the LHC for this year should officially stop. If all goes well they will be aiming to reach this years maximum luminosity by this date. Which will mean filling with 1404 bunches per beam to provide something like 70/pb per day. From 6th June there are 124 days marked on the plan for running proton physics. Do the sums and you will get my new estimate for this years total of 10/fb, easily enough to find the Higgs boson whatever mass it has, or rule it out.
Update: If you dont like my estimate of 10/fb here is your chance to say how much luminosity you think the LHC will deliver this year