sPHENIX discussion of physics

[Gunther M Roland <rolandg AT mit.edu>]

Hi Tony, 

 I agree that we should clarify that this was for the two-track plot, and we could point out the obvious - it's going to be worse for a three-track cut.The statement was based on the two-track efficiency plot from the upgrade proposal, which shows the difference between 100% and 70% efficiency for the two-track selection (if I understood the plot correctly) I don't know if a similar plot exists for a three-track selection. If one of the experts is prepared to provide a stronger statement (in the absence of new simulations), we could quote that. Absent that, it felt safer to include a statement where we could point to an existing plot for the time being.

Cheers,

Gunther

On Jun 5, 2016, at 10:36 PM, Frawley, Anthony <afrawley AT fsu.edu> wrote:

Dear Dave and Gunther,

From a very quick look, one statement caught my eye:

Line 567:

"For a given b-jet purity, the reduced VTX pixel single track efficiency implies a  50%

lower b-jet efficiency than the MAPS based solution, in addition to the reduced tagging efficiency
due to the lower DCA resoluton."

It sounds like this assumes only two tracks are used in the B jet tagging (the single track efficiency for the pixels is lower by a factor of ~ 0.7). But I thought that the preferred tagging method uses three large-DCA tracks, which would imply an efficiency lower by a factor of ~ 0.34. It would be good, in any case, to mention what goes into that 50% number.

Cheers

Tony

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From: sphenix-physics-l-bounces AT lists.bnl.gov <sphenix-physics-l-bounces AT lists.bnl.gov> on behalf of David Morrison <dave AT bnl.gov>
Sent: Sunday, June 5, 2016 8:33 PM
To: sphenix-physics-l AT lists.bnl.gov; sphenix-l AT lists.bnl.gov
Subject: [Sphenix-physics-l] near final draft

 

Dear collaborators,

There was a very good discussion of the response to the ALD’s charge at the Friday general meeting, and here is a draft that incorporates some of the advice we received.  For example, there is now a table of scenarios in the executive summary.  There is also an appendix with summary budget numbers.  We’d like to consider this draft provisionally final (we’d turn off the line numbers in the truly final version of course), but we’d be happy for any specific comments by noon ET on Monday.  After the Friday meeting, we had arranged with Berndt Mueller to move the deadline from Friday to Monday.

https://www.dropbox.com/s/qsy19ir6z551ls1/draft_v3.pdf?dl=0

draft_v3.pdf www.dropbox.com Shared with Dropbox

I’m tripping over some technical problems trying to produce a diff between this version and the previous one, but if I manage to overcome those I’ll post a link to a diff too.

Regards,

Dave and Gunther

David Morrison Brookhaven National Laboratory phone: 631-344-5840
Physics Department, Bldg 510 C email: dave AT bnl.gov
Upton, NY 11973-5000

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