sPHENIX cold QCD topical group

[Alexander Bazilevsky <shura AT bnl.gov>]

Hi Itaru ans All,

Some correction to my proposal.
After looking more careful in the vernier scan analyses we did in the 
past, I found that the vertex distribution evolution vs different beam 
displacements was studied with ZDC triggers (as its efficiency is not 
z-dependent, unlike BBC/MBD which is z-dependent), so we'd better 
increase the collected statistics for ZDC-Coincidence. So, my corrected 
proposal for scaledowns:

CLOCK: 10k
MBD N&S >= 1: 10
ZDC Coincidence: 0

(actually almost the same as we run it in PHENIX)

and if we can afford collecting also single-side triggers (just in case):

ZDC-North and ZDC-South: 100
MBD S >= 1 and MBD N >= 1: 500

Regards,
Sasha.

On 7/9/24 9:51 AM, Alexander Bazilevsky wrote:
> Thanks, Itaru, for compiling the info!
>
> Besides the scaler (GL1P) data, we also need event data: as a maximal 
> set - for all triggers included in GL1P, and as a minimal set - for 
> MBD coincidence trigger and CLOCK (e.g. to study vertex distribution 
> at each beam position to understand the hour glass effect).
>
> Since during the vernier scan run our rates vary by a few orders of 
> magnitude, we can not set up reasonable trigger scaledowns which would 
> provide both good life time and good DAQ rate at each step. Therefore 
> we used to release the scaledowns for triggers we collect to saturate 
> the DAQ rate regardless the life time (with the goal to collect as 
> many as possible of triggers we want).
>
> So, I suggest the following scale downs:
>
> CLOCK: 10k
> MBD N&S >= 1: 0
> ZDC Coincidence: 0
>
> Not sure how useful could be the one-side trigger data, but if we can 
> afford enabling them, I'd suggest the scaledowns:
> ZDC-North and ZDC-South: 10
> MBD S >= 1 and MBD N >= 1: 50
>
> In this configuration, the major bandwidth will be occupied by CLOCK 
> and MBD N&S, and only a few % for all other triggers (not necessary, 
> but may be useful).
>
> Regards,
> Sasha.
>
>
>
> On 7/9/24 5:01 AM, Itaru Nakagawa wrote:
> > Dear Sasha and Ralf,
> >
> >  Here is the draft instruction for the vernier scan. Unfortunately I 
> > cannot find any instruction of the data taking in PHENIX, but here is 
> > what I think is the procedure. Please have a look and send me feedback.
> >
> > Best regards,
> >
> > -itaru

--
Alexander Bazilevsky
Brookhaven National Laboratory, Bldg. 510D, 2-232
Upton, NY 11973 Tel: 631-344-3712
Email: shura AT bnl.gov
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