sPHENIX cold QCD topical group

["Aidala, Christine" <caidala AT bnl.gov>]

 

Below are brief minutes from today’s discussions.

 

Christine

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sPHENIX cold QCD run plan discussion

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-For 3-year run plan requested for PAC, assume 11.5 weeks each of p+p and p+A.

 

-Streaming DAQ – assume only tracking is included, and ~10% of data collected with streaming DAQ.

 

-Beam crossing angle – TPC ion backflow and SiPM radiation damage are both issues if run p+p the in “standard” configuration with no crossing angle.  Shrinking vertex distribution from sigma_z ~40 cm to ~10 cm costs more than a factor of 5 in sampled luminosity as well as the more forward rapidity measurements.  Would be a major loss.

 

-May be possible to run with a smaller crossing angle.  Jamie is requesting projections from Wolfram.  Will need to convert to estimates of the tracks/second in A+A, p+A, and p+p to understand impact on TPC and SiPMs.

 

-At this point, no forward EMCal upgrade will be pursued for 2024.

 

-Local polarimetry – Need to understand if PHENIX ZDC+SMD can be reused, or if needs to be refurbished/rebuilt.

 

-Relative luminosity – GL1P scalers have been retired.  Need a group/people to actively work on incorporating functionality of STAR scalers into sPHENIX trigger.

 

-With only 11.5 weeks of p+p in a 3-year run plan, don’t expect double-helicity asymmetry measurements to be impactful.  Conclude that should run with transverse (vertical) polarization.

 

-p. 8 – D meson A_N projections – assumed only 50 pb^-1 sampled.  D0->K pi decay channel.  Note that electron ID will probably not be good enough to do single electron open heavy flavor measurement effectively. 

 

-Need to prioritize and update projection plots, and add comparisons to existing measurements and/or theory.

 

-Need to investigate any possible effects of crossing angle on transverse spin measurements.  Position of ZDC for local polarimetry would need to be adjusted?

 

-Should also prepare projections and physics case for two extra years of running to show to the PAC.

 

 

RHICf-II proposal for sPHENIX – Yuji Goto

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In 2017, RHICf-I ran at the STAR IR, using 510 GeV p+p collisions, with EMCal installed directly in front of the ZDC.  Dedicated running time of ~5 days, with beta*=8 m.  Interested in follow-up measurements in 200 GeV p+p and p+A at sPHENIX in 2024.  Physics interest in transversely polarized proton measurements for far-forward particle production and studies related to cosmic rays.  First results released for transverse single-spin asymmetry in far-forward pi0 production as a function of xF and pT.  Already for pT ~ 0.2 GeV, asymmetries remarkably similar to pT>1 GeV asymmetries measured at STAR, PHENIX, and FNAL. 

 

Originally planning to present to PAC next year, but may make sense to include in sPHENIX run plan discussion at PAC this year. 

 

As a high priority, need to do detailed statistical projections for 200 GeV running in order to understand how many days would be needed of p+p and/or p+A beamtime.  This will inform future discussions.

 

It was noted that hardware development will continue independently of any sPHENIX/RHIC decision to dedicate beam time to RHICf-II, as the hardware development is part of the LHCf experiment planned at ALICE.

 

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Christine A. Aidala

Associate Professor

Department of Physics

University of Michigan

(734) 764-7611

 

From: sPHENIX-cold-QCD-l <sphenix-cold-qcd-l-bounces AT lists.bnl.gov> On Behalf Of Aidala, Christine
Sent: Monday, July 27, 2020 8:06 PM
To: sphenix-cold-qcd-l AT lists.bnl.gov
Subject: Re: [Sphenix-cold-qcd-l] Cold QCD TG meeting, 9 am EDT, Tue, July 28

 

Dear all,

 

This is a reminder of the Cold QCD TG meeting tomorrow at 9:00 am EDT. 

 

9:00-9:45 am – Discussion of run plan and updating/creating projection plots

9:45-10:05 am – RHICf-II proposal for sPHENIX – Yuji Goto and Itaru Nakagawa

 

https://indico.bnl.gov/event/9011/

https://bluejeans.com/345777492

 

Best regards,

Sasha and Christine

 

--

Christine A. Aidala

Associate Professor

Department of Physics

University of Michigan

(734) 764-7611

 

From: sPHENIX-cold-QCD-l <sphenix-cold-qcd-l-bounces AT lists.bnl.gov> On Behalf Of Aidala, Christine
Sent: Tuesday, July 21, 2020 4:35 PM
To: sphenix-cold-qcd-l AT lists.bnl.gov
Subject: [Sphenix-cold-qcd-l] Cold QCD TG meeting, 9 am EDT, Tue, July 28

 

Dear cold QCD enthusiasts,

 

We will have a Cold QCD TG meeting next Tuesday, July 28, starting at 9:00 am EDT (before the annual Cost & Schedule Review).

The agenda page is at https://indico.bnl.gov/event/9011/.

Bluejeans connection: https://bluejeans.com/345777492

 

In preparation for the September PAC meeting, we have two closely coupled discussions on the agenda:

 

-sPHENIX run plan

-Updating cold QCD projection plots

 

Best regards,

Sasha and Christine

 

--

Christine A. Aidala

Associate Professor

Department of Physics

University of Michigan

(734) 764-7611