sPHENIX cold QCD topical group

["Riedl, Caroline" <criedl AT illinois.edu>]

Hi Audrey,

Thanks for a very nice set of slides! I can see that you got a hold of the latest materials, so I just have a few comments.

• slide 17 - I would change the title to "Timeline of installations and data taking" (the markers / text in blue are the installations) 
  
  
• still slide 17 - pp data taking was completed 30.9 (Monday), i.e. you could add this on the slide and say "two days ago" (assuming you'll give the talk on Wednesday
  
  
• slide 21 - I would add the projection plot for "hadrons in jets". It is in the 2024-2028 RHIC cold QCD plan, available here https://drupal.star.bnl.gov/STAR/files/RHIC_Spin_Plan_2024_0.pdf, Section 3.2.3. There is also the 2-hadron figure with better resolution (your slide 20)
  
  
• slide 21- typo 🙂 "mi-rapidity"
  
  
• slide 21 - flavor separation / charge tagging also helps for the di-jet signature - one can then attempt to separate kT of u-quarks and d-quarks and a gluon-enhanced sample. STAR has very recently done this [STAR arXiv:2305.10359]
  
  
• slide 22, after the "features large and hermetic EM and hadronic calorimetry", I strongly suggest adding also the tracking detectors since they are needed for the HF, displaced vertices, full jet reconstruction, etc., and thus also for the cold QCD program. This could be done by adding "and tracking for precision vertexing, timing, and momentum resolution" (listing them in the order MVTX, INTT, TPC/TPOT, without the urgent need to repeat the names). Probably also add "streaming readout" 
  
  
• slide 22 - (sPHENIX has also the first RHIC HCal at mid-rapidity, just as a remark)
  
  
• slide 22 - I suggest adding something like this (probably between now paragraphs 1&2): "Optimized for jets, heavy-flavor measurements & displaced vertices" 
  
  
• slide 22 - in the very last part, I would be a bit more specific (what you have is not incorrect)...
  "tri-gluon correlation function in the collinear twist-3 framework,
  transversity (Collins effect), Sivers effect and TMD factorisation"
  --> something like this:
  "tri-gluon correlation function in the collinear twist-3 framework,
  transversity PDF via Collins effect and IFF,
  quark and gluon Sivers TMD PDF,
  studies of TMD universality and factorisation breaking "
  Remark on the last line: factorization (into hard scattering part, PDF, FF) may not hold in hadronic interactions (like pp). For example, the "hadrons-in-jets" measurement can be used to test whether factorization holds, and universality, for that matter, by comparing the measured asymmetries to model calculations from semi-inclusive DIS and ee annihilation. These calculations assume both factorization and universality. If they won't match the data, we could attempt to draw some conclusions... (see what STAR did in their publication, https://journals.aps.org/prd/abstract/10.1103/PhysRevD.106.072010) Ralf's "hadrons-in-jets" projection plots very clearly shows how sPHENIX can improve the current STAR measurement. 
  
  
• General: it would be good to cite https://arxiv.org/abs/2302.00605v1 and https://drupal.star.bnl.gov/STAR/files/RHIC_Spin_Plan_2024_0.pdf

Good luck with the talk!

Best,

Caroline

⎯⎯⎯⎯⎯⎯⎯

Caroline Riedl
Research Professor

UIUC

---

From: sphenix-cold-qcd-l-request AT lists.bnl.gov <sphenix-cold-qcd-l-request AT lists.bnl.gov> on behalf of FRANCISCO Audrey <audrey.francisco AT cea.fr>
Sent: Monday, September 30, 2024 9:49 AM
To: sPHENIX-cold-QCD-l AT lists.bnl.gov <sPHENIX-cold-QCD-l AT lists.bnl.gov>
Subject: [[Sphenix-cold-qcd-l] ] Slides for IWHSS-CPHI-2024

 

Dear all,

I apologise again for the late posting. I was asked to give a presentation about the “cold QCD program at sPHENIX” at the Joint 20th International Workshop on Hadron Structure and Spectroscopy and 5th workshop on Correlations in Partonic and Hadronic Interactions.

Please find the draft of my slides here (I am currently having difficulties uploading to invenio, will do it asap). I am exclusively reusing previously shown material by various speakers. 

Will probably have a second version with enhanced cosmetics but no change in content.

Inputs are very welcome!

Cheers,
Audrey

— 

Audrey Francisco, Ph.D.
Research Scientist
IRFU, CEA, Université Paris-Saclay, France
+33169087007
she/her/hers