sPHENIX MAPS tracker discussion

[Hideki Okawa <Hideki.Okawa AT cern.ch>]

Introduction - Jin, Hideki

Please join us!

https://wiki.bnl.gov/sPHENIX/index.php/Heavy_Flavor_Topical_Group#Study_plans 

and various MatterMost channels.

Last talk: AUM2020

Next talk: Initial Stages

Pythia8 tune for D-D correlation study - Long Ma

Jin: How much is the impact of pTHat on the xsec? (p.2)

Long: Not much on the inclusive xsec, but more on the

differential pT spectrum.

 

Jin: Single charm pT spectrum on p.3?

Long: This is D0 pT spectrum, not a single charm.

Zhaozhong: Prompt D0 only?

Long: This is inclusive D0.

Ming: Why pT not below 1 GeV?

Long: The binning is large, so it actually goes below

1 GeV. (->Minimum is at 0.6 GeV according to the paper)

MC is generated between pT=0-10 GeV.

Jin: What is "PYTHIA 8.1 MB" on p.5?

Long: It means the default tune.

Jin: Please double-check the statistical uncertainty

calculation for MC.

Jin: Which eta range on p.7?

Long: |eta|<1

Sanghoon: What is the trigger requirement for MB?

Long: Coincidence in the VPD. Will check the number of

hits required. (Feedback after the meeting: the eta range

of VPD is 4.2-5.1) The data is unfolded.

Jin: Let's follow up the details of the unfolding whether

the trigger effect is also removed or not.

Jin: Which PDF did you use?

Long: The default

Jin: What do you mean by embedding on p.8?

Long: Actually, event mixing or reweighting of the two

samples (default & Long's tune) to better reproduce

the pion pT spectrum, etc.

Jin: OK, that is non-trivial and requires detailed

investigations to implement.

PDF & MPI tunes - Sanghoon Lim

Jin: Is the color reconnection enabled?

Sanghoon: Enabled only for those with Mode=2 on p.5,6.

Yuanjing: If you enable the color reconnection, you also

have to turn on the softQCD. The color reconnection is

tuned with the softQCD on.

Jin: Will that be a problem for the sample generation

regarding the CPU time?

Sanghoon: No, the current production finished within a day.

Hideki: How many events did you try this time?

Sanghoon: Don't have the exact numbers at hand, but

2 hours with 1kCPU for the samples used in my slides.

Ming: Are the outputs available somewhere?

Sanghoon: I can put the HepMC files in RCF next time.

Jin: If you only need to do a quick test, you can also

generate Pythia8 samples with HardQCD:hardbbbar flag on.

Discussions & Plans

Sanghoon and Long will re-generate samples with:

- 2 PDFs: CTEQ6L and NNPDF2.3

- Color reconnection (Mode 2): on

- MPI K-factor: 1.0

- alpha_s(M_Z) = 0.1180 for CTEQ6L, 0.130 for NNPDF2.3