sPHENIX discussion of physics

[Jakub Kvapil <jakub.kvapil AT cern.ch>]

Dear Xin,

many thanks for the comments, please see embedded answers in red below.

1) Physics Motivation

     - "initial parton kinematics", I think you meant "heavy quark kinematics". "Initial parton" may be mixed with the parton inside nucleon or nuclei.

I think we should have access by both, we have direct access to the heavy quarks' kinematics by the jet theoretical definition (though the experimental definition is a bit hand wavy)

However, by studying the b-jet more in depth (using different substructure observable) we should see contribution by higher order production mechanism, like gluon splitting etc. so by referring to initial parton, is to address q->b vs g->b productions.

Not sure how to phrase it better

     - I would suggest to separate out the sub-bullet "HF hadronization, fragmentation and flow" from the "energy loss in the QGP"

Good point, I will change it as main bullet as: HF hadronization, fragmentation, and flow and its modification by QGP

2) Particle flow

     - Is the figure for inclusive jet or for b-jet? If this is for inclusive jet, you may want to move your bullet "First look at b-jets ..." to a later section.

Good point, the plot is for inclusive jets and this way it could be misleading. I will remove the bullet as I mention it explicitly in the conclusion anyway

3) Result

     - sDCA figure, you need to add the unit for the X-axis

X axis is unitless, it is significance - DCA divided by its uncertainty as defined in the box on the left side

     - do you understand why the 2 or 3 largest sDCAxy for light flavor jet starts to skew towards the negative side?

Yes, this is by the sign definition (on the left box) the LF jets should be produced primarly in the primary vertex (with exception for long lived LF particles, that will modify it) and since the DCA is ordered from biggest positive to smallest positive to smallest negative to biggest negative this will do the shift towards negative for LF. For B we expect the values highly skewed towards positive values.

I will upload the next version on Thursday after(if) I receive more comments.

Thanks

Best regards

Jakub

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From: Xin Dong <xdong AT lbl.gov>
Sent: Monday, August 21, 2023 11:54 AM
To: Jakub Kvapil <jakub.kvapil AT cern.ch>
Cc: Jin Huang <jhuang AT bnl.gov>; sphenix-jet-structure-l AT lists.bnl.gov <sphenix-jet-structure-l AT lists.bnl.gov>; sphenix-hf-Jets-l AT lists.bnl.gov <sphenix-hf-jets-l AT lists.bnl.gov>; sphenix-physics-l AT lists.bnl.gov <sphenix-physics-l AT lists.bnl.gov>
Subject: Re: [Sphenix-hf-jets-l] Quark Matter poster - bjets

 

Hi Jakub,

Thanks for the nice presentation. I have a few comments/suggestions for you to consider.

1) Physics Motivation

     - "initial parton kinematics", I think you meant "heavy quark kinematics". "Initial parton" may be mixed with the parton inside nucleon or nuclei.

     - I would suggest to separate out the sub-bullet "HF hadronization, fragmentation and flow" from the "energy loss in the QGP"

2) Particle flow

     - Is the figure for inclusive jet or for b-jet? If this is for inclusive jet, you may want to move your bullet "First look at b-jets ..." to a later section.

3) Result

     - sDCA figure, you need to add the unit for the X-axis 

     - do you understand why the 2 or 3 largest sDCAxy for light flavor jet starts to skew towards the negative side?

Thanks and Best Regards

/xin

On Mon, Aug 21, 2023 at 10:37 AM Jakub Kvapil via sPHENIX-HF-jets-l <sphenix-hf-jets-l AT lists.bnl.gov> wrote:

Dear Jin, Dear all,

thanks a lot for the comments, I have implemented them

ad: Could you clarify which observables behind “flow” (given it is “complementary to v2”)?

Thanks for spotting this, it was a leftover from my substructure talk...I meant the substructure measurement to be complementary - modified

I have uploaded next version to:

https://sphenix-invenio.sdcc.bnl.gov/uploads/whpxp-hsb91

Before making it public let me know and I will go through LANL approval and upload a version with UR number.

Thanks

Best regards

Jakub

---

From: Huang, Jin <jhuang AT bnl.gov>
Sent: Thursday, August 17, 2023 9:12 PM
To: Jakub Kvapil <jakub.kvapil AT cern.ch>; sphenix-jet-structure-l AT lists.bnl.gov <sphenix-jet-structure-l AT lists.bnl.gov>; sphenix-hf-Jets-l AT lists.bnl.gov <sphenix-hf-jets-l AT lists.bnl.gov>; ming AT bnl.gov <ming AT bnl.gov>; Xuan Li <xuanli AT lanl.gov>; cdean AT bnl.gov <cdean AT bnl.gov>; sphenix-physics-l AT lists.bnl.gov <sphenix-physics-l AT lists.bnl.gov>
Subject: RE: Quark Matter poster - bjets

 

Dear Jakub

 

Thanks for both the poster and the notes. Both are well written. Here are a few suggestions on the poster, and hope useful to you:

 

• Physics Motivation:

• “HF hadronization, fragmentation and flow”

• Could you clarify which observables behind “flow” (given it is “complementary to v2”)?

Tagging techniques:

• Please also mention “Lepton tagger”, which has lower efficiency due to Branching but it is a strong indicator of HF jet if one is found. It can be used together with track counting methods, as part of the markers in the jet probability.

Conclusion and next steps:

• First bullet can be “Optimize the track selection and jet tagger under the Run24 condition, including the pile up.”

 

Cheers,

 

Jin

 

______________________________

 

Jin HUANG

 

Physicist, Ph.D.

Brookhaven National Laboratory

Physics Department, Bldg 510 C

Upton, NY 11973-5000

 

Office: 631-344-5898

Cell:   757-604-9946

______________________________

 

From: sPHENIX-physics-l <sphenix-physics-l-bounces AT lists.bnl.gov> On Behalf Of Jakub Kvapil
Sent: Wednesday, August 16, 2023 6:04 PM
To: sphenix-jet-structure-l AT lists.bnl.gov; sphenix-hf-Jets-l AT lists.bnl.gov; Liu, Ming <ming AT bnl.gov>; xuanli AT lanl.gov; Dean, Cameron <cdean AT bnl.gov>; sphenix-physics-l AT lists.bnl.gov
Subject: [Sphenix-physics-l] Quark Matter poster - bjets

 

Dear HF, Dear JS WG's,

 

please see my poster for Quark Matter 2023.

Let me know if we have updated DCA_xy resolution plot I can use or what is the source of the one I used (currently cropped from slides)

Any comments and tips are highly appreciated.

 

Thanks a lot

Best regards

Jakub

 

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Xin Dong
Nuclear Science Division, Lawrence Berkeley National Laboratory
MS70R0319, One Cyclotron Road
Berkeley, CA 94720, USA
Tel: +1-510-486-4121
Email: XDong AT lbl.gov
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