Kun's weekly discussion with students

Wednesday 31 May 2023, 16:00 → 17:50 Asia/Shanghai

N642 (TDLI)

Tencent meeting room: https://meeting.tencent.com/dm/NXVVKc7PPZSs

Meeting number: 695-8098-7502

16:00 → 16:05 Introduction

General items.

Speaker: Prof. Kun LIU (TDLI/SPA, SJTU)

16:05 → 16:15 ATLAS ttWML and ttHML analyses status

Speaker: Nihal BRAHIMI (Tsung-Dao Lee Institute & Shanghai Jiao Tong University)

ttWML analysis status :

• Current focus of the team is directed towards having the paper draft ready for the second circulation ASAP.
• The main outstanding items concern the preparation of the inputs for the HEP data release.
• RIVET routine validation studies ongoing to solve remaining discrepancies in the jets related observables.
• Data bootstrap replicas, also needed for HEP data release, are being prepared.

ttHML analysis status:

• Given the tight timescale of the analysis, we need to freeze the MVAs strategy ASAP. Studies ongoing to inform the decision on adding a tH node to the nominal MVAs and final results are expected today.
• Setup for CR+SR Asimov fits (and hybrid fits) in 2lSS channel is being prepared by Jialin accounting for all systematics (modeling+instrumental) --> needed for EB
• A new round of ttHML production is needed to include proper b-tagging SFs variations (fixed WP) and latest recommendation for JES, electron reconstruction and muon trigger SFs. The code is being prepared but issues encountered with missing electron isolation WPs in AT. A new release including a fix is expected soon. Once the code is ready, the production will be launched.
• The ttHML INT note is being filled with the documented studies from different teams. Material is being reviewed.

16:15 → 16:25 ATLAS ttH analysis

Speaker: Jialin Li

20230531_kun.pdf

Comments：

1. remove tH region to fit. 
2. For page 4, understand why the central value and uncertainty of norm_ttW are larger. 
3. Remove ttW_xs systematics to check 1.(why)
4. Understand why adding ttW_xs uncertainty at 50% doesn't work at the red/blue block.
5. Understand and list all the systematics used(including the value).
6. For page 7, list the difference to compare( the difference between 2l and 3l is physics phase space not only some samples), and maybe ttbar CR in 3l is the issue, can remove it to check.
7. For pages 9 and 10, why the post-fit plots don't have QMisID samples?
8. For pages 9 and 10, why the post-fit plots have tiny uncertainty?

16:25 → 16:35 ATLAS photon ID efficiency & Zgamma analysis

Speaker: Kang Liu

data18unconv_nofracs1_noweta1cut.png

I have calculated the ID efficiency of data18 (unconv_trans) without cuts of fracs1 and weta1. Because I don't have fudge factors of frasc1 and weta1 yet .

I'm modifying the script that calculates PDFs of shower shape variables. After I prepared PDFs of data and mc, then I can calculate fudge factors. 

16:35 → 16:45 DarkSHINE analysis general

Speaker: Yufeng Wang (TDLI)

Moved alternative signal production from LUT method to root injection method (use distribution produced from generator).

• re-producing signal samples (1e6 x4).
• debugging 3-body process.

Added DConvertor into framework: 

• DConvertor [lhe] [root] [signal_process]
• convert .lhe file to root file, containing a TTree of p, e, theta, phi, mass.
• adapt to different signal process.

Fixed a bug with biasing option with signal production.

16:45 → 16:55 DarkSHINE tracker study

Speaker: Junhua Zhang

Current focus of me is directed towards having the proposal draft (totally 4000 words in English for Intro part) ready for the first circulation ASAP.

Update for darkshine simulation: 

1.Generated 1e7 events for the geometry mentioned @ last week. All of such events have 8GeV firing momenta with a bias shown in following: 

Bias hardware is target, Bias particle: electron. BiasProcess: "photonNuclear". BiasFactor: maximum. BiasEmin: [ 7.97, "GeV" ]

2.Next, I will analysis such data.

Dedicating to my dissertation proposal: 

1. The contents are shown as follow with highlight. Additionally, I finished drafting the first three chapters.

2. It has been polished from the beginning to Section 2.1 by myself. 

• CONTENTS
• 1. Background and significance
• 2. Situation and progress in phenomenology
  • 2.1 The dark photon portals
  • 2.2 Dark photon models
  • 2.3 Dark photon productions
  • 2.4 Dark photon decays
• 3. Situation and progress in accelerator-based experiments
  • 3.1 Searches for visible dark photons for mA′ > 1 MeV 
    • 3.1.1 Experiments at colliders. 
    • 3.1.2 Beam-dump experiments. 
  • 3.2 Searcher for invisible dark photons for mA′ > 1 MeV 
    • 3.2.1 Searches at e⁺ e^- colliders
    • 3.2.2 Searches at Electron Beam Dumps 
    • 3.2.3 Searches at Proton Beam Dumps 
    • 3.2.4 Searches at Meson Decays
  • 3.3 Searcher for dark photons for mA′ < 1 MeV
• 4. Challenges for searching dark photon at accelerators.

16:55 → 17:05 Silicon strip sensor

Speakers: Hanqing Liu, Jialin Li, Junhua Zhang, Kang Liu, Yufeng Wang (TDLI)

I have already passed the defesne! ^_^

17:05 → 17:25 Undergraduate students projects

Speakers: Dian Yu, Lin Yang

17:25 → 17:30 Non-academic items

Anything else?