Kun's weekly discussion with students

Wednesday 15 Mar 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 (Tsung-Dao Lee Institute & Shanghai Jiao Tong University)

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

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

ttWML analysis status:

• The paper draft 1.0 entered first ATLAS circulation since Feb 28th. Deadline for comments was yesterday March 14th. We have received 8 set of comments that need to be addressed before PAM.
• PAM is scheduled for this Friday at noon (CERN time): https://indico.cern.ch/event/1264415/

ttHML analysis status:

• Jialin presented the MC modeling checked for all the input training variables at last week’s analysis meeting. Useful feedback and suggestions to understand the mismodeling observed especially in the “Other” region. These checks need to be redone with DD QMisID and latest MVA training.
• The option to adopt a looser b-tagging WP for the events selection is considered as it was shown to result in enhanced MVAs performance. First comparisons w.r.t previous samples (v07) showed a degraded performance. This is now understood and confirmed to be resulting from a different network architecture (activation function). Retraining was carried out and same level of performance is now recovered.
• We had a chat with Higgs and HTop conveners yesterday to clarify the analysis timeline and scope. We have agreed to set prioritise inclusive and STXS cross-section measurement for which we will target end of May for EB request. We aim to have the analysis approved by September-November to make it for the Higgs combination planned for Spring 2024. This means that interpretations (CP, EFT, Higgs self-coupling) if not ready on this timeline, might need to be documented either in a separate paper or follow-up PUB note (not decided yet).  

16:15 → 16:25 ATLAS ttH analysis

Speaker: jialin li

1. Check the QmisID DD samples in the inclusive region. The yield dropped compared to QMisID MC samples. And the Undershot of data in the HFel MT region still appears.

2. The SLTorDLT or DLT trigger checking with new weigh observables is ongoing.

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

Speaker: Kang Liu

PhotonID EE for Egamma 2023 workshop.pdf

16:35 → 16:50 ATLAS Zgamma & diphoton analysis

Speakers: Yufeng Wang (TDLI), yufeng wang

Investigated expected sensitivity of ALP diphoton search on ATLAS.

KSVZ-ALP (simplest QCD axion model): run-2 very-low-mass search (10~70 GeV). boosted photon pairs are selected (pTyy>50GeV). statistic limited. best results given in the search region: f_a~O(1e4) GeV. need better identification, isolation and reconstruction efficiencies in low-pT region. limited improvement from background estimation.

possible improvement: using tracks info from conv photon?

Yanagida's visile QCD axion model: limits above ~5e3 for m_a > 10 GeV, otherwise already excluded.

16:50 → 17:00 DarkSHINE analysis general

Speakers: Yufeng Wang (TDLI), yufeng wang

>>>> 966569 out of 990278 events are good (97.6058%) <<<<
number of vector with size zero: 
TagTrk2_track_chi2: 0 (0%)
RecTrk2_track_chi2: 8667 (0.875209%)
TagTrk2_pp: 0 (0%)
RecTrk2_pp: 8667 (0.875209%)
ECAL_E_total: 0 (0%)
HCAL_E_total: 0 (0%)
HCAL_E_Max_Cell: 0 (0%)
Event hits gap: 15183 (1.53321%)
Killed due to large track p: 240 (0.0242356%)

also checking dark axion portal (invisible decay) model.

17:00 → 17:10 DarkSHINE tracker study

Speaker: Junhua Zhang

Rec_track_XZ_EventNo==4521271_in_simu-14.png

use new master to run 1 of 1.5.3simu file: (5e5 events in one simu file)

No. of 0-size vector is decreased: ~0.2%

Bug fixed for "normal" events which del theta > 0. Only one event in that simu-file, with a positive charge track.

17:10 → 17:20 DarkSHINE HCAL Study

Speaker: Hanqing Liu

1. Writing the thesis

2. Summarize the scintialltor work.

17:20 → 17:30 Silicon strip sensor

Speakers: Hanqing Liu, Junhua Zhang, Kang Liu, Yufeng Wang (TDLI), jialin li, yufeng wang

17:30 → 17:35 Non-academic items

Anything else?