Kun Liu weekly discussion with students [ATLAS]

Wednesday 19 Oct 2022, 16:00 → 17:05 Asia/Shanghai

Online

1 Introduction

General items.

Speaker: Prof. Kun LIU (Tsung-Dao Lee Institute & Shanghai Jiao Tong University)

2 ttWML and ttHML analyses status

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

ttWML analysis status:

• Analysis was granted approval to unblind almost two weeks ago.
• However, as unblinded fits were being rolled out, a bug was found leading to an underestimated generator modelling systematic being used in the fiducial fit. After the fix, the sensitivity became unexpectedly worse compared to the inclusive fit (+12%-11% vs +15%-13%)
• Detailed tests are being carried out to make sure acceptances for the fiducial fit are correctly calculated for the nominal and alternative generator ttW samples.
• Rest of fit setups are not problematic (inclusive, ratio and differential fits) and are being run in unblinded mode in parallel.
• Due to this delay, we are going to miss the Higgs 2022 milestone but the current backup plan is to go public for the LHCHWG meeting towards end of November. A decision will be made by the end of this week.

ttHML analysis status:

• Most of the efforts focussed on defining MVA discriminants to be used in the 0-tau channels.
• Working closely with Jialin to come up with a good discriminant using DNN. Multiple configurations tested so far. Main bottleneck is the ttW CR and ttH SR definitions. Large anti-correlation (70%) observed between NF(ttH) and NF(ttW) which is not desirable.
• Currently preparing config to combine candidate SRs and fakes CRs from ttWML analysis as a proof of principle.

3 ttH analysis

Speaker: jialin li

1019_Kun_groupmeeting.pdf

4 photon ID efficiency measurement & Zgamma analysis

Speaker: Kang Liu

Progress of QT 20221019.pdf

5 silicon tracker: HGTD

proposing paper structure & needed figs:

 

1. introduction

(Cross section of sensor, sensor pic; table of parameters)

2. measurement setup

(Pics of lab - Probe table, wiring, beta-scope/laser)

3. IV and CV test results, uniformity among the 4?

(IV plot, CV plot, 1/C^2 plot — for each sensor/pad, VBD/VGL of the 4 sensors)

4. Charge collection 

(Waveform (amplitude, collected charge, RMS noise etc.),

data analysis: pulse integral vs. injected charge, Bias voltage vs. charge)

5. Position resolution & design optimization

(collected charge @ each pad for 3 set of strips,

data analysis: Bias voltage vs. resolution for 3 set of strips)

6. Conclusion

6 Non-academic items

Anything else?