CEPC Physics and detector regular meeting

Wednesday 22 Aug 2018, 15:00 → 18:40 Asia/Shanghai

A415 (IHEP)

Rolling CDR Indico Page: https://indico.ihep.ac.cn/event/8650/

document main_CDR.pdf

Attending: Joao, Manqi,  Ouyang,  Zian,  Chengdong, Zhaoru

Vidyo: Liantao, Mang Wang, Shufang

 

1. Joao’s talk:

• Liantao said theory chapter has something to update. The flavor section need much improvement and some people are reading, they have input in the next several days. Joao said the chapter 12 future plan also need a paragraph from theory.
• Joao asked people to read the list of known issues in draft v1.0 early in document, and indicated in red in the text. Please CHECK and give us FEEDBACK
• Read this draft version and provide comments. Encourage senior people in your institution to read it. This draft can be given to people that want to consider being an author.

2. Manqi’s update for Chapter 10

• Fig 10.9 the photon's plot are updated. Now they are using 10*10 mm cell for baseline. The difference in left plot become smaller because they veto the events with photon converted. Also the caption is expanded.
• Fig 10.10 (b) is updated, but need some explanation in the text.
• Fig 10.11(b) is updated. They fixed the bug and it is the final result. b and c quark results are updated also. It was excluded before, but they thought it is also worth to show the difference of including the b,c quark. The size of (a) and (b) plots are different, which need to be updated.
• Fig 10.12 and 10.15 are updated.

Now all the red mark in this chapter are all fixed.

 

3. Inclusion of statement on muon identification inside jets

Studies have been done the show muon identification inside jets is far from 100% using PFA-only information. This problem may be asked in the review.

Joao provided some support statement from other experiments and it has been seen by others, and it is documented in all previous CDRs and TDRs.

The aim is to show that we know the limitation of PFA so we need muon detector to improve the efficiency. We can make the combination of some information from Joao's slides and add statement that muon chamber can improve the efficiency to 95%. This statement can be shown in muon and performance chapters.

Manqi suggested that the efficiency and purity table is not shown in CDR because we don’t understand the result well. replace the table with statement, with reference added.

We will go both algorithm study and muon detector optimization together.

 

4. Magnet:

Zian said this chapter has all the right figures and dimensions for the Yoke now.

Joao said the reviewer may ask whether the Booster is too close to the magnet, Zian will check the distance and prepare to answer the question. The question is about the stray field for the magnet. This can justify the need for a larger Yoke.

Joao suggested to make a separate note to explain FTS and refer it in the CDR. Manqi will help Zian to prepare the note.

5. Joao said that we should decide which document No. will be used. Manqi suggested to keep IHEP-CEPC-DR-2018-01 for accelerator CDR and 02 for detector&physics. Rmove the IHEP-EP-2018-XX and IHEP-TH-2018-XX, since we didn't keep tracking these categoty.

 

6 Vertex

• Joao mentioned some question for the “distance to beam pipe” section in vertex chapter. Zhigang and Ouyang gave answer by email, Joao will write this paragraph based on the answer.
• Ouyang said that he introduction of Chapter 4 is too simple. It is better to be expanded, for example, explain why we have different options. Joao will help to improve it.

 

7. Full silicon

Joao asked that since the d0 resolution for full silicon vertex is as good as baseline, why the impact parameter is worse?

Weimin( not present at the meeting?) explained it is caused by less material. Chengdong said the vertex in full silion tracker is different with baseline. The two first layers in the baseline vertex detector are close together, in the same support, but in the FST the second layer is placed at a larger radius. This can explain the worse impact parameter resolution.

The amount of material for the support structure is just split in half for the first two layers, so the material is the same for the baseline and the FST. This is not realistic because one is not likely to build such thin support structure. So it is the same material for the support,  the only difference is the position of layer 2.

Chengdong will help to read the text and try to find mistakes.

15:00 → 15:20 Introduction

Speaker: Joao Guimaraes Costa

Slides CEPC-physics-detector-introduction-20180822.pdf

15:20 → 18:40 Quick CDR reports from conveners

15:20 Ch1 Summary

Speaker: Joao Guimaraes Costa

15:30 Ch2 Theory

Speaker: Liantao Wang (University of Chicago)

15:40 Ch3 detector concept

Speakers: Jianming Qian (University of Michigan) , Joao Guimaraes Costa, Mr Manqi Ruan (IHEP)

Slides main_CDR.pdf

15:50 Ch4.1 Silicon Vertex

Speakers: Prof. Qun OUYANG (IHEP) , Dr Yunpeng LU (Institute of High Energy Physics, CAS)

16:00 Ch4.2 Silicon Tracker

Speaker: Meng Wang (高能所)

16:10 Ch4.3 TPC

Speaker: Dr Huirong Qi (Institute of High Energy Physics, CAS)

16:20 Ch4.4 Full silicon concept

16:30 Ch4.5 Drift Chamber

Speaker: Francesco Grancagnolo (INFN-Lecce)

16:40 Ch5 Calorimeter

Speakers: Haijun Yang (Shanghai Jiao Tong University) , Prof. Haijun Yang (Shanghai Jiao Tong University) , Dr Jianbei Liu (University of Science and Technology of China) , Prof. Tao HU (IHEP)

16:50 Ch5 Dual Readout Calorimeter

Speaker: Roberto Ferrari (INFN)

17:00 Ch6 Magnet

Speakers: Dr Feipeng NING Feipeng (高能所) , Mr Zian ZHU Zian (高能所)

17:10 Ch7 Muon Detector

Speakers: Prof. Liang Li (Shanghai Jiao Tong University) , Paolo Giacomelli (INFN-Bo)

17:20 Ch8 DAQ

Speakers: Mr Kejun ZHU (高能所) , Prof. Zhen An LIU Zhenan (IHEP)

17:30 Ch9 MDI

Speaker: Dr Hongbo ZHU (IHEP)

17:40 Ch10 Detector Performance

Speakers: LI Gang ( EPC.IHEP ), Mr Manqi Ruan (IHEP) , Prof. Yaquan FANG Yaquan (高能所)

17:50 Ch11 Physics analysis

Speakers: LI Gang ( EPC.IHEP ), Mr Manqi Ruan (IHEP) , Prof. Yaquan FANG Yaquan (高能所) , Prof. Zhijun Liang (IHEP)