赵忠尧奖学金申请
报告人：安芬芬 (IHEP)
导师： 阮曼奇 (IHEP)
2017.04.24
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Resume
− 2nd Postdoc, IHEP, 2017.02 – present
 50% Circular Electron-Positron Collider + 50% ATLAS, basically at
Iowa State University
 Feasibility study of dE/dx measurement in TPC at CEPC
− Postdoc, IHEP, 2014.07 – 2017.01
 MRPC simulation for Endcap TOF upgrade at BESIII
− Ph. D. in particle physics, IHEP, 2009.09 – 2014.06
Thesis: Experimental study of D+ → K − π+ e+ νe , with Prof. Huaimin, Liu
 PWA of D+ → K − π+ e+ νe
 dE/dx simulation and calibration at BESIII
− B. Sc. in physics, Sichuan University, 2005.09 – 2009.06
Thesis: Study of hit efficiency in Main Drift Chamber at BESIII, with
Prof. Zepu, Mao
 5-month internship in IHEP
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Feasibility Study of dE/dx Mea. in TPC @CEPC
Motivation: dE/dx performance study and detector optimization. Effective PID
(particle identification) ability of 𝐾/𝜋 will greatly enhance the physics outreach at
CEPC.
dE/dx ~ p/m
Gas volume
(95% Ar+3%CF4+2%iC4H10)
drift
222 rows of pads
to detect signals
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Feasibility Study of dE/dx Mea. in TPC @CEPC
Based on GEANT4 Simulation
Sep~(𝑝, cos𝜃)
Sep~(𝑁𝑝𝑎𝑑 , Δ𝑅)
𝐾/𝜋 Separation ability in hadronic events @91
or 250 GeV would hopefully exceeds 3𝜎 in the
interesting momentum region.
Optimization plan on the geometry is suggested.
Paper is in preparation.
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MRPC Simulation for Endcap TOF
upgrade @BESIII
Motivation: consistent PID efficiency between data and MC
TOF measures the time of flight (𝑡𝑚𝑒𝑎𝑠 )
of charged particles, perform PID using
flight path (L) and momentum (p)
measured by MDC
𝛽=
𝑝
𝑝2 + 𝑚2
𝐿
Δ𝑡 = 𝑡𝑚𝑒𝑎𝑠 −
𝛽⋅𝑐
Δ𝑡(𝑛𝑠)~ 𝑝(𝐺𝑒𝑉/𝑐)
𝝅
𝑲
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MRPC Simulation for Endcap TOF
upgrade @BESIII
 Detector Simulation using GEANT4
 Alignment of modules
Missing hits of extrapolated tracks (collision data taken by prototype modules)
dZ = 6mm
dθ1 = 3o
dθ2 = 2o
Before Alignment
After Alignment
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MRPC Simulation for Endcap TOF
upgrade @BESIII
Control samples: 𝑒 + 𝑒 − →KK𝜋𝜋, KK𝜋𝜋𝜋 0 , 𝜋𝜋𝜋𝜋, 𝜋𝜋𝜋𝜋𝜋 0 , 𝜋𝜋𝜋𝜋𝜋𝜋, 𝐾𝐾𝜋𝜋𝜋𝜋, KKKK
𝜀𝑝𝑖𝑑(𝐾/𝜋) =
N𝑃𝑟𝑜𝑏
𝐾/𝜋 >𝑃𝑟𝑜𝑏(𝜋/𝐾)
NMDC 𝑡𝑟𝑘
𝜃 demotes the polar angle
relative to the beam
PID efficiencies of hadrons are
generally 1% consistent
MC comparison with data by
prototypes published by JINST.
Another paper in preparation
about MC using the final data.
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dE/dx Calibration & Simulation @BESIII
Motivation: Effective separation of particles based on dE/dx measurements in Main
Drift Chamber. Consistent PID efficiencies between data and MC
60%He+40%C3 H8
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dE/dx Calibration & Simulation @BESIII
• dE/dx calibration (Gas, Cell nonhomogeneity, saturation, drift path …):
resolution better than 5% (Bhabha)
• dE/dx simulation (data-driven method):
PID efficiency consistent within 1%
𝝌𝒅𝑬/𝒅𝒙 ~𝒑
𝝅
𝑲
• Daily maintenance
• More efficient calibration procedure: 2/3 time cut off from 3 weeks
• Investigation into dE/dx correction (charge asymmetry)
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+
− + +
PWA of D → K π e νe
Motivation: 1. Precise measurement of the form factors. Test LQCD calculations.
2. 𝐾𝜋 S wave phase 𝛿𝑆 . Helpful for B&D-meson PWAs.
Tag Side
Signal Side
 Large statistics:
2.9 fb−1 BESIII data
 Clean: DD production
threshold, <1% bkg
 Abundant physics
1st 5-demensional PWA within RooFit framework at BESIII (Resolution consideration,
signal MC integration, IO check …)
Paper published by PRD
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+
− + +
PWA of D → K π e νe
Projections on the five kinematic variables
94% P-wave + 6% S-wave
BESIII mea. in a model dependent (red line)
and independent (blue dots) way
𝒎𝑲𝝅
𝒒𝟐
𝒄𝒐𝒔𝜽𝒆
𝝌
𝒄𝒐𝒔𝜽𝑲
BESIII mea. in a model dependent
(blue line) and independent (black
squares) way
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Publications
Published:
• “Study of D+ → K − π+ e+ νe ”, Phys. Rev. D 94, 032001 (2016) (1st).
• “Monte-Carlo Study of the MRPC prototype for the upgrade of BESIII”, JINST
11 C09022 (2016) (1st).
• “Semi-leptonic D decays at BESIII”, Charm 2015 proceeding (2015).
• “Multi-peak pattern in Multi-gap RPC time-over-threshold distributions and an
offline calibration method”, JINST 12 C01012 (2017).
• “BESIII飞行时间探测器的离线数据质量监测”, Nuclear Electronics & Design
Technology V36, NO.4, P382 (2016).
In preparation:
• “MRPC simulation for BESIII ETOF upgrade”.
• “Feasibility study of particle identification using dE/dx information in gaseous
trackers” (Note is ready).
• “Study of 𝐷 → 𝜋𝜋𝑒𝜈𝑒 ” (co-work, memo stage).
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Representative Presentations
International:
• “Semi-leptonic D-decays at BESIII”, Charm 2015 workshop in Detroit, America, 2015.05
(parallel)
• “Study of MRPC simulation performance at BESIII”, RPC 2016 workshop in Belgium,
2016.02 (plenary)
• “MRPC and dE/dx Software at BESIII & Study of 𝐷 + → 𝐾 − 𝜋 − 𝑒 + 𝜈𝑒 ”, Seminar in INFN,
Roma, Italy, 2016.12 (plenary)
Plenary home meetings:
• “dE/dx measurement in TPC”, CEPC workshop in Wuhan, 2017, 04
• “MRPC MC Tuning With Hadron Samples”, BESIII collaboration in Beijing, 2016.11
• “MC tuning of MRPC”, BESIII workshop in Beijing, 2016.08
• “Status of MRPC Simulations”, BESIII workshop in Beijing, 2015.09
• “Partial Wave Analysis of 𝐷+ → 𝐾 − 𝜋 − 𝑒 + 𝜈𝑒 ”, BESIII collaboration in Huangshan, 2013.11
• “Update Analysis of 𝐷+ → 𝐾 − 𝜋 − 𝑒 + 𝜈𝑒 ”, BESIII collaboration in Beijing, 2013.06
• “Calibration and Simulation of dE/dx”, BESIII workshop in Beijing, 2012.03
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Future Research Plan
• Complete the papers: “MRPC simulation for BESIII ETOF upgrade”
and “dE/dx study in gaseous trackers”
• Joint research at ISU (2017.02-2019.02)
50% CEPC
 Develop, upgrade and maintain the CEPC software system
 Conduct the CEPC detector performance and develop the key CEPC reconstruction
algorithms
50% ATLAS
 Qualification task (b tagging)
 Search for LFV process 𝑍 → 𝑒𝜇 with ATLAS 13TeV data
Hope more complete and intensive training on HEP
experiments can be obtained in the following two years!
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𝐾/𝜋 separation Using ETOF @BESIII
The main task of MRPC is 𝐾/𝜋 separation
Δ𝑡(𝑛𝑠)~ 𝑝(𝐺𝑒𝑉/𝑐)
𝝅
𝑲
Control samples: 𝑒 + 𝑒 − →KK𝜋𝜋, KK𝜋𝜋𝜋 0 , 𝜋𝜋𝜋𝜋, 𝜋𝜋𝜋𝜋𝜋 0 , 𝜋𝜋𝜋𝜋𝜋𝜋, 𝐾𝐾𝜋𝜋𝜋𝜋, KKKK
Control samples have been purified with background less than 1%.
Most optimistic selection requirements are explored on tracking in MDC and PID by
dE/dx and barrel TOF. About 40,000 𝜋 and 8,600 𝐾 are obtained (see backup).
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