Post on 13-Dec-2015
The The -charm Physics @ BESIII-charm Physics @ BESIII
SHEN Xiaoyan
Institute of High Energy Physics, CAS
International Review Meeting
Oct. 21, 2013, IHEP, Beijing
OutlineOutline
• Introduction
• Highlights from -charm physics
• Management structure of BESIII
• Future prospects
• Summary
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Standard Model (EW+QCD)Standard Model (EW+QCD) Many precision tests on SM, especially EW theory,
mainly in 4 exps. at LEP in CERN
Higgs discovered at LHC in CERN
Great success of EW theory !
QCD has been tested extensively at the high momentum transfer by lots of high precision experiments (> 10 GeV).
At low energy, QCD is difficult to be tested due to its non-perturbative nature.
• How does QCD work at low energy? Do the new forms of hadrons predicted by QCD exist ? How to calibrate QCD at low energy ?
• Does the physics beyond Standard Model exist? How to test EW theory precisely in -charm region? Where is the new physics in -charm sector ?
Fundamental questions need to be answeredFundamental questions need to be answered
What can we do at BEPC2/BESIII ?
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BESIII detector
LINAC
2004: started BEPCII upgrade, BESIII construction2008: test run2009 - now: BESIII physics run
Beijing Electron Positron Collider (BEPC)Beijing Electron Positron Collider (BEPC)
BEPCII/BESIII – unique facility at BEPCII/BESIII – unique facility at -charm -charm energy region in the word now.energy region in the word now.
Features of the BEPC Energy RegionFeatures of the BEPC Energy Region Rich of resonances: charmonia and charmed mesons Threshold characteristics (pairs of , D, Ds, …) Energy location of the glueballs, hybrids and multi-quark states Energy location of the XYZ’s Transition between smooth and resonances, perturbative and non-
perturbative QCD
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6The Y’s are here ….
PDG
• How does QCD work at low energy? Do the new forms of hadrons predicted by QCD exist ? How to calibrate QCD at low energy ?
• Does the physics beyond Standard Model exist? How to test EW theory precisely in -charm region? Where is the new physics in -charm sector ?
Fundamental questions need to be answeredFundamental questions need to be answered
Search for the new hadrons and systematic study of the spectroscopy – a way of understanding the internal structure of hadrons.
Conventional hadrons consist of 2 or 3 quarks: Naive Quark Model:
QCD predicts the new forms of hadrons:• Multi-quark states : Number of quarks > = 4
• Hybrids : qqg , qqqg …• Glueballs : gg , ggg …
None of them is settled after many years’ efforts.
New forms of hadronsNew forms of hadrons
g
gg
g
None of the new forms of hadrons is settled !None of the new forms of hadrons is settled !
Precision measurement of CKM elements-- Test EW theory
Precision measurement of CKM elements-- Test EW theory
b
s
d
VVV
VVV
VVV
b
s
d
tbtstd
cbcscd
ubusud
'
'
' CKM matrix
Three generations of quark? Unitary matrix?
5% precision 10% precision
Expected precision < 2% at BESIII
BESIII + B factories + LQCD
Precision measurement of CKM matrix elements -- a precise test of SM model New physics beyond SM?
Precision measurement of CKM matrix elements -- a precise test of SM model New physics beyond SM?9
CKM matrix elements are fundamental SM parameters that describe the mixing of quark fields due to weak interaction.
BESIII + B factories + LHCb + LQCD
Hadron spectroscopy search for the new forms of hadrons meson spectroscopy baryon spectroscopy
Study of the production and decay mechanisms of charmonium states: J/, (2S), C(1S), C{0,1,2} , C(2S), hC(1P1), (3770), etc.
Calibrate QCD
Precise measurement of R values, mass, ...
Precise measurement of CKM matrix
Search for DD mixing, CP violation, etc.
Physics Topics at BESIIIPhysics Topics at BESIII
Int. J. Mod. Phys. A, Vol. 24 (2009)
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TOFBTOF: two layersETOF: 48 crys. for each
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BESIII DetectorBESIII Detector MDC
R inner: 63mm ; R outer: 810mm Length: 2582 mm Layers: 43
CsI(Tl) EMC
Crystals: 28 cm(15 X0)
Barrel: |cos|<0.83Endcap: 0.85 < |cos| < 0.93 RPC MUC
BMUC: 9 layers – 72 modulesEMUC: 8 layers – 64 modules
BESIII Detector PerformanceBESIII Detector Performance
Exps.MDC
Spatial resolution
MDC
dE/dx resolution
EMC
Energy resolution
CLEOc 110 m 5% 2.2-2.4 %Babar 125 m 7% 2.67 %Belle 130 m 5.6% 2.2 %
BESIII (2013) 115 m <5%
(Bhabha) 2.2%
Exps.
TOF
Time resolution
CDFII 100 psBelle 90 ps
BESIII (2013)
68 ps (BTOF)98 ps (ETOF)
MUC: Efficiency ~ 96% BG level: < 0.04 Hz/cm2(B-MUC), < 0.1 Hz/cm2(E-MUC)
Data/Monte-Carlo ConsistencyData/Monte-Carlo Consistency• For tracking efficiency, data/MC difference < 1%• For particle identification efficiency, data/MC difference < 2%
BESIII Physics Results BESIII Physics Results
• Hadron spectroscopy– Search for non-qq, non-qqq states– Meson & baryon spectroscopy
• Charmonium physics – Transitions and decays
• Charm physics– Decay constant fD
– CKM matrix elements: Vcd, Vcs• Precision measurement of R, • Search for new physics
BESIIIBESIII Physics Results (since 2009)Physics Results (since 2009)
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• Papers published:– 53 papers published (PRL 12, PRD 37 , PLB 1, CPC 3)
2010: 4 (PRL 2, PRD 1, CPC 1)
2011: 11 (PRL 3, PRD 8)
2012: 17 (PRL 5, PRD 10, PLB 1, CPC 1)
2013: 21 (PRL 2, PRD 18, CPC 1)
-- Submitted 6 (PRL 5, CPC 1) International conference talks
About 50 talks at the international conferences every year. Among them, about half are the invited talks.
Highlights from Highlights from -charm Physics-charm Physics
• Below open charm threshold
All charmonium states observed. No surprising found.
• Above open charm threshold:
many expected states not observed
many unexpected discovered
X(3872)
XYZ(3940)
X(3915)
X(4160)
Y(4008)
Y(4140)
Y(4260)
Y(4360)
X(4350)
Y(4660)
X(3915)
X(4160)
Y(4008)
Y(4140)
Y(4260)
Y(4360)
X(4350)
Y(4660)
Z(4430)Z(4250)Z(4050)Z(3900)
Charmonium spectroscopyCharmonium spectroscopy
Data taking at 4260 and 4360 MeV Data taking at 4260 and 4360 MeV for XYZ study for XYZ study
BESIII: Observation of the ZBESIII: Observation of the Zcc(3900) (3900) — a charged charmonium-like structure — a charged charmonium-like structure
BESIII: PRL110, 252001 (2013)
BESIIISignificance >8
What is Zc(3900)?
• Couples to cc• Has electric charge• At least 4-quarks
• DD* molecule?• Tetraquark state?• Cusp?• Threshold effect?• …
Many theoretical interpretations:
Submitted the paper on March 24, 2013. Already got 81 citations !
Impacts of the ZImpacts of the Zcc(3900) (3900)
PRL referee says: ”Since a chargedcharmonium-like state cannot be conventional ccbar meson, the Z(3900)may be the first indisputable example of a multi-quark meson.
81 citations PRL110, 252001 (2013)
Observation of ZObservation of Zcc(3900) in D(3900) in DDD*0*0
Any more decay modes for ZAny more decay modes for Zcc(3900) ?(3900) ?
Zc(3900) 6(Zc(3900) DD*0)
(Zc(3900) J/)
JP favors 1+
Very important in understanding ZVery important in understanding Zcc(3900) !(3900) !
arXiv: 1310.1163, submitted to PRL
Observation of ZObservation of Zcc(4020)(4020)
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Does the charged ZDoes the charged Zcc(3900)’s partner exist ? (3900)’s partner exist ?
What is Zc(4020)?
• Couples to cc• Has electric charge• At least 4-quarks
BESIII
arXiv: 1309.1896, submitted to PRL
BESIII confirmed X(1835) and observed X(2120) & X(2370) BESIII confirmed X(1835) and observed X(2120) & X(2370) BESIII: Phys. Rev. Lett. 108 (2011)112003
• Glueballs can be largely produced in J/ radiative decays.
• First observed the resonant structures in the 2.4 GeV/c2 region in J/
radiative decays.
• LQCD predicts the lowest lying 0-+ glueball at around 2.4 GeV/c2.
• What is the nature of X(2120)/X(2370) ?
0-+ glueball ? excited /’ state ?
• Is X(1835) the same state as pp enhancement?
Measurement of fMeasurement of fDD from D from D++
Japan (1)Tokyo Univ.
US (5)Univ. of Hawaii
Carnegie Mellon Univ. Univ. of Minnesota Univ. of Rochester
Univ. of Indiana
Europe (13)Germany: Univ. of Bochum,
Univ. of Giessen, GSI Univ. of Johannes Gutenberg
Helmholtz Ins. In MainzRussia: JINR Dubna; BINP Novosibirsk
Italy: Univ. of Torino , Frascati Lab, Ferrara Univ.Netherland : KVI/Univ. of Groningen
Sweden: Uppsala Univ. Turkey: Turkey Accelerator Center
China(29)IHEP, CCAST, GUCAS, Shandong Univ.,
Univ. of Sci. and Tech. of ChinaZhejiang Univ., Huangshan Coll.
Huazhong Normal Univ., Wuhan Univ.Zhengzhou Univ., Henan Normal Univ.
Peking Univ., Tsinghua Univ. ,Zhongshan Univ.,Nankai Univ., Beihang Univ.
Shanxi Univ., Sichuan Univ., Univ. of South ChinaHunan Univ., Liaoning Univ.
Nanjing Univ., Nanjing Normal Univ.Guangxi Normal Univ., Guangxi Univ.Suzhou Univ., Hangzhou Normal Univ.
Lanzhou Univ., Henan Sci. and Tech. Univ.
Korea (1)Seoul Nat. Univ.
Pakistan (2)Univ. of Punjab
COMSAT CIIT
~400 members52 institutions from 11 countries
The BESIII CollaborationThe BESIII Collaboration
25~180 members from IHEP
BESIII Management StructureBESIII Management StructureSpokespersons (3, 3 years term)EB(~9)
Run coordinator
Software and Computing coordinator
Physics coordinators
Speakers bureau
Publicationcommittee
Shift committee
Membershipcommittee
IB(~51)
Convener-1 Convener-2 ………
Similar to other International Collaborations
Rules and policiesRules and policies• BESIII Collaboration Governance Rules • BESIII membership rules• Publication Policy• Responsibilities of the Speakers Bureau
……..Data TakingData Taking
• Data taking proposals presented and discussed at CM, decision made by EB and collaboration
• Adjust the data taking plans accordingly taking into account the importance of the physics, the competitions from other exps.
• Run coordinator, weekly run coordinators, chief shifters, shifters, on-call people, …. to ensure the high quality data.
IHEP Contribution IHEP Contribution
MDC & electronics
EMC & electronics
BTOF
ETOF & electronics MUC MUC
electronicsTrigger & DAQ
IHEP IHEP IHEP USTC IHEP USTC IHEP
MDC EMC TOF MUC Physics tools
IHEP+SDU IHEP IHEP PKU+IHEP IHEP+USTC
• BESIII softwareBESIII software
• The design, construction & operation of BESIIIThe design, construction & operation of BESIII
• BESIII papersBESIII papers
Total IHEP IHEP supervisors + univ. students Universities
59 30.5 13.5 15
IHEP ManpowerIHEP Manpower
• Currently, 57 faculties (16 profs. ) and 42 Students & post-docs for the maintenance, operation, upgrade of BESIII, and for the software and physics analysis.
Leading scientistsLeading scientists• WANG Yifang (Spokesperson from 2005 to Nov. 2011)• SHEN Xiaoyan (Spokesperson from Dec. 2011)• LOU Xinchou (EB member, IHEP IB)• ZHU Kejun, HE Kanglin (Run coordinators)• YUAN Changzheng (Physics coordinator)• LI Weidong (Software coordinator, EB member)• LI Haibo, JIN Shan (Were physics coordinators)• DONG Liaoyuan, ZHANG JIngzhi, FANG Shuangshi, MO Xiaohu, LIU Huaimin, …… (conveners)
BESIII data taking status & planBESIII data taking status & plan
Previous data
BESIII present & near future
Goal
J/ BESII: 58M 1.2 B 20* BESII 10 B
’ CLEO: 28 M 0.5 B 20* CLEOc 3B” CLEO: 0.8/fb 2.9/fb 3.5*CLEOc 10/fb
4040)/4170)/4260) ….
CLEO: 0.6/fb @ 4160)
2011: 0.5/fb @ 4040)2013 : 2/fb@4260, 0.5/fb@4360
5-10 /fb
R scan BESII
Prospects of BESIIIProspects of BESIII
• In 2013-2014 physics run, R scan above 3.8 GeV. The goal: reach the precision of ~2% for R values.
• More results on XYZ particles will come understand the nature of XYZ
• Search for glueballs, hybrids,… with huge J/ data.
• Precision measurement of CKM elements• mass Expected to have an error of 0.1MeV.
Prospects of BESIIIProspects of BESIII
fD
Summary Summary • Observed Zc(3900), Zc(4020) at BESIII, opened a new
window big impact. More results on XYZ particles will come understand the nature of XYZ
• Produced many important results on charmonium physics, hadron spectroscopy, ….
• BESIII will run another 7-10 years Upgrade of BESIII on going– MRPC for ETOF– New inner drift chamber– CGEM for drift chamber
• More data will come, more physics output• Keep the leading role in -charm physics in these years.
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Backup slidesBackup slides
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Matters are made of leptons and quarks:
Interactions are mediated by: photons — electromagnetic W± and Z — weak gluons — strong QCD
Origin of masses Higgs (Discovered at LHC in 2012)
e
e
bsd
tcu
Electroweak theory (EW)
Standard Model Standard Model (SM)(SM)
37
Pure leptonic decays
• All quantities are well measured except fD.• Use world average |Vcd| to extract fD
• Compare fD with LQCD for the validation of LQCD
Preliminary study of D+ at BESIII• 9 singly D- tag modes
The error is still statistical dominated.
Comparison of fD with theories
fD (MeV)
ZZcc(4020)’s other decay mode ?(4020)’s other decay mode ?
Observation of ZObservation of Zcc(4025) in D*(4025) in D*DD*0*0
arXiv: 1308.2760, submitted to PRL
Standard Model and BES PhysicsStandard Model and BES Physics• Three generations of quarks and leptons
• Interactions– Electromagnetic interaction– Weak interaction– Strong interaction
BES -charm Physics
} EW theory
QCD theory
Y.B. Yang, et al, Phys. Rev. Lett. 111, 091601 (2013)
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10)9(8.3 ,)8(35.0)/(
tot
keVGJ
• The widths of J/ radiatively decay to glueballs are calculated directly in lattice QCD .
• This result can be compared to the production rates of scalar mesons f0(1710), f0(1500)
3
0
40
100.3)(1.5 )1710(/
100.321.01 )1500(/
fJ
fJ
Support fSupport f00(1710) to be dominantly a scalar glueball.(1710) to be dominantly a scalar glueball.
Scalar glueball production in Scalar glueball production in J/J/ radiative decays from LQCD radiative decays from LQCDScalar glueball production in Scalar glueball production in
J/J/ radiative decays from LQCD radiative decays from LQCD
Tensor glueball production Tensor glueball production in J/in J/ radiative decays from LQCD radiative decays from LQCD
Tensor glueball production Tensor glueball production in J/in J/ radiative decays from LQCD radiative decays from LQCD
• The tensor glueball production rate in J/ radiative decay
2
21 0)2(1.1/)/( t o tGJ
• With the largest J/psi events sample, the LQCD results can provide useful information for BESIII to identify the tensor glueballs.
L. Gui, et al, Phys. Rev. Lett. 110 (2013) 021601
Paper submission proceduresPaper submission procedures• Talk at the group meeting, get approval by the group and group convener, get the analysis memo ready.
• Talk at the phys. & software meeting, get approval
• Physics coordinators assign 3 internal referees to review the analysis, memo draft be approved
• Collaboration wide review
• Spokespersons’ approval
The time from the submission to the journal to finally being accepted for publication is short.