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Hesheng ChenInstitute of High Energy Physics

Beijing 100049, China

High Energy Physics in China High Energy Physics in China

1. BEPC/BES/BSRF and latest results 2. BEPCII3. Particle Astrophysics 4. Medium and long term plan

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Institutions and Univ. Groups for Particle Physics Experiments

• Institute of High Energy Physics, Beijing

• Univ. of Science and Technology of China, Hefei • Peking Univ. Beijing• Tsinghua Univ. Beijing • Shandong Univ. Jinan • Huangzhong Normal Univ. Wuhan• ……

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Major projects• BEPC/BESII → BEPCII/BESIII• Yangbajing Cosmic Ray Observatory • Daya Bay Reactor Neutrino Experiment• International Collaborations:

– CMS, Atlas and LHCb at LHC, – AMS– Belle at KEKB– D0 at Tevatron– STAR at RHIC– ILC– ……

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Major Facilities • Beijing Electron-Positron Collider (BEPC)

• Beijing Spectrometer (BES)

• Yangbajing Cosmic Ray Observatory

• Beijing Synchrotron Radiation Facility (BSRF)

• Shanghai Light Source

• Hefei Synchrotron Radiation Lab.

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Institute of High Energy PhysicsInstitute of High Energy PhysicsChinese Academy of Sciences

Comprehensive and largest fundamental research center in China for : :

– Particle physicsParticle physics– Accelerator technologies and applications Accelerator technologies and applications – Synchrotron radiation technologies and applicationsSynchrotron radiation technologies and applications1000 employees, ~ 650 physicists and engineers, 400 PhD Students and postdoctors

Established at 1950, and became an independent inEstablished at 1950, and became an independent institute for HEP at 1973 . stitute for HEP at 1973 .

Reforming and changing…Reforming and changing…

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Bird’s Eye View of Bird’s Eye View of BEPCBEPC

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BEPC constructed in 1984 –1988 with beam energy: 1 – 2.8 GeV– Physics Run ： Luminosity 1031cm-2s-1 @ 1.89GeV, 5 month/year– Synchrotron Radiation Run ： 140mA @ 2.2 GeV, 3 month/year

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Korea (4)

Korea University Seoul National University

Chonbuk National UniversityGyeongsang Nat. Univ.

Japan (5)

Nikow UniversityTokyo Institute of Technology

Miyazaki UniversityKEK

U. Tokyo

USA (4)

University of HawaiiUniversity of Texas at Dallas

Colorado State University Stanford Linear Accelerator Center

UK (1)Queen Mary University

China (18)IHEP of CAS

Univ. of Sci. and Tech. of ChinaShandong Univ., Zhejiang Univ.

Huazhong Normal Univ. Shanghai Jiaotong Univ.

Peking Univ., CCAST Wuhan Univ., Nankai Univ.

Henan Normal Univ.Hunan Univ., Liaoning Univ.

Tsinghua Univ., Sichuan Univ. Guangxi Univ., Guangxi Normal Univ.

Jiangsu Normal Univ.

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World‘s largest J/ and data sample (10(1066))More interesting physics results are expected.

J/

0

10

20

30

40

50

60

MarkIII DM2 BESI BESII

01.11-02.399.11-01.3

0

2

4

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MKI MKII MKIII CBAL BESI BESII CLEOc

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Latest results from BES:Latest results from BES:

— Precision measurement of R

— Threshold Enhancement

and New resonance

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R/R(%)

Before BES 15-20

BES 6.6

BESII BESII Results R Measurement at 2-5GeV R Measurement at 2-5GeV (91 points)(91 points)

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Impact of BES’s New R Values on the Impact of BES’s New R Values on the SM FitSM Fit for for α (Mα (Mzz

22) and Higgs mass) and Higgs mass

090.0890.128)( 12 ZM

046.0936.128)( 12 ZM

1995 1995 beforebefore BES R dataBES R data

2001 2001 withwith BES R dataBES R data

g – 2 experiment

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Observation of an anomalous enhancement near the threshold of mass spectrum at BES II

M=1859 MeV/c2

< 30 MeV/c2 (90% CL)

J/pp

M(pp)-2mp (GeV)

0 0.1 0.2 0.33-body phase space

acceptance

2/dof=56/56

acceptance weighted BW +3 +5

10 25

pp

BES II

Phys. Rev. Lett. 91, 022001 (2003)   

X(1860)

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Statistical Significance 7.7

BESII Preliminary

J

BES: X(1835) in

X(1835)7.7

BESII Preliminary

2

2

MeV/c 7.73.207.67

MeV/c 7.21.67.1833

54264

M

Nobs

410)4.04.02.2()()( XBXJB59.1

8.0 10)4.00.7()()(:.. ppXBXJBfc

'/J

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X(1835) could be the same structure as X(1860) indicated by pp mass threshold

enhancement

• X(1835) mass is consistent with the mass of the S-wave resonance X(1860) indicated by the pp mass threshold enhancement.

Its width is 1.9 higher than the upper limit of the width obtained from pp mass threshold enhancement.

• On the other hand, if the FSI effect is included in the fit of the pp mass spectrum, the width of the resonance near pp mass threshold will become larger.

published PRL Dec. 31 2005

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BEPC future development

High Precision Frontier: precise measurement in charm energy region (2-4 GeV), and search for new phenomena.

• Transition between continuum and resonance's, perturbative and non-perturbative QCD

• Rich of resonance's, charmonium and charmed mesons.

• New type of hadronic matter predicted in the region, e.g. glueball and hybrid ， pentquark, exotic particles…

• Advantages at Threshold : large , low multiplicity, pure initial state, S/B optimum

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Future development: BEPCIIFuture development: BEPCII

•Upgrade BEPC into two ring collider, increasing luminosity by a factor 100, rebuild detector to adapt high event rate and reduce sys. errors.

•Cost: 77M US$. •Comparison with CESRc:

– Lumi. of BEPCII is a factor of 3-7 higher than designed value of CESRc

– Beam energy spread of BEPCII is about half

→ → BEPCII BEPCII statistics will be about one order of statistics will be about one order of magnitude higher than CLEOcmagnitude higher than CLEOc

– Detector performance similar

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2. BEPCII: High Lumi. Double–ring Collider

Build new ring inside existing ring . Two half new rings and two half old rings cross at two IR’s, forming a double ring collider.

BEPCII

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BEPC II Double ring Design• In the existing BEPC tunnel, add another ring, cross over at south a

nd north points, two equal rings for electrons and positrons. Advanced double-ring collision technology.

• 93 bunches ， total current > 0.9A in each ring. • Collision spacing ： 8 ns.• In south, collision with large cross-angle （ ±11 mr ） .• Calculated luminosity ： 1033 cm-2 s-1 @ 3.78GeV of C.M. energy.• Linac upgrade: e+ 50mA/min. , Full energy injection up to 1.89GeV • In north cross point, connecting SR beam between two outer rings, in south cross point, use dipole magnet to bend the beam back to out

er ring.• SR run ： 250mA @ 2.5 GeV.• Major detector upgrade ： BES III.

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Installation of Linac Upgrade Finished

RF Gallery

Linac Tunnel

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Parameters Goal Measured

Beam energy (GeV) 1.89 1.89 (e-); 1.89 (e+)

Beam current (mA) e+ 40 > 63

e- 500 > 500

Repetition rate (Hz) 50 50

Emittance (1σ) ( mmm rad )

e+ 0.53 0.32 ~ 0.20

e- 0.067 0.080 ~ 0.096

Energy spread (%)

e+ 0.50 0.73@1.30GeV

(0.50@1.89Gev)

e- 0.50< 0.80@1.30GeV

< (0.55@1.89Gev)

Summary of the Linac commissioning

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2/3 of Storage Ring installed

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BEPCII Interaction Region

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Schedule• May – Oct. 04. : √

– Linac upgrade – BESII detector removing– Transformer system 630KW →1600KW

• Nov. 04 – June 05: Tuning and SR running √• July 05 – Oct. 06: Long shutdown

– Remove existing ring √– Upgrade infrastructure √– Install two rings: about 2/3 – Cryogenics system ready for SC devices, field mapping

• Oct. 06 - July. 07: Tuning of machine + SR running • Aug. 07: BESIII detector moved into beam line• Sept. 07 : Starting machine-detector tuning. • Physics run by Autumn 2007

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Resonance Mass(GeV)CMS

Peak Lum.(1033cm-2s-1)

Physics Cross Section (nb)

Nevents/yr

J/ 3.097 0.6 3400 10 109

3.670 1.0 2.4 12 106

(2S) 3.686 1.0 640 3.2 109

D0D0bar 3.770 1.0 3.6 18 106

D+D- 4.030 1.0 2.8 14 106

DsDs 4.030 0.6 0.32 1.0 106

DsDs 4.140 0.6 0.67 2.0 106

Average Lum: L = 0.5×Peak Lum.; One year data taking time: T = 107s

Nevent/year = exp L T

Charm Productions at BEPCII

Huge J/ and (2S) sample at BESIII;Note: assuming all R&D study are based on 4 years for D and Ds ( 20 fb-1) and one year for J/ (10 billion) and (2S) (3.0 billion).

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Physics Topics covered by BESIII

Charmonium: J/, (2S), C(1S) in J/ decay, C{0,1,2} , C(2S) and hC(1P1) in ’ decay , (1D) and so on Exotics : hybrids, glueballs, other exotics in J/, ’radiative decays Baryons and excited baryons in J/ and ’ hadronic decays; Mesons and mixing of quark and gluon in J/ and ’decays; Open charm factory :

• Absolute BR of D and Ds decays, • Rare D decay, D0-D0bar mixing, CP violation,• f D+, fDs , form factors in semi-leptonic D decays,• precise measurement of CKM (Vcd, Vcs)• CP violation and strong phase in D Dalitz Decays,• light spectroscopy in D0 and D+ Dalitz Decays.

Electromagnetic form factors and QCD cross section; New Charmonium states above open charm threshold--R values ... tau physics near the threshold.

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Particle Astrophysics

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Yangbajing Cosmic Ray Observatory （ a.s.l. 4300m ）

IHEP-INFN RPC China-Japan Air Shower Array

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AMS02: ECAL IHEP/LAPP/PisaFlight module is ready.

AMS01 permanent and structure were built at Beijing, and became the first big magnet in space as payload of Discovery June 1998.

Alpha Magnetic Spectrometer

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Hard X-ray Modulate Telescope Satellitescan sky for hard X ray point sources, study for black holes.

Charged particle shielding

Collimator

Crystals

PMTSupport structure

Approved by Chinese Gov. to

be launch by 2010

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Comparison between HXMT and INTEGRAL

Angular Resolution 2’ 15’Source Location 0.2’ 2’Sensitivity (10-7 / cm2 S keV) 3 10Observation Mode survey yes no local imaging yes yes pointing yes no

the HXMT satellite is expected to be launched by 2010

HXMT INTEGRAL

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International cooperation activities

• LHC : – CMS (1/3 end cap muon CSC ) & Atlas (MDT) detector p

roduction finished in Beijing, installation team @cern – Physics and MC actively. – Tier 2 at IHEP for CMS and Atals. CMS LCG cooperate

with CMS • ILC:

Parameter choice, IHEP & Tsinghua U., Damping Ring study, IHEP group;Positron source study, sponsored by NSFC RF power and modulators ATF2 collaboration, magnet production is in progress ;Superconducting RF cavity study (IHEP and Peking)

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Medium Term PlanMedium Term Plan• Charm physics @ BEPCII • Modulated hard X-ray telescope satellite• Neutrino experiments:

– Daya Bay Reactor neutrino to measure sin2213 – National underground Lab.– Very LBL oscillation experiment: J-Prac→ Beijing

• LHC exp. And ILC • High power proton Accelerator:

– Chinese Spallation Neutron Source 100KW→200 KW– Accelerator Driven Subcritical system

• Hard X-ray FEL• Convert BEPC into dedicated SR source after BEPCII fi

nished physics runningIHEP extents research fields, to protein structure, nano-sci

ence, material science… → Multiple Sciences Center

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Parameterization of neutrino mixing

6 fundamental parameters in neutrino physics ： Known ： | m2

32|,sin2232 ， m221,sin2221

Unknown: sin22 ， , sign of m232

Exp. ： reactor VLBL oscillation

Daya Bay Reactor J-Parc → Beijing

Neutrino mixing parameters

U 1 0 0

0 cos23 sin23

0 sin23 cos23

cos13 0 e i sin13

0 1 0

e i sin13 0 cos13

cos12 sin12 0

sin12 cos12 0

0 0 1

e

Ue1 Ue2 Ue3U1 U2 U3

U1 U2 U 3

1

2

3

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Experiment to measure sin2213 using Daya Bay reactor neutrino

• Daya Bay NPS is the best site in the world: – 60 km from Hong Kong, – 12GW now, 18 GW @ 2010– good mountain near NPP for near and far detectors.

• Near (500m) and Far detector (1.8km), modular, expect accuracy of 1% in sin2213 • NPS jointed the experiment • Site study finished and the tunnel design is underway • Chinese funding agencies and local governments agreed to support CAS approved the project. • US physicists from LBL, BNL … joined collaboration

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√√

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VLBL Experiment of J-PARC to Beijing

• V LBL experiment with 2000 - 4000 km is very interesting to study many important physics:– Sign of the difference of mass square– τappearance – CP violation of

• V LBL experiment from JHF to Beijing– Good tunnel: 20 km north of Beijing, near highway

to Great Wall – The tunnel is 560 m long, 34 meter wide, 13 meter

height , 150 m rock on top– Good infrastructure available– 2200 km to JHF with 9.5o dip angle

Visit ORNL

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BSNS site preliminary layout

Chinese Gov. approved BSNS in principleChinese Gov. approved BSNS in principle

Visit ORNL

39多学科应用平台─ 散裂中子源

BSNS• Repetition rate ： 25 Hz• Average proton current： 62.5 A• Proton kinetic energy： 1.6 GeV• Average beam power： 100 kW• Target: Tungsten• Moderators(wing,three): H2O,LCH4 ,LH2

• Spectrometers: HRPD (high resolution powder diffractometer)HIPD (high intensity powder diffractometer) Reflectometer,SANS (small angle diffractometer), Direct-geometry inelastic spectrometer

Engineering powder diffractometer (Northeastern Univ.)High-pressure powder diffractometer (Jilin Univ.)

Principal Characteristics of BSNS (Phase I)

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Welcome US particle physicists

to join BESIII and

Daya Bay neutrino experiment

Thanks !