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Particle Physics in China
Yifang Wang
Institute of High Energy Physics
IAS, HKUST, Jan. 19, 2015
Particle Physics in China
Yifang Wang
Institute of High Energy Physics
IAS, HKUST, Jan. 19, 2015
Experimental
at IHEP
The Starting of Particle Physics in China
• Experimental particle physics in China started from the
construction of BEPC in early 80’s
• A very brave move at that moment:
– No HEP/accelerator experience at all ( a few ~MeV accelerators)
– Very limited manpower & industrial support (disconnected from
the world)
– Only 10 years behind SPEAR, best tau-charm e+e- collider
• A very rewarding move:
– Leading position on
tau-charm physics
for ~30 years
– Development of
accelerator &
detector related
technologies
ADONE
BEPCII
CESRc BEPC
SPEAR
DORIS I
IHEP is now a comprehensive research center for particle physics,
astro-particle physics with synchrotron radiation and spallation
neutron source facilities to serve the whole science community
Beijing Electron-Positron Collider
IHEP Today
Research
Administration
Support
Dongguan CSNS
Experimental Physics
Astro-particle physics
Theoretical Physics
Accelerator Physics
Multi-discipline research
Computer center
Institu
te o
f Hig
h E
nerg
y Ph
ysics
Employee: ~ 1500 Students: ~ 400 Visitors: ~ 400 Budget:~ 1.4 B RMB/year
Applied tech. center
Particle & Astro-Particle Physics at IHEP
Current Future
Accelerator-based
Precision frontier
BESIII
International: ILC
CEPC SppC
International projects: Belle II、PANDA、COMET
Energy frontier CMS、ATLAS
Non-accelerator
-based
underground Daya Bay
JUNO EXO
Surface ARGO/ASg LHASSO
Space AMS HERD
XTP HXMT
Science at BEPC/BEPCII
Study of the ultimate structure of matter
Normal hadrons are made of 2 or 3 quarks:
New type of hadrons ?
Multi-quark states:No. of quarks >= 4
Hybrids: qqg,qqqg …
Glue balls:gg, ggg …
Study of interactions between the ultimate constituent
(quark) of matter
How quarks are bound into hadrons(quantitatively, by QCD) ?
How quarks, electrons and neutrinos interact with each other
(electroweak) ?
Study of the interactions between ultimate constituent of
matter
Quark Model:
How to do the study ?
A theoretical framework
Existing experimental data can be explained by the Standard Model
Need new data to test every corner of the Standard Model
Try to find new phenomena beyond the Standard Model
An accelerator at an appropriate beam energy
Collide e+ & e- with sufficient no. of interested events(luminosity)
A detector
Reconstruct the physics process after the collision
Standard Model of Our Matter World
Building blocks of matter
Particles mediate interactions:
photons — electromagnetic
W± and Z — weak
Gluons — strong QCD
Origin of mass
Higgs
e
e
bsd
tcu
Electroweak
This model is very successful
There are still predictions to be tested
It is not an ultimate theory, but rather
an effective theory
BEPC II Storage ring: Large angle, double-ring
Beam energy: 1.0 – 2.1 GeV
Luminosity: 1×1033 cm-2s-1
Optimum energy: 1.89 GeV
Total current: 0.91 A
SR mode: 0.25A @ 2.5 GeV
BESIII Detector: cover the collision point to
obtain particle type, energy, momentum, …
Time Of Flight (TOF)
T =80-90 ps Barrel 100-110 ps endcap
Main Drift Chamber (MDC)
P/P @1GeV= 0.5-0.7 %
dE/dx (0/0) = 6-8%
EMC: E/√E(0/0) = 2.5 -3 % (1 GeV)
(CsI) z,(cm) = 0.5 - 0.7 cm/√E
Super-conducting magnet: 1.0 tesla
Total weight: 730t,readout ch.: 40000, data rate: 50MB/s,
man power: ~1000 man*yr, Cost: 30M$
Muon counter:
8-9 layers of RPC
R=1.4 cm~1.7 cm
Japan (1)
Tokyo Univ.
US (6)
Univ. of Hawaii Univ. of Washington
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 Mainz
Russia: 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 China Zhejiang 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 China Hunan 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 members from 11 countries and 52 institutions
BESIII International Collaboration
12
Highlights: Observation of Zc(3900)
S-wave Breit-Wigner with efficiency
correction
Mass = (3899.0±3.6±4.9) MeV
Width = (46±10±20) MeV
Fraction = (21.5±3.3±7.5)%
• Close to M(DD*)
• Couples tocc
• Has electric charge
• At least 4-quarks
• What is its nature?
Y(4260) +-J/
> 8
By collecting a lot of data, we
may understand the nature of
Y(4260), Zc and probably,
many XYZ particles with the
help of LQCD
PRL110, 252001 (2013)
Zc(4025)/Zc(4020): Excited State of Zc(3900) ?
PRL 112, 132001 (2014)
e+e-+-hc(1P)
M(Zc(4020)) = 4022.90.82.7 MeV (Zc(4020)) = 7.92.72.6 MeV
〉8
e+e-- (D*D*)++c.c.
M(Zc(4025)) = 4026.32.63.7 MeV; (Zc(4025)) = 24.85.77.7 MeV
PRL 111, 242001 (2013)
Many New States and New Processes
Significance: 7.2
J/wX,X+-h
f1(1285) h(1405)
X(1870)
X(1835)
X(2120) X(2370) PRL107, 182001 (2011) PRL 106 (2011) 072002
PRL109, 042003 (2012) ghc
BEPCII/BESIII is the best facility in the world for light hadrons and charmonium physics. It can measure precisely fD, fDs, R values in 2.0-4.6 GeV, as well as the tau mass.
A lot of results from BESIII since 2009. A total of ~70 papers published so far, and will continue to publish more than 20 papers per year.
BESIII will continue to take data for another 8-10 years.
After 2020, we are thinking about a circular Higgs factory which can be converted to a pp collider.
Summary of BEPCII/BESIII
The Future: CEPC+SppC • For about 8 years, we have been talking about “What can be
done after BEPCII in China”
• Thanks to the discovery of the low mass Higgs boson, and
stimulated by ideas of Circular Higgs Factories in the world,
CEPC+SppC configuration was proposed in Sep. 2012
LTB : Linac to Booster
BTC : Booster to Collider Ring
BTC
IP1
IP2
e+ e-
e+ e- Linac
(240m)
LTB
BTC
Medium Energy Booster(4.5Km)
Low Energy Booster(0.4Km)
IP4 IP3
Proton Linac
(100m)
High Energy Booster(7.2Km)
A 50-70 km tunnel is
relatively easier NOW
in China
Scientific Goals
• CEPC ( e+e-: 90-250 GeV)
– Higgs Factory: Precision study of Higgs(mH, JPC, couplings) • Same as SM prediction ? Other Higgs ? Composite ? New
properties ? CP effect ?
– Z & W factory: precision test of SM • New phenomena ? Rare decays ?
– Flavor factory: b, c, and QCD studies
• SppC (pp: 50-100 TeV)
– Directly search for new physics beyond SM
– Precision test of SM • e.g., h3 & h4 couplings
Complementary with each other
Timeline (dream)
• CPEC – Pre-study, R&D and preparation work
• Pre-study: 2013-15
– Pre-CDR by the end of 2014 for R&D funding request
• R&D: 2016-2020
• Engineering Design: 2015-2020
– Construction: 2021-2027
– Data taking: 2028-2035
• SppC – Pre-study, R&D and preparation work
• Pre-study: 2013-2020
• R&D: 2020-2030
• Engineering Design: 2030-2035
– Construction: 2035-2042
– Data taking: 2042 -
Site • Preliminarily selected: Qinhuangdao (秦皇岛)
• Strong support by the local government
Why for China? Higgs Discovery as an Example
Efforts by > 10,000 scientists and engineers for > 30 years. Rich in science & technology, engineering & management, international collaboration & cultures, etc.
Global influence: More than thousand media coverage;
Big push to the society & our life;
Invention of WWW & Browser
For China to be a better member
of the international community
US
EU
China Japan
Tevatron
LHC
BEPC
KEKB
CEPC-SppC
ILC
GDP of major countries Large accelerators in the world
Current Status • Conceptual design & preliminary cost estimate completed
• Pre-CDR ready for international review
• R&D issues identified and funding request soon: – Machine design & optimization
– SRF cavity fabrication & processing
– Cryo. module design and fabrication
– Cryo. system
– Beam diagnosis
– Vacuum pipes & heat dissipation
– SC dipole magnet for SPPC
• Seed money for R&D from IHEP
• Seek government support
P.S.
P.S.
P.S.
IP1
IP4
IP3
IP2 D = 17.3 km
½ RF
RF
RF
RF
RF
½ RF
½ RF
½ RF
RF RF
(4 IPs, 1038.4 m each)
C = 54.374 km
Important for Tech. Dev. anyway
No show-stoppers
Particle & Astro-Particle Physics at IHEP
Current Future
Accelerator-based
Precision frontier
BESIII
International: ILC
CEPC SppC
International projects: Belle II、PANDA、COMET
Energy frontier CMS、ATLAS
Non-accelerator
-based
underground Daya Bay
JUNO EXO
Surface ARGO/ASg LHASSO
Space AMS HERD
XTP HXMT
Supernova
Sun Earth reactor
Galaxy
Big bang
accelerator
人体
Neutrinos Around Us
Astrophysics
Cosmology
Nuclear Physics Geology
Particle physics
Quark
s
Leptons
Why Neutrinos Intersting ?
Fundamental building blocks of matter, but least known (Mass,
properties, …):
Only particles with properties not consistent with the Standard
Model, which needs to be modified in way not yet known.
Extremely abundant, same as photons(~ 300/cm3) mass is a
crucial issue
Very important in the formation and evolution of the Universe
e
e
bsd
tcu
A hot topic of particle physics, astrophysics and cosmology
Neutrino Oscillation
Up to now the most sensitive way to probe neutrino masses
is via neutrino oscillations
If the neutrino mass eigenstate is different from that of the
weak interaction, neutrinos can oscillate: from one type to
another during the flight:
e e
Oscillation
probability:
P(e->)=sin2(2q)sin2(1.27Dm2L/E)
Osc. Amplitude Osc. Frequency
Oscillation matrix for 3 generations:
Bruno Pontecorvo
Discovery of the Neutrino Oscillation Solar neutrino oscillation since 70’s:
Atmospheric neutrino oscillation since 80’s:
Discovered in 1998 by Superkamiokande. Nobel prize in 2002
0.25 /day for 25 years
4 /day for 5 years
R. Davis
Masatoshi
Koshiba
Daya Bay: for a New Type of Oscillation
1
2
3
q12 Solar
Oscillation
q23 Atm.
Oscillation
q13 ?
Fundamental principles
Fundamental parameter
Direction of future neutrino physics:
If q13 is too small,CPV cannot be figured out in the near future
How to Measure q13at Reactors ?
Precision of past experiments (typically 3-6%):
Reactor power: ~ 1%
Spectrum: ~ 0.3%
Fission rate: 2%
Backgrounds: ~1-3%
Target mass: ~1-2%
Efficiency: ~ 2-3%
Past searches: sin22q13< 0.15 @ 90%C.L.
Model prediction: sin22q13~0-0.20, but mostly around 0.01
Our design goal:D(Nobs/Nexp) ~ 0.4% 10 improvement !
Pee 1 - sin22q13sin2 (1.27Dm213L/E) - cos4q13sin22q12sin2 (1.27Dm2
12L/E)
Daya Bay Experiment: Layout
Relative measurement to cancel Corr. Syst. Err. 2 near sites, 1 far site
Multiple AD modules at each site to reduce Uncorr. Syst. Err.
Far: 4 modules,near: 2 modules
Multiple muon detectors to reduce veto eff. uncertainties
Water Cherenkov: 2 layers
RPC: 4 layers at the top + telescopes
Redundancy !!!
Cross check; Reduce errors by 1/N
The Daya Bay Collaboration
Europe (2)
JINR, Dubna, Russia
Charles University, Czech Republic
North America (16)
BNL, Caltech, LBNL, Iowa State Univ.,
Illinois Inst. Tech., Princeton, RPI,
UC-Berkeley, UCLA, Univ. of Cincinnati,
Univ. of Houston, Univ. of Wisconsin,
William & Mary, Virginia Tech.,
Univ. of Illinois-Urbana-Champaign, Siena
Asia (20)
IHEP, Beijing Normal Univ., Chengdu Univ.
of Sci. and Tech., CGNPG, CIAE, Dongguan
Polytech. Univ., Nanjing Univ., Nankai Univ.,
NCEPU, Shandong Univ., Shanghai Jiao tong
Univ., Shenzhen Univ.,
Tsinghua Univ., USTC, Zhongshan Univ.,
Univ. of Hong Kong, Chinese Univ. of Hong Kong,
National Taiwan Univ., National Chiao Tung Univ.,
National United Univ. ~250 Collaborators
Aug. 2003: Experimental plan and the detector design is proposed
2006: Project approved in China, and afterwards in other countries
Oct. 2007: Civil construction started
Dec.2010: All the blasting for the tunnel and underground hall completed
2008-2011: Detector construction, assembly and installation
Aug. 2011: Near detector data taking started
Dec. 2011: Far detector data taking started full detector data taking
Timeline of the Experiment
Opening ceremony:Oct. 2007
Tunnel and Underground Lab
•Tunnel: ~ 3100m
•3 Exp. hall
•1 hall for LS
•1 hall for water
A total of ~ 3000
blasting right next
reactors. No one
exceeds safety limit
set by National
Nuclear Safety
Agency(0.007g)
Water Cerenkov Detector Installation
PMT frame & Tyvek Completed pool PermaFlex painting
Cover Install AD Pool with water
Neutrino Detector Assembly
SSV 4m AV
PMT
SSV lid ACU
Bottom reflector
Top reflector 3m AV
Leak check
Experimental Hall in Operation
A New Type of Oscillation Discovered
Observation of electron anti-neutrino disappearance:
R = 0.940 ±0.011 (stat) ±0.004 (syst)
Sin22q13 = 0.092 0.016(stat) 0.005(syst)
c2/NDF = 4.26/4, 5.2 σ for non-zero θ13
F.P. An et al., NIM. A 685(2012)78
F.P. An et al., Phys. Rev. Lett. 108,
(2012) 171803
announced on
Mar. 8, 2012
Remarkable achievements on q13
Accelerator experiments assuming δCP=0, θ23=45⁰
Why Interesting ?
Neutrinos oscillate in a “normal way” no new symmetry,
no surprises
Sin22q13 is ~10 larger than expected a big surprise
It is now possible to plan the next generation neutrino experiment for
the mass hierarchy and CP phase
1
2
3
sin22q12 ~ 0.9
sin22q23 ~ 1
sin22q13 ~ 0.1
Pe ≈ sin2q23sin22q13sin2(1.27Dm223L/E) +
cos2q23sin22q12sin2(1.27Dm212L/E) -
A(r)cos2q13sinq13sin()
Still a Lot of Unknowns
Neutrino oscillation:
Neutrino mass hierarchy ?
Unitarity of neutrino mixing matrix ?
Θ23 is maximized ?
CP violation in the neutrino mixing matrix as in the case of
quarks ? Large enough for the matter-antimatter asymmetry in
the Universe ?
What is the absolute neutrino mass ?
Neutrinos are Dirac or Majorana ?
Are there sterile neutrinos?
Do neutrinos have magnetic moments ?
Can we detect relic neutrinos ?
……
Next Step: Mass Hierarchy
Daya Bay Huizhou Lufeng Yangjiang Taishan
Status running planned approved Construction construction
power/GW 17.4 17.4 17.4 17.4 18.4
Daya Bay
Huizhou Lufeng
Previous site
Current site
Yangjiang Taishan
Hong Kong
Daya Bay 60 km JUNO
Physics Reach
Thanks to a large θ13
Current Daya Bay II
Dm212 4% 0.6%
Dm223 4% 0.6%
sin2q12 6% 0.7%
sin2q23 10% N/A
sin2q13 6% 4% ~ 15%
• Mass hierarchy
• Precision measurement of
mixing parameters
• Supernova neutrinos
• Geoneutrinos
• Sterile neutrinos
• ……
For 6 years,mass hierarchy cab
be determined at 4 level, if Δm2
can be determined at 1% level
Detector size: 20kt
Energy resolution: 3%/E
Thermal power: 36 GW
Y.F. Li et al., arXiv:1303.6733
Challenge I: Large Detector Structure
A D~35m detector in the water pool: Mechanics,optics, chemistry, …
How to keep it clean during and after
the assembly ?
Possibility of assembly within 2 years
Current design: Default: acrylic tank(D~35m) + SS
structure
Acrylic bonding, creeping,stress,
steel support at acrylic, deformation,
event reconstruction with total
refection, …
Backup: SS tank(D~38m) + acrylic
panel + balloon
Balloon materials, cleanness, leaks,
deployment, …
R&D and prototyping underway
Challenge II: Liquid Scintillator Our choice: LAB+PPO+BisMSB
At Daya Bay: 15m
Our target: 30 m
R&D efforts: Improve raw materials
Improve the production process
Purification Distillation, Filtration, Water
extraction, Nitrogen stripping…
Optimization of fluor concentration
Other works: Rayleigh scattering measurement
Energy non-linearity study
Aging study
Material selection: BKG & purity issues
Engineering issues for 20kt Equipment, logistics, safety, …
Linear Alky Benzene Atte. L(m)
@ 430 nm
RAW 14.2
Vacuum distillation 19.5
SiO2 coloum 18.6
Al2O3 coloum 22.3
LAB from Nanjing, Raw 20
Al2O3 coloum 25
0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,70,0
0,2
0,4
0,6
0,8
1,0
LIg
ht
ou
tpu
t, r
ela
tive
un
its
PPO mass fraction, %
KamLAND
Challenge III: High QE PMT
Three types of high QE 20” PMTs under
development: A new type of MCP-PMT
Hammamatzu with SBA photocathode
Photonics-type PMT
MCP-PMT development led by IHEP: Technical issues mostly resolved
Successful 8” & 20” prototypes
HQE 20” under development
Mass production of 20,000 20” !!!
R3600 R12860 MCP-
PMT
QE@410nm ~25% ~ 30% ~25%
Rise time ~ 6 ns ~ 6ns ~ 1.2ns
P/V of SPE >2.5 >2.5 > 2.5
Dark
rate(KHz)
~30 ~30 50
SPE
QE
Challenge IV: Civil Construction
A 600m vertical shaft
A 1300m long tunnel(40% slope)
A 50m diameter, 80m high cavern
How to control the
schedule and budget ?
How to control risks ?
Surface Lab at the Tunnel Entrance
Schedule & Current Status
Schedule:
Civil preparation:2013-2014
Civil construction:2014-2017
Detector component production:2016-2017
PMT production:2016-2019
Detector assembly & installation:2018-2019
Filling & data taking:2020
Grounding breaking on Jan. 10, 2015
Collaboration Established
52
Europe (23) APC Paris
Charles U.
CPPM Marseille
FZ Julich
INFN-Frascati
INFN-Ferrara
INFN-Milano
INFN-Padova
INFN-Perugia
INFN-Roma 3
U. libre de Bruxelles
IPHC Strasbourg
JINR,INP
LLR Paris
RWTH Aachen U.
Subatech Nantes
TUM
U.Hamburg
U.Mainz
U.Oulu
U.Tuebingen
US(8)
Maryland U.,
BNL, UIUC, Houston on
behalf of US institutions*
Asia (28) Beijing Normal U.
CAGS,
CIAE
DGUT
ECUST
Guangxi U.
IHEP
Jilin U.
Nanjing U.
Nankai U.
Natl. Chiao-Tung U.
Natl. Taiwan U.
Natl. United U.
NCEPU
Pekin U.
Shandong U.
Shanghai JT U.
Sichuan U.
SYSU
Tsinghua U.
UCAS
USTC
Wuhan U.
Wuyi U.
Xi'an JT U.
Xiamen U.
Chongqin U.
HIT
*Subject to funding agency approval
Particle & Astro-Particle Physics at IHEP
Current Future
Accelerator-based
Precision frontier
BESIII
International: ILC
CEPC SppC
International projects: Belle II、PANDA、COMET
Energy frontier CMS、ATLAS
Non-accelerator
-based
underground Daya Bay
JUNO EXO
Surface ARGO/ASg LHASSO
Space AMS HERD
XTP HXMT
CR & g-astronomy: from ASg/ARGO to LHAASO
Air shower array @ 4400 m Al.
Cosmic-Ray: spectra &
composition of individual spices
over two knees
g-astronomy: comple. to CTA:
All the time & the sky
Time-variant & extended
sources
Fast indication
Current Space Program
Hard X-ray modulated telescope
(HXMT): Total mass:1021kg; Power: 350 W
to be launched in 2015
Gamma-ray burst polarization
(POLAR): onboard China’s Spacelab: TG-2
An international collaboration:
China, Switzerland, France, Poland
Launch time ~ 2015
SVOM Redefined program: On board
Chinese spacecraft
A collaboration of China and France
to be launched in 2017-2018
AMS
ME
LE HE
HERD: Next Generation Exp. after AMS
• Science goal – Dark matter search: γ from
0.1 – 10,000 GeV
– Spectral and composition
measurements of CRs
between 300 GeV to PeV
complementary to LHAASO
• Main feature: ~ 10
acceptance
• Status – On Chinese space station
– Mission concept selected &
design reviewed
– R&D funding available
– Groups from China,Italy,Switzerland,Sweden,…
– Launch in ~202x (?)
X0(λ)
∆E/E for e
e/p sep
e GF m2sr @ 200GeV
p GF m2sr@100TeV
HERD (2020) 55(3) 1% 10-6 3.1 2.3
Fermi (2008) 10 12% 10-3 0.9 -- AMS02 (2011) 17 2% 10-6 0.12 -- DAMPE (2015) 31 1% 10-4 0.3 -- CREAM (2015) 20(1.5) -- -- -- 0.2
Chinese Spallation Neutron Source
Phase I: 100 kW Phase II: 500 kW Start time: 2011 Completion time: 2017
Started: mass production of
equipment, LINAC installation
Completed: target station &
spectrometer engineering design,
Civil construction of office
ADS R&D
High beam power (CW) Very high stability Very low beam loss:<1W/m .
Currently for injectors
CW RFQ with a high intensity
Very Low beta SC cavities
Light source: from BSRF to HEPS
北京同步辐射装置
BSRF: 3 months operation in specific mode;6 months parasitic mode. Every year ~500 experiments.
用户的学科分布
HEPS R&D: a new machine with 1260 m circumference. R&D project to be approved soon
Large Projects at IHEP
BESIII
Daya Bay
JUNO
LHAASO
ASg/ARGO
2020 2050 2040 2030
CEPC
CSNS
ADS
HEPS
SppC
CEPC
SppC
JUNO
LHAASO
HXMT HXMT
HERD HERD
XTP XTP
construction
operation
Summary
• Particle and astro-particle physics are growing rapidly in China
• A lot of projects in neutrino physics, hadron physics and TeV high energy physics
• IHEP will be a center of HEP in the world
• Let’s explore more opportunities
Thanks 谢谢
Mass Hierarchy at Reactors
DM223
L. Zhan et al., PRD78:111103,2008;
PRD79:073007,2009