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