Particle Physics at IHEP

Yifang Wang

Institute of High Energy Physics

Sep. 19, 2014

Content

• Introduction of IHEP

• BEPCII/BESIII

• Neutrino experiments

• Future program

• Summary

IHEP Campus Map

Electron-Positron Collider

3/45

Beijing Electron-Positron Collider(BEPC)

4/45

• IHEP is developed

after the construction

of BEPC in late 80’s

• Upgrade of BEPC

(BEPCII) is completed

in 2008. It leads IHEP

to be one of the most

active HEP centers in

the world.

• The research of IHEP

now covers particle

physics, astrophysics

, synchrotron

radiation, spallation

neutron source, etc.

ADONE

BEPCII

CESRc BEPC

SPEAR

DORIS I

AMS g-ray-burst detector

Moon exploration

Space Projects

ME

LE HE

HXMT

Light Source & Spallation Neutron Source

6/45

Sino-Italian ARGO experiment (RPC hall)

Sino-Japanese AS γ experiment (scintillation detector array)

Sino-Italian ARGO experiment (part of RPC carpet)

High Altitude Cosmic-Ray Physics

~3TeV ~300GeV

LHAASO

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

BEPC II Storage ring: Large angle, double-ring

RF RF SR

IP

22 mrad

2.5m8ns

1.5cm

0.1cm

Beam energy:

1-2 GeV

Luminosity:

1×1033 cm-2s-1

Optimum energy:

1.89 GeV

Energy spread:

5.16 ×10-4

No. of bunches:

93

Bunch length:

1.5 cm

Total current:

0.91 A

SR mode:

0.25A @ 2.5 GeV

10

TOF BTOF: two layers

ETOF: 48 crys. for each

11

BESIII Detector MDC

R inner: 63mm ;

R outer: 810mm

Length:2582 mm

Layers: 43

CsI(Tl) EMC

Crystals: 28 cm(15 X0)

Barrel: |cos|<0.83

Endcap:

0.85 < |cos| < 0.93

RPC MUC

BMUC: 9 layers – 72 modules

EMUC: 8 layers – 64 modules

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 成员 来自11个国家的52 个单位

BESIII International Collaboration

12

Some of us

BESIII Data Taking Status & Plan Previous Data set BESIII now Goal

J/psi BESII: 58M 1.2 B 10B

Psi’ CLEO：28 M 0.5 B 3B

Psi” CLEO：0.8 /fb 3.0/fb 20 /fb

y(4040)/y(4160)

/X(4260) etc.

CLEO：0.6/fb @

y(4160)

0.5/fb y(4040); 2.3/fb @~4260,

0.5/fb@ ~4360; 1/fb@~4420;

0.5/fb@~4600

~ 10 /fb

R scan & Tau BESII @10K/pnts 105 pnts@3.8-4.6 GeV 100K/pnts

BESIII will continue for the next 8-10 years: Unique in the world

Normal hadrons are made of 2 or 3 quarks：

Quark Model：

QCD predict new type of hadrons: • Multi-quark states：No. of quarks >＝ 4

• Hybrids： qqg，qqqg …

• Glue balls：gg， ggg …

New Type of Hadrons

g

g g

g

No experimental proof of new types of hadrons

• Below the open charm

threshold: • All the chamonium states are

discovered.

• Above the open charm

threshold: • Many theoretically predicted

particles are not found

• Many unpredicted particles

are found

X(3872)

XYZ(3940)

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 states

open charm 阈

BESIII: 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/y

> 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)

New Zc(3900) Decay Mode

Zc(3900)

6

(Zc(3900) DD*0)

(Zc(3900) J/y)

JP favors 1+

Very important for the understanding of Zc(3900)

BESIII：PRL 112, 022001 (2014)

M(Zc) = 3883.91.54.2 MeV

(Zc) = 24.83.311.0 MeV

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/ywX, X+-h

f1(1285) h(1405)

X(1870)

X(1835)

X(2120） X(2370) PRL107, 182001 (2011) PRL 106 (2011) 072002

PRL109, 042003 (2012) yghc

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, t 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 -

CEPC Accelerator Design

LINAC to generate and accelerate electrons to 6 GeV

Booster to accelerate electrons to 120 GeV

Main Ring to accumulate electrons to 16.9 mA, FODO lattice, single

ring with the Pretzel scheme …

BTC

IP1

IP2

e+ e-

e+ e- Linac

(240m)

LTB

BTC

Parameters Unit Value Parameters Unit Value Beam energy [E] GeV 120 Circumference [C] km 53.6

Number of IP[NIP] 2 SR loss/turn [U0] GeV 3

Bunch number/beam[nB] 50 Bunch population [Ne] 3.71E+11

SR power/beam [P] MW 50 Beam current [I] mA 16.6

Bending radius [r] m 6094 momentum compaction factor [ap] 4.15E-05

Revolution period [T0] s 1.79E-04 Revolution frequency [f0] Hz 5991.66 emittance (x/y) nm 6.79/0.021 bIP(x/y) mm 800/1.2

Transverse size (x/y) mm 73.7/0.16 xx,y/IP 0.1/0.074

Beam length SR [s.SR] mm 2.35 Beam length total [s.tot] mm 2.66

Lifetime due to Beamstrahlung

min 80 lifetime due to radiative Bhabha scattering [tL]

min 56

RF voltage [Vrf] GV 6.87 RF frequency [frf] MHz 650

Harmonic number [h] 116244 Synchrotron oscillation tune [ns] 0.199

Energy acceptance RF [h] % 5.56 Damping partition number [Je] 2

Energy spread SR [d.SR] % 0.13 Energy spread BS [d.BS] % 0.07

Energy spread total [d.tot] % 0.15 ng 0.22

Transverse damping time [nx] turns 81 Longitudinal damping time [ne] turns 40

Hourglass factor Fh 0.679 Luminosity /IP[L] cm-2s-1 1.8E+34

Main Parameters of CEPC

SppC Accelerator Design

• Proton-proton collider luminosity

• Main constraint: high-field superconducting dipole magnets

– 50 km: Bmax = 12 T, E = 50 TeV

– 50 km: Bmax = 20 T, E = 70 TeV

– 70 km: Bmax = 20 T, E = 90 TeV

22

0

,

( 1 )4 2

p b rep c z

n IP x IP

N N fL F F

g

e b

+

x =Nprp

4pen

£ 0.004

min

0

2 ( )BB

C

r

Parameter Value Unit

Circumference 52 km

Beam energy 35 TeV

Dipole field 20 T

Injection energy 2.1 TeV

Number of IPs 2 (4)

Peak luminosity per IP 1.2E+35 cm-2s-1

Beta function at collision 0.75 m

Circulating beam current 1.0 A

Max beam-beam tune shift per IP 0.006

Bunch separation 25 ns

Bunch population 2.0E+11

SR heat load @arc dipole (per aperture) 56 W/m

SppC Main Parameters

Site • Preliminarily selected: Qinhuangdao (秦皇岛）

• Strong support by the local government

Neutrinos 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

tm nnn

tm

e

e

bsd

tcu

A hot topic of particle physics, astrophysics and cosmology

Neutrino Oscillation If the neutrino mass eigenstate is different from that of the

weak interaction, neutrinos can oscillate: from one type to

another during the flight:

ne ne nm nm

Oscillation

probability：

P(ne->nm) sin2(2) sin2(1.27Dm2L/E)

Oscillation

amplitude

Oscillation

frequency

Oscillation matrix

for 3 generations：

Known parameters： 23，12，DM223， DM2

12，

Recent progress: 13

Unknown parameters: mass hierarchy(DM223), CP phase d 2014/10/9 32

How to Measure 13 at 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: sin2213 < 0.15 @ 90%C.L.

Model prediction: sin2213 0-0.20, but mostly around 0.01

Our design goal：D(Nobs/Nexp) ~ 0.4% 10 improvement !

2014/10/9 33

Pee 1 - sin2213sin2 (1.27Dm213L/E) - cos413sin2212sin2 (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 2014/10/9 34

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

2014/10/9 35

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）

36 2014/10/9

Water Cerenkov Detector Installation

PMT frame & Tyvek Completed pool PermaFlex painting

Cover Install AD Pool with water

2014/10/9 37

Neutrino Detector Assembly

SSV 4m AV

PMT

SSV lid ACU

Bottom reflector

Top reflector 3m AV

Leak check 2014/10/9 38

Experimental Hall in Operation

39 2014/10/9

A New Type of Oscillation Discovered

40 2014/10/9

Observation of electron anti-neutrino disappearance:

R = 0.940 ±0.011 (stat) ±0.004 (syst)

Sin2213 = 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 13

2014/10/9 41 Accelerator experiments assuming δCP=0, θ23=45⁰

Why Interesting ?

Neutrinos oscillate in a “normal way” no surprises

Sin2213 is almost 10 larger than what we expected a big

surprise

Now it is possible to plan the next generation neutrino experiment for

the mass hierarchy and CP phase d

2014/10/9 42

n1

n2

n3

sin2212 ~ 0.9

sin2223 ~ 1

sin2213 ~ 0.1

Pme ≈ sin223sin2213sin2(1.27Dm223L/E) +

cos223sin2212sin2(1.27Dm212L/E) -

A(r)cos213sin13sin(d)

2014/10/9 43

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 ?

……

2014/10/9 44

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

Talk by YFW at ICFA seminar 2008,

Neutel 2011; by J. Cao at NuTurn 2012 ;

Paper by L. Zhan, YFW, J. Cao, L.J. Wen,

PRD78:111103,2008; PRD79:073007,2009

Mass Hierarchy at Reactors

DM223

L. Zhan et al., PRD78:111103,2008;

PRD79:073007,2009

– LS volume: 20 for more statistics (40 events/day)

– light(PE) 5 for better resolution (DM212/ DM2

23 ~ 3%)

The Plan: a Large LS Detector

20 kt LS

Acrylic tank：F34.5m

Stainless Steel tank ：F37.5m

Muon detector

Water seal

~15000 20” PMTs

coverage: ~80%

Steel Tank

6kt MO

20kt water

1500 20” VETO PMTs 2014/10/9 47

40 events/day

Physics Reach

2014/10/9 48

Thanks to a large θ13

Current Daya Bay II

Dm212 4% 0.6%

Dm223 4% 0.6%

sin212 6% 0.7%

sin223 10% N/A

sin213 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 Δm2mm

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

49

Challenge II: Transparent 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

50 2014/10/9

Challenge III: High QE PMT

Three types of high QE 20”

PMTs under development: A new type of MCP-PMT:

4 collection

Hammamatzu R5912-100

with SBA photocathode

Photonics-type PMT

MCP-PMT development: Technical issues mostly

resolved

Successful 8” prototypes

A few 20” prototypes

51

SPE Gain R5912 R5912

-100

MCP-

PMT

QE@410nm 25% >30% 25-30%

Rise time 3 ns 3.4ns 5ns

SPE Amp. 17mV 18mV 17mV

P/V of SPE >2.5 >2.5 ~ 2

TTS 5.5ns 1.5 ns 3.5 ns

2014/10/9

Challenge IV: Civil Construction

52

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 ?

2014/10/9

Current Status & Brief Schedule

Project approved by CAS for R&D and design

Geological survey completed

Granite rock, tem. ~ 31 oC, little water

EPC contract signed:

Engineering design by July

Construction work by Nov.

Paper work towards the construction:

Land, environment, safety, …

53

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

2014/10/9

Collaboration Established

2014/10/9 54

54

Europe (20)* 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 (Observer)

IPHC Strasbourg

JINR

LLR Paris

RWTH Aachen U.

Subatech Nantes

TUM

U.Hamburg

U.Mainz

U.Oulu

U.Tuebingen

US*

BNL, UIUC, Houston

Observers on behalf of

US institutions

Asia (25) 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.

*Subject to funding agency approval

Race for the Mass Hierarchy

• JUNO is competitive for measuring MH using reactor neutrinos – Independent of the yet-unknown CP phase, matter effects and 23

• Many other science goals: Precision measurement of Δm31

2, θ12, Δm212

Geo-, solar, supernova, …, neutrinos 55

NOvA, LBNE: d PINGU, INO: 23=40-50 JUNO: 3%-3.5%

M. Blennow et al., JHEP 1403 (2014) 028

2014/10/9

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

• We are very eager to establish more collaborations with Asian countries

• Let’s explore more opportunities

2014/10/9 56

Thanks 谢谢 ขอบคุณครับ