Overview of the CEPC Project Xin Chou Lou

Overview of the CEPC Project Xin. Chou Lou Institute of High Energy Physics, Beijing July 15, 2016 1

Outline HEP Program in China – a brief reminder CEPC and Spp. C Ø Ø Ø Physics Accelerators: progress and status The detector at the CEPC Site and civil engineering Other activities International collaboration R&D Funding Summary July 15, 2016 2

The High Energy Physics Program China July 15, 2016 3

Experimental Particle Physics Program pursued by physicists in China Neutrino physics Daya Bay Underground dark matter /bb decay experiment New hadrons LHC Pandax and CEDEX BESIII experiment BELLEII/PANDA ATLAS/CMS/LHCb/Alice + upgrades Future high luminosity, high energy accelerators p a variety of experiments ongoing or planned p CEPC-Spp. C the very long term future July 15, 2016 4

CEPC-Spp. C Phase 1: e+e- Higgs (Z) factory two detectors, 1 M ZH events in ~10 yrs Circular Electron Positron Collider (CEPC) Ecm 240 Ge. V, luminosity ~2 1034 cm-2 s-1, can also run at the Z-pole Precision measurement of the Higgs boson (and the Z boson) Phase 2: a discovery machine; pp collision with Ecm 50 -100 Te. V; ep, HI options Super proton-proton Collider (Spp. C) e+e- ZH e+ IP 1 e- LTB e+ e. Linac (240 m) BTC Booster(50 K m) CEPC Co llider IP 2 Ring(50 Km ) Ecm(Ge. V) favored post BEPCII accelerator based particle physics program in China July 15, 2016 5

CEPC Organization • Institution Board and Steering Committee formed in the kick-off meeting in September 2013; conveners appointed for the three working groups: Accelerator, Theory and Detector & Physics Find out more: http: //cepc. ihep. ac. cn/index. html International workshops and regular group meetings to coordinate efforts Schools and hand-on tutorials to train students – important to inspire more young people to directly participate in the activities – • • Ø The CEPC management was reorganized in May 2015, after the pre. CDR, July 15, 2016 to move forward with the CDR process; 6

CEPC and Spp. C Physics July 15, 2016 7

CEPC-Spp. C Accelerators • e+e- collider first phase Higgs produced above the e+e- ZH threshold Collide e+e- at Ecm~240 Ge. V，σ~ 200 fb Need 250 fb-1/year/IP —> 1 M Higgs particles in 10 years Goal • pp collider after upgrade Ecm ~70 Te. V or higher July 15, 2016 8

CEPC design goal • Limit SR power to 50 MW per beam • CEPC: single ring, head-on collision, up to 250 Ge. V • FCC-ee: double ring, large crossing angle, up to 350 Ge. V CEPC: 106 Higgs 1010 Z FCC-ee: 107 Higgs 1012 -13 Z July 15, 2016 9

Science at CEPC and Spp. C • Electron-positron collider (90, 250 Ge. V) – Higgs Factory: Precision study of Higgs(m. H, JPC, couplings) • Similar & complementary to ILC • Looking for hints of new physics – Z & W factory: precision test of SM • Deviation from SM ? Rare decays ? – Flavor factory: b, c, t and QCD studies • Proton-proton collider( 70 - 100 Te. V) – Directly search for new physics beyond SM – Precision test of SM • e. g. , h 3 & h 4 couplings Precision measurement + searches: Complementary with each other July 15, 2016 10

CEPC q Precise measurements of the Higgs properties as a Higgs Factory (similar to ILC@250 Ge. V) q q Mass, JPC, couplings, etc. → reach (sub-) percentage accuracy Precise measurements of Electroweak Symmetry-Breaking parameters at Z-pole and WW threshold q etc. + searches for rare decays July 15, 2016 11

CEPC Precision Higgs Physics by CEPC % precision M ~ 1 Te. V CEPC/FCC-ee to new physics ~ 10 over LHC July 15, 2016 CEPC pre. CDR Volume 1 (p. 9) 12

CEPC Search for Deviations from SM CEPC pre. CDR Volume 1 (p. 10) July 15, 2016 13

CEPC and Spp. C Accelerators progress and status July 15, 2016 14

CEPC Accelerator (pre. CDR) CEPC Accelerator Baseline Design Single ring: cheap, low lumi. 6~10 Ge. V Energy Ramp 10 ->120 Ge. V Electron Linac Double ring: expensive, high lumi Local Double ring: a balance? Booster Positron injection CEPC Accelerator local double rings Collision ring Pretzel scheme to separate opposing beams at crossings July 15, 2016 15

CEPC main parameters Parameter Design Goal Parameter Unit Value 120 e+, e. Circumference [C] m 54752 2 SR loss/turn 240[UGe. V 0] Ge. V 3. 11 -1 Integrated luminosity (per IP per year) 250 fb SR power/beam [P] MW 51. 7 Beam current [I] 50 (48) Bunch population [Ne] 　 3. 79 E+11 m. A 16. 6 Bending [r] No. radius of IPs m 6094 momentum 2 compaction factor [ap] 　 3. 36 E-05 Revolution period [T 0] s 1. 83 E-04 Revolution frequency [f 0] Hz 5475. 46 emittance (x/y) nm 6. 12/0. 018 b. IP(x/y) mm 800/1. 2 (3) Transverse size (x/y) mm 69. 97/0. 15 xx, y/IP 　 0. 118/0. 083 Bunch length SR [ss. SR] mm 2. 14 Bunch length total [ss. tot] mm 2. 65 Lifetime due to Beamstrahlung min 47 lifetime due to radiative Bhabha scattering [t. L] min 51 RF voltage [Vrf] GV 6. 87 MHz 650 Harmonic number [h] Particles RF frequency [frf] 　 118800 Synchrotron p, poscillation tune [ns] 　 0. 18 Energy acceptance RF [h] % 5. 99 Damping partition number [Je] 　 2 % 0. 096 　 0. 23 Particles Beam energy [E] Unit Value Ge. V Number of IP[N Center of. IP] mass 　 energy Bunch number/beam[n. B] 　 Parameter Center of mass energy Energy spread SR [s ] % d. SR Energy spread total luminosity [sd. tot] %(per Integrated 0. 132 Parameter Design Goal 70 Te. V Energy spread BS [s 0. 163 year) ng IP per (TBD) d. BS] Transverse damping time [nx] turns 78 Longitudinal damping time [n e] turns 39 Hourglass factor Fh 0. 68 Luminosity /IP[L] cm-2 s-1 2. 04 E+34 No. of IPs 2 July 15, 2016 16 16

J Gao et. al. CEPC Accelerator Preliminary July 15, 2016 17

CEPC accelerator layout J Gao et. al. Preliminary July 15, 2016 18

Spp. C Accelerator Design considerations cross section of CEPC tunnel • Proton-proton collider luminosity • Main constraint: high-field superconducting dipole magnets – 50 km: Bmax = 12 T, E = 50 Te. V – 50 km: Bmax = 20 T, E = 70 Te. V – 70 km: Bmax = 20 T, E = 90 Te. V July 15, 2016 19

Spp. C accelerator general design Parameter • • Value Circumference 54. 36 km Beam energy 35. 3 Te. V Dipole field 20 T Injection energy 2. 1 Te. V Number of IPs 2 (4) Peak luminosity per IP 1. 2 E+35 cm-2 s-1 Beta function at collision 0. 75 m Circulating beam current 1. 0 A Max beam-beam tune 0. 006 shift per IP Bunch separation 25 ns Bunch population 2. 0 E+11 SR heat load @arc 56. 9 W/m dipole (per aperture) 8 arcs (5. 9 km) and long straight sections (850 m*4+1038. 4 m*4) 20 July 15, 2016

Spp. C challenges • High field magnets: both dipoles (20 T) and quadrupoles (pole tip field: 14 -20 T). • Beam screen and vacuum: very high synchrotron radiation power inside the cold vacuum: • Collimation system: high efficiency collimators in cold sections: new method and structure ? • …… A R&D plan is developed. Main focus is the magnet seeking collaboration with industry, HT conductor research units, international partners A Conceptual design of 20 -T Nb 3 Sn + July HTS 15, common coil dipole magnet from IHEP 2016 21

Can be downloaded from http: //cepc. ihep. ac. cn/pre. CDR/volume. html 403 pages, 480 authors 328 pages, 300 authors July 15, 2016 22 Volume III: Civil Engineering (in Chinese)

International Review of pre-CDR July 15, 2016 23

CEPC and Spp. C The detector at the CEPC July 15, 2016 24

CEPC Detector (pre. CDR) ILD-like detector with additional considerations (incomplete list): p p p • Shorter L* (1. 5/2. 5 m) → constraints on space for the Si/TPC tracker No power-pulsing → lower granularity of vertex detector and calorimeter Limited CM (up to 250 Ge. V) → calorimeters of reduced size Lower radiation background → vertex detector closer to IP … Similar performance requirements to ILC detectors – Momentum: – Impact parameter: – Jet energy: ← recoiled Higgs mass ← flavor tagging, BR ← W/Z di-jet mass separation Sub-detector groups consider design options, identify challenges, plan R&D July 15, 2016 25

Ouyang Qun, HB Zhu et. al. CEPC Detector – Pixel Vertex Detector S CMOS Sensor design and production July 15, 2016 Funding from Key Lab, IHEP 26

Ouyang Qun, HB Zhu et. al. CEPC Detector – Pixel Vertex Detector July 15, 2016 27

CEPC Detector – TPC July 15, 2016 28

CEPC Detector – TPC July 15, 2016 29

CEPC Detector – Calorimeters July 15, 2016 T. Hu et. al. Funding：IHEP IF 30

CEPC Detector – Detctor Magnet L. Zhao et. al. Funding：IHEP IF Key technology: • Optimization of Magnetic filed • Superconductor • Inner winding and impregnating • Coil cryogenic system • Power lines with HTS • Manufacturing and assembling of huge scale yoke July 15, 2016 31

G. Li, MQ Ruan, YQ Fang et. al. CEPC Detector – Software & Tools Funding：IHEP IF Analysis Tools July 15, 2016 32

G. Li, MQ Ruan, YQ Fang et. al. CEPC Detector – Software & Tools shrink the ILD detector an important step towards sizing, design & optimization of the CEPC detector Plus: • full simulation of all analyses • two papers: one published and other answering the referee’s questions July 15, 2016 33

CEPC and Spp. C Site and civil engineering July 15, 2016 34

A candidate site for CEPC Qinhuangdao Beidaihe Beijing Tianjing • 300 km from Beijing • 3 h by car • 1 h by train July 15, 2016 35

Civil construction consideration • A credible design with cost estimate • The key to keep the cost low – Find a site geologically the best(granite) – Optimize of the design – Choose the right designer & construction contractor – Management July 15, 2016 36

CEPC and Spp. C Other activities July 15, 2016 37

Other activities • International workshops – – – ICFA Higgs factory workshop, Oct. 2014 Workshop on CEPC organized by IAS HKUST, Jan. 2015 ICFA workshop on SC Magnet, June 2015 IHEP-DOE CEPC physics workshop in Aug. 10 -12, 2015 Beijing-Chicago workshop on CEPC in Sep. 2015 IAS Conference Accelerator Program(Jan. 18 -21, 2016) More in 2016 • Training & professional development • Communication, education & Outreach July 15, 2016 38

Training and Professional development First Weihai Summer School (July-August, 2015) CAS Center for Excellence in Particle Physics & Ministry of Education Innvation Center for Particle Physics and Interactions co-hosted WHSS at Shangdong University Te. V Physics Series in Huairou (July 26–August 9, 2015) 4 parts focus on LHC run 2, CEPC CDR discussion on 8/9 CEPC Analysis Week (August 17 -28, 2015) 30 young physicists from 10 universities and institutes participated in the CEPC analysis (2) weeks, organized by IHEP staff Manqi RUAN and Gang LI in August 2015 July 15, 2016 39

CEPC and Spp. C International collaboration July 15, 2016 40

International Collaboration • Why we need international collaboration ? – Not only because we need technical help – But also for financial & political support in China • • A way to integrate China better to the international community A way to modernize China’s research system(“open door” policy) • A machine for the community • Right now the pre-CDR is mainly Chinese efforts with international help – An excise for us – Build confidence for the Chinese HEP community July 15, 2016 41

International Collaboration • A new scheme of international collaboration to be explored: – Not the same as ITER, ILC, CERN, … – A new institution, a consortium, or just a new project ? • An international advisory board is formed to discuss in particular this issue, together with others – Working groups – Workshops – Preliminary organizations next year –… July 15, 2016 42

R&D Funding July 15, 2016 43

R&D Funding • IHEP seed money 12 M RMB/3 years (2015 -2017) • Chinese Ministry of Sci. & Technology ~ 90 M / 6 years (2016 -2021) 1 st grant of ~36 M RMB approved • China National Commission on Dev. & Reform No funding in 13 th 5 -year plan we are seeking funding from other sources July 15, 2016 44

Summary • CEPC is the first Chinese effort for a science project at such a large scale; challenges are everywhere • Tremendous progresses up to now, but we have a long way to go • It is difficult but very exciting • Let’s work together to make it happen We fully support a global effort, even if the next big circular collider is not built in China July 15, 2016 45

CEPC-SPPC Timeline (preliminary/ideal) Pre-studies (2013 -2015) R&D Engineering Design (2016 -2020) Construction (2021 -2027) 2035 2030 2020 2015 CEPC 2025 2 nd Milestone: 13 th 5 yr-plan R&D (12 M IHEP, ~100 M MOST) Data taking (2028 -2035) 1 st Milestone: Pre-CDR (Spring of 2015) → R&D funding request to Chinese government in 2016 (China’s 13 th Five-Year Plan 2016 -2020) R&D (2014 -2030) 2040 2030 2020 SPPC Engineering Design (2030 -2035) Construction (2035 -2042) Data taking (2042 -2055) This is a good schedule to follow July 15, 2016 46

CEPC-Spp. C Physics wise， CEPC+SPPC is ideal Some considerations Timing (after BEPCII) Technological feasibility (experience at BEPC/BEPCII) Economy new funding to the community Large & young population new blood to the community Affordable tunnel & infrastructure still cheap in China now Money will be taken by somebody anyway It is a pity if we miss it • Too expensive ? • • • – – – – BEPC cost/4 y/GDP of China in 1984 0. 0001 SSC cost/10 y/GDP of US in 1992 0. 0001 LEP cost/8 y/GDP of EU in 1984 0. 0002 LHC cost/10 y/GDP of EU in 2004 0. 0003 ILC cost/8 y/GDP of Japan in 2018 0. 0002 CEPC cost/6 y/GDP of China in 2020 0. 0001 SPPC cost/10 y/GDP of China in 2036 0. 0001 - 0. 0002 July 15, 2016 47

Surface & underground July 15, 2016 48

Tunnel • Concrete/Steel is not needed in granite for the stability of the structure • Water leaks are mainly cured by Concrete + water proof material • Concrete/Steel could bear more than half of the tunnel cost • Solution: steel plate ~ 50% cost saving July 15, 2016 49

CEPC Detector – Calorimeters July 15, 2016 T. Hu et. al. 50

Current Status • Initiated a global effort for the Conceptual Design • pre-CDR completed – No show-stoppers – Technical challenges identified R&D issues – Preliminary cost estimate • R&D issues identified and funding request underway – Seed money from IHEP available: 12 M RMB/3 years – MOST: ~ 100 M / 5 yr, hopefully next year – NCDR: ~1 B RMB / 5 yr, maybe 2017 • Working towards CEPC CD by 2016 – A working machine on paper • Site selection • Internationalization & organization July 15, 2016 51