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

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

3. The High Energy Physics Program China 3July 15, 2016

4. Underground dark matter /  decay experiment BESIII experiment BELLEII/PANDA ATLAS/CMS/LHCb/Alice + upgrades Neutrino physics New hadrons LHC Future high luminosity, high energy accelerators Experimental Particle Physics Program pursued by physicists in China  a variety of experiments ongoing or planned  CEPC-SppC the very long term future July 15, 20164 Daya Bay Pandax and CEDEX

5. e + e -  ZH favored post BEPCII accelerator based particle physics program in China Phase 1: e + e - Higgs (Z) factory two detectors, 1M ZH events in ~10yrs Circular Electron Positron Collider (CEPC) E cm  240GeV, luminosity ~ 2  10 34 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 E cm  50-100 TeV; ep, HI options Super proton-proton Collider (SppC) CEPC-SppC E cm (GeV) BTC IP1 IP2 e+e- e+ e- Linac (240m) LTB CEPC Collider Ring(50Km) Booster(50Km) BTC 5July 15, 2016

6. 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.htmlhttp://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  The CEPC management was reorganized in May 2015, after the preCDR, to move forward with the CDR process; 6July 15, 2016

7. CEPC and SppC Physics 7July 15, 2016

8. CEPC-SppC Accelerators e + e - collider first phase Higgs produced above the e + e -  ZH threshold Collide e + e - at E cm ~240GeV ， σ~ 200 fb Need 250 fb -1 /year/IP —> 1M Higgs particles in 10 years Goal pp collider after upgrade E cm ~70 TeV or higher July 15, 20168

9. Limit SR power to 50 MW per beam CEPC: single ring, head-on collision, up to 250 GeV FCC-ee: double ring, large crossing angle, up to 350 GeV CEPC: 10 6 Higgs 10 10 Z FCC-ee: 10 7 Higgs 10 12-13 Z CEPC design goal 9July 15, 2016

10. Science at CEPC and SppC July 15, 201610 Electron-positron collider (90, 250 GeV) –Higgs Factory: Precision study of Higgs(m H, J PC, 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 TeV) –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

11.  Precise measurements of the Higgs properties as a Higgs Factory (similar to ILC@250 GeV)  Mass, J PC, couplings, etc. → reach (sub-) percentage accuracy  Precise measurements of Electroweak Symmetry-Breaking parameters at Z-pole and WW threshold  etc. + searches for rare decays CEPC July 15, 201611

12. CEPC July 15, 201612 Precision Higgs Physics by CEPC % precision  M ~ 1 TeV CEPC/FCC-ee to new physics  ~  10 over LHC CEPC preCDR Volume 1 (p.9)

13. CEPC July 15, 201613 CEPC preCDR Volume 1 (p.10) Search for Deviations from SM

14. CEPC and SppC Accelerators progress and status 14July 15, 2016

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

16. CEPC main parameters ParameterDesign Goal Particlese+, e- Center of mass energy240 GeV Integrated luminosity (per IP per year)250 fb -1 No. of IPs2 16 ParameterDesign Goal Particlesp, p Center of mass energy70 TeV Integrated luminosity (per IP per year)(TBD) No. of IPs2 ParameterUnitValueParameterUnitValue Beam energy [E]GeV120Circumference [C]m54752 Number of IP[N IP ] 2SR loss/turn [U 0 ]GeV3.11 Bunch number/beam[n B ] 50 (48)Bunch population [Ne] 3.79E+11 SR power/beam [P]MW51.7Beam current [I]mA16.6 Bending radius [  ] m6094 momentum compaction factor [  p ] 3.36E-05 Revolution period [T 0 ]s1.83E-04Revolution frequency [f 0 ]Hz5475.46 emittance (x/y)nm6.12/0.018  IP (x/y) mm800/1.2 (3) Transverse size (x/y) mm 69.97/0.15  x,y /IP 0.118/0.083 Bunch length SR [  s.SR ] mm2.14 Bunch length total [  s.tot ] mm2.65 Lifetime due to Beamstrahlungmin47 lifetime due to radiative Bhabha scattering [  L ] min51 RF voltage [V rf ]GV6.87RF frequency [f rf ]MHz650 Harmonic number [h] 118800 Synchrotron oscillation tune [ s ] 0.18 Energy acceptance RF [h]%5.99 Damping partition number [J  ] 2 Energy spread SR [  .SR ] %0.132 Energy spread BS [  .BS ] %0.096 Energy spread total [  .tot ] %0.163nn 0.23 Transverse damping time [n x ]turns78Longitudinal damping time [n  ]turns39 Hourglass factorFh0.68Luminosity /IP[L]cm -2 s -1 2.04E+34 16 July 15, 201616

17. CEPC Accelerator J Gao et. al. July 15, 201617 Preliminary

18. CEPC accelerator layout J Gao et. al. July 15, 201618 Preliminary

19. SppC Accelerator Design considerations Proton-proton collider luminosity Main constraint: high-field superconducting dipole magnets – 50 km: B max = 12 T, E = 50 TeV – 50 km: B max = 20 T, E = 70 TeV – 70 km: B max = 20 T, E = 90 TeV cross section of CEPC tunnel July 15, 201619

20. 8 arcs (5.9 km) and long straight sections (850m*4+1038.4m*4) 20 ParameterValue Circumference54.36 km Beam energy35.3 TeV Dipole field20 T Injection energy2.1 TeV Number of IPs2 (4) Peak luminosity per IP1.2E+35 cm -2 s -1 Beta function at collision0.75 m Circulating beam current1.0 A Max beam-beam tune shift per IP 0.006 Bunch separation25 ns Bunch population2.0E+11 SR heat load @arc dipole (per aperture) 56.9 W/m SppC accelerator general design July 15, 2016

21. 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 21 A Conceptual design of 20-T Nb 3 Sn + HTS common coil dipole magnet from IHEP SppC challenges seeking collaboration with industry, HT conductor research units, international partners July 15, 2016

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

23. International Review of pre-CDR July 15, 201623

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

25. CEPC Detector (preCDR) ILD-like detector with additional considerations (incomplete list):  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 GeV) → calorimeters of reduced size  Lower radiation background → vertex detector closer to IP  … Similar performance requirements to ILC detectors – Momentum: ← recoiled Higgs mass – Impact parameter: ← flavor tagging, BR – Jet energy: ← W/Z di-jet mass separation July 15, 201625 Sub-detector groups consider design options, identify challenges, plan R&D

26. CEPC Detector – Pixel Vertex Detector Ouyang Qun, HB Zhu et. al. S CMOS Sensor design and production Funding from Key Lab, IHEP July 15, 201626

27. CEPC Detector – Pixel Vertex Detector Ouyang Qun, HB Zhu et. al. July 15, 201627

28. CEPC Detector – TPC 28 July 15, 201628

29. CEPC Detector – TPC 29 July 15, 201629

30. CEPC Detector – Calorimeters 30 T. Hu et. al. Funding ： IHEP IF July 15, 201630

31. CEPC Detector – Detctor Magnet 31 L. Zhao et. al. 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 Funding ： IHEP IF July 15, 201631

32. CEPC Detector – Software & Tools 32 G. Li, MQ Ruan, YQ Fang et. al. Funding ： IHEP IF July 15, 201632 Analysis Tools

33. CEPC Detector – Software & Tools 33 G. Li, MQ Ruan, YQ Fang et. al. 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 shrink the ILD detector July 15, 201633

34. CEPC and SppC Site and civil engineering 34July 15, 2016

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

36. 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 Civil construction consideration 36July 15, 2016

37. CEPC and SppC Other activities 37July 15, 2016

38. 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 Other activities 38July 15, 2016

39. Training and Professional development 39 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 TeV Physics Series in Huairou (July 26–August 9, 2015) 4 parts focus on LHC run2, 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

40. CEPC and SppC International collaboration 40July 15, 2016

41. 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 International Collaboration 41July 15, 2016

42. 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 – … International Collaboration 42July 15, 2016

43. R&D Funding 43July 15, 2016

44. R&D Funding July 15, 201644 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 ~36M RMB approved China National Commission on Dev. & Reform No funding in 13 th 5-year plan we are seeking funding from other sources

45. Summary 45July 15, 2016 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

46. CEPC-SPPC Timeline (preliminary/ideal) 20152020202520302035 R&D Engineering Design (2016-2020) Construction (2021-2027) Data taking (2028-2035) Pre-studies (2013-2015) 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) CEPC 202020302040 R&D (2014-2030) Engineering Design (2030-2035) Construction (2035-2042) Data taking (2042-2055) SPPC 2 nd Milestone: 13th 5yr-plan R&D (12M IHEP, ~100M MOST) This is a good schedule to follow July 15, 201646

47. 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/10y/GDP of US in 1992  0.0001 – LEP cost/8y/GDP of EU in 1984  0.0002 – LHC cost/10y/GDP of EU in 2004  0.0003 – ILC cost/8y/GDP of Japan in 2018  0.0002 – CEPC cost/6y/GDP of China in 2020  0.0001 – SPPC cost/10y/GDP of China in 2036  0.0001- 0.0002 Physics wise ， CEPC+SPPC is ideal CEPC-SppC Some considerations 47July 15, 2016

48. Surface & underground 48July 15, 2016

49. 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 Tunnel 49July 15, 2016

50. CEPC Detector – Calorimeters 50 T. Hu et. al. July 15, 201650

51. Current Status July 15, 201651 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 / 5yr, 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