Status and Prospect of HIEPA/STCF in China

Transcription

1 Status and Prospect of HIEPA/STCF in China Yangheng Zheng (On behalf HIEPA/STCF Steering Committee) eefact2018, September 24-27, HKUST,Hongkong

2 Outline High Intensity Electron Positron Accelerator (HIEPA) Super Tau Charm Facility (STCF) + SR Light Source Conceptual Design status of STCF Funding Status Potential sites Strategy & Prospect of Science- Technology Review About CEPC & STCF project in China Summary 2

3 Broad Physics at τ-c Energy Region Unique features :Rich of resonance, Threshold characteristics, Quantum Correlation Abundant physics R=s(e + e - hadron)/ s(e + e - m + m - ) Hadron form factors Y(2175) resonance Mutltiquark states with s quark, Zs MLLA/LPHD and QCD sum rule predictions 3 Light hadron spectroscopy Gluonic and exotic states Process of LFV and CPV Rare and forbidden decays Physics with τ lepton XYZ particles f D and f Ds D 0 -D 0 mixing coherent D mesons decays Charm baryons LHCb, (Super)B factory, (Super)τ-c factory, φ factories are complementary.

4 Some limitations for BEPCII/BESIII BEPCII/BESIII have run 9 years, and are playing a leading role in tau-charm physics area. Limited by length of storage ring, no space and potential for the upgrade Physics study limited by the Statistics (luminosity), CME Charmonium-like physics Charmed hadron physics & CKM physics Tau physics Challenged by Belle II BEPCII/BESIII will end her mission in 5-7 years (up to 2025) A Super τ-charm Facility is the nature extension and a viable option for a post-bepcii HEP project in China 4

5 Highlight Physics STCF Rich of physics program, unique for physics with c quark and τ leptons, important playground for study of QCD, exotic hadrons and search for new physics. Charmonium-like XYZ (luminosity and CME) Charmed mesons (Luminosity) Charmed baryons (CME) τ Lepton CP (polarized beam) New physics (luminosity).. More details see Xiaorui s talk on Sept. 25 (WG1) 5

6 Charmonium-Like Physics Fruitful results in past decade, a new territory to study exotic hadrons τ-c Factory : e + e - Y/ψ Z c + X B Factory : ISR, B decay Belle with ISR: PRL110, fb -1 in 10 years running 4.26 GeV for π + π - J/ψ ε BESIII = 46%, ε Belle = 10% >5.2σ B factory : Total integrate effective luminosity between 4-5 GeV is 0.23ab -1 for 50 ab -1 data τ-c factory : scan in region 4-5 GeV, 10 MeV/step, every point have 20 fb -1 /year, 10 time of Belle II for 50 ab -1 data τ-c factory have much higher efficiency than B Factory BESIII at GeV: PRL110, fb -1 in one month running time >8σ 6

7 clfv Decay τ B Factory From A. Bondar, Charm2010 Current limit : ~ ( τ-pairs) BABAR : 516fb -1 [PRL, 104, ] BELLE : 545fb -1 At Υ(4S) : ISR background e+e- τ + τ - γ Upper Limit 1/ L Expected limit : -1 ( τ-pairs) Background e + e - τ + τ - γ Super-B 75 ab τ-pairs Does not contribute below s 4m τ / GeV. 7

8 τ CPV in Angle Distribution Measurement on the angular CPV asymmetry is desirable Use T-odd rotationally invariant products in >=2 hadrons, such as τ π π 0 ν τ /k π 0 ν τ, τ π π + π ν τ /K π + π ν τ : Polarized of τ and beam are necessary tau-charm Figure of Merits Y. S. TSAI, PRD 51 (1995) (10 33 cm -2 s -1 ) FOM= (10 35 cm -2 s -1 ) FOM=100 (8x10 35 cm -2 s -1 ) FOM=52 B factory 8

9 Synergies: γ Sensitivities LHCb is here. Future sensitivities (scaled according to statistical uncertainties) CLEOc Q.C. inputs contribute ~2 o [LHCb-PUB ] 9 Q.C. inputs from BESIII (contribute ~1 o with existing data set, ~0.4 o with 20 fb -1 ) or from Super τ- charm factory will be crucial!

10 STCF in China Peak luminosity cm -2 s -1 at 4 GeV Energy range E cm = 2 7GeV Polarization available on beam (Phase II) Basic Features of machine : Symmetric machine with dual-ring, meters Large Piwinski angle collision + crabbed waist solution for the Interaction Region Siberia snake for polarization (Phase II option) Accelerator team is just formed in August and working very hard. ( Experts from Hefei Synchrotron Radiation National Lab are playing the leading role. ) USTC & UCAS are recruiting accelerator physics experts 10 (different level: Postdoc, Permanent or Visiting positions)

11 Parameters and Plan of the Machine Parameters 1 2 Circumference/m ~600 ~600 Beam Energy/GeV 2 2 Current/A Emmmmmmmmmmmmmmmm εε xx /εε yy /nm rad 5/0.05 5/0.05 β IP ββ xx /ββ yy /mm Collision Angle(full θ)/mrad 100/ / Tune Shift ξξ yy Hour-glass Factor Luminosity/ cm -2 s -1 ~0.5 ~ Strategy : (Phase 0) Pilot: (Phase I) Nominal: (Phase II) Polarized beam.. Final: 90% Polarization e- injection, 80% Upgrade: Polarized e+ Preliminary Lattice design results and more details can found Qing Luo s talk on Sept. 25 (WG3).

12 Detector Layout 245 cm 185 cm 135 cm 105 cm 85 cm Superconducting magnet (0.7-1 T) PID-barrel MDC York/Muon PIDendcap EM C York/Muon MUD µ/π suppression power >10/30 EMC Energy range: GeV At 1 GeV σ E (%) EnBarrel(Cs(I): 2 dcap (Cs): 4 PID π/k (and K/p) 3-4σ separation 20 up to 2GeV/c MDC (Low mass ) σ xy =130 mm de/dx<7%, σ p /p =0.5% at 1 GeV ~6 cm cm cm IP PXD/SSD 140 cm 120 cm 190 cm 240 cm 300 cm PXD Material budget ~0.15%X 0 /layer σ xy =50 mm 12

13 General Consideration of Detector Much larger radiation tolerance, especially at IP and forward regions Efficient event triggering, exclusive state reconstruction and tagging The Systematic uncertainty control Reasonable cost STCF Detector team has been formed. (Currently, USTC team is playing the leading role.) Lots of progress on Tracking, PID, EMC and Muon system R&D. 13 Tracking: Several Micro-Pattern Detector (DEPFET, MAPS, GEM/MicroMegas/ urwell) Technologies for inner tracking are testing. PID: RICH/DIRC for Barrel and DIRC-like TOF for EndCap EMC: CsI(Tl), CsI, BSO, PbWO4, LYSO Muon Counter with precise timing (σ T <80 ps, Space reolution~0.6 mm)

14 Strategy & Activities CDR TDR project application construction commissioning Strategy: focus on CDR (2 years) and TDR (6 years) depend on the available resources. Open to the construction site. Webpage: Domestic Workshops (2011, 12, 13, 14, 16) International Workshops (2015, 18) Report to USTC Scientific Committee and USTC presidents Report to Hefei High-tech Development Zone Report to Anhui Development Planning Commission Form the Organization for the project 14

15 Activities Proposals to USTC, CAS, Local government & Central government 15 Regular meetings Steering Committee :once per month Detector regular meeting : Every Wednesday Accelerator regular meeting : Every Friday

16 USTC Scientific Committee Review USTC president agreed, and scientific committee endorsed supporting R&D 10 M RMB for this year 16

17 Organization Institutional Board Steering Committee Chair:Zhengguo Zhao (USTC) Project Director Haiping Peng (USTC), Yangheng Zheng (UCAS) International Advisory Committee (IAC) Theory &MC simulation Accelerator Detector Light Hadron Charmonium, XYZ Charm decay, charm Spectroscopy Tau R&QCQ New Physics. 17 Design RF IP Vacuum Beam diagnose Linear. Tracking PID ECAL Muon SC Trigger, DAQ Software Computing & Network

18 Tentative Plan & Estimated Budget Form International Collaboration Conception Design Report (CDR) Technical Design Report (TDR) Construction Commissioning Upgrade A unique precision frontier in the world for 30 years! R&D budget: 200M RMB Total budget: 4B RMB 18

19 International Collaboration Super Charm-Tau at Novosibirsk, RUSSIA, Budker Institute of Nuclear Physics Long history.. Pre-Agreement of Joint effort on R&D, details are under negotiation Joint workshop between China, Russia, and Europe 2018 UCAS (March), Novosibirsk (May), Orsay (December)

20 Science & Technology Review Two international workshop : Hefei (2015), Beijing(2018) More than 100 participants, more than 50% of them are from oversea Presented project status, overview the physics potential and discuss the design and key technology of accelerator and detection 20

21 Joint workshop on future τ-c factory 21 Welcome to join the workshop!

22 Institutions shown Interest University of Science and Technology of China Stanford University, USA Institute of High Energy Physics, CAS Wayne State University, USA Institute of Theoretical Physics, CAS Carnegie Mellon University, USA Tsinghua University GSI Darmstadt and Goethe University University of Chinese Academy of Sciences Frankfurt, Shandong University Germany Shanghai Jiaotong University Goethe University Frankfurt, Germany Peking University GSI Darmstadt, Germany Zhejiang University Johannes Gutenberg University Mainz, Germany Nanjing University Helmholtz Institute Mainz, Germany Nankai University LAL (IN2P3/CNRS and Paris-Sud Wuhan University University), Central China Normal University Lanzhou University Orsay, France University of Southern China Sezione di Ferrara, Italy Beijing University of Aeronautics and Astronautics L'Istituto di Fisica Nucleare di Torino, Italy. L'Istituto di Fisica Nucleare di Firenze, Italy Institute for Basic Science, Daejeon, Korea Scuola Normale Superiore, Pisa, Italy Dubna, Russia University of Silesia, Katowice, Poland Budker Institute and Novosibirsk University, Russia Laboratori Nazionali di Frascati, Italy T. Shevchenko National University of Kyiv, Kyiv, Ukraine INFN, Padova, Italy University Ljubljana and Jozef Stefan Institute Ljubljana, Slovenia University of Pavia, Pavia, Italy University of Parma, Italy Jozef Stefan Institute Ljubljana, Slovenia 22

23 Pre-Conceptual Design Report 23

24 Candidate site 1: Hefei, Anhui province One of three integrated national science centers, which will play important role in Megascience of China in near future Hefei Integrated National Science Center Pay a lot of attention on accelerator facilities Hefei Advanced light source is under design STCF is listed in future plan University of Science and Technology of China (USTC) National Synchrotron Radiation Lab and Hefei Light Source, operated by USTC The only National Lab operated by University in China. (Totally Four officially approved National Labs in China) 24

25 Candidate site 2: Canton province Institute of Modern Physics, CAS, proposed building HIAF-EicC in Huizhou, Canton STCF Share the design effort of the electron accelerator of EicC? SUN YAT-SEN UNIVERSITY proposed building Southern Synchrotron Radiation light source in Canton 25

26 Candidate site 3: Huairou, Beijing Planned Scientific City : km 2 (One of three integrated national science centers) UCAS Huairou Scientifi c City Synchrotron radiation light source 26 So far, no dedicated facility for particle physics yet!

27 CEPC and STCF in China Consensus in HEP community (about on accelerator based particle physics project) Chinese Physics Society, Division of High Energy Physics There are viable options for China s next big project in High Energy Physics :CEPC (includes a Higgs factory and a Z factory) and HIEPA. 27 the CEPC project is the top choice for future development in Highenergy Accelerator Physics in China.

28 CEPC and STCF in China Physics:very different CMS energy (240 GeV vs 2-7 GeV) Budget: different order of magnitude (35 B RMB vs 4 B RMB) Civil Construction: Km vs Km in circumference Detector/Electronics:Many common detector/electronics R&D efforts can be shared. Accelerator: Need a lot more experts; Share R&D efforts on high luminosity e+e- collision technologies 28

29 Summary Super τ-c Facility (STCF): nature extension and a viable option for a post-bepcii HEP project Status of STCF project in China: Physics: Rich & unique for physics with c quark and τ leptons. Detector & Electronics: Significant progress in R&D at USTC Accelerator: Design group is formed and working hard, progress are ongoing. More experts are needed. Funding: 10M RMB for initial R&D from USTC; More communication to CAS and Local governments An international collaboration is under preparing Strategy & Plan Complete CDR in 2 years, TDR in 6 years Construction site: Currently open 29

30 Welcome to join the effort Thank you! 30

31 31 Backup Slides

32 30 Years of τ-c facility in China BEPCI ( ) Single Ring cm -2 s cm -2 s -1 BEPCII (2006 now) Double Ring BESI/I I BESIII BEPCII/BESIII are playing a leading role in tau-charm physics area and will end her mission in 5-7 years 32

33 Perspective of STCF SKEK B STCF BEPC-II BEPC A luminosity cm -2 s -1 at 4 GeV at 2028 is reasonable!!

34 Integral Luminosity of STCF No Synchrotron radiation mode, assume running time 9 months/year Assume data taking efficiency 90% cm -2 s s 270days 90% 2.0ab -1 /year 10 years data taking, total 20 ab -1 conservatively Excellent opportunities for the τ-charm physics BELLE-II Native question : Compete between STCF and BELLE-II? 34

35 Data samples Data samples with 1 ab -1 integral luminosity STCF have more yields /per luminosity STCF is expected to have higher detection efficiency Belle II can have larger integral luminosity Detail simulations are ongoing to study the potential for the physics research. 35

36 τ-c Factory ψ/y/hybrid(ccg) (1 ) produced in the e + e collision To determine the resonance parameters for the excited ψ or Y state Precisely measure the x-sec of inclusive/exclusive final states at different Ecms Charge parity c=+1 states produced via radiative transition from vector ψ/y The decay rate ψ(ns/nd) γx(3872), X(3940) Search for χ cj (2P) χ cj (3P) η c (3S) η c (4S) PLB 660, 315 (2008) PRL 112, (2014) B(ψ(3S) γχ cj ) = (7, 3, 1) x 10-4 for J=2,1,0 [Rev. Mod. Phys. 80, 1161 (2008) ] Search for new states from hadronic transition To search for Zc, Zcs, hc(2p). σ(y(4260) γx(3872)) 6pb 36

37 Expected τ µγ Br upper limit E(GeV) σ(nb) L(ab -1 ) N ττ (10 10 ) Total Dominant background τ decays, direct (τ + π + π 0 ν τ ) and combinatorial QED processes: e + e - µ + µ - γγ, e + e - e + e - µ + µ - γ Continuum hadron production e + e - qq ψ(2s) and D-meson decays σ E /E=1.5% σ E /E=2.5% Signal (Br=10-9 ) Muon background 7 11 Pion background Expected 90% CL upper limit for Br Expected 90% CL upper limit for Br with pion suppression by a factor of Supper-B Expected limit : -1 ( τ-pairs) 37

38 CP Violation in τ Decay CP violation is observed in B, D and K sectors to date, but not observed in lepton sector yet. The discovery of CPV in the tau sector would be a clean signature of NP One of the most promising CPV channels is τ K S π ν SM CP asymmetry from K S -K L mixing is expected to be : [Bigi & Sanda, PLB 625, 2005, Grossman &Nir JHEP 1204 (2012) 002] BaBar measurement [PRD 85, ] Belle measurement [PRL 107, ] A cp = (1.8±2.1± 1.4) W [ ] GeV Charge Higgs, new Scalar, W L -W R Mixings, LeptonQuarks? 38

39 Accelerator Physics Lattice Design: Ring and Interaction Region Lattice: β ξξ yy Non-linearity Focus Dynamic Aperture etc. Collective Effect Current Bunch Size Beam Instability 39

40 40 Listed in the future project of Anhui government 4. High Intensity Electron Positron Accelerator (HIEPA) R&D --- undertaken by USTC

41 Key Technologies Polarization RF Spin Polarized Electron Source Polarization Rotation and Maintenance for Rings and Final Focus Superconducting Cavities, Deflecting Cavities, Higher Harmonic Cavities, etc. Magnets High Quality Magnets with high strength, Superconducting Magnets and Solenoids Diagnostics and Control 41 Low Emittance Measurement, Transverse and Longitudinal Feedback, etc.

42 Collaboration Needed Accelerator Physics IR Design Polarization: Spin Rotation and Maintenance Collective Effects: Simulation and Bench Measurements Advanced Computational Accelerator Physics Accelerator Technologies Superconducting Cavities and Magnets Polarized Beam Sources Ultrahigh Vacuum Chamber with Small Aperture, Optimized Impedance and Low SEE 42