1 / 67

Status and Prospects of Super KEKB and Belle II Zdenek Dolezal Charles University in Prague for Belle II

Status and Prospects of Super KEKB and Belle II Zdenek Dolezal Charles University in Prague for Belle II. Belle II Graphic by Rey.Hori. Contents. Physics case for a Super B factor y SuperKEKB/Belle-II@KEK Accellerator D etector S tatus and prospects of the project. B 0 tag. _.

ornice
Download Presentation

Status and Prospects of Super KEKB and Belle II Zdenek Dolezal Charles University in Prague for Belle II

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Status and Prospects ofSuper KEKB and Belle IIZdenek DolezalCharles University in Praguefor Belle II Belle II Graphic by Rey.Hori

  2. Contents • Physics case for a Super B factory • SuperKEKB/Belle-II@KEK • Accellerator • Detector • Status and prospects of the project ECFA Plenary 24/11/2011

  3. B0 tag _ B0 tag B-factories: a success storya huge success! Measurements of CKM matrix elements and angles of the unitarity triangle Observation of direct CP violation in B decays Measurements of rare decays (e.g., Btn, Dtn) bs transitions: probe for new sources of CPV and constraints from the bsg branching fraction Forward-backwardasymmetry(AFB) in bsllhas become a powerfull tool to search for physics beyond SM. Observation of D mixing Searches for rare t decays Observation of newhadrons ECFA Plenary 24/11/2011

  4. B e+ e- Dz ~ cbgtB ~ 200mm B Asymmetric B factories √s=10.58 GeV Υ(4s) Υ(4s) BaBarp(e-)=9 GeV p(e+)=3.1 GeVbg=0.56 Bellep(e-)=8 GeV p(e+)=3.5 GeVbg=0.42 Belle IIp(e-)=7 GeV p(e+)=4 GeVbg=0.28 ECFA Plenary 24/11/2011

  5. Full Reconstruction Method Fully reconstruct one of the B’s to Tag B flavor/charge Determine B momentum Exclude decay products of one B from further analysis Decays of interest BXu l n, BKn n BDtn, tn B e- (8GeV) e+(3.5GeV) Υ(4S) p B full reconstruction BDpetc. (neural net reconstruction)  Offline B meson beam! Powerful tool for B decays with neutrinos ECFA Plenary 24/11/2011

  6. “Super” B Factory strategy B factories  is SM with CKM right? Super B factories  How is the SM wrong? • Need much more data (two orders!) because the SM worked so well until now  Super B factory However: it will be a different world in four years, there will be new knowledge fromLHCb, BESIII, ... Still, e+e- machines running at (or near) Y(4s) will have considerable advantages in several classes of measurements, and will be complementary in many more Recent update of the physics reach with 50 ab-1 (75 ab-1): Physics at Super B Factory (Belle II authors + guests) hep-ex > arXiv:1002.5012 SuperB Progress Reports: Physics (SuperB authors + guests) hep-ex > arXiv:1008.1541

  7. Need O(100x) more data Next generationB-factories SuperKEKB+ SuperB 1036 40 times higher luminosity KEKB PEP-II ECFA Plenary 24/11/2011

  8. Charged Higgs limits from B- t- nt H+ t+  limit on charged Higgs mass vs. tanb Belle SuperB 50 ab-1 Atlas, 30 fb-1 ECFA Plenary 24/11/2011

  9. Why FCNC decays? Flavour changing neutral current (FCNC) processes (like bs, bd) are forbidden at the tree level in the Standard Model. Proceed only at low rate via higher-order loop diagrams. Ideal place to search for new physics. - b→sg, sll, snn example of constraints on right-handed currents with B →K(*)nn with 50 ab-1 current constraints ECFA Plenary 24/11/2011

  10. Physics at a Super B Factory Full ohysics case of Belle II documented in arXiv:1002.5012 ECFA Plenary 24/11/2011 There is a good chance to see new phenomena; • CPV in B decays from the new physics (non KM). • Lepton flavor violations in t decays. They will help to diagnose (if found) or constraint (if not found) new physics models. Even in the worst case scenario (such as MFV), Btn, Dtn can probe the charged Higgs in large tanb region. Physics motivation is independent of LHC. • If LHC finds NP, precision flavor physics is compulsory. • If LHC finds no NP, high statistics B/t decays would be a unique way to search for the TeV scale physics.

  11. Super B factory: an important part of abroad unbiased approach to New Physics n experiments, gm-2, mgeg, etc. LHC, ILC Mass spectrum, interactions n mass and mixing, CPV, and LFV Lepton sector Energy frontier New physics Quark sector • LFV, • t CPV Flavor mixing, CP phases Super B factory, LHCb, K experiments… ECFA Plenary 24/11/2011

  12. ECFA Plenary 24/11/2011 How to do it? Upgrade KEKB & Belle

  13. ECFA Plenary 24/11/2011 Schedule (Beam starts in Fall 2014) Goal of Belle II/SuperKEKB Integrated luminosity (ab-1) We will reach 50 ab-1 in 2022 9 months/year 20 days/month Commissioning startsin 2015. Shutdown for upgrade Peak luminosity (cm-2s-1) Year

  14. ECFA Plenary 24/11/2011 Belle detector Ares RF cavity e+ source The KEKB Collider & Belle Detector • e- (8 GeV)on e+(3.5 GeV) • √s ≈ mΥ(4S) • Lorentz boost: βγ=0.425 • 22 mrad crossing angle • Operating 1999-2010 • Integrated lumi 1015/fb SCC RF(HER)‏ Peak luminosity (WR!) : 2. 1 x 1034 cm-2s-1 ARES(LER)‏

  15. ECFA Plenary 24/11/2011 The keyfactor in KEKB performance: crab cavity 22 mrad. crossing crab crossing Installed in the KEKB tunnel (February 2007) Electron Ring Positron Ring 15

  16. ECFA Plenary 24/11/2011 sx~100mm, sy~2mm sx~10mm, sy~60nm Super KEKB in nano-beam scheme • To increase luminosity: →squeeze beams to nanometer scale and enlarge crossing angle (minimize by*) →decrease beam emittance (keep current ξy) • Squeezing beams in stronger magnetic field saturated by hourglass effect→ intersect bunches only at highly focused region I: beam current b*: trajectories envelope at IP xy  (by */ey ) beam-beam parameter e: beam emittance σ*: beam size RL,Rξy: geometrical reduction factors (crossing angle, hourglass effect)

  17. ECFA Plenary 24/11/2011 SuperKEKB collider e+ 4GeV 3.6 A Colliding bunches Belle II New IR e- 7GeV 2.6 A New superconducting /permanent final focusing quads near the IP SuperKEKB New beam pipe & bellows Replace short dipoles with longer ones (LER) Add / modify RF systems for higher beam current Low emittance positrons to inject Positron source Damping ring Redesign the lattices of HER & LER to squeeze the emittance New positron target / capture section Low emittance gun TiN-coated beam pipe with antechambers Low emittance electrons to inject Target: L = 8x1035/cm2/s

  18. ECFA Plenary 24/11/2011 Requirements for the Belle II detector Critical issues at L= 8 x 1035/cm2/sec 4Higher background ( 10-20) 4Higher event rate ( 10) 4Special features required • radiation damage and occupancy • fake hits and pile-up noise in the EM - higher rate trigger, DAQ and computing • low pm identification fsmm recon. eff. • hermeticityfn “reconstruction” Result: significant upgrade

  19. ECFA Plenary 24/11/2011 CDC: Tracking + dE/dx small cell + He/C2H6 → remove inner lyrs large outer radius faster timing smaller cell 6 Si vtx. det. 4 lyr. DSSD →2 DEPFET pixel lyrs. + 4 lyr. DSSD Belle to Belle II Upgrade TDR: KEK Report 2010-1 ECL: CsI(Tl) 16X0 SC solenoid 1.5T PID: Aerogel Cherenkov counter + TOF counter pure CsI (endcap)‏ new electronics (waveform sampling) / KL detection 14/15 lyr. RPC+Fe →“TOP”(barrel) + Aerogel RICH (EC) →scint. bars in endcap + SiPM →New DAQ and computing system

  20. ECFA Plenary 24/11/2011 Interaction Region Design

  21. ECFA Plenary 24/11/2011 Vertex detector Beam Pipe r = 10mm DEPFET pixels Layer 1 r = 14mm Layer 2 r = 22mm DSSD Layer 3 r = 38mm Layer 4 r = 80mm Layer 5 r = 115mm Layer 6 r = 140mm Imp.par. z0 Belle: 20mm Prototype DEPFET pixel sensor and readout Belle II: <10mm DCDB R/O chip DEPFET matrix Switcher control chip Mechanical mockup of pixel detector 21

  22. DEPFETs in Belle II radius pixel thickness • Layer 1 r = 14mm 50x50mm2 75mm(0.18%X0) • Layer 2 r = 22mm 50x75mm2 75mm total of 8 M pixels Mechanical mockup Power consumption in sensitive area: 0.1W/cm² => air-cooling sufficient

  23. Silicon Vertex Detector • DSSD Layer 3 r = 38mm Layer 4 r = 80mm Layer 5 r = 115mm Layer 6 r = 140mm Bonding wires for top side strips Kapton flex circuit Fanout for back side strips APV25 chips Cooling tube

  24. longer lever arm Improve momentum resolution and dE/dx Central Drift Chamber small cell normal cell 18 mm 10 mm 10~20 mm 6~8 mm Belle Belle II

  25. CDC Readout New electronics has been designed and tested The drift time is measured with an FPGA-based TDC A slow FADC (around 30MSa/s) measures the signal charge. X-T relation s~100mm Residual distribution

  26. ECFA Plenary 24/11/2011 Barrel PID: Time of propagation (TOP) counter • Cherenkov ring imaging with precise time measurement. • Reconstruct angle from one coordinate and the time of propagation of the photon • Quartz radiator (2cm) • Photon detector (MCP-PMT Hamamatsu 16ch MCP-PMT)‏ • Good time resolution < 35 ps

  27. ECFA Plenary 24/11/2011 Endcap PID: Aerogel RICH (ARICH) End-cap PID: Aerogel RICH • Proximity focusing RICH with aerogel radiator Aerogel Test Beam setup Hamamatsu HAPD Q.E. ~33% (recent good ones) 200mm Cherenkov photon Aerogel radiator n~1.05 Hamamatsu HAPD + new ASIC Clear Cherenkov image observed

  28. ECFA Plenary 24/11/2011 ECL upgrade • Increase of dark currents due to neutron flux • Fake clusters & pile-up noise Barrel • Barrel: 0.5s shaping + 2MHz w.f. sampling. • Endcap (may have to be staged): pure CsI + photopentods 30ns shaping + 43MHz w.f. sampling x1/1.5 BW endcap x1/5 Pure CsI & photopentods

  29. ECFA Plenary 24/11/2011 KLM upgrade Scintillator-based KLM (endcap)‏ • Two independent (x and y) layers in one superlayer made of orthogonal strips with WLS read out • Photo-detector = avalanche photodiode in Geiger mode (SiPM) • ~120 strips in one 90º sector (max L=280cm, w=25mm)‏ • ~30000 read out channels • Geometrical acceptance > 99% y-strip plane Iron plate x-strip plane Mirror 3M (above groove & at fiber end)‏ Optical glue increase the light yield ~ 1.2-1.4‏ Aluminium frame WLS: Kurarai Y11 1.2 mm GAPD Strips: polystyrene with 1.5% PTP & 0.01% POPOP Diffusion reflector (TiO2)‏ September 5, 2008 NIKHEF Toru Iijima, INSTR08 @ BINP, Novosibirsk 2008/2/28 29

  30. Endcap KLM upgrade Replace RPCs with Scintillator-based approach y-strip plane Iron plate x-strip plane Mirror 3M (above groove & at fiber end) Optical glue increase the light yield ~ 1.2-1.4) Aluminium frame WLS: Kurarai Y11 1.2 mm GAPD Strips: polystyrene (with 1.5% PTP & 0.01% POPOP) Diffusion reflector (TiO2) • Two independent (x and y) layers per superlayer made of orthogonal strips with WLS read out • Photo-detector = avalanche photodiode in Geiger mode (SiPM) • ~150 strips in one 90º sector (max L=280cm, w=25mm) • ~16800 read out channels • Geometrical acceptance > 99% Toru Iijima, INSTR08 @ BINP, Novosibirsk 2008/2/28 30

  31. ECFA Plenary 24/11/2011 Belle II Computing Model Common frameworkfor DAQ and offline basf2 based on root I/O Grid-based Distributed Computing Raw Data Storageand Processing Belle II detector MC Production(optional) MC Production and NtupleProduction NtupleAnalysis 31

  32. KEKB being disassembled after 11 years of successful run

  33. Belle is also being disassembled to revive as Belle-II.

  34. ECFA Plenary 24/11/2011 The Earthquake M22 bolts!! As is well known, Japan suffered a terrible earthquake and tsunami on　March 11,　which has caused tremendous damage, especially in the Tohoku area. Fortunately,　all KEK personnel and users were safe. The injection linac did suffer significant but manageable damage, and repairs are underway. The damage to the KEKB main rings appears to be less serious, though non-negligible. No serious damage has been reported so far at Belle.

  35. ECFA Plenary 24/11/2011 KEKB/Belle status Fortunately enough: • KEKB stopped operation in July 2010, and the low energy ring was to a large extent disassembled • Belle was rolled out in its parked position The 1400 tons of Belle moved by ~6cm (most probably by 20cm in one direction, and 14cm back)... We are checking the functionality of the Belle spectrometer (in particular the CsI calorimeter), so far checks out OK in LED and cosmic ray tests The lab (Tsukuba campus) has to a large extent recovered from the earthquake, back to normal operation – very little impact on the upgrade schedule

  36. ECFA Plenary 24/11/2011 Accelerator upgrade + 50% of the detector - ca320 M€ approved in March 2011 Funding of the contribution to the remaining 50% of the detector – ca20 M€ - in many other countries approved or on the way First MoU between German FAs and KEK signed SuperKEKB/Belle II Funding Status

  37. ECFA Plenary 24/11/2011 A very strong group of ~400 highly motivated scientists! Next open general meetings: KEK March 14-17 2012 Bad Aibling (Bavaria) July 26-29 2012

  38. ECFA Plenary 24/11/2011 Belle II Collaboration (Europe) • Significant European participation + funding • 19 institutes with ca 130 physicists (A, CZ, D, E, PL, RUS, SLO) • Spokesperson P. Križan, Ljubljana

  39. ECFA Plenary 24/11/2011 SuperKEKB/Belle II aims for (discovering and) understanding the New Physics. Target luminosity of SuperKEKB is 8x1035/cm2/s, will provide 50ab-1 by 2021-2022. Belle II gives similar or better performance than Belle even under higher beam background. Project has been approved by Japanese Government. KEKB/Belle operation has been terminated and construction started. Next collaboration meeting: 14-17 March 2012 @KEK, still open to everyone. New collaborators welcome! Project officially started with the Groundbreaking ceremony last week Summary 40

  40. ECFA Plenary 24/11/2011 Many thanks to CERN DG for his nice words! Groundbreaking ceremonyNov 18 2011, KEK

  41. ECFA Plenary 24/11/2011 Groundbreaking ceremonyNov 18 2011, KEK

  42. ECFA Plenary 24/11/2011 Backup

  43. Luminosity at the B Factories Fantastic performance much beyond design values! ECFA Plenary 24/11/2011

  44. ECFA Plenary 24/11/2011 Belle’06 (~0.5ab-1) 5ab-1 50ab-1 S(K0) 0.22 0.073 0.029 S(’K0) 0.11 0.038 0.020 S(KSKSKS) 0.33 0.105 0.037 Search for H± in B→ S(KS0) 0.32 0.10 0.03 Br(Xs) 13% 50ab-1 assume 5 discovery ACP(Xs) 0.058 0.01 0.005 C9 [AFB(K*ll)] --- 11% 4% C10 [AFB(K*ll)] --- 13% 4% Br(B+ → K+) <9Br(SM) 33ab-1 for 5 discovery Upper limits Br(B+ →) 3.5 10% 3% Br(B+ →) <2.4Br(SM) 4.3ab-1 for 5 discovery Br(B+ → D) --- 7.9% 2.5% Br( →) <45 <30 <8 Br( →) <65 <20 <4 Br( → 3) <209 <10 <1 sin21 0.026 0.016 0.012 2 () 68°ー95° 3° 1° CKM at 50ab-1 3( Dalitz) 20° 7° 2.5° Integ. Lum.（ ab-1） Vub (incl.) 7.3% 6.6% 6.1% Reach of B factories Upgraded KEKB Physics reach at a Super KEKB/Belle CP asymmetry in B→KKK, K and ’K ★■● 0.3 (3 discovery lim.) 0.1 Present exp. limits Deviation from SM 0.03 5ab-1 50ab-1 0.01 1 10 100 Integ. luminosity (ab-1) X10-9 45 Physics at Super B Factory [hep-ex/0406071] Currently being updated.

  45. AFB(BK* l+ l-)[q2] at a Super B Factory current 5 ab-1 C7SM C7=-C7SM 0 2 4 6 8 10 12 14 16 18 4Zero-crossing q2 for AFB will be determined with a 5% error with 50ab-1. Strong competition from LHCb and ATLAS/CMS ECFA Plenary 24/11/2011

  46. ECFA Plenary 24/11/2011 Comparison with the LHCb LHCb has advantages in… eehas advantages in… CPV inB→JKS CPV inB→KS, ’KS,… CPV inB→KS0 Most of B decays not including  or  B→K, , D(*) Time dependent measurements of BS Inclusive b→s, see → and other LFV B(s,d)→ D0D0mixing Bcand bottomed baryons Complementary!!

  47. ECFA Plenary 24/11/2011 Item Gain Purpose beam pipe x 1.5 high current, short bunch, electron cloud 3 years shutdown IR(*x/y=20cm/3 mm)‏ x 1.5 small beam size at IP low emittance(12 nm)‏ x → 0.5 x 1.3 mitigate nonlinear effects with beam-beam crab crossing x 2 mitigate nonlinear effects with beam-beam RF/infrastructure x 3 high current DR/e+ source x 1.5 low* injection, improve e+ injection charge switch x ? electron cloud, lower e+ current Luminosity gain and upgrade items (preliminary)

  48. ECFA Plenary 24/11/2011 Item Object Oku-yen ~1.0 M$ Luminosity New beam pipes Enable high current Reduce e-cloud 178 (incl. BPM, magnets, etc.) x 1.5 New IR Small β* 31 x 2 e+ Damping Ring Allow injection with small increase e+ capture 40 incl. linac upgrade if not, x 0.75 More RF and cooling systems High current 179 (incl. facilities) x 3 Crab Cavities Higher beam-beam param. 15 x (2 – 4) Major KEKB components • Tunnel already exists. • Most of the components (magnets, klystrons, etc.) will be re-used. Items are interrelated.

  49. ECFA Plenary 24/11/2011

More Related