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Super KEKB Masashi Hazumi (KEK) Super KEKB Masashi Hazumi (KEK) An executive summary to explain 5W1H: • What is Super KEKB ? • When will Super KEKB start ? • Who are we ? • Where do we stand ? • Why do we need Super KEKB ? • How is Super KEKB designed ? WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) What is Super KEKB ? • A high luminosity~1km upgrade of the existing KEKB Collider and the Belle Detector. • Target luminosity of 1035 cm-2s-1 (x 20 as large as the present level), which is quite feasible ! • Physics programs complementary and competitive to hadron experiments. – Beyond SM (e.g. SUSY flavor physics) nt ! – Final states with neutrals. ronme n Envi – Inclusive measurements. Clea – Direct CP Violation in many modes. WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) When will Super KEKB start ? • Commissioning in 2006 Without Super KEKB WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) When will Super KEKB start ? 3 With Super KEKB • Commissioning in 2006 2 • Running in 2006-2009 • Integrated luminosity /year > 1000 fb-1 ) -1 • Integrated luminosity by 2009 > 3000 fb-1 (3 ab-1) (ab – Number of BB pairs > 3 x 109 1 2007 2008 2009 WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) Who are we ? Where do we stand ? • “Expression of Interest” (EoI) with more than 200 people from 42 institutions. EoI will be available as a hep-ex article soon. WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) Why do we need Super KEKB ? • Ideal place to study flavor physics beyond the SM. – New amplitudes (mostly FCNC) – New CP violating phases B J l 0 • Final states with neutrals ( , , , KL, ) – B0 J D , l (), K* 0 J – B Ks, ’Ks (for new CP violating phases) GeV/c2 0 J 0 0 – B (for precise measurement of sin2 2) – B J l • Inclusive measurements – b J sl+l–, b J s, b J d GeV/c2 • Direct CP violation in many modes CPV factory ! • 3000fb-1 enough for many cases. Important to achieve it as early as possible. • If SUSY is discovered at LHC, our target will be clearer – SUSY flavor problem – SUSY CP problem WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) Example: BJD , Charged Higgs at tree level 100 200 300 MH(GeV) Full reconstruction technique (eff ~ 0.2%) will be used. WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) Example: Search for new CP-violating phases ( NP) CP eigenstates at Belle as of July 2001 • For sin21 analysis sin21 = 0.99 ±0.14 ±0.06 candidates purity int. lumi. J/ Ks(J + ) 457ev. 97% 29.1fb-1 Other (cc) Ks 290ev. 84% 29.1fb-1 -1 J/ KL 569ev. 61% 29.1fb • “Rare” decays Penguin Tree (JK+K ) Ks 10ev. 80% 21.3fb-1 b J sss (uus) ’Ks 26ev. 63% 10.4fb-1 b J suu, sdd uus D*D(*) 27ev. 82% 21.3fb-1 b J ucd, ccd Ks 0 12ev. 67% 10.4fb-1 b J dds, uus, dds WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) Expected CP Reach for NP 2001 2005 2009 We can reach the level of hadronic uncertainties. Hadronic uncertainties in new phase measurements Grossman, Isidori, Worah (1998), London and Soni (1997) Hadronic uncertainties in sin21 measurements WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) Goals of Rare B Decay Program 1) Discover / Establish “Direct” CPV 2) Precise Measurements of CKM elements : J angles and lengths 3) Beyond SM BJ , BJ l * V V * Vtd Vtb f : BJ l J ud ub 2 B B Ds (BJ - J - 0 B DCPK 3 1 B J’Ks, Ks BJ /K 0 *+ (*)- V V * B J D D (K) BJ 3 body cd cb B0 J D(*)-l+ dileptons J J + - EM/EW Penguin : B Kx B Kl l WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) Sensitivity Comparisons WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) How is Super KEKB designed ? • Peak luminosity: 10^35 cm-2s-1 (10^9 BB pairs/year) – Squeeze beam size at IP(y*) (6.5~7 3 mm) – Squeeze bunch length (5~6 3 mm) – Larger crossing angle (2 x 11 2 x 15 mrad) Evolution rather than Revolution – Larger beam currents, overcoming photo-electron instability WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) Injection Linac • Two options to achieve 8GeV positrons – C-band option 21 40 MV/m – Recirculation option WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) Belle Detector Performance Silicon Vertex Detector (SVD) Impact parameter resolution : 55 m for p=1GeV/c at normal incidence Central Drift Chamber (CDC) 2 2 2 2 ( Pt/Pt) = (0.0019Pt) + (0.0034) (Pt in GeV/c) K/ separation with dE/dx in CDC ( dE/dx =6.9%) TOF ( TOF = 95ps) Aerogel Cerenkov (ACC) 6m Efficiency = ~85%, Fake rate = ~10% up to 3.5GeV/c , eM with CsI crystals (ECL) E/E ~ 1.8% @ E=1GeV eM : effic. > 90% w/ ~0.3% fake for p > 1GeV/c M KL and with KLM (RPC chambers) M : effic. > 90% with ~2% fake at p > 1GeV/c WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) Detector upgrade issues Present technologies are sufficient in most of the cases. However, we prefer to improve the performance as much as possible. WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) Vertex Measurements • Better vertex resolution for background rejection – Beampipe radius of 1cm – Rad. Hard ( ~7 MRad/year) – Occupancy should be low enough. • DSSDs not possible for the innermost layer Pixel Typical configuration (r view) • DSSDs should cover larger volume (in radius) • Pixel candidates – Monolithic Active Pixel Sensor (MAPS) – Hybrid pixel – CCD WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) Particle Identification TOP counter principle • Ring imaging for improvement • Two R&Ds ongoing – Time-of-Propagation (TOP) counter – Aerogel RICH (for endcap) WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) Summary • Super KEKB is a major upgrade of the KEKB collider and the Belle detector. • Target luminosity is 1035 cm-2s-1, which is quite feasible. • Major upgrade in 2006. The experiment will start in a timely manner. • 3 x 109 BB pairs (3000 fb-1) with 3 years of data taking. • Unique B physics programs to study “beyond the SM” – Flavor problem and CP problem • Leading faciliy for charm and tau physics • Precision for bread-and-butter CPV measurements comparable to hadron experiments. • EoI preparation just finished. Design work has just started. Your participation is very very welcome. WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) Backup Slides WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) SUSY scenario WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) KEKB’s Special Features • Small beam sizes low beam currents – 4.5x1033 with less than 1 Amp in each ring • M 11 mrad beam crossing angle 22mrad + e e- – No strong bending magnets near the IR – Fewer spent particles into Belle – Synchrotron X-rays easily handled WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) Particle Identification • Clear K/ separation is essential to distinguish decays. – DK/D dE/dx (CDC) ∆ dE/dX ~7 % –K / /KK etc. TOF (only Barrel) ∆ T ~ 100 ps (r = 125cm ) Barrel ACC n = 1.010 ∼ 1.028 –K*/ Endcap ACC n = 1.030 ( only flavor tagging ) 01234 p (GeV/c) • Belle use dE/dx + ToF + ACC 1 – Wide momentum coverage 0.9 iciency f – ACC: Aerogel Cherenkov Ef 0.8 – Combined into likelihood; 0.7 0.6 K track (eff.) L(K) ~1 for K 0.5 PID(K)= 0.4 L(K) + L(π) track (fake) ~0 for 0.3 0.2 • Calibration with D*+ →D0 +, D0 →K- 0.1 0 0 0.5 1 1.5 2 2.5 3 3.5 4 P (GeV/c) WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) sin2 1 2 3 1 WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) 0J - + Towards |Vub | : B l Important to check large sin2 1 update 21.3 fb-1 B0J -l+ Missing mass recon. 2 2 2 Mmiss = Emiss -pmiss < 2 GeV GeV/c2 p > 1.2 GeV l M pl + p > 3.1 GeV 107 16 signals Br = (1.28 M 0.2 M 0.26) x10-4 (trk/g rec.) GeV/c2 WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) J b s Penguin or NP ? Large Br for ’K, K* (found by CLEO): confirmed 0J *0 +5.4 M -6 21.3 fb-1(New) Br(B K ) = (21.2 -4.7 2.0)x10 +J + +12 M -6 Br(B ’K ) = (79 -1 1 9)x10 -1 0 0 +19 -6 10.4 fb Br(B J’K ) = (55 -1 6 M 8)x10 [to PLB] Larger than theoretical expectation Br(B+JK+) = (11.2 +2.2 M 1.4)x10-6 -2.0 21.3 fb-1 0J 0 +3.4 M -6 (update) Br(B K ) = (8.9 -2 . 7 1.0)x10 Time dependent CPV : 1 or New phase/Physics WIN02, 21-26 Jan., 2002, Christchurch, New Zealand Masashi Hazumi (KEK) New phases in b s (d) penguins M. Ciuchini, et al. “Gold-plated modes” are Ks and ’Ks WIN02,CPV 21-26 Jan., in 2002, b Christchurch, s New Zealandalso importantMasashi Hazumi (KEK) Clear Manifestation of New Physics ! Acp(J/ Ks) U Acp(Bcp with Penguin) b c c No new phase vs.
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