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Physics Results of Belle and Prospects for Belle II. Y.Sakai KEK. Reference for physics prospects. Physics at Super B Factory [arXiv:1002.5012] SuperB Progress Report [arXiv:.10081541]. Physics at B factory. B physics (~1.1nb) - CP violation & CKM - Rare decays
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Physics Results of Belle and Prospects for Belle II Y.Sakai KEK Reference for physics prospects • Physics at Super B Factory [arXiv:1002.5012] • SuperB Progress Report [arXiv:.10081541]
Physics at B factory • B physics(~1.1nb) • - CP violation & CKM • - Rare decays • Charm physics (~1.3 nb) • t physics (~0.9nb) • two-photon processes • New Resonance • - ordinary & exotics B Y(4S) _ B c t- _ c t- Variety of Physics ! Complement/Cooperative with t/Charm factory !
Goal/Milestones of B-factory Step1 2001 summer ! Discovery of CPV in B decays 2008 Step2 Precise test of KM and SM Step3 Search for NP Hints of NP Establish procedures (SUSY, Extra-dim…) SuperB-factory ~50 times more data (higher luminosity)
CP Violation Difference between particle & anti-particle (matter & anti-matter) Universe: almost “matter” only (no anti-matter) Big-Bang N(particles) = N(anti-particles) Sakhalov’s 3 conditions (1967): 1. baryon number violation 2. CP violation 3. existence of non-equiblium CPV is a key for Existence of Universe & us ! Andrei Sakharov (1921-1989)
W- dj Vkj uk Kobayashi-Maskawa: CPV CPV: due to acomplex phase in the quark mixing matrix CKM matrix Unitarity triangle * Vud Vub Wolfenstein representation 2 (a) * Vtd Vtb 3 (g) 1(b) Vcd Vcb *
Mt. Tsukuba KEKB Belle ~1 km in diameter KEKB Accelerator Belle detector Ares RF cavity e+ source 8 GeV e- x 3.5 GeV e+: 22mrad crossing Lpeak = 2.11x1034 Integ. Lum. ~1040 fb-1
Peak Luminosity 2.11x1034 1.21x1034 >1fb-1/day >1 M BB _
Data at B-factories (have to switch to new units, 1 ab-1) (fb-1) _ 772MBB “Intense Analysis Phase” _ 487MBB
Belle Detector • , p0 reconstruction e+-, KLidentification K/pseparation Aerogel Cherenkov Counter n = 1.015~1.030 Electromagnetic Calorimeter CsI(Tl) 16X0 3.5 GeV e+ TOF counter K/pseparation charged particle tracking 8.0 GeV e- Central Drift Chamber momentum, dE/dx 50-layers + He/C2H6 B vertex Muon / KLidentification Si Vertex Detector 4-layer DSSD KLm detector 14/15 layer RPC+Fe
15 countries, ~60 institutes, ~400 collaborators The Belle Collaboration Shinshu U. Sungkyunkwan U. U. of Sydney Tata Institute Toho U. Tohoku U. Tohuku Gakuin U. U. of Tokyo Tokyo Inst. of Tech. Tokyo Metropolitan U. Tokyo U. of Agri. and Tech. Toyama Nat’l College Torino Wayne S.U. VPI Yonsei U. Nagoya U. Nara Women’s U. National Central U. National Taiwan U. National United U. Nihon Dental College Niigata U. Osaka RCNP Osaka City U. Panjab U. Peking U. PNNL Riken Saga U. USTC Seoul National U. BINP Bonn U. Charles U. Chiba U. U. of Cincinnati Fu-Jen C.U. Giessen U. Gyeongsang Nat’l U. Goethingen Hanyang U. U. of Hawaii Hiroshima Tech. IHEP, Beijing IHEP, Moscow IHEP, Vienna Indiana U. ITEP Kanagawa U. KEK Karlsruhe U. KISTI Korea U. Krakow Inst. of Nucl. Phys. Kyungpook Nat’l U. EPF Lausanne Jozef Stefan Inst. / U. of Ljubljana / U. of Maribor Luther U. of Melbourne MPI
_ _ _ _ c _ J/y _ A d b b c t w B0 B0 B0 fcp _ B0 = w w t s b d d - K0 B0 A d Initial: B0 B0 _ B0 fcp B0 B0 CPV in B0 decays _ A Sanda Bigi Carter mixing Decay: A V*td V*cb V*td Interference Direct decay Mixing + Decay Weak Phase difference Oscillation frequency: Dmd (BH, BL) Decay-time dependent CPV
A B0 fcp = - B0 A * Vud Vub 2(a) * Vtd Vtb fcp B0 3(g) 1(b) B0 Vcd Vcb * CPV in B0 decays _ A Sanda Bigi Carter mixing Decay: A mixing -hfsin2f1 sin(Dmd Dt) _ B0 B0 Prob. ACP sin2f1 Decay (hf : CP eigenvalue) Dt (decay time)[ps]
Flavor-tag (B0 or B0 ?) Reconstruction J/(f,h’) e fCP e t=0 z Vertexing KS B0 B0 B0-tag B0-tag Dt z/cbg Time-dep CPV Measurement eeff ~30% sDt~140ps fit Extract CPV bg=0.425 (KEKB) 0.56 (PEP-II) same analysis method applied for all modes
31M BB _ B0 tag sin2f1: CPV observation 1137 events B0 tag 2001 Asymmetry First observed CPV in B (2001)
535M BB B0 tag _ B0 tag sin2f1: Precision meas. 14000 signals 2006 0.6870.0280.012 0.670 0.023 3.4% error !
Measurement of CKM Determination of UT Complete test of KM & SM Bpp, rp, rr * Vtd Vtb * bul-n Vud Vub 2 B0-mixing (Dmd) Bp/r l n (a) Brg 3 1 (g) (b) B- DcomK- * Vcd Vcb B0 (cc)K(*)0 B0 D(*)+p- bcl-n B0 D*+D(*)-(K) B D(*)l n Over constraint ! B experiments can provide all measurements !
Verification of KM for CPV All consistent CPV: caused by a single phase of CKM matrix Verified by B-factory experiments 2008 Physics Nobel Prize
Next Challenge In spite of Great Success of SM, there must be New Physics beyond SM at High Energy scale (SM is valid effective theory at current E-scale) Observed CPV in SM is not enough to explain matter dominance of Universe [>O(1010)] ! New Source of CPV should exists (beyond SM) One of Next important goals of Flavor Physics Energy Frontier Note) NP effects appear in Flavor Physics in various way !
Search for New Physics CPV in B provide Powerful tool for Search NP ( New Phase ) [ bsqq tCPV] Rare B decays excellent opportunities for NP search Loop diagram Penguins [bs(d) g, bs(d) l+l-] Key Decays involving t ( H) ANP ~ ASM(small/forbidden) t Decays(Lepton Flavor Violation = NP) : B-factory = t-factory SuperKEKB Establish analyses Hint of NP KEKB
NP : Precise CKM Still ~10% room for NP 50ab-1
- b b SM: bs Penguin phase = (cc) K0 d d d d - s s t X s s s s New Source of CPV: b sqq f,h’.. f,h’.. _ B0 + KS KS Vts Vtb * + New Physics with New Phase Sbs¹ Sbc , ADCP can ¹ 0 _ “b ccs: sin2f1” (SM reference)deviation 21
Summary of New CPV search B0 J/yK0 Reference point of SM No clear deviation seen in all modes (1~2s) New CPV effect can be seen with much larger data Super B-factory
SuperKEKB prospect BfK0 at 50/ab with ~present WA values MC J/K0 fK0 bs This would establish the existence of a NP phase in bs penguins. • Prospect • δ(Sbs) ~ 0.012 @ 50ab–1 Compelling measurement in a clean mode 23
KπPuzzle in B⁰/B⁺CPViolation _ B⁰ K⁻π⁺ B⁰ K⁺π⁻ B⁰ B⁻K⁻π⁰ B⁺ K⁺π⁰ B⁺ Expected to be same DAKp = A(K+p−)− A(K+p0) = −0.147 ± 0.028 S.-W. Lin et al. (The Belle collaboration), Nature 452, 332 (2008). 5.3σ deviation Hint of NP ?
Solutions to the DAKp Puzzle See Nature commentary by Michael Peskin T T Expectation from current theory T & P are dominant DAKp ~ 0 P C PEW T P Enhancement of large PEW Newphysics • Enhancement of large C with large strong phase to T strong inter. !? Chiang et. al. 2004 Li, Mishima & Sanda 2005 Yoshikawa 2003; Mishima & Yoshikawa 2004; Buras et. al. 2004, 2006; Baek & London 2007; Hou et. al. 2007; Feldmann, Jung & Mannel 2008 Can this issue be resolved in a model-independent way by experiment ?
Model-indep. Sum Rule A(K0p0) B →Kp A(K0p+)=0.009 ±0.025 A(K+p0)=0.050 ±0.025 A(K+p-)=-0.098 ±0.012 A(K0p0)=-0.01 ±0.10 HFAG, ICHEP08 dA(K+p0) sum rule A(K0p+) measured (HFAG) expected (sum rule) Sum rule proposed by: M. Gronau, PLB 627, 82 (2005); D. Atwood & A. Soni, Phys. Rev. D 58,036005(1998). 26
SuperKEKB prospect Belle II, 50 ab-1 A(K0p0) dA(K+p0) Important to measure A(K0p0) precisely sum rule A(K0p+) B →K0p0 : main syst. uncertainty full systematics treated as non-scaling (conservative) 27
Charged Higss Hunting B-Factory: Variety of Modes sensitive to Charged Higgs Some are only possible at B-Factory
657M BB Inclusive b s g SM Fully Inclusive measurement Data Background subtracted
H+ Search: B+ + (Decays with Large Missing Energy) Sensitivity to new physics from charged Higgs The B meson decay constant, determined by the B wavefunction at the origin (|Vub| taken from indep. measurements.)
e+ _ Always > 2 neutrinos appear in B t n decay (4S) B- B+ ne n n B++, +e+e B-X B->ν: Experimental Challenge Signature : 1 track +invisible Experimental Challenge !
e+ (4S) B- B+ ne n n B++, +e+e B-X B->ν: Experimental Challenge Tag-side: Full reconstruction Also for B D(*)tn B Knn _ Can be measured only by B-Factory !
B->ν Results 2.8s
B D(*)tn • B D*tn : Lepton (t) polarization info. • Expected B ~ 1.4% in SM (large) • But, large background (D*(**)ln, D*X) [e.g. D.S.Hwang EPJ C14,271(2000)] • Always involve > 2 n (Missing E):
657M BB B D(*)tn Results B0 D*-t+n [PRL 99, 191807(2007)] First Observation ! [PRD 82, 0720005(2010)]
Constraints on charged Higgs U. Haisch, hep-ph/0805.2141; ATLAS curve added by Steve Robertson Also see (MSSM),D. Eriksson,F.Mahmoudi and 0.Stal
- D0-D0 Mixing Quark level: Box diagram (~ B0-mixing) SM box: O(10-9) +Long distance: O(10-3~10-2) x=Dm/G y=DG/2G Large mixing, |x|>>|y|, CPV New Physics ! • Only mixing with up-type quark complementarity to down-type FCNC
D0-mixing : yCP Decays to CP eigenstates D0→ K+K- / p+p- “lifetime” difference First Evidence (2007) ! PRL 98, 211803 (2007), 540fb-1
D0-mixing : Wrong sign D0K-p+ : normal decay D0K+p- : Mixing Signal But, two sources need decay-time analysis to extract D0-D0 mixing likelihood contours _ “Wrong Sign” 3.9s 1s 400fb-1 2s PRL 96, 151801 (2006) BaBar, PRL 98, 211802 (2007), 384fb-1 3s 4s (0,0) CL 96.1% 5s CDF, PRL 100, 121802 (2008), 1.5fb-1
D0-mixing : t-dep. Dalitz t D0KSp+p- most precise x meas. y (%) x (%) Belle, PRL 99, 131803 (2007), 540fb-1
D0-mixing : Summary HFAG x~y~1% ~ SM limit ! Mixing parameters global fit to observables, only KK/pp, Kp and Kspp projected sensitivities included (no external constraints, e.g. dKp)
D0-mixing : prospect 1 s @ 50 ab-1 A.G. Akeroyd et al., arXiv:1002.5012 Mixing parameters global fit to observables, only KK/pp, Kp and Kspp projected sensitivities included (no external constraints, e.g. dKp) 1 s @ 50 ab-1
Vub’* Vcb’ Vcb’ Vub’* u c W+ D0 b’ D0 b’ W- c u Constraints from D0-mixing 4th generation of fermions R-parity violating SUSY D0 D0 R couplings lines of constant |x| allowed area [GeV] mb’ [GeV] allowed area lines of constant |x| |Vub’Vcb’| E. Golowich et al., PRD76, 095009 (2007) E. Golowich et al., PRD76, 095009 (2007)
Hints/Sensitive to NP CPV in b s Penguin? A(B Kp) Puzzle Forwad-Backword Asy,.B K*ℓ+ℓ− C7=−C7SM SM CKM Unitarity Triangle fL(B VV) ≠ 1 Large D0-mixing tree Theoretical calculations using Vub, Dmd,eK ….. penguin Direct measurement
Identification of NP type Identify by the pattern of deviations from SM SUSY models … Measurements … ✔: deviation from SM [based on T.Goto et.al. PRD77, 095010(2008)]
Physics at Super B-factory is “DNA chip of New Physics” + LHC,… D. Hitlin
~ ~ c c ~ ~ q q ~ _ g q Energy Frontiervs Flavor Physics Direct Production by High Energy Coll. Virtual Production via Quantum Eff. s p p b g ~ n q l- Luminosity Frontier Tunnel effect Energy Frontier Off-diagonal terms Diagonal terms Higher Energy Scale Can be searched (even if LHC finds no New Physics)
LHC observes NP in TeV scale Complementarity of Flavor Physics (Luminosity Frontier) & Energy Frontier • Identify NP typeSUSY, Extra Dim. Little Higgs,..? • Mechanism of Symm. Breaking • CPV via NP Era of NP Exploration SU(5)+R degenerate MSSM+R degenerate SU(5)+R non-degenerate New Physics Belle II = Compass U(2)FS MSSM+R non-degenerate Higgs Standard Model top Energy Frontier Luminosity Frontier Map W, Z S.Nishida