Physics Results of Belle and Prospects for Belle
Physics Results of Belle and Prospects for Belle II Y. Sakai KEK Reference for physics prospects • Physics at Super B Factory [ar. Xiv: 1002. 5012] • Super. B Progress Report [ar. Xiv: . 10081541] 1
Physics at B factory • B physics (~1. 1 nb) - CP violation & CKM - Rare decays • Charm physics (~1. 3 nb) B Y(4 S) _ B c - • physics (~0. 9 nb) _ c - • two-photon processes • New Resonance - ordinary & exotics Variety of Physics ! Complement/Cooperative with /Charm factory ! 2
Goal/Milestones of B-factory Step 1 Discovery of CPV in B decays 2001 summer ! 2008 Step 2 Precise test of KM and SM Step 3 Search for NP Hints of NP (SUSY, Extra-dim…) Establish procedures ~50 times more data (higher luminosity) 3
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) 4
Kobayashi-Maskawa: CPV: due to a complex phase in the quark mixing matrix CKM matrix Wdj Vkj uk Unitarity triangle Wolfenstein representation * Vud Vub 2 (a) 3 (g) Vtd Vtb* 1(b) * Vcd Vcb 5
KEKB Accelerator Mt. Tsukuba KEKB Belle detector Belle ~1 km in diameter Ares RF cavity e+ source 8 Ge. V e- x 3. 5 Ge. V e+: 22 mrad crossing Lpeak = 2. 11 x 1034 Integ. Lum. ~1040 fb-1 6
Peak Luminosity 2. 11 x 1034 1. 21 x 1034 >1 fb-1/day _ >1 M BB 7
Data at B-factories -1 (fb-1) ( have to switch to new units, 1 ab ) _ 772 MBB “Intense Analysis Phase” _ 487 MBB 8
Belle Detector , p 0 reconstruction e+-, KL identification Electromagnetic Calorimeter Cs. I(Tl) 16 X 0 K/p separation Aerogel Cherenkov Counter n = 1. 015~1. 030 3. 5 Ge. V e+ TOF counter K/p separation 8. 0 Ge. V e- B vertex Si Vertex Detector 4 -layer DSSD charged particle tracking Central Drift Chamber momentum, d. E/dx 50 -layers + He/C 2 H 6 Muon / KL identification KL m detector 14/15 layer RPC+Fe 9
The Belle Collaboration 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 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. Shinshu U. Sungkyunkwan U. U. of Sydney Tata Institute Toho U. Tohoku U. Tohuku Gakuin U. U. of Tokyo Inst. of Tech. Tokyo Metropolitan U. Tokyo U. of Agri. and Tech. Toyama Nat’l College Torino Wayne S. U. VPI Yonsei U. 15 countries, ~60 institutes, ~400 collaborators 10
A B 0 mixing _ B 0 _ d b CPV in B 0 decays _ A B 0 V*td w = fcp _ t t A B 0 Sanda Bigi Decay: A Carter fcp B 0 _ b w d V*td Initial: B 0 _ Oscillation B 0 frequency: md (BH, BL) _ B 0 b V*cb w d Interference Direct decay Mixing + Decay _ c c _ s d J/ K 0 Weak Phase difference Decay-time dependent CPV 11
A B 0 mixing CPV in B 0 decays _ fcp A B 0 = A B 0 Sanda Bigi Decay: A Carter fcp mixing 2(a) -hf sin 2 1 sin(Dmd Dt) Vtd Vtb * 3(g) Vcd Vcb* 1(b) Prob. Vud Vub* ACP Decay (hf : CP eigenvalue) B 0 _ B 0 sin 2 1 Dt (decay time)[ps] 12
Time-dep CPV Measurement Flavor-tag (B 0 or B 0 ? ) eeff ~30% e e t=0 Vertexing Reconstruction J/ (f, h’) f. CP z KS s. Dt~140 ps B 0 B 0 -tag fit Extract CPV t z/cbg bg=0. 425 (KEKB) 0. 56 (PEP-II) same analysis method applied for all modes 13
sin 2 1 : CPV observation 1137 events _ B 0 tag Asymmetry 2001 31 M BB First observed CPV in B (2001) 14
sin 2 1 : Precision meas. 14000 signals 0 B _ tag B 0 tag 2006 535 M BB 0. 687 0. 028 0. 012 0. 670 0. 023 3. 4% error ! 15
Measurement of CKM Determination of UT Complete test of KM & SM B pp, rr b u l Vud Vub* B p/r l Dcom B 0 D(*)+p B K 2 Vtd Vtb * (a) 3(g) (b) Vcd Vcb* b c l B D(*)l B 0 -mixing (Dmd) B rg 1 B 0 (cc)K(*)0 B 0 D*+D(*)-(K) Over constraint ! B experiments can provide all measurements ! 16
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 17
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(10 10)] ! 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 ! 18
Search for New Physics CPV in B provide Powerful tool for Search NP ( New Phase ) [ b sqq t. CPV] Rare B decays excellent opportunities for NP search Loop diagram Penguins [b s(d) , b s(d) l+l-] Key Decays involving ( H ) ANP ~ ASM (small/forbidden) Decays (Lepton Flavor Violation = NP) : B-factory = -factory Establish analyses Hint of NP 19
NP : Precise CKM Still ~10% room for NP 50 ab-1 20
New Source of CPV: b sqq _ B 0 b t d s f, h’. . b s + s d d KS X s f, h’. . s s K d S Vts Vtb* SM: b s Penguin - K 0 phase = (cc) + New Physics with New Phase Sbs ¹ Sbc , ADCP can ¹ 0 _ “b ccs: sin 2 1” (SM reference) deviation 21
Summary of New CPV search B 0 J/ K 0 Reference point of SM No clear deviation seen in all modes (1~2 s) New CPV effect can be seen with much larger data Super B-factory 22
Super. KEKB prospect B f. K 0 at 50/ab with ~present WA values MC J/ K 0 f. K 0 b s This would establish the existence of a NP phase in b s penguins. 23 Compelling measurement in a clean mode 23
Kπ Puzzle in B⁰/B⁺ CP Violation _ B⁰ K⁻π⁺ B⁰ K⁺π⁻ B⁻ K⁻π⁰ B⁺ K⁺π⁰ B⁰ B⁺ Expected to be same DAK = A(K+ −) − A(K+ 0) = − 0. 147 ± 0. 028 S. -W. Lin et al. (The Belle collaboration), Nature 452, 332 (2008). 5. 3σ deviation Hint of NP ? 24
Solutions to the AKp Puzzle See Nature commentary by Michael Peskin T P Expectation from current theory T & P are dominant AKp ~ 0 T P • Enhancement of large C with large strong phase to T strong inter. !? Chiang et. al. 2004 Li, Mishima & Sanda 2005 C PEW Enhancement of large PEW New physics Yoshikawa 2003; Mishima & Yoshikawa 2004; Buras et. al. 2004, 2006; Baek & London 2007; Hou et. al. 2007; Feldmann, Jung & Mannel 2008 25 Can this issue be resolved in a model-independent way by experiment ?
Model-indep. Sum Rule A(K 0 0) sum le ru 0) + A(K 0 +)=0. 009 ± 0. 025 A(K+ 0)=0. 050 ± 0. 025 A(K+ -)=-0. 098 ± 0. 012 A(K 0 0)=-0. 01 ± 0. 10 (K HFAG, ICHEP 08 d. A B →K A(K 0 +) 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 26
Super. KEKB prospect Belle II, 50 ab-1 Important to measure A(K 0 p 0) precisely sum le ru 0) + (K d. A A(K 0 0) A(K 0 +) B →K 0 0 : main syst. uncertainty full systematics treated as non-scaling (conservative) 27 27
Charged Higss Hunting B-Factory: Variety of Modes sensitive to Charged Higgs Some are only possible at B-Factory 28
Inclusive b s g SM Fully Inclusive measurement 657 M BB Data Background subtracted 29
b s g Summary 30
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. ) 31
B > ν : Experimental Challenge e+ (4 S) BB- X B+ e B+ + , Always _ > 2 neutrinos appear in B decay + e+ e Signature : 1 track +invisible Experimental Challenge ! 32
B > ν : Experimental Challenge e+ BB- X (4 S) B+ e B+ + , + e+ e Tag-side: Full reconstruction Also for B D(*)_ B K Can be measured only by B-Factory ! 33
B > ν Results 2. 8 s 34
B D(*) n • B D* tn : Lepton ( ) polarization info. Expected B ~ 1. 4% in SM (large) [e. g. D. S. Hwang EPJ C 14, 271(2000)] But, large background (D*(**)ln, D*X) Ø Always involve > 2 (Missing E): 35
B D(*) n Results 657 M BB B 0 D*- +n [PRL 99, 191807(2007)] First Observation ! [PRD 82, 0720005(2010)] 36
B D(*) n Summary 37
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 38
-0 0 D -D Mixing Quark level: Box diagram (~ B 0 -mixing) SM box: O(10 -9) +Long distance: O(10 -3~10 -2) x=Dm/G y=DG/2 G Large mixing, |x|>>|y|, CPV New Physics ! u Only mixing with up-type quark complementarity to down-type FCNC 39
D 0 -mixing : y. CP Decays to CP eigenstates D 0 → K + K - / p + p “lifetime” difference First Evidence (2007) ! PRL 98, 211803 (2007), 540 fb-1 40
D 0 -mixing : Wrong sign D 0 K-p+ : normal decay D 0 K+p- : Mixing Signal But, two sources need decay-time _ analysis “Wrong Sign” to extract D 0 -D 0 mixing 400 fb-1 PRL 96, 151801 (2006) Ba. Bar, PRL 98, 211802 (2007), 384 fb-1 likelihood contours 3. 9 s 1 s 2 s (0, 0) CL 96. 1% CDF, PRL 100, 121802 (2008), 1. 5 fb-1 3 s 4 s 5 s 41
D 0 -mixing : t-dep. Dalitz D 0 K Sp + p - t y (%) most precise x meas. x (%) Belle, PRL 99, 131803 (2007), 540 fb-1 42
D 0 -mixing : Summary HFAG x~y~1% ~ SM limit ! Mixing parameters global fit to observables, only KK/ , K and Ks projected sensitivities included (no external constraints, e. g. d. K ) 43
D 0 -mixing : prospect 1 s @ 50 ab-1 A. G. Akeroyd et al. , ar. Xiv: 1002. 5012 Mixing parameters global fit to observables, only KK/ , K and Ks projected sensitivities included (no external constraints, e. g. d. K ) 44
Constraints from D 0 -mixing 4 th generation of fermions u W+ D 0 b’ b’ D 0 W- u Vub’* Vcb’ D 0 c ow all [Ge. V] ed are a lines of constant |x| allo wed mb’ [Ge. V] Vub’* Vcb’ c R-parity violating SUSY area lines of constant |x| |Vub’Vcb’| E. Golowich et al. , PRD 76, 095009 (2007) R couplings E. Golowich et al. , PRD 76, 095009 (2007) 45
Hints/Sensitive to NP CPV in b s Penguin? A(B K ) Puzzle Forwad-Backword Asy, . B K*ℓ+ℓ− C 7=−C 7 SM SM CKM Unitarity Triangle Theoretical calculations using Vub, Dmd, e. K Large D 0 -mixing f. L(B VV) ≠ 1 tree …. . penguin Direct measurement 46
Identification of NP type Identify by the pattern of deviations from SM SUSY models m. SU GRA MSSM+ R degenerate nondegenerate SU(5)+ R degenerate nondegenerate S(K* ) ✔ ✔ ✔ S( KS) ✔ ✔ ✔ S(Bs J/ ) ✔ ✔ ✔ ? e ✔ ✔ e … … ✔ ACP(s ) Measurements U(2) FS ✔ ✔ ✔: deviation from SM [based on T. Goto et. al. PRD 77, 095010(2008)] 47
Physics at Super B-factory is “DNA chip of New Physics” + LHC, … D. Hitlin 48
Energy Frontier vs Flavor Physics Direct Production by High Energy Coll. p p ~ g ~ ~ ~ q c n _ lq q Energy Frontier Diagonal terms Virtual Production via Quantum Eff. ~ q b ~ c Tunnel effect s Luminosity Frontier Off-diagonal terms Higher Energy Scale Can be searched (even if LHC finds no New Physics) 49
Complementarity of Flavor Physics (Luminosity Frontier) & Energy Frontier LHC observes NP in Te. V scale • Identify NP type SUSY, Extra Dim. Little Higgs, . . ? • Mechanism of Symm. Breaking • CPV via NP Era of NP Exploration SU(5)+ R degenerate MSSM+ R SU(5)+ R degenerate non-degenerate Belle II = Compass MSSM+ R New Physics U(2)FS non-degenerate Energy Frontier Luminosity Frontier Higgs top W, Z Standard Model Map S. Nishida 50
In case of No New Physics in Te. V scale • FCNC process currently gives various limits on NP ⇒ further explore NP Search by Flavor Physics in Dark SU(5)+ R degenerate MSSM+ R SU(5)+ R degenerate non-degenerate Belle II = Compass MSSM+ R New Physics U(2)FS non-degenerate Energy Frontier Luminosity Frontier Higgs top W, Z Standard Model Map S. Nishida 51
Comparison with LHCb Complementary ! 52
Summary Step 1 Discovery of CPV in B decays 2001 summer ! 2008 Step 2 Precise test of KM and SM Step 3 Search for NP Hints of NP (SUSY, Extra-dim…) Establish procedures LHC: New particle, masses Super. KEKB: couplings Understand NP need Both ~50 ab-1 data (L ~1036 cm-2 s-1 ) 53
Discovery of New Resonances X(3915), Y(4350) Yb Z(4050), Z(4250) Y(4660) Z(4430) Y(4008) Integrated Luminosity D 0*0 Ds. J(2860) Ds. J(2700) Xcx(3090) X(3940), Y(3940) Sc* baryon triplet & D 1*0 “Exotic Hadrons” Charged u c c d u u c c Y(4320) cc 2’ Y(4260) X(3872) Ds. J(2317/2460) hc’ & e+e- cccc Tetraquark Neutral u c c cluster g c c u Hybrid 54
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SM CPV: too small WMAP Too Small in SM Why? Jarlskog Invariant in SM (need 3 generation in KM) Normalize by T ~ 100 Ge. V masses too small ! in SM is common (unique) area of triangle CPV Phase [W. S. Hou] 56
CPV in B 0 decays (General) B 0 * Vud Vub 2(a) B 0 3(g) 1(b) * Vcd Vcb t made by H. Miyake Vtd Vtb* A CP = S sin(Dm. Dt) + A cos (Dm. Dt) B 0 mixing q/p Mixing induced CPV A B 0 A fcp = Direct CPV fcp B 0 57
f 1 Measurement _ B 0 _ V*td d w b _ t t b w V*td * Vud Vub 2(a) 3(g) _ _ Vtd Vtb* 1(b) * Vcd Vcb d B 0 b _ V*cb c c _ s d w d J/ K 0 A CP = - xcpsin 2 1 sin(Dm. Dt) +A cos (Dm. Dt) Mixing induced CPV Direct CPV x. CP : CP eigenvalue A@0 First observed CPV in B (2001) 58
A(K 0 p 0) measurement B KS 0 Signal +1 st B KL 0 Signal 285 52 57 (3. 7σ incl. systematics) 3 -d fit gives a signal of 657 37 events Use flavor tagging to distinguish B 0 and anti-B^0 These modes will be very difficult at a hadron machine 59
B > ν : Tension measurements Indirect fit prediction sin 2 1 60
and more… 61
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