Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review Selection of the most important Belle results since last SAB review (2005):  B 0   'K 0 : first observation  of time dependent CPV in rare B decays;  B -   -  : evidence for purely leptonic decay (decay with missing energy);  New particles with charm;  First results from B s (  (5S) run).  B 0 (  db) B - (  ub)  B s (  sb) 0 Highlights of the Belle Experiment Precision tests of the Standard Model and New Physics searches at the B-Factory e + e -  (4S)  B 0 B 0 / B - B + Precision tests of the Standard Model and New Physics searches at the B-Factory e + e -  (4S)  B 0 B 0 / B - B + A.Bożek NZ11

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review Rare B decays: b  s: B -  f 0 (980)K -, B 0  f 0 (980)K *0 B decays with missing energy: b  c  -  : B 0  D* -  +  New particle searches : -D sj (2700) in B -  D 0 D 0 K - analysis - Charmed baryons study Physics analyses in Kraków Krakow’s Belle group 5 PhD physicists 3 electronics eng. 3 PhD students 1 diploma student

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review B Factory Physics Program W±W± qiqi qjqj V ij Cabibbo-Kobayashi- Maskawa (CKM) matrix 1()1() Unitarity Triangle being overconstrained at B factories dsb u c t Studies of rare B, D and  decays with potential sensitivity to new physics; Precise tests of the most stringent Standard Model (SM) predictions, e.g. unitarity relations between elements of the quark mixing matrix. 2()2() 3()3()

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review ~710x10 6 BB pairs 13 countries, 57 institutes, ~400 collaborators More than milion BB pairs per day Asymmetric e  e  collider 8GeV (e - )  3.5GeV (e + )

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review Time-dependent CP violation (t CP V) “double-slit experiment” with particles and antiparticles a flagship measurement at B-factories b c d c s d J/  KSKS b d c KSKS B0B0 b c s ddt t + Quantum interference between two diagrams tree diagram box diagram + tree diagram You need to “wait” (  t  0) to have the box diagram contribution. B0B0 B0B0

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review B 0  J/  K 0 sin2  1 = ±0.031 (stat) ±0.017 (syst) B 0 tag _ 535 M BB pairs _ hep-ex/ 1()1() Obtained precision is 1.3 o +sin2  1 tCPV

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review d b _ _ s s s d _ gt B0B0 K0K0 ,  ’... w d b _ _ s s s d _ g B0B0 K0K0 g b s B decays with b  s transition one of the best new physics probes SUSY as an example d b _ c c s d _ w B0B0 J/  K0K0 Extra CPV phase from New Physics = ? SM

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review tCPV in B 0   'K 0 sin2  1 (b →s) =  0.64  0.10(stat)  0.04(syst) _ 535M BB First observation of tCPV (5.6  in a single b  s mode First observation of tCPV (5.6  in a single b  s mode  t distribution and asymmetry PRL 98, (2007)

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review Smaller than b  ccs in all of 9 modes Smaller than b  ccs in all of 9 modes  1 from b  s transition Theory tends to predict positive shifts Naïve average of all modes sin2  1 (b→s) = 0.52 ±  deviation Naïve average of all modes sin2  1 (b→s) = 0.52 ±  deviation We need more statistics and more b  s modes B 0  J/  K 0…

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review B 0  f 0 (980)K* 0 Motivation: Not observed yet, expected BF ~10 -6 Expected to be dominated by b  s transitions -mode with simple final state In addition nature of f 0 (980) can be studied (candidate for four quark state or other exotic combinations). Results should be published this year Started as a diploma work; can lead to an important physics output in hot field. Very Preliminary

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review B decays with missing energy Fully reconstruct one of the B’s to : - tag BB events –determine other B flavor/charge & momentum Υ(4S) e  (8GeV) e+(3.5GeV) B B  fully reconstructed second B i.e. B  D  Decays of interests B  X u l, B  K  B  D ,  Powerful tools to study B decays with neutrinos Method sensitive to new physics

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review B +   +  B +  D 0  + K +  -  +  - K +  -  +  - B -   -   e -  e  e -  e  Missing momentum

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review Observation based on the residual energy in the electromagnetic calorimeter not used in both B reconstruction. The First B   Evidence Signal + background Background B   Signal 17.2 events in the signal region Measured branching fraction: PRL 97, (2006) Another „multi-neutrino” mode: B 0  D* -  +  experimentally more difficult analysis is carried on in Kraków, results are expected this year.

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review DsDs b ccc q csq b c q csq e e e e  BaBar at slac B-factory Belle D sJ (2317) D sJ (2458) X(3872) Y(3940) Y(4260) Z(3930) New charmed mesons : new unresolved questions about charm spectroscopy Picture: R. Faccini, DOE review 2005 New particles, charm spectroscopy B factories are an abundant source of other particles:  charmed mesons and baryons : e + e -  cc, B decays, …   lepton „factory” : e + e -   +  - ~700 M events D ,  c, X K „cs” type Charmonium type

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review efficiencysideband New D sJ in B + →D 0 D 0 K + N=399  40 D sJ (2700) new state Dalitz plot M(D 0 D 0 ) vs M(D 0 K) differs from 3-body phase space Interpretation still open hep-ex/

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review We are in high statistics era at B factories ( 1ab -1 ~10 9 BB) - many interesting & unexpected results 38 papers in Phys.Rev.Lett. (with discovery status) during 2005/ powerful tool to study rare and experimentally difficult B decays that are not accessible in other environments Good prospects for next generation experiment at Super B-Factory SuperKEKB (50 ab -1 ~5*10 10 BB) New physics searches in rare B &  decays, that are not accessible on hadron machines e.g: B  K , B  D ,  B  D* , B  X s /X u   →  →e  … solve the b  s & other ~2.5  puzzles Conclusions and prospects

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review Future plans ~10 10 BB/ year !! & similar number of  +  - L peak = 1.7  cm -2 s -1 L tot = 710 fb -1 (Dec. 2006) 1.7x fb -1 5x10 34 ~1 ab -1 8x10 35 ~10 ab -1 L peak (cm -2 s -1 ) L int Major upgrade of KEKB & Belle detector (>1yr shutdown) world records ! We are here

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review e + e - -> Y(5S) -> BB, B * B, B * B *, BB , BB , B s B s, B s * B s, B s * B s * 1985: CESR (CLEO,CUSB) ~116 pb -1 at Y(5S) 2003: CESR (CLEO III) ~0.42 fb -1 at Y(5S) 2005: Belle, KEKB ~ 1.86 fb -1 at Y(5S) CLEO PRL 54, 381 (1985 )  ( 5S ) 2006, June 9-31: Belle, KEKB ~21.7 fb -1 at Y(5S)  (5S) test runs B s -> D s +  - 9 events in B s * B s * 5.408< M BC <5.429 GeV/c 2 B s * N ev =20.0 ±  B s B s, B s *B s, B s *B s * MC sum of all Bs decay modes

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review Hunting Rare Decays Observation of B  K l + l - CPV in B decay Beginning of B->  K 0 saga Direct CPV in B 0  K +   FB asymmetry in B  K* l + l - Evidence of B   Observation of b  d  High luminosity Good detector (PID, vertex…) Analysis techniques –qq background suppression –Fully reconstructed tag Success of B factories brought rare B decays in leptonic and neutrino modes on the stage ! Success of B factories brought rare B decays in leptonic and neutrino modes on the stage !

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review Major Achievements Expected at SuperKEKB Discovery of B  K Discovery of B  D  Discovery of B   CKM Angle Measurements with 1 degree precision Discovery of CP Violation in Charged B Decays Discovery of Direct CP Violation in B 0  K  Decays (2005) Discovery of CP Violation in Neutral B Meson System (2001) |Vub| with 5% Precision Search for New CP-Violating Phase in b  s with 1 degree precision “Discovery” with significance > 5  Discovery of New Subatomic Particles sin 2  W with O(10 -4 ) precision Observations with  (5S),  (3S) etc. Case 2: New Physics with Extended Flavor Structure # SUSY GUT with gluino mass = 600GeV, tan  = 30 Discovery of Lepton Flavor Violation in    Decays # Discovery of New Right-Handed Current in b  s Transitions # Discovery of New CP Violation in B    K 0 Decays # Discovery of New CP Violation in B    K 0 Decays #

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review  = (Belle) 0.56 (BaBar) Principle of tCPV measurement CP-side Flavor tag and vertex reconstruction 1.Fully reconstruct one B-meson which decays to CP eigenstate 2.Tag-side determines its flavor (effective efficiency = 30%) 3.Proper time (  t) is measured from decay-vertex difference (  z) electron positron  (4S) resonance B1B1 B2B2 ++ -- K+K+ --  ++ -- K S/L J/   z ~ 200  m (Belle) B0B0 B0B0 _

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review tCPV in B 0 decays Mixing-induced CPVDirect CPV e.g. for J/  Ks S =  CP sin2  1 = +sin2  1 A = 0 to a good approximation (  CP : CP eigenvalue) e.g. for J/  Ks S =  CP sin2  1 = +sin2  1 A = 0 to a good approximation (  CP : CP eigenvalue) + Vtd

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review K.UlmerUpdate after ICHEP2006 !

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review Belle 2006: tCPV in B 0   K 0 “sin2  1 ” =  0.50  0.21(stat)  0.06(syst) A =  0.07  0.15(stat)  0.05(syst) “sin2  1 ” =  0.50  0.21(stat)  0.06(syst) A =  0.07  0.15(stat)  0.05(syst)   K S and  K L combined  background subtracted  good tags   t  –  t for  K L  t distribution and asymmetry _ 535M BB Consistent with the SM (~1  lower ) The most precise measurement now Consistent with the SM (~1  lower ) The most precise measurement now unbinned fit SM hep-ex/

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review B 0  D* -  +  search Experimentally very difficult: At least 2 in decay chain Low effective Br: Effective Br for decay chain ~ – Motivations: B  D (*)  not observed yet Decays with heavy fermions  enhancement of effects beyond SM Many avaiable observables from  decays  transverse or longitudinal polarisation Semileptonic heavy quark decay – clear theoretical situation:  good description of b quark in HQET BG for B  D  decay  need for more effective reconstruction of B tag or/and higher statistics Results should be presented this year

Andrzej Bożek nz11Highlights of the Belle Experiment SAB Review New D sJ in B + →D 0 D 0 K + N=399  40 hep-ex/ efficiencysideband Dalitz plot M(D 0 D 0 ) vs M(D 0 K) differs from 3-body phase space D sJ (2700) new state J P = 1 - ψ(4160) reflection