Recent results from B factories A Oyanguren IFIC

Recent results from B factories A. Oyanguren IFIC, UV-CSIC III Jornadas CPAN, Barcelona 2 nd – 4 th Nov. 2011

Outline B factories (Belle & Ba. Bar) Leptonic decays: B , Ds Semileptonic CPV decays: B D* , Vub, charm (B, c and decays) Rare decays: B s , B K , B , D , Xc h Plans at Super Flavour Factories (Belle II & Super. B) III Jornadas CPAN, Barcelona A. Oyanguren 2

B factories KEKB √s=10. 58 Ge. V e+ B eΥ(4 s) Ba. Bar p(e -)=9 Ge. V p(e +)=3. 1 Ge. V Belle p(e -)=8 Ge. V p(e +)=3. 5 Ge. V III Jornadas CPAN, Barcelona Υ(4 s) =0. 56 A. Oyanguren B z ~ c B ~ 200 m =0. 42 3

B factories # of produced (n. S) In addition to (4 S) also large samples of other (n. S) decays! Fantastic performance far beyond design values! III Jornadas CPAN, Barcelona A. Oyanguren 4

Leptonic decays Motivation: Weak annihilation processes (helicity suppressed) sensitive to New Physics effects B : a charged Higgs could enhance the SM branching fraction: From semileptonic decays: by: |Vub|=(3. 89 ± 0. 44) x 10 -3 [PDG 2010] From Lattice QCD calculations: f. B = 191 ± 3 ± 13 Me. V [Lenz et al. , PRD 83, 036004 (2011)] 0 = radiative correction ~1%) III Jornadas CPAN, Barcelona A. Oyanguren 5

Leptonic decays Experimental method: Reconstruct one B meson in hadronic B D(*) X or B J/ X decays ( tag ~1%) Look for signal in the recoil: using kinematical and event shape information Look for extra energy E extra = sum of neutral clusters in the ECM calorimeter Study Extra using double tag events to control the bkg. 426 fb-1 Extract B from unbinned max. likelihhod fit To E extra: Ba. Bar combined: 3. 3 significance Belle: III Jornadas CPAN, Barcelona A. Oyanguren 6

Leptonic decays sin 2 from CP measurements in B 0 → cc K 0 Belle, preliminary, 710 fb -1 Final measurement of sin 2 Tension between B( B→ ) and sin 2 (~2. 5 ) remains III Jornadas CPAN, Barcelona A. Oyanguren 7

Leptonic decays Ds can also be enhanced by a charged Higgs or leptoquarks: f. Ds calculated by LQCD with small error f. Ds = (248. 6 ± 2. 5) Me. V At Ba. Bar D s e , , measured from fully reconstructed events using the recoil mass and the E 521 fb-1 Ba. Bar extra Agreement with theory [PRD RC 82, 091103 (2010)] III Jornadas CPAN, Barcelona A. Oyanguren 8

Semileptonic: B ( ) D * Motivation: Sensitive to charged-Higgs effects Involve form factors which can be measured in B D(*)e/ decays Observables: R(D) and R(D*) ratios - can be enhanced by the charged-Higgs (tan /m. H ) - several syst. and theo. uncertainties cancel out SM predictions: R(D) = 0. 31 0. 02 R(D*) = 0. 25 0. 02 III Jornadas CPAN, Barcelona [Nierste, Trine, Westhoff PRD 78 (08) 015066] A. Oyanguren 9

Semileptonic: B ( ) D * Experimental method: e e Ba. Bar: Btag fully reconstructed into hadrons (Improved efficiencies (lepton and Btag)) Bsig: D (*) and lepton ( , e) - 4 signal samples: (D 0, D+, D* 0, D* +) (to extract B D(*) ) 0, - 4 control samples: (D (to derive D** bkg) D+, D* 0, D* +) 0 mmiss 2 = (p e+e- -p. Btag-p. D(*) -p )2 426 fb -1 2 D unbinned ML fit m miss 2 -p* (3 x 4 par. ) Yields for: B (D 0, D+, D* 0, D* +) 0 R(D) and R(D*) III Jornadas CPAN, Barcelona Large signal significance (>5 ) for all channels A. Oyanguren 10

Semileptonic: B ( ) D * SM predictions: R(D) = 0. 31 0. 02 R(D*) = 0. 25 0. 02 Results (preliminary): R(D) = 0. 456 0. 053 0. 056 R(D*)= 0. 325 0. 023 0. 027 SM 1. 8 larger than SM prediction favors large tan Comparison with previous results: (w/o 2011) III Jornadas CPAN, Barcelona (w/o 2011) A. Oyanguren 11

Semileptonic: Vub Motivation: Charmless semileptonic decays allow us to measure Vub (upper UT vertex) Challenge: suppress charm background B X = B Xc + B Xu (50 : 1) B X u Two different experimental methods: - Inclusive: high stat. but much bkg: use kinematic cuts: E , q 2, MX and P+ = E X -|p X| Theory: Shape function from QCD - Exclusive: final meson ( , , …): low stat. but better bkg rejection. Theory: Form factors from QCD III Jornadas CPAN, Barcelona A. Oyanguren 12

Semileptonic: B Xu - K+ Experimental Method: At Ba. Bar, Btag fully reconstructed hadronically ( ~0. 3 -0. 5%) + or e from the Bsig Tag side - + Xu from all remaining tracks and neutral clusters estimated from missing E and p Signal side D 0 B 0 (4 S) Xu Bkg supression: 426 fb -1 - Combinatorial subtracted from m. ES - Charm: B D* partial reconstructed kaon veto, only 1 lepton p * > 1 Ge. V Several PS regions, 2 D fit for B(B Xu )/B(B X ) in q 2 -Mx for p * > 1 Ge. V Ba. Bar B Xc bkg and B Xu signal yields B(B Xu )= 1. 80 (13) (15) x 10 -4 Vub extraction: BNLP: [Bosch et al. , PRD 72 (05) 073006] DGE: [Andersen et al. , JHEP 0601 (06) 097] GGOU: [Gambino et al. , JHEP 0710 (07) 058] ADFR: [Aglietti et al. , EPJ. C 59 (09) 831] III Jornadas CPAN, Barcelona A. Oyanguren Average: |Vub|= (4. 31 0. 25 exp 0. 16 theo )10 -3 [to be submitted to PRD] 13

Semileptonic: B The exclusive B semileptonic decay rate is described as function of form factors: = , h, h’, , QCD calculations: Lattice data III Jornadas CPAN, Barcelona A. Oyanguren 14

Semileptonic: B PRD 83 (2011) 032007 Ba. Bar, untagged analyses PRD 83 (2011) 052011 Loose reconstruction from full event Fit to Ba. Bar + Belle + LQCD Background suppression by cuts or Neural Net Fit using E = (PBPbeams-– s /2)/ 2 , m. ES = [(s/2 + p. Bpbeams- )2 /E 2 beams - p 2 B] and q 2 = (p + p )2 = (p. B- p )2 (in 12 or 6 bins) B(B e )= 1. 42 (5) (7) x 10 -4 Ba. Bar: B (B e ) =1. 41 (5) (7) x 10 -4 Belle: |Vub| = (3. 19 ± 0. 14 ± 0. 27) x 10 -3 B (B e ) = 1. 49 (4) (7) x 10 -4 (V. Luth, J. Dingfelder) [ar. Xiv: 1012: 0090 ] III Jornadas CPAN, Barcelona A. Oyanguren 15

Semileptonic: Vub Exclusive: |Vub| = (3. 19 ± 0. 14 ± 0. 27) x 10 -3 (V. Luth, J. Dingfelder) Inclusive: |Vub| = (4. 34 ± 0. 13 ± 0. 15) x 10 -3 (V. Luth, [NS 61 CH 06 -Luth]) Inclusive |Vub| Exclusive |Vub| >2 difference since many years ago and Vub from B larger than for B New Physics contribution? (RH currents modification) III Jornadas CPAN, Barcelona A. Oyanguren

Semileptonic: charm Charm semileptonic decays allow to measure form factors in the charm sector, validating LQCD methods increase theory precision involving B decays trust LQCD calculations ensuring possible New Physics signs Example: the leptonic constant f Ds: >3 !? ! f. Ds puzzle: exp theo contribution from a charged Higgs? Kronfeld plot, N. Simone: FERMILAB-CONF-10 -594 -T Several charm semileptonic channels have been studied at Ba. Bar from e +e- cc using a partial reconstruction technique: D Ke , Ds KKe , D+ K e published D e (soon) can be related to B e access to Vub III Jornadas CPAN, Barcelona A. Oyanguren 17

Semileptonic: charm Quite precise form factor measurements from Ba. Bar need LQCD improvements [PRD 76, 052005 (2007)] f. K+(q 2) [PRD 78, 051101(R) (2008)] Ba. Bar 214 fb-1 Ba. Bar D s e Ba. Bar 75 fb-1 D 0 K-e+ Experiments [PRD 83, 072001 (2011)] Ba. Bar 348 fb-1 D + K*e+ A 1(q 2), A 2(q 2), V(q 2) III Jornadas CPAN, Barcelona Ba. Bar r 2=A 2(0)/A 1(0) D + K*e+ rv=V(0)/A 1(0) A. Oyanguren 18

CP Violation The CKM matrix Motivation: • CP violation discovered ~50 years ago observing the decay K L → π+π • In the SM CPV arises from the not vanishing phase of the CKM matrix • New Physics can induce additional FCNC and CP-violating phases • Many observations of CPV processes in the last decade in the beauty and strange sectors Global consistency with SM predictions • No observation yet of CPV effects in the charm sector • No observation yet of CPV effects in the lepton sector III Jornadas CPAN, Barcelona A. Oyanguren 19

CP Violation in D decays Motivation: Direct CP violation in D decays arises through interference between: In the SM is CKM suppressed O(10 -3) or less: Vcs New Physics can increase or reduce the effect: - e. g. additional CP phase from charged Higgs boson [PRD 75, 036008 (2007)] [hep-ph/0104008 (2001)] SCS decays are more likely to show the effect if present [PRD 51, 003478 (1995)] Current experimental sensitivity O(10 -3) III Jornadas CPAN, Barcelona A. Oyanguren 20

CP Violation in D decays Experimental method: Due to CPV in mixing in the kaon sector, the direct CP asymmetry for D+ Ks + is expected to be [hep-ph/0104008 (2001)] At Ba. Bar: signal yields from likelihood fit to m( +K 0 s), with selection based on a Boosted Decision Tree with 7 variables: 807 K D ± signal events Measure Forward-Backward asymmetry Detector charge asymmetry Data-driven method to correct for A o Use tracks from e +e- (4 S) BB decays (isotropic in rest frame) to map the ratio of +/ - detection efficiencies o Offset on ACP +0. 05% III Jornadas CPAN, Barcelona A. Oyanguren 21

CP Violation in D decays Use data-driven method to extract AFB, and ACP in bins of polar angle D+ Ks + [PRD 83, 071103(R) (2011)] Consistent with SM (-0. 332± 0. 006)% At Belle D 0 KS 0 , tag D flavour with the D* decay ACP = -0. 28 0. 19 0. 10 [PRL 106, 211801 (2011)] III Jornadas CPAN, Barcelona A. Oyanguren 22

CP Violation in Ks Motivation: t- t CP violation not yet observed in the lepton sector Search for direct CP violation in tau decays: W- - -Ks u d within the SM, due to the K s presence, the asymmetry: Tree is expected to be - s d K 0 [Bigi and Sanda, PLB 625, 47 (2005)] (same argument than for D Ks decays) A deviation of the measured ACP from ACP SM would be a hint of New Physics o e. g. an additional CP violating phase from an exotic charged Higgs boson [PLB 398, 407 (1997)] Can consider - -Ks(>=0 0) since 0 s are not expected to change the asymmetry III Jornadas CPAN, Barcelona A. Oyanguren 23

CP Violation in Ks Experimental method: Reconstruct from continuum - -Ks(>=0 0) (up to 3 0 s) Electron and muon tags with p * > 4 Ge. V (reduce bkg from non- -pairs) Reconstructed hadronic mass < 1. 8 Ge. V (rejects q q bkg) Remaining background further reduced using information of: qq events: visible energy, number of neutral clusters, thrust, total transverse momentum Fake K 0 s: displaced vertex, invariant mass, momentum and polar angle of the K 0 s candidate III Jornadas CPAN, Barcelona Invariant mass of the hadronic final state (0 0 s) 340 k events A. Oyanguren 24

CP Violation in Ks Experimental method: Measured raw ACP value (after subtraction of q q background and non-K 0 s decays) has to be corrected by: o Different nuclear reaction cross-section of K 0 and K 0 with material detector o (0. 14± 0. 03)% for e-tag, (0. 14± 0. 02)% for -tag o Errors include uncertainties from kaon-nucleon cross-sections and isospin o Dilution from background modes including K 0 s Source Fraction e-tag (%) Fraction -tag (%) SM expected ACP t- -K 0 S( 0 0) t 78. 4 ± 4. 0 77. 4 ± 4. 0 (0. 33± 0. 01)% t- K-K 0 S( 0 0) t 4. 2 ± 0. 3 4. 0 ± 0. 3 (-0. 33± 0. 01)% t- -K 0 K 0( 0 0) t 15. 6 ± 3. 7 15. 7 ± 3. 7 0 Result: [Preliminary, submitted to PRD-RC ar. Xiv: 1109. 1527] Systematic uncertainties 3 from the SM prediction III Jornadas CPAN, Barcelona A. Oyanguren 25

CP Violation in B c decays Motivation: Many such decays are dominated by b s penguins o Tree amplitudes subdominant in SM o Time-dependence and FSI (intermediate states) allow to measure the CKM angles Tre e New Physics can change CP asymmetries, BRs and polarizations in B VV decays Experimental method: Penguin Use kinematic constraints from beam energies Event shape variables combined into a linear (Fisher) or non linear (NN) combination. Tagging (other “B”) information often used Apply selection to reject continuum as variable in ML fit III Jornadas CPAN, Barcelona A. Oyanguren 26

CP Violation in B c decays Direct CP violation difference in B K+ - and K+ 0 at Belle AK = ACP(K 0) - ACP (K ) preliminary Update the 2008 result with the full data set and improved reconstruction - ~2 x more data 772 M BB Belle preliminary: AK = +0. 112 ± 0. 028@4 III Jornadas CPAN, Barcelona A. Oyanguren 27

CP Violation in B c decays Direct CP violation difference in B 0 K+ - 0 and B+ K+ 0 0 at Ba. Bar Perform ML fit with m. ES and NN, and for K+ - 0 only, also E and Dalitz plot For B 0 K+ - 0 [PRD 83, 112010 (2011)] o BF(B 0 K+ - 0) = (38. 5 ± 1. 0 ± 3. 9) 10 -6 3. 1 evidence for direct CPV o ACP(K*+ -) = -0. 29 ± 0. 11 ± 0. 02 ACP(K*+ -) = -0. 24 ± 0. 07 ± 0. 02 o When combined with B 0 Ks + - : For B + K+ 0 0 o First inclusive measurement o Measure resonances in a two-body fashion o 10 significance Decay Nsignal B+ K+ 0 0 7427± 518 16. 2± 1. 5 -0. 06± 0. 04 B+ K*+ 0 1078± 197 8. 2± 1. 5± 1. 1 -0. 06± 0. 24± 0. 04 B+ f 0( 0 0)K+ 1186± 241 2. 8± 0. 6± 0. 5 +0. 18± 0. 04 B+ cc 0 K+ -0. 96± 0. 37± 0. 04 245± 105 BF( 10 -6) 182± 78± 32± 8 III Jornadas CPAN, Barcelona 471 x 10 6 BB pairs ACP A. Oyanguren 454 x 10 6 BB pairs ACP(K*+ 0) = -0. 06 ± 0. 24 ± 0. 04 Preliminary 28

Rare decays Rare processes are quite sensitive to New Physics effects B : Belle: fully reco tag + nothing in the signal side BR< 1. 3 x 10 -4 @ 90% CL ( Ba. Bar: BR< 2. 2 x 10 -4 ) B K : Ba. Bar: semileptonic tag + K and 2 in the signal side [PRD 82, 112002 (2010)] B (s+d) : Ba. Bar: semileptonic tag + 1 in the signal side: A CP = 0. 056 ± 0. 060 ± 0. 018 ( SM) x 10 -5 B : Ba. Bar: upper limit (UL) lowered by a factor 2: BR< 3. 2 x 10 -7 @ 90% CL D : Ba. Bar: BR< 2. 4 x 10 -6 @ 90% CL B : D Most of LFV and LNV X c h BF ULs down by 1 order of magnitude (10 -6) III Jornadas CPAN, Barcelona A. Oyanguren 29

Future: Super. B, Belle-II Two new facilities aiming to an integrated luminosity of 50 -75 ab -1 around 2020 Super. B, Frascati (Italy) Belle-II, Tsukuba (Japan) Approved, build a new tunnel, upgrade PEP-II Approved, major upgrade at KEK in 2010 -14 and Ba. Bar, quickly ramping up Super. KEKB+Belle II, construction started Physics: Sensitivity B( ) ~ 10 -9 , B( )~10 -10 , B( h)~10 -10 Charm Physics: Precision CP parameters: (K ) (~10 -5), sensitivity FCNC: D (h) (~10 -8) B Physics: Precision B K (~20%), B (~ 4%), B (~ 5%), B D (~ 2%), ACP(b s ) (~ 0. 002 ), Vub (~ 2%) III Jornadas CPAN, Barcelona A. Oyanguren 30

Summary III Jornadas CPAN, Barcelona A. Oyanguren 31

Summary B D(*) Improved measurements at Ba. Bar B D 0 and B D+ more than 5 significance R(D(*)) exceed by 1. 8 the SM values favors large tan Vub |Vub| excl. = (3. 19 ± 0. 14 ± 0. 27) x 10 -3 |Vub| incl. = (4. 34 ± 0. 13 ± 0. 15) x 10 -3 Despite the experimental and theoretical efforts the discrepancy between exclusive and inclusive measurements remains: what does it means? what don’t we understand? Charm Semileptonic form factors Quite precise results from Ba. Bar for D Ke , Ds e , D K*e , form factors allow to check QCD methods: need LQCD improvements III Jornadas CPAN, Barcelona A. Oyanguren 32

Introduction B and charm semileptonic decays are tree level processes involving CKM matrix elements: VCKM = PDG 10 Vud Vcd Vtd 0. 230(11) Vus Vcs Vts Vub Vcb Vtb 0. 00389(44) 0. 0406(13) 1. 023(36) New Physics contributions can only be seen: in semileptonic decays involving leptons: coupling ~ mbm tan 2 B D( ) by comparing CKM matrix elements in leptonic and semileptonic decays Vub: Inclusive B Xu , exclusive B Note: Must control (by measuring) QCD effects (form factors) Charm semileptonic decays III Jornadas CPAN, Barcelona A. Oyanguren 33

Charm sl decays Analysis procedure: Partial reconstruction method; e +e- cc; only electrons D* tag in case of D Ke , no tag for D s or D+ decays Compute the D (s) direction from all tracks signal tracks q 2 and angular distributions: kinematic fit with signal tracks momenta and missing energy information Background suppression using event shape and topological variables Background control, test of the analysis technique and the normalization are obtained from hadronic data samples (ex: D K , D K ) III Jornadas CPAN, Barcelona A. Oyanguren 34

Semileptonic: B ( ) D * Fit results (preliminary) : (isospin) large signal significance (> 5 ) for all channels Systematics (preliminary) : - Selection cuts: ~6%(D*), ~9%(D) - D** fitted in D (*) 0 samples: ~4%(D*), ~5%(D) III Jornadas CPAN, Barcelona A. Oyanguren 35

B X u Summary of V ub measurements: Exclusive: (V. Luth, J. Dingfelder) |Vub| = (3. 19 ± 0. 14 ± 0. 27) x 10 -3 Inclusive: |Vub| = (4. 34 ± 0. 13 ± 0. 15) x 10 -3 III Jornadas CPAN, Barcelona (V. Luth, [NS 61 CH 06 -Luth]) A. Oyanguren 36

Leptonic decays III Jornadas CPAN, Barcelona. A. Oyanguren 37

Vub exclusive: Ba. Bar combined result: Small event overlap of B 0 - (<1%) Uncorrelated statistical uncertainties Highly correlated systematics Ba. Bar Fit to BGL LCSR Lattice Ba. Bar fit to BGL including Lattice data points ( B : LCSR q 2 < 12 Ge. V 2, LQCD q 2 > 16 Ge. V 2) (fits from J. Dingfelder and V. Luth) III Jornadas CPAN, Barcelona. A. Oyanguren 38

Vub exclusive: B PRD 83 (2011) 052011 PRD 83 (2011) 032007 Analyses procedure: Ba. Bar data samples: 423 fb -1 , 349 fb -1 Untagged analyses (high stat. , more bkg. ), e + Loose reconstruction from full event (p = p beams - pi) Background suppression by cuts or NN 2 D or 3 D fit E = (P BPbeams- – s /2)/ 2 , m. ES = [(s/2 + p Bpbeams- )2 /E 2 beams - p 2 B]½ q 2 = (p + p )2 = (p B- p )2 to extract the signal yield q 2 in 12 or 6 bins III Jornadas CPAN, Barcelona A. Oyanguren 39

Charm sl decays Analysis procedure: Partial reconstruction method; e +e- cc; only electrons D* tag in case of D Ke , no tag for D s or D+ decays Compute the D (s) direction from all tracks signal tracks q 2 and angular distributions: kinematic fit with signal tracks momenta and missing energy information Background suppression using event shape and topological variables Background control, test of the analysis technique and the normalization are obtained from hadronic data samples (ex: D K , D K ) III Jornadas CPAN, Barcelona A. Oyanguren 40

Fit results: [to be submitted to PRD] data B Xu 1441 102 Xu Most precise result : 2 D fit q 2 -Mx for p * > 1 Ge. V Fit for B Xc bkg and B Xu signal yields Xc B Xu Vub extraction: Average: |Vub|= (4. 31 0. 25 exp 0. 16 theo )10 -3 BNLP: [Bosch et al. , PRD 72 (05) 073006] DGE: [Andersen et al. , JHEP 0601 (06) 097] GGOU: [Gambino et al. , JHEP 0710 (07) 058] ADFR: [Aglietti et al. , EPJ. C 59 (09) 831] III Jornadas CPAN, Barcelona A. Oyanguren 41