Measurements of B  X c l Decays Vera Lüth, SLAC BABAR Collaboration Inclusive BR (B  X c l ) and |V cb | Hadronic Mass Moments (Preliminary Measurement)

Slides:



Advertisements
Similar presentations
Semileptonic and EW Penguin Decay Results from BaBar John J. Walsh INFN-Pisa BaBar Collaboration XXXXth Rencontres de Moriond QCD and Hadronic Interactions.
Advertisements

CW 07/09/03 O.Buchmüller 1 Measurement of the First and Second Moment of the Hadronic Mass Distribution in Semileptonic B Decays O.Buchmüller(SLAC) and.
14 Sept 2004 D.Dedovich Tau041 Measurement of Tau hadronic branching ratios in DELPHI experiment at LEP Dima Dedovich (Dubna) DELPHI Collaboration E.Phys.J.
Electroweak and Radiative Penguin Transitions from B Factories Paoti Chang National Taiwan University 2 nd KIAS-NCTS Joint Workshop on Particle Physics,
Measurement of non BB Decays of Y(4S) to Y(1S)     and Y(2S)     Silvano Tosi Università & INFN Genova.
M.Mevius Open and hidden beauty production in 920 GeV proton –nucleus collisions at HERA-B M.Mevius DESY.
1 Semiexclusive semileptonic B->charmdecays C. Gatto - INFN Napoli A. Mazzacane - Universita’ di Napoli April 10, 2003.
August 12, 2000DPF Search for B +  K + l + l - and B 0  K* 0 l + l - Theoretical predictions and experimental status Analysis methods Signal.
EPS, July  Dalitz plot of D 0   -  +  0 (EPS-208)  Kinematic distributions in  c   e + (EPS-138)  Decay rate of B 0  K * (892) +  -
Study of B  D S ( * )  D*  *   and D ( * ) (4  )   at CLEO Jianchun Wang Syracuse University Representing The CLEO Collaboration DPF 2000 Aug 9.
Determination of and related results from B A B AR Masahiro Morii, Harvard University on behalf of the B A B AR Collaboration |V cb | MESON 2004, Krakow,
Radiative B Decays (an Experimental Overview) E.H. Thorndike University of Rochester CLEO Collaboration FPCP May 18, 2002.
Sep. 29, 2006 Henry Band - U. of Wisconsin 1 Hadronic Charm Decays From B Factories Henry Band University of Wisconsin 11th International Conference on.
16 May 2002Paul Dauncey - BaBar1 Measurements of CP asymmetries and branching fractions in B 0   +  ,  K +  ,  K + K  Paul Dauncey Imperial College,
1 Inclusive B Decays - Spectra, Moments and CKM Matrix Elements Presented by Daniel Cronin-Hennessy University of Rochester (CLEO Collaboration) ICHEP.
DPF Victor Pavlunin on behalf of the CLEO Collaboration DPF-2006 Results from four CLEO Y (5S) analyses:  Exclusive B s and B Reconstruction at.
Heavy Flavor Production at the Tevatron Jennifer Pursley The Johns Hopkins University on behalf of the CDF and D0 Collaborations Beauty University.
CHARM 2007, Cornell University, Aug. 5-8, 20071Steven Blusk, Syracuse University D Leptonic Decays near Production Threshold Steven Blusk Syracuse University.
Search for B     with SemiExclusive reconstruction C.Cartaro, G. De Nardo, F. Fabozzi, L. Lista Università & INFN - Sezione di Napoli.
16 April 2005 APS 2005 Search for exclusive two body decays of B→D s * h at Belle Luminda Kulasiri University of Cincinnati Outline Motivation Results.
Alex Smith – University of Minnesota Determination of |V cb | Using Moments of Inclusive B Decay Spectra BEACH04 Conference June 28-July 3, 2004 Chicago,
Jochen Dingfelder, SLAC Semileptonic Decay Studies with B A B AR Annual DOE HEP Program Review, June 5-8, 2006, SLAC B D   X c,X u.
Radiative and Rare B-Decays at BaBar All results are preliminary unless journal ref. is given limit values are 90% CL unless otherwise specified Carsten.
1 BaBar Collaboration Randall Sobie Institute for Particle Physics University of Victoria.
Preliminary Measurement of the BF(   → K -  0  ) using the B A B AR Detector Fabrizio Salvatore Royal Holloway University of London for the B A B AR.
Elisabetta Barberio University of Melbourne Beauty 2006: Oxford September 2006 Measurements of V cb and Form Factors.
The BaBarians are coming Neil Geddes Standard Model CP violation BaBar Sin2  The future.
1 Semileptonic B Decays at BABAR Beauty 2005 Assisi (Perugia), June 20–24, 2005 Vladimir Golubev Budker Institute of Nuclear Physics, Novosibirsk, Russia.
Radiative Leptonic B Decays Edward Chen, Gregory Dubois-Felsmann, David Hitlin Caltech BaBar DOE Presentation Aug 10, 2005.
Measurement of B (D + →μ + ν μ ) and the Pseudoscalar Decay Constant f D at CLEO István Dankó Rensselaer Polytechnic Institute representing the CLEO Collaboration.
Measurement of the Branching fraction B( B  D* l ) C. Borean, G. Della Ricca G. De Nardo, D. Monorchio M. Rotondo Riunione Gruppo I – Napoli 19 Dicembre.
Luca Lista L.Lista INFN Sezione di Napoli Rare and Hadronic B decays in B A B AR.
DPF 2009 Richard Kass 1 Search for b → u transitions in the decays B → D (*) K - using the ADS method at BaBar Outline of Talk *Introduction/ADS method.
Moriond EW March 5-12, 2005 Antonio Limosani KEK Slide 1 Mini- Review( Belle & BaBar ) By Antonio Limosani JSPS Fellow (KEK-IPNS JAPAN) XLth Rencontres.
Wolfgang Menges, Queen Mary Measuring |V ub | from Semileptonic B Decays Wolfgang Menges Queen Mary, University of London, UK Institute of Physics: Particle.
Wolfgang Menges, Queen Mary Measurement of the CKM Sides at the B-Factories Wolfgang Menges On behalf of the BaBar and Belle Collaborations Queen Mary,
Charmonium Production at BaBar Jamie Boyd University of Bristol Photon 2003, Frascati 7 th -11 th April 2003 On behalf of the Collaboration.
5th International Conference on Hyperons, Charm and Beauty Hadrons, Vancouver David Waller, Carleton University Ottawa, Canada Semileptonic BR of b hadrons.
Irakli Chakaberia Final Examination April 28, 2014.
Rare B  baryon decays Jana Thayer University of Rochester CLEO Collaboration EPS 2003 July 19, 2003 Motivation Baryon production in B decays Semileptonic.
Gavril Giurgiu, Carnegie Mellon, FCP Nashville B s Mixing at CDF Frontiers in Contemporary Physics Nashville, May Gavril Giurgiu – for CDF.
RHUL Group Meeting 18. Dec. 03Henning Flächer 1 Hadronic Mass Moments from Semileptonic B Meson Decays at BABAR Henning Flächer OUTLINE Mass Moment Measurement.
Evidence for the Flavor Changing Neutral Current Decays ICHEP 2002, Amsterdam, July 27, 2002 Jeffrey D. Richman UC Santa Barbara for the B A B AR Collaboration.
1- 2 /2  1- 2 /2 u c dsb A 3 (1-  -i  ) - A 2 t d, s b b V td,V ts B Oscillations A 3 (  i  ) A 2 1 V tb c,u B decays b V ub,V cb Wolfenstein parametrization.
Semileptonic B decays in BaBar Cristiano Borean University and I.N.F.N. of Trieste on behalf of the BaBar Collaboration CIPANP 2003, New York.
Semileptonic Decays from Belle Youngjoon Kwon Yonsei Univ. / Belle.
1 B meson semileptonic decays Physics Motivation Inclusive properties: oSemileptonic width oMoments of inclusive quantities Exclusive decays What is the.
Semileptonic D Decays from CLEO and BELLE Yongsheng Gao Southern Methodist University (CLEO Collaboration) ICHEP04, Beijing, Aug. 16 ─ 23, 2004.
Inclusive semileptonic B decays: experimental Elisabetta Barberio University of Melbourne FPCP: Vancouver April 2006.
BNM Tsukuba (KEK) Sep Antonio Limosani KEK Slide 1 Antonio Limosani JSPS Fellow (KEK-IPNS JAPAN) BMN
Recent b physics results from OPAL David Waller, Carleton University for the OPAL Collaboration EPS Conference HEP2003 Heavy Flavour Physics Session Aachen,
Properties of B c Meson On behalf of DØ Collaboration Dmitri Tsybychev, SUNY at Stony Brook, PANIC05, Santa Fe, New Mexico B c is ground state of bc system.
Mike HildrethEPS/Aachen, July B Physics Results from DØ Mike Hildreth Université de Notre Dame du Lac DØ Collaboration for the DØ Collaboration.
A High Statistics Study of the Decay M. Fujikawa for the Belle Collaboration Outline 1.Introduction 2.Experiment Belle detector 3.Analysis Event selection.
Measurement of V cb Tom Browder (University of Hawaii) Inclusive approaches Exclusive approaches (B  D * l ν, B  D l ν) Moments and Form factors (if.
E. Robutti Enrico Robutti I.N.F.N. Genova HEP 2003 Europhysics Conference July 17-23, Aachen, Germany Recent BABAR results in Charmonium and Charm Spectroscopy.
Inclusive and Exclusive  V ub  Measurements Edward H. Thorndike University of Rochester CLEO FPCP /5/2003.
Guglielmo De Nardo for the BABAR collaboration Napoli University and INFN ICHEP 2010, Paris, 23 July 2010.
1 Inclusive B → X c l Decays Moments of hadronic mass and lepton energy PR D69,111103, PR D69, Fits to energy dependence of moments based on HQE.
Charm Mixing and D Dalitz analysis at BESIII SUN Shengsen Institute of High Energy Physics, Beijing (for BESIII Collaboration) 37 th International Conference.
Charm Form Factors from from B -Factories A. Oyanguren BaBar Collaboration (IFIC –U. Valencia)
ICHEP 2002, Amsterdam Marta Calvi - Study of Spectral Moments… 1 Study of Spectral Moments in Semileptonic b Decays with the DELPHI Detector at LEP Marta.
Measurements of V cb, branching fractions, form factors E.Barberio University of Melbourne FPCP: Daegu October 2004.
Charmless Hadronic B Decays at BaBar
Radiative Penguin B Decays at BABAR
For the BaBar Collaboration
B  at B-factories Guglielmo De Nardo Universita’ and INFN Napoli
CP Violation lectures Measurement of the time dependence of B0B0bar oscillation using inclusive dilepton events [BABAR-CONF-00/10] G. Cerminara.
Charmed Baryon Spectroscopy at BABAR
Presentation transcript:

Measurements of B  X c l Decays Vera Lüth, SLAC BABAR Collaboration Inclusive BR (B  X c l ) and |V cb | Hadronic Mass Moments (Preliminary Measurement)

V. Lüth ICHEP02 Amsterdam 2 Semileptonic B Decays  Semileptonic decays are  relatively simple theoretically at the parton level  accessible experimentally  sensitive to quark couplings to W ±, i.e. CKM elements |V cb | and |V ub |  probe the dynamics of decays  probe impact of strong interactions  BR for semileptonic B decays can be related to |Vcb|   c requires theoretical input (perturbative and non-perturbative)  We try to measure other inclusive variables, like mass distributions, to extract more information +

V. Lüth ICHEP02 Amsterdam 3 The BaBar Detector Cerenkov Detector Cerenkov Detector (DIRC) 144 quartz bars PMTs 1.5 T Solenoid Electromagnetic Calorimeter 6580 CsI(Tl) crystals Drift Chamber 40 stereo layers Instrumented Flux Return iron / RPCs (muon / neutral hadrons) Silicon Vertex Tracker 5 layers, double sided strips e + (3.1 GeV) e - (9 GeV) SVT: 97% efficiency, 15  m z hit resolution (inner layers, perp. tracks) SVT+DCH:  (p T )/p T = 0.13 %  p T % DIRC: K-  separation GeV/c  > GeV/c EMC:  E /E = 2.3 %  E -1/4  1.9 %

V. Lüth ICHEP02 Amsterdam 4 Inclusive Electrons with Electron Tags  Analysis based on small sample: 4/fb on Y(4s), 1/fb off Y(4s)  Data Selection  Electron tag: p cms >1.4 GeV/c  Electron signal: p cms > 0.6 GeV/c  Electron ID: Combined likelihood based on:  Electromagnetic Calorimeter (E/p, shower shape)  DIRC (Cherenkov angle, # of photons)  Driftchamber (dE/dx)  Two signal samples:  Right sign: + -  Wrong sign: ++ or - -  e  (92.5  1.3) % efficiency Mis-ID

V. Lüth ICHEP02 Amsterdam 5 Electron Tagged Sample : Background  Principal e  Backgrounds  Conversion/Dalitz pairs  Hadron mis-ID  Continuum background  Physics background  Secondary electrons from other B:  b  c  e +  b   -  e -, b  c cs  e -  Secondary electrons from same B  charmonium  B   e + e -  B – B Mixing  Secondary tag electrons  + - pairs from same B Cut: cos  +p* e >1.0 cos  >- 0.2 background P* e =0.75 GeV/c cos  >0.25

V. Lüth ICHEP02 Amsterdam 6 Right- and Wrong Sign Spectra  Mixing  both spectra contain prompt and secondary e ±  with  oa = Efficiency of cut on opening angle  : right-signwrong-sign  N prompt =25,070 (after correction for electron and tracking efficiency) right wrong

V. Lüth ICHEP02 Amsterdam 7 Fully Corrected Electron Spectrum  Corrections of prompt spectrum:  external bremsstrahlung 2.20 ± 0.35%  geom. acceptance 84%  single/di-lepton eff. 98%  Total electron signal 25,070 ± 413  Total electron tags: 304,000 ± 880 ± 2100  Extrapolation to p = 0: correction: 6.1± 0.9% Fit to sum of spectra from: B  D e, D * e, D ** e, D (*)  e B A B AR

V. Lüth ICHEP02 Amsterdam 8 Semileptonic Branching Ratio and |V cb |  Integration over spectrum & extrapolation to p l *=0 :  ARGUS : (9.7  0.5  0.4)% OPAL: (10.78  0.08  0.5)%  CLEO2: (10.49  0.17  0.43)% L3: (10.89  0.20  0.51)%  BELLE : (10.90  0.12  0.49)% ALEPH: (10.70  0.10  0.35)%  Relation to |V cb | (A. Hoang, Z. Ligeti, A.V.Monahar) [1] :  With  B =(1.6010.022)ps, and BR(B  X u e ) = (1.7  0.5) N.B. the theoretical errors have been added linearly BR(B  X e ) = (10.87  0.18 stat  0.30 sys )% | V cb | =  exp  theory [1] Phys. Rev. Lett. 82 (1999) 591.

V. Lüth ICHEP02 Amsterdam 9 OPE Parameters and Mass Moments  Parameterization of decay rate in terms of Operator Product Expansion in HQET in powers of  s (m b )  0 and  /m B:       are non-perturbative parameters  1 (-) kinetic energy of the motion of the b-quark  2 chromo-magnetic coupling of b-quark spin to gluon from B*-B mass difference, 2 =0. 12GeV 2   = m B – m b + ( )/2m B …  Additional parameters enter at higher orders (             ) use theoretical estimates  Similar expressions for moments of hadron mass spectrum or the lepton energy spectrum  Coefficients c i (not dependent on quark masses) can be calculated, as a function of the minimum lepton momentum (Luke, Falk) [1] [1] PR D57, 424 (1998)

V. Lüth ICHEP02 Amsterdam 10 Definition of Mass Moments  First hadron mass moment = f D (M D 2 -M Dspin 2 ) + f D* (M D* 2 -M Dspin 2 ) + f XH f: fractions obtained by fit to data M Dspin =(m D +3m D* )/4=1.975 GeV/c 2 Decay Mode f p*min =0 Model D l 1.867≈0.20ISGW2 D* l 2.009≈0.50HQET-FF X H res l ≈2.40≈0.21ISGW2 X H non-res l ≈2.86≈0.16P.S.

V. Lüth ICHEP02 Amsterdam 11 Event Selection  Data set:55 M BB events  Analysis based on events with one fully hadronic B decay  B  D Y  with D=(D 0, D +, D *0, D *+ ) and Y ± =(n 1  , n 2 K , n 3 K S, n 4  0 )  Select candidates cut  The events are further selected  ≥ 1 e or  with p* > 0.9 GeV/c  |Q| ≤ 1  Q l = Q B for B ±  |M miss 2 | <1.0 GeV 2  Final Sample 5819 Signal Events, 3585 Background

V. Lüth ICHEP02 Amsterdam 12 Kinematic Fits to Events  A 2-C kinematic fit is performed to the whole event  B 1  D Y  B 2  X l  Constraints of energy-momentum conservation  |M miss 2 |= 0  M 1 =M 2 Fit relies on event-by-event errors of measured particles and M miss 2.  The fit improves the resolution and reduces the need to reconstruct all final state particles  The fitted M X is largely bias free

V. Lüth ICHEP02 Amsterdam 13 Fit to M x Distribution Binned  2 fit to M X Distribution: 4 Contributions D = f D P D + f D* P D* + f HX P HX + f BG (fixed)P BG

V. Lüth ICHEP02 Amsterdam 14 Cross Checks of Fit to M X  Multiple checks – vary fit input  branching fractions of high mass resonance and non-resonant contributions  Background levels, M miss 2 cut  M ES sideband subtractions  Sample purity  Check subsamples,  e vs      vs    sample purity  Translate fraction f into BR  standard 3 distributions  split M XH into M XH res and M XH non-res  Observed variations are basis of estimate for systematic errors  Data highly correlated in p * min Branching Fractions

V. Lüth ICHEP02 Amsterdam 15 Check of High Mass Charm States  Largest systematic uncertaintes are the high mass charm states, both resonant and non-resonant  Estimate contribution from data:  assume PDG BR for D l and D*l  fix background  Subtract these contributions from data  Resultant distribution is fully compatible with MC prediction  The mean is consistent with the mean M X used in the determination of the moments! NB distribution not corrected for detector effects.

V. Lüth ICHEP02 Amsterdam 16  Strong dependence of moments on p* min  For p * min =1.5 GeV/c and  =0.35 ± 0.13 GeV [1] ( reliance on b  s  spectrum) 1 = ± 0.06 ±0.07GeV 2 CLEO [1] 1 = ± 0.07  0.08 GeV 2 Extraction of HQET Parameter 1 and  p * min [GeV/c] OPE (Falk,Luke)  = 0.35 GeV But these parameters do not describe P* dependence of the moments!  (0.9 GeV/c) –  (1.5 GeV/c) = 0.22±0.04±0.05 GeV 2 OPE (Falk, Luke) , 1 free param. NB: Data points highly correlated B A B AR Preliminary CLEO [1] CLEO PRL 87, (2001) No non-resonant states (MC)

V. Lüth ICHEP02 Amsterdam 17 Summary  From an electron tagged sample of BB events B A B AR measured  BR = (10.87 ± 0.18 stat ± 0.30 syst )%  |Vcb| = ± exp ± theory  These measurements agree well with previous measurements  From a B tagged sample of BB events B A B AR measured the hadronic mass spectrum down to lepton momenta of p*=0.9 GeV/c.  Observe a strong rise as p* decreases, this is attributed to high-mass, non-resonant D(*)  states  Momentum dependence of moments not consistent with  measurements from b  s  but can be described by HQE with other values of   Measurement for p*>1.5 GeV/c, fully consistent with  =0.35±0.07GeV 1 = ± 0.06 ±0.07GeV 2

V. Lüth ICHEP02 Amsterdam 18 Outlook  More data and more detailed studies of higher moments expected  Extend measurements to lower p * min  Differential measurements  Higher moments of hadronic mass distributions  Moments of lepton momentum in lepton tagged and fully tagged B events  Photon spectrum in b  s   Also studies of b  u l  Measurements of exclusive BR in progress  We are looking forward to these new measurements, more data, and a full assessment of uncertainties.