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.

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

Current limits (95% C.L.): LEP direct searches m H > GeV Global fit to precision EW data (excludes direct search results) m H < 157 GeV Latest Tevatron.

Gavril Giurgiu, Carnegie Mellon 1 B s Mixing at CDF Seminar at Fermi National Accelerator Laboratory Gavril Giurgiu Carnegie Mellon University August 16,

Tau dilepton channel The data sample used in this analysis comprises high-p T inclusive lepton events that contain an electron with E T >20 GeV or a muon.

Measurement of non BB Decays of Y(4S) to Y(1S)     and Y(2S)     Silvano Tosi Università & INFN Genova.

1 Semiexclusive semileptonic B->charmdecays C. Gatto - INFN Napoli A. Mazzacane - Universita’ di Napoli April 10, 2003.

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.

16 May 2002Paul Dauncey - BaBar1 Measurements of CP asymmetries and branching fractions in B 0   +  ,  K +  ,  K + K  Paul Dauncey Imperial College,

Recent Electroweak Results from the Tevatron Weak Interactions and Neutrinos Workshop Delphi, Greece, 6-11 June, 2005 Dhiman Chakraborty Northern Illinois.

1 Inclusive B Decays - Spectra, Moments and CKM Matrix Elements Presented by Daniel Cronin-Hennessy University of Rochester (CLEO Collaboration) ICHEP.

1 Measurement of f D + via D +   + Sheldon Stone, Syracuse University  D o D o, D o  K -  + K-K- K+K+ ++  K-K- K+K+ “I charm you, by my once-commended.

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.

Search for B     with SemiExclusive reconstruction C.Cartaro, G. De Nardo, F. Fabozzi, L. Lista Università & INFN - Sezione di Napoli.

Alex Smith – University of Minnesota Determination of |V cb | Using Moments of Inclusive B Decay Spectra BEACH04 Conference June 28-July 3, 2004 Chicago,

Hadronic Moments in Semileptonic B Decays Ramon Miquel Lawrence Berkeley National Laboratory (for the CDF II Collaboration)

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.

Chris Barnes, Imperial CollegeWIN 2005 B mixing at DØ B mixing at DØ WIN 2005 Delphi, Greece Chris Barnes, Imperial College.

Exclusive Semileptonic b  u Decays at CLEO Sheldon Stone Syracuse University.

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.

Luca Lista L.Lista INFN Sezione di Napoli Rare and Hadronic B decays in B A B AR.

Guglielmo De Nardo Napoli University and INFN 7th Meeting on B Physics, Orsay, France, October 4th 2010.

 Candidate events are selected by reconstructing a D, called a tag, in several hadronic modes  Then we reconstruct the semileptonic decay in the system.

Lepton/Photon 2003, Batavia, IL, USA August 11 th – 16 th Measurement of  b Branching Ratios in Modes Containing a  c Why are the  b branching fractions.

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.

1 Multi-body B-decays studies in BaBar Ben Lau (Princeton University) On behalf of the B A B AR collaboration The XLIrst Rencontres de Moriond QCD and.

Section of experimental particle physics Per Hansson Top D0 Summer Physics Workshop June Top Charge Measurement using Jet Charge Templates.

Gavril Giurgiu, Carnegie Mellon, FCP Nashville B s Mixing at CDF Frontiers in Contemporary Physics Nashville, May Gavril Giurgiu – for CDF.

Kalanand Mishra April 27, Branching Ratio Measurements of Decays D 0  π - π + π 0, D 0  K - K + π 0 Relative to D 0  K - π + π 0 Giampiero Mancinelli,

Possibility of tan  measurement with in CMS Majid Hashemi CERN, CMS IPM,Tehran,Iran QCD and Hadronic Interactions, March 2005, La Thuile, Italy.

Branching Ratios and Angular Distribution of B  D*  Decays István Dankó Rensselaer Polytechnic Institute (CLEO Collaboration) July 17, 2003 EPS Int.

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.

A measurement of the B 0 B 0 oscillation frequency and determination of flavor-tagging efficiency using semileptonic and hadronic B 0 decays S. Bolognesi.

Sergey Burdin FNAL DØ Collaboration 8/12/2005 Chicago Flavor New Bs Mixing Result from DØ.

CHARM MIXING and lifetimes on behalf of the BaBar Collaboration XXXVIIth Rencontres de Moriond  March 11th, 2002 at Search for lifetime differences in.

CP Violation Studies in B 0  D (*)  in B A B A R and BELLE Dominique Boutigny LAPP-CNRS/IN2P3 HEP2003 Europhysics Conference in Aachen, Germany July.

JPS 2003 in Sendai Measurement of spectral function in the decay 1. Motivation ~ Muon Anomalous Magnetic Moment ~ 2. Event selection 3. mass.

Preliminary Measurement of the Ke3 Form Factor f + (t) M. Antonelli, M. Dreucci, C. Gatti Introduction: Form Factor Parametrization Fitting Function and.

Recent b physics results from OPAL David Waller, Carleton University for the OPAL Collaboration EPS Conference HEP2003 Heavy Flavour Physics Session Aachen,

B   and B  D ( * )   decays at BaBar Guglielmo De Nardo University of Napoli “Federico II” and INFN Representing the BaBar collaboration 36 th International.

Matthew Martin Johns Hopkins University for the CDF collaboration andBranching Ratios from Flavor Physics & CP Violation Ecole Polytechnique, Paris, France.

1 Absolute Hadronic D 0 and D + Branching Fractions at CLEO-c Werner Sun, Cornell University for the CLEO-c Collaboration Particles and Nuclei International.

Susan Burke DØ/University of Arizona DPF 2006 Measurement of the top pair production cross section at DØ using dilepton and lepton + track events Susan.

1 Measurement of the Mass of the Top Quark in Dilepton Channels at DØ Jeff Temple University of Arizona for the DØ collaboration DPF 2006.

Extract the partial rates We can make fits to the partial decay rates to extract (1) normalization f + (0)|V cx | (2) Form factor shape parameters r 1.

4/12/05 -Xiaojian Zhang, 1 UIUC paper review Introduction to Bc Event selection The blind analysis The final result The systematic error.

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)

Kalanand Mishra June 29, Branching Ratio Measurements of Decays D 0  π - π + π 0, D 0  K - K + π 0 Relative to D 0  K - π + π 0 Giampiero Mancinelli,

Sinéad Farrington University of Glasgow for the CDF Collaboration European Physical Society Aachen, 17 th -23 rd July 2003 B Lifetimes and Flavour Tagging.

Stano Tokar, slide 1 Top into Dileptons Stano Tokar Comenius University, Bratislava With a kind permissison of the CDF top group Dec 2004 RTN Workshop.

Belle General meeting Measurement of spectral function in the decay 1. Motivation 2. Event selection 3. mass spectrum (unfolding) 4. Evaluation.

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)

B s Mixing Results for Semileptonic Decays at CDF Vivek Tiwari Carnegie Mellon University on behalf of the CDF Collaboration.

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.

Charmless Hadronic B Decays at BaBar

University of South Alabama

B  at B-factories Guglielmo De Nardo Universita’ and INFN Napoli

Susan Burke, University of Arizona

Observation of non-BBar decays of (4S)p+p- (1S, 2S)

Presentation transcript:

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 2002

Outline Introduction Analysis strategy Main aspects of the analysis Branching ratio results on data set.

Riunione Gruppo I – Napoli 19 Dicembre 2002 The decay B  D*l proceeds by the quark level decay b  c.  The decay rate therefore depends on |V cb |. The picture is complicated by the strong interaction b WW c gV cb B  D*l and the CKM element V cb On general ground, the amplitude is exact leptonic current : hadronic term calculated by means of non perturbative methods:

Riunione Gruppo I – Napoli 19 Dicembre 2002 Measurement of |V cb | from B  D*l Strong interaction effects can be studied by means of the Heavy Quark Effective Theory (HQET). differential decay rate Kinematics function Form factor. theoretical uncertainty of ~4% when w  1 Fitting dГ/dw, |V cb |F(w) is obtained. Theory ( HQET) provides F(w) allowing the extraction of |V cb |, by means of an extrapolation w  1 (zero recoil). CLEO

Riunione Gruppo I – Napoli 19 Dicembre 2002 Analysis strategy  Define selection criteria for the signal.  Study the backgrounds directly from data as far as possible.  Estimate remaining backgrounds from Monte Carlo simulation.  Determine the selection efficiency. Correct the Monte Carlo simulation evaluating the corresponding systematic uncertainty.  Fit signal and residual background from resonant and non-resonant semileptonic decays, exploiting available physical constraints (we studied both electron and muon channel and 4 D 0 decay modes)

Riunione Gruppo I – Napoli 19 Dicembre 2002 The data set analyzed 2000:20.25fb -1 on-resonance 2.60fb -1 off-resonance 2001:35.54 fb -1 on-resonance 3.79fb -1 off-resonance 2002: 24.30fb -1 on-resonance 3.19fb -1 off-resonance 2000 MC2001 MC2002 MC

Riunione Gruppo I – Napoli 19 Dicembre 2002 Event selection A Charged D* meson and a lepton (muon and electron) of opposite charge are reconstructed  the D* meson is reconstructed from the D *  D 0  soft  D 0 reconstructed in 4 modes The Neutrino is NOT reconstructed e/e/ D0D0 ss B D 0 is reconstructed in 4 decay modes Constrained vertex fit on D 0 decay products, soft pion and lepton The signal is measured in 2  4 independent signal samples.

Riunione Gruppo I – Napoli 19 Dicembre 2002 Backgrounds The event is not from BB (continuum) Reconstructed D* is fake (combinatorial) lepton is fake (fake lepton) B  D* X the other B  l X (uncorrelated) The amount of these backgrounds are be estimated directly from experimental data

Riunione Gruppo I – Napoli 19 Dicembre 2002 Data samples definition

Riunione Gruppo I – Napoli 19 Dicembre 2002 Combinatorial background The mass difference  m=(M D * -M D ) discriminate real D* events against combinatorial events. Maximum likelihood fit, using a double gaussian for the peaking component and an empirical distribution for the background. The data set has been subdivided in several samples sharing the same peak and combinatorial parameters according to the different resolutions ( i.e. SVT only tracks w.r.t. DCH tracks) and background distributions.

Riunione Gruppo I – Napoli 19 Dicembre 2002 Continuum background D*  soft D0D0 K  e,  e+e+ e–e– c – c X The peak yield fitted in off-resonance experimental data has been scaled according to the known ratio of data collected on- resoncance and off-resonance. D*  soft D0D0 K  B0B0 e,  Signal

Riunione Gruppo I – Napoli 19 Dicembre 2002 Fake lepton background Signal leptons are tight leptons (maximum purity) Fake lepton sample composed by lepton candidates which fail the loose lepton identification criteria The PID selection efficiencies and mis-id probabilities as a function of momentum and direction are re-weighted according to our sample lepton momentum distribution the fraction of fake leptons in all samples are extracted measured yield efficiency matrixtrue number of events

Riunione Gruppo I – Napoli 19 Dicembre 2002 Uncorrelated background Events with a D* and a lepton in the same side are enriched in uncorrelated background. D*  soft D0D0 K  B0B0 e,  Signal Opposite-side Same- side signal other B D*  soft D0D0 K  B 0(+-) X B 0(-+) e,  Y

Riunione Gruppo I – Napoli 19 Dicembre 2002 Background characterization Fake D* Fake lepton continuum uncorrelated From data control samples

Riunione Gruppo I – Napoli 19 Dicembre 2002 Fitted Yields

Riunione Gruppo I – Napoli 19 Dicembre 2002 Correlated background  several decay modes contributing  the overall amount is small  Estimated from Monte Carlo simulation D*  soft D0D0 K  B 0(+–) e,  X D*  soft D0D0 K  B0B0 e,  - Signal

Riunione Gruppo I – Napoli 19 Dicembre 2002 Extraction of the signal After the background subtraction, the signal sample is composed by B  D*l and B  D** l and non resonant semileptonic decays with a D*. To disentangle the signal the variable cos  BY is used: muonselectrons signal D**

Riunione Gruppo I – Napoli 19 Dicembre 2002 Fit of signal and background components Least square fit to the 4 (D mode)  2 (lepton mode) data samples  all parameters free or imposing equal ratio of D* / D** fractions  signal and backgrounds shapes taken from Monte Carlo

Riunione Gruppo I – Napoli 19 Dicembre 2002 Examples of fit results electron - D 0  K  - year 2000muon - D 0  K  - year 2002

Riunione Gruppo I – Napoli 19 Dicembre 2002 Monte Carlo correction and systematics uncertainties Correction for PID Correction for tracking and  0 reconstruction efficiencies.  lepton, D 0 decay products but most important soft  tracking.

Riunione Gruppo I – Napoli 19 Dicembre 2002 Soft pion tracking efficiency The soft  momentum spectrum is really soft: 50 MeV <p T < 200 MeV From control sample D* decays the relative tracking efficiency between soft  and ordinary tracks has been measured

Riunione Gruppo I – Napoli 19 Dicembre 2002 Other systematics uncertainties D** background composition and shape modeling in Monte Carlo ( 2%). vertexing algorithm (1%) stability in the binning (1%) lepton momentum cut (1%)

Riunione Gruppo I – Napoli 19 Dicembre 2002 Branching fraction (blind!)

Riunione Gruppo I – Napoli 19 Dicembre 2002 Conclusions We have analyzed the largest D*l sample ever Systematics is dominant in the uncertainty. Some modes have large uncertainty. Most probably the K  and K 3  mode will be used for the measurement leaving the other two for a cross check. Dominant uncertainties does not depend on us f+/f0 ratio and D 0 PDG branching fractions! D** modeling is 2%. It may improve when D** measurements will be performed. soft pion efficiency is historically the main concern. We think we have it under control. Results are blind. BABAR internal review is started. They will give the OK for unblinding. Conference target: Moriond ( march 2003)

Riunione Gruppo I – Napoli 19 Dicembre 2002 Backup slides

Riunione Gruppo I – Napoli 19 Dicembre 2002