0000000000295249

AUTHOR

Mohammad Alam Saeed

showing 9 related works from this author

Measurement of the spin of the Xi(1530) resonance

2008

The properties of the Xi(1530) resonance are investigated in the Lambdac+ --> Xi- pi+ K+ decay process. The data sample was collected with the BaBar detector at the SLAC PEP-II asymmetric-energy e+ e- collider operating at center of mass energies 10.58 and 10.54 GeV. The corresponding integrated luminosity is approximately 230 inverse fb. The spin of the Xi(1530) is established to be 3/2. The existence of an S-wave amplitude in the Xi- pi+ system is inferred, and its interference with the Xi(1530)0 amplitude provides the first clear demonstration of the Breit-Wigner phase motion expected for the Xi(1530). The P_1(cos[theta(Xi-)]) Legendre polynomial moment indicates the presence of a sig…

Nuclear and High Energy PhysicsBABARElectron–positron annihilationFOS: Physical sciencesDalitz plotMASSPARTICLE PHYSICS; PEP2; BABAR01 natural sciencesHigh Energy Physics - ExperimentNuclear physicsHigh Energy Physics - Experiment (hep-ex)Particle decay0103 physical sciencesPEP2MASS; PARITY; WIDTH[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]010306 general physicsPhysicsPARITY010308 nuclear & particles physicsHyperonWIDTHResonanceBABAR detectorHEPCharmed baryonsAmplitudeBaBarPARTICLE PHYSICSCenter of massFísica de partículesExperiments
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Measurements of Branching Fractions andCP-Violating Asymmetries inBMeson Decays to Charmless Two-Body States Containing aK0

2003

We present measurements of branching fractions and \CP-violating asymmetries in decays of $B$ mesons to two-body final states containing a \Kz. The results are based on a data sample of approximately 88 million \upsbb decays collected with the \babar detector at the \pep2 asymmetric-energy $B$ Factory at SLAC. We measure $\BR(\Bp\to\Kz\pip) = (22.3 \pm 1.7 \pm 1.1)\times 10^{-6}$, $\BR(\Bz\to\Kz\piz) = (11.4\pm 1.7\pm 0.8)\times 10^{-6}$, $\BR(\Bp\to\Kzb\Kp) < 2.5\times 10^{-6}$, and $\BR(\Bz\to\KzKzb) < 1.8\times 10^{-6}$, where the first uncertainty is statistical and the second is systematic, and the upper limits are at the 90% confidence level. In addition, the following \CP-violating a…

Systematic errorPhysicsParticle physicsMeson010308 nuclear & particles physicsBranching fractionmedia_common.quotation_subjectElectron–positron annihilationAnalytical chemistryGeneral Physics and AstronomyBranching (polymer chemistry)Asymmetry01 natural sciencesNuclear physicsParticle decayPion0103 physical sciencesCP violationB meson010306 general physicsmedia_commonPhysical Review Letters
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Search forB-meson decays to two-body final states witha0(980) mesons

2004

We present a search for B decays to charmless final states involving charged or neutral a0 mesons. The data sample corresponds to 89 million BBbar pairs collected with the BABAR detector operating at the PEP-II asymmetric-energy B Factory at SLAC. We find no significant signals and determine the following 90% C.L. upper limits: BR(B0 -> a0-pi+) a0-K+) a0-K0bar) a00pi+) a00K+) a00K0) a0X and a0 -> etapi, where X indicates K or pi.

PhysicsNuclear and High Energy PhysicsParticle physicsMeson010308 nuclear & particles physicsBranching fractionHadronElementary particle01 natural sciencesParticle identificationB-factoryNuclear physicsParticle decay0103 physical sciencesB meson010306 general physicsPhysical Review D
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Searches for Lepton Flavor Violation in the Decaysτ±→e±γandτ±→μ±γ

2010

Searches for lepton-flavor-violating decays of a tau lepton to a lighter mass lepton and a photon have been performed with the entire data set of (963 +/- 7) x 10(6) tau decays collected by the BABAR detector near the Y(4S), Y(3S) and Y(2S) resonances. The searches yield no evidence of signals and we set upper limits on the branching fractions of B(tau(+/-) -> e(+/-)gamma) mu(+/-)gamma) < 4.4 X 10(-8) at 90% confidence level.

PhysicsParticle physics010308 nuclear & particles physicsBranching fractionElectron–positron annihilationHigh Energy Physics::PhenomenologyGeneral Physics and AstronomyElementary particle01 natural sciencesParticle identificationNuclear physicsParticle decay0103 physical sciencesCP violationHigh Energy Physics::ExperimentB meson010306 general physicsLeptonPhysical Review Letters
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Measurement of Branching Fractions and Charge Asymmetries inBDecays to anηMeson and aK*Meson

2006

We present measurements of branching fractions and charge asymmetries for the decays B-->etaK*, where K* indicates a spin 0, 1, or 2 Kpi system. The data sample corresponds to 344x10(6) BB pairs collected with the BABAR detector at the PEP-II asymmetric-energy e+ e- collider at SLAC. We measure the branching fractions (in units of 10(-6): B(B0-->etaK*0(892))=16.5+/-1.1+/-0.8, B(B+-->etaK*+(892))=18.9+/-1.8+/-1.3, B(B0-->eta(Kpi)0*0)=11.0+/-1.6+/-1.5, B(B+-->eta(Kpi)0*+)=18.2+/-2.6+/-2.6, B(B0-->etaK2*0(1430))=9.6+/-1.8+/-1.1, and B(B+-->etaK2*+(1430))=9.1+/-2.7+/-1.4. We also determine the charge asymmetries for all decay modes.

PhysicsParticle physicsMeson010308 nuclear & particles physicsBranching fractionElectron–positron annihilationEta mesonGeneral Physics and AstronomyBranching (polymer chemistry)01 natural sciencesParticle decayPair production0103 physical sciences010306 general physicsPhysical Review Letters
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Measurement of branching fractions and charge asymmetries for exclusive B decays to charmonium

2005

We report measurements of branching fractions and charge asymmetries of exclusive decays of neutral and charged B mesons into two-body final states containing a charmonium state and a light strange meson. The charmonium mesons considered are J/Psi, Psi(2S) and Chi_c1, and the light meson is either K or K*. We use a sample of about 124 million BBbar events collected with the BABAR detector at the PEP-II storage ring at the Stanford Linear Accelerator Center.

Molecular dynamicElectron–positron annihilationHigh Energy Physics::LatticeBABARNuclear TheoryGeneral Physics and Astronomy01 natural sciences13.25.Hw 11.30.Er 12.15.HhElectron positronlaw.inventionHigh Energy Physics - ExperimentHigh Energy Physics - Experiment (hep-ex)Mathematical modellawB mesons; charm particles; chi mesons; kaon production; meson hadronic decay; psi mesons[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]PEP2B mesonNuclear ExperimentConstraint theorymedia_commonPhysicsAnnihilationEnergy dissipationSettore FIS/01 - Fisica SperimentaleQuarkonium strange mesonParticle physicsMESONSpair production [B]PARTICLE PHYSICSBranching fractionSLACOptimizationParticle physicsSiliconMesonmedia_common.quotation_subjectFOS: Physical sciencesCharged particleAnnihilationAsymmetryPARTICLE PHYSICS; PEP2; BABARNuclear physics0103 physical sciencesbranching ratio [B0]Colliding beamsMESONS; BABAR; SLACBeam directionResistive plate chambers (RPC)010306 general physicshadronic decay [B]Calorimeter010308 nuclear & particles physicsBranching fractionHigh Energy Physics::PhenomenologyParticle acceleratorHEPbranching ratio [B+]Quantum theoryElectromagnetic calorimeters (EMC)High Energy Physics::ExperimentFísica de partículesExperimentsStorage ring
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Measurement of partial branching fractions of inclusive charmlessBmeson decays toK+,K0, andπ+

2011

We present measurements of partial branching fractions of B→K+X, B→K0X, and B→π+X, where X denotes any accessible final state above the endpoint for B decays to charmed mesons, specifically for momenta of the candidate hadron greater than 2.34 (2.36) GeV for kaons (pions) in the B rest frame. These measurements are sensitive to potential new-physics particles which could enter the b→s(d) loop transitions. The analysis is performed on a data sample consisting of 383×106BB pairs collected with the BABAR detector at the PEP-II e+e- asymmetric energy collider. We observe the inclusive B→π+X process, and we set upper limits for B→K+X and B→K0X. Our results for these inclusive branching fractions…

PhysicsNuclear and High Energy PhysicsParticle physicsMeson010308 nuclear & particles physicsBranching fractionHadronElementary particle7. Clean energy01 natural scienceslaw.inventionNuclear physicsParticle decayPionlaw0103 physical sciencesHigh Energy Physics::ExperimentB meson010306 general physicsColliderPhysical Review D
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Observation and study of the baryonicB-meson decaysB→D(*)pp¯(π)(π)

2012

We present results for B-meson decay modes involving a charm meson, protons, and pions using 455×106 BB pairs recorded by the BaBar detector at the SLAC PEP-II asymmetric-energy e^+e^- collider. The branching fractions are measured for the following ten decays: B ^0→D^0pp, B^0→D^(*0)pp, B^0→D^(*+)ppπ^-, B^0→D^(*+)ppπ^-, B-→D0ppπ^-, B-→D^(*0)ppπ^-, B^0→D^0pp π^-π^+, B^0→D^(*0)pp π^-π^+, B^-→D^+pp π^-π^-, and B^-→D^(*+)pp π^-π^-. The four B^- and the two five-body B^0 modes are observed for the first time. The four-body modes are enhanced compared to the three- and the five-body modes. In the three-body modes, the M(pp) and M(D^((*)0)p) invariant-mass distributions show enhancements near thre…

PhysicsNuclear and High Energy PhysicsParticle physicsMeson010308 nuclear & particles physicsElectron–positron annihilationDalitz plotBaBar detector01 natural scienceslaw.inventionBaryonPionlaw0103 physical sciencesMass spectrumB meson010306 general physicsColliderPhysical Review D
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Dalitz plot analysis of B−→D+π−π−

2009

We report on a Dalitz plot analysis of B- -> D+pi(-)pi(-) decays, based on a sample of about 383 x 10(6) Y(4S) -> B (B) over bar decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We find the total branching fraction of the three-body decay: B(B- -> D+ pi(-)pi(-)) = (1.08 +/- 0.03 +/- 0.05) x 10(-3). We observe the established D-2*(0) and confirm the existence of D-0*(0) in their decays to D+pi(-), where the D-2*(0) and D-0*(0) are the 2(+) and 0(+) c (u) over bar P-wave states, respectively. We measure the masses and widths of D-2*(0) and D-0*(0) to be: m(D2)*(0) = (2460.4 +/- 1.2 +/- 1.2 +/- 1.9) MeV/c(2), Gamma(D2*0) = (41.8 +/- 2.5 +/- 2.1 +/- 2.…

PhysicsNuclear and High Energy Physics010308 nuclear & particles physicsBranching fractionElectron–positron annihilationAnalytical chemistryParticle physicsDalitz plot01 natural sciencesB-factoryNuclear physicsParticle decay0103 physical sciencesPi010306 general physicsFísica de partículesExperimentsBar (unit)
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