Absolute measurement of hadronic branching fractions of the Ds+ meson

The branching fractions of D(s)(+/-) meson decays serve to normalize many measurements of processes involving charm quarks. Using 298 pb(-1) of e(+)e(-) collisions recorded at a center of mass energy of 4.17 GeV, we determine absolute branching fractions for eight D(s)(+/-) decays with a double tag technique. In particular we determine the branching fraction B(D(s)(+)-->K(-)K(+}pi(+))=(5.50+/-0.23+/-0.16)%, where the uncertainties are statistical and systematic, respectively. We also provide partial branching fractions for kinematic subsets of the K(-)K(+)pi(+) decay mode.     

Precise measurement of B meson lifetimes with hadronic decay final states

The lifetimes of the B(0) and B- mesons are extracted from 29.1 fb(-1) of data collected with the Belle detector at the KEK B factory. A fit to the decay length differences of neutral and charged B meson pairs, measured in events where one of the B mesons is fully reconstructed in several hadronic modes, yields tau(B(0)) = 1.554+/-0.030(stat)+/-0.019(syst) ps, tau(B-) = 1.695+/-0.026(stat)+/-0.015(syst) ps, and tau(B-)/tau(B(0)) = 1.091+/-0.023(stat)+/-0.014(syst).     

On the lifetime of the kappa meson

The lifetime of a hypotheticalκ meson with low mass, introduced byGlashow andWeinberg in a model for simultaneous breaking ofSU(3) and chiral symmetry, is calculated. The coupling constant of theκ toKπ is obtained by assuming that the divergence of the strangeness changing vector current is dominated by theκ pole.     

A theoretical prediction of the B_s meson lifetime difference

We present the results of a quenched lattice calculation of the operator matrix elements relevant for predicting the width difference. Our main result is , obtained from the ratio of matrix elements . was evaluated from the two relevant B parameters and , which we computed in our simulation. Received: 13 June 2000 / Published online: 13 November 2000     

Observation of the decay Bc+/--->J/psipi+/- and measurement of the Bc+/- mass

The Bc+/- meson is observed through the decay Bc+/--->J/psipi+/-, in data corresponding to an integrated luminosity of 2.4 fb(-1) recorded by the Collider Detector at Fermilab II detector at the Fermilab Tevatron. A signal of 108+/-15 candidates is observed, with a significance that exceeds 8sigma. The mass of the Bc+/- meson is measured to be 6275.6+/-2.9(stat)+/-2.5(syst) MeV/c2.     

Feasibility study for the measurement of Bc meson mass and lifetime with the general purpose detector at the LHC

In this paper a feasibility study of the Bc meson to measure its mass and lifetime is described with the general purpose detector at the LHC.The study solely concentrated on the J/Ψπ+,J/Ψ→μ+μ- decay channel of the Bc and it was concluded that about 120 events can be selected in the first fb-1 of data.With this data sample,the mass resolution was estimated to be 2.0(stat.) MeV/c2 while the cr resolution was found to be 13.1(stat.) μm,I.e.the lifetime resolution to be 0.044(stat.) ps.     

Feasibility study for the measurement of Bc meson mass and lifetime with the general purpose detector at the LHC

In this paper a feasibility study of the B_c meson to measure its mass and lifetime is described with the general purpose detector at the LHC. The study solely concentrated on the J/ψπ⁺, J/ψ→μ⁺μ^－ decay channel of the B_c and it was concluded that about 120 events can be selected in the first fb^－1 of data. With this data sample, the mass resolution was estimated to be 2.0(stat.)MeV/c² while the cτ resolution was found to be 13.1(stat.)μm, i.e. the lifetime resolution to be 0.044(stat.)ps.     

Measurement of the lifetime difference in D0 meson decays

We report a measurement of the D0-D macro(0) mixing parameter y(CP) using 23.4 fb(-1) of data collected near the Upsilon(4S) resonance with the Belle detector at KEKB. y(CP) is measured from the lifetime difference of D0 mesons decaying into the K(-)pi(+) state and the CP-even eigenstate K(-)K(+). We find y(CP) = (-0.5+/-1.0(+0.7)(-0.8))x10(-2), where the first error is statistical and the second is systematic, corresponding to a 95% confidence interval -0.030相似文献   

Study of pure and semileptonic decays of Ds meson within R-parity violating supersymmetric model

We present the comaprative study of semileptonic and leptonic decays of Ds, D±and D0meson（D →M l＋-αl-β, D → l＋αlβ, D → l＋αvα;α,β=e,μ） within the framework of R-parity violating the（ Rp） Minimal Supersymmetric Standard Model（MSSM）. The comparison shows that combination and product couplings,（λβiα λ＊ ij qor λβqkλ＊αj k）contribution to the branching fractions of the said processes（under consideration） is consistent with or comparable to the experimental measurements in most of the cases. However, some cases exist where these contributions are highly suppressed. We identify such cases in our analysis and single out the important ones suitable for exploring in the future and current experiments.     

A measurement of the τ lifetime

We have reconstructed 695 three-track τ decay vertices using a high resolution drift chamber close to the interaction point. From the distribution of decay lengths we measure the lifetime to be (3.06 ±0.20±0.14)×10⁻¹³ s. Using this result we find that the ratio of charged weak coupling constant for the τ to that of the μ,G _τ/G _μ=0.967±0.040 consistent with the concept of lepton universality. On leave from Warsaw University, Poland Now at Hasylab, DESY Supported by Bundesministerium für Forschung und Technologie Supported by UK Science and Engineering Research Council Supported by CAICYT Supported by the Minerva Gesellschaft für Forschung GmbH Supported by US Dept. of Energy, contract DE-AC02-76ER000881 and by US Nat. Sci. Foundation Grant no INT-8313994 for travel Partially supported by grant CPBP 01.06