相关论文: \Lambda_b Lifetime from the HQET Sum Rule

We present the CDF results using 1.0 fb^{-1} of data on the mixing frequency measurement in the B_s system and the lifetime measurements of several B hadrons. We obtain \Delta m_s=17.77 +- 0.1 +- 0.07 ps^{-1} and c\tau(\Lambda_b)=473.8 +-…

A phenomenological analysis of lifetimes of bottom and charmed hadrons within the framework of the heavy quark expansion is performed. The baryon matrix element is evaluated using the bag model and the nonrelativistic quark model. We find…

Over the last decade, conflicting values of the hypertriton ${}_{\Lambda}^3\mathrm{H}$ lifetime $\tau({}_{\Lambda}^3\mathrm{H})$ were extracted from relativistic heavy-ion (RHI) collision experiments, ranging from values compatible with the…

We present a calculation of subleading 1/m_b corrections to spectator effects in the ratios of beauty hadron lifetimes in heavy-quark expansion. We find that these effects are sizable and should be taken into account in systematic analyses…

We report a measurement of the Lambda_b lifetime in the exclusive decay Lambda_b --> J/psi Lambda0 in p-pbar collisions at sqrt(s) = 1.96 TeV using an integrated luminosity of 1.0 fb^{-1} of data collected by the CDF II detector at the…

In this work, we evaluate the contributions of non-spectator effects to the lifetimes of $\Lambda_b$ and B-mesons. Based on the well-established models and within a reasonable range of the concerned parameters, the contributions can reduce…

We have measured the Lambda_b lifetime using the exclusive decay Lambda_b to J/psi Lambda, based on 1.2 fb-1 of data collected with the D0 detector during 2002-2006. From 171 reconstructed Lambda_b decays, where the J/psi and Lambda are…

We review the current status of theoretical predictions for mixing quantities and lifetimes in the $B$-sector. In particular, due to the first non-zero measurement of the decay rate difference in the neutral $B_s$-system, $\Delta \Gamma_s/…

Kolya Uraltsev was one of the inventors of the Heavy Quark Expansion (HQE), that describes inclusive weak decays of hadrons containing heavy quarks and in particular lifetimes. Besides giving a pedagogic introduction to the subject, we…

We summarize theoretical calculations of B_c decays and lifetime in the framework of QCD sum rules and compare the results with the estimates by the methods of Operator Product Expansion in the inverse heavy quark masses as well as of…

The Standard Model prediction of the $B_c$ lifetime is discussed, together with the dominant uncertainties and strategies on how to improve them. Furthermore, a new method to compute the $B_c$ lifetime based on the operator product…

We study lifetimes and weak decays of the triply heavy tetraquarks ${b\bar c}{b\bar q}$. Following the heavy quark expanding(HQE), the lifetimes of tetraquarks ${b\bar c}{b\bar q}$ can be expressed as the summation of different dimension…

The heavy quark expansion implemented through an operator product expansion provides us with a treatment of inclusive decays of beauty and charm hadrons that is genuinely derived from QCD,though it requires one additional assumption, namely…

We review the theoretical status of the lifetime ratios $\tau_{B^+} / \tau_{B_d}$, $\tau_{B_s} / \tau_{B_d}$, $\tau_{\Lambda_b} / \tau_{B_d}$ and $\tau_{B_c}$ and of the mixing quantities $\Delta M_s$, $\Delta \Gamma_s$ and $\phi_s$.…

The hadronic matrix elements of dimension-six $\Delta F=0,2$ operators are crucial inputs for the theory predictions of mixing observables and lifetime ratios in the $B$ and $D$ system. We determine them using HQET sum rules for three-point…

The B-$\bar B$ mixing, B-meson lifetimes, the $B_{s}$-$\bar{B}_{s}$ lifetime difference and SUSY FCNC effects in $\Delta B=2$ processes are very important measurable quantities in B-meson phenomenology whose theoretical predictions depend…

B decay sum rules relate exclusive B semileptonic decay matrix elements to forward B-meson matrix elements of operators in HQET. At leading order the operators that occur are the b-quark kinetic energy $\lambda_1$ and chromomagnetic energy…

We calculate the dimension-six $\Delta Q=0$ four-quark matrix elements describing heavy-meson lifetime ratios using the gradient flow with its short flow-time expansion as a renormalization procedure. On six RBC/UKQCD 2+1-flavor domain-wall…

We calculate the lifetime of the hypertriton as function of the $\Lambda$ separation energy $B_\Lambda$ in an effective field theory with $\Lambda$ and deuteron degrees of freedom. We also consider the impact of new measurements of the weak…

Conflicting values of the hypertriton ($_{\Lambda}^{3}$H) lifetime were extracted in recent relativistic heavy-ion collision experiments. The ALICE Collaboration's reported $_{\Lambda}^{3}$H lifetime $\tau(_{\Lambda}^{3}$H) is compatible…