Related papers: $\tau_{B_c}$ in the Standard Model
The collection of a large number of $B$ hadron decays to hadronic final states at the CDF II detector is possible due to the presence of a trigger that selects events based on track impact parameters. However, the nature of the selection…
We give a review and present a comprehensive calculation for the leptonic constant B_{c} of the low-lying pseudoscalar and vector states of B_{c}-meson in the framework of static and QCD-motivated nonrelativistic potential models taking…
Recently hints of lepton flavor non-universality emerged when the BaBar Collaboration observed deviations from the standard model predictions in $R(D^{(*)}) \equiv {\cal B}({\bar B} \to D^{(*)+} \tau^- {\bar\nu}_\tau) / {\cal B}({\bar B}…
A measurement of the effective $B^0_s\rightarrow K^+K^-$ lifetime is presented using approximately $37 pb^{-1}$ of data collected by LHCb during 2010. This quantity can be used to put constraints on contributions from processes beyond the…
We use the heavy quark expansion to investigate the width difference $\Delta\Gamma_{B_s}$ between the $B_s$ mass eigenstates. The corrections of ${\cal O}(\Lambda_{QCD}/m_b)$ and ${\cal O}(m_s/m_b)$ to the leading order expression in the…
\Lambda_b matrix element of four-quark operator relevant to its lifetime is reanalyzed by QCD sum rule. The new ingredients introduced are that (1) more vacuum condensates are considered; (2) different quark-hadron duality is adopted; and…
The article provides a theoretical substantiation for a significant increase in the level of accuracy in determining the neutron lifetime using an alternative concept of neutron beta decay. Neutrons are distributed among different subsets…
We study $B_c \to (D,\,D^{\ast})\,l\,\nu$ semileptonic decays mediated via $b \to u\,l\,\nu$ charged current interactions using the $B_c \to (D,\,D^{\ast})$ transition form factors obtained in the covariant light front quark model. We give…
We study the lifetime and weak decays of the full-heavy S-wave $0^+$ tetraquark $T^{\{bb\}}_{\{\bar c\bar c\}}$. Using the operator product expansion rooted in heavy quark expansion, we find a rather short lifetime, at the order…
The author considers a hypothesis of neutron lifetime splitting in beta-decay and shows that the beta-decay of neutrons could be described by the triad of lifetimes tau_{Left}, tau_{Mean}, tau_{Right}. The lifetime tau_{Left} is the…
We present the first lattice QCD calculation of the decay constants f_B and f_{B_s} with physical light quark masses. We use configurations generated by the MILC collaboration including the effect of u, d, s and c HISQ sea quarks at three…
We present a study of the decay B_s^0 -> J/psi phi We obtain the CP-odd fraction in the final state at time zero, R_perp = 0.16 +/- 0.10 (stat) +/- 0.02 (syst), the average lifetime of the (B_s, B_sbar) system, tau (B_s^0)…
We present updated predictions for lifetimes of doubly charmed baryons, within the heavy quark expansion, including available NLO $\alpha_s$ contributions and newly-computed terms in the $1/m_c$ series. Our improved results confirm the…
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…
We present a model-independent prediction for $R(\eta_c) \! \equiv \! \mathcal{BR} (B_c \rightarrow \eta_c \, \tau^+\nu_\tau)/ \mathcal{BR} (B_c \rightarrow \eta_c \, \mu^+\nu_\mu)$. This prediction is obtained from the form factors through…
The neutron lifetime is determined for now most accurately by two methods --the so-called "beam method" and the method of neutron storage in a trap. The goal of this research is to obtain the neutron lifetime with a higher precision by…
In this work, we have conducted a comprehensive and systematic theoretical investigation of the full cascade decays of charged pseudoscalar mesons, specifically $D_s$, $D$, $B$, and $B_c$, into $\tau \nu_\tau$, followed by the subsequent…
Recent measurements of lifetimes of some $b$-flavored hadrons are presented and interpreted in the context of theoretical models, especially the Heavy Quark Expansion. Decay widths and decay width differences in the $B_s^0-\overline{B}_s^0$…
We study the lifetimes and inclusive semileptonic decay widths of doubly heavy baryons within the framework of heavy quark expansion. Our analysis includes next-to-leading-order corrections to the dimension-3, -5, and -6 operators, together…
The HQET sum rule analysis for the \Lambda_b matrix element of the four-quark operator relevant to its lifetime is reported. Our main conclusion is that the lifetime ratio \tau(\Lambda_b)/\tau(B^0) can be as low as 0.91.