We present recent measurements by the CDF and D0 Collaborations at the Tevatron Collider on the masses and lifetimes of B hadrons. The results are compared to predictions based on Heavy Quark Effective Theory, lattice gauge theory, and quark models.
Measurements of the masses, lifetimes and decay modes of hadrons at Tevatron
Tevatron提供1.96 TeV ppbar碰撞,并允许收集丰富的b-强子样品到两个实验CDF和D 0。对重口味特性的研究为研究标准模型(SM)的口味部分和寻找新物理学(NP)的线索提供了一个富有成效的机会。在这里,我们报告的第一次测量的极化振幅在B^0_s的无粲衰变,世界领先的结果,b-强子寿命,和测量的其他几个性质的b-强子。
We present the theoretical status of the lifetimes of weakly decaying heavy hadrons containing a bottom or a charm quark, and discuss the current predictions, based on the framework of the Heavy Quark Expansion (HQE), for both mesons and baryons. Potential improvements to reduce the theoretical uncertainties are also highlighted.
Hadronic resonances, having very short lifetime, like $\rm{K}^{*0}$, can act as useful probes to understand and estimate lifetime of hadronic phase in ultra-relativistic proton-proton, p--Pb and heavy-ion collisions. Resonances with relatively longer lifetime, like $ϕ$ meson, can serve as a tool to locate the QGP phase boundary. We estimate a lower limit of hadronic phase lifetime in Cu--Cu and Au--Au collisions at RHIC, and in pp, p--Pb and Pb--Pb collisions at different LHC collision energies. Also, we obtain the effective temperature of $ϕ$ meson using Boltzmann-Gibbs Blast-Wave function, w…
We provide an extensive study of the lifetimes of singly charmed baryons and mesons, within the heavy quark expansion with all known corrections included. A special attention is devoted to the choice of the charm mass and wavefunctions of heavy baryons. We give our predictions for lifetimes, lifetime ratios, and semileptonic branching ratios of singly charmed baryons. Our results accommodate the experimentally-favoured hierarchy of singly charmed baryon lifetimes \begin{eqnarray*} τ\left(Ξ_c^{0}\right) < τ\left(Λ_c^{+}\right)< τ\left(Ω_c^{0}\right) < τ\left(Ξ_c^{+}\right)\, \end{eqnarray*} in …
We report on absolute lifetime measurements of charmed hadrons using the data collected by the Belle II experiment between 2019 and 2021. The measured lifetimes of $D^0$, $D^+$, and $Λ_c^+$ are the most precise to date and consistent with previous measurements. Our result indicates that $Ω_c^0$ is not the shortest-living singly charmed baryon.
Measurements are presented of the lifetimes of the B$^0$, B$^0_\mathrm{s}$, $Λ^0_\mathrm{b}$, and B$_\mathrm{c}^+$ hadrons using the decay channels B$^0\to$ J/$ψ$K*(892)$^0$, B$^0\to$J/$ψ$K$^0_\mathrm{S}$, B$^0_\mathrm{s}\to$J/$ψπ^+π^-$, B$^0_\mathrm{s}\to$J/$ψϕ$(1020), $Λ^0_\mathrm{b}\to$J/$ψΛ^0$, and B$_\mathrm{c}\to$J/$ψπ^+$. The data sample, corresponding to an integrated luminosity of 19.7 fb$^{-1}$, was collected by the CMS detector at the LHC in proton-proton collisions at $\sqrt{s}=$ 8 TeV. The B$^0$ lifetime is measured to be 453.0 $\pm$ 1.6 (stat) $\pm$ 1.8 (syst) $μ$m in J/$ψ$K*(892…
The lifetimes of bottom and charmed hadrons are analyzed within the framework of the heavy quark expansion (HQE). Lifetime differences arise from the spectator effects such as weak $W$-annihilation and Pauli interference. Spectator effects originating from dimension-7 four-quark operators are derived. Hadronic matrix elements of four-quark operators are parameterized in a model-independent way. Using the dimension-6 bag parameters recently determined from HQET sum rules and the vacuum insertion approximation for meson matrix elements of dimension-7 operators, the calculated $B$ meson lifetime …
The color confinement can be decently explained by assuming the global $SU(3)$ color symmetry. A hadron is viewed as a bag of a finite size, whose energy is contributed by the color fields within the hadron. In the large momentum frame, the mass of a hadron can be quantized and can be expressed as the sum of the current masses of quarks involved plus a flavor independent term which depends on a universal parameter and can be identified to be the contribution from the QCD trace anomaly. This term depicts the Regge's trajectories of light hadron masses, from which the parameter can be determined…
Using a simple geometric framework with a realistic nuclear density distribution, we fit published HERMES data to determine fundamental properties of hadronization using the nuclear medium as a spatial analyzer. Our approach uses a fit to the transverse momentum broadening observable and the hadronic multiplicity ratio; the simultaneous fit to two different observables strongly constrains the outcome. Using the known sizes of the target nuclei, we extract the color lifetime, finding a z$\mathrm{_h}$-dependent range of values from 2 to 8 fm/c for these data. We also extract estimates for the $\…
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 review the development and the current status of the HQE, which just recently passed several non-trivial experimental tests with an unprecedented precision. In view of many new experimental results for lifetimes of heavy hadrons, we also update several theory predictions: $τ(B^+) / τ(B_d) = 1.04^{+0.05}_{-0.01} \pm 0.02 \pm 0.01$, $τ(B_s) / τ(B_d) = 1.001 \pm 0.…