Related papers: Bag Parameters for Heavy Meson Lifetimes
We non-perturbatively determine the renormalization constant and the improvement coefficients relating the renormalized current and subtracted quark mass in O(a) improved two-flavour lattice QCD. We employ the Schr\"odinger functional…
We study the light-quark mass and spatial volume dependence of the matrix elements of $\Delta B=0$ four-quark operators relevant for the determination of $V_{ub}$ and the lifetime ratios of single-$b$ hadrons. To this end, one-loop diagrams…
The gradient flow exponentially suppresses ultraviolet field fluctuations and removes ultraviolet divergences (up to a multiplicative fermionic wavefunction renormalization). It can be used to describe real-space Wilsonian renormalization…
We review the theoretical status of the lifetime ratios $\tau_{B^+} / \tau_{B_d}$ and $\tau_{B_s} / \tau_{B_d}$ and of the mixing quantities $\Delta M_s$, $\Delta \Gamma_s$ and $\phi_s$. We show that the ratio $\Delta \Gamma_s / \Delta M_s$…
Lifetime differences of heavy hadrons can be consistently computed in heavy-quark expansion. The leading effects appear through spectator interactions at order 1/m_b^3. We compute a well-defined subset of 1/m_b^4 corrections to the lifetime…
We propose a continuous real space renormalization group transformation based on gradient flow, allowing for a numerical study of renormalization without the need for costly ensemble matching. We apply our technique in a pilot study of…
A critical review of the theoretical understanding of the lifetimes of beauty hadrons is given. A model-independent analysis using the heavy-quark expansion allows for a description of the lifetime ratios tau(B-)/tau(B0) and…
We present a determination of the charm quark mass in lattice QCD with three active quark flavours. The calculation is based on PCAC masses extracted from $N_\mathrm{f}=2+1$ flavour gauge field ensembles at five different lattice spacings…
Heavy fermion pair production in $e^+e^-$ annihilation is a fundamental process in hadron physics and is of considerable interest for various phenomena. In this paper, we will apply the Principle of Maximum Conformality (PMC) to provide a…
The masses, current couplings and widths of the fully heavy scalar tetraquarks $X_{\mathrm{4Q}}=QQ\overline{Q}\overline{Q}$, $Q=c, b$ are calculated by modeling them as four-quark systems composed of axial-vector diquark and antidiquark.…
We discuss the renormalisation properties of the full set of $\Delta F=2$ operators involved in BSM processes, including the definition of RGI versions of operators that exhibit mixing under RG transformations. As a first step for a fully…
Using quasipotential approach, we have studied exclusive semileptonic decays of heavy mesons with the account of relativistic effects. Due to more complete relativistic description of the $s$ quark more precise expressions for semileptonic…
We study heavy quarkonium production associated with gluons in $\rm e^+e^-$ annihilation as an illustration of the perturbative QCD (pQCD) factorization approach, which incorporates the first nonleading power in the energy of the produced…
Event-by-event viscous hydrodynamics is combined with heavy quark energy loss models to compute heavy flavor flow cumulants $v_2\{2\}$, $v_3\{2\}$, and $v_2\{4\}$ as well as the nuclear modification factors of $D^0$ and $B^0$ mesons in PbPb…
The lifetimes of charmed mesons have been measured using 2.75fb$^{-1}$ of data collected with the Belle detector at KEKB. Each candidate is fully reconstructed to identify the flavor of the charmed meson. The lifetimes are measured to be…
We present results of a lattice QCD application of a coordinate space renormalization scheme for the extraction of renormalization constants for flavour non-singlet bilinear quark operators. The method consists in the analysis of the…
We calculate the four-top quark operator contributions to the two-loop renormalization constants of the fermion and gluon fields, necessary to obtain the renormalization group equations for the fermion masses and the strong coupling…
X-space schemes are gauge-invariant, regulator-independent renormalization schemes that are defined by requiring position-space correlation functions of gauge invariant operators to be equal to their noninteracting values at particular…
Using the non-perturbative renormalization technique, we calculate the renormalization factors for quark bilinear operators made of overlap fermions on the lattice. The background gauge field is generated by the JLQCD and TWQCD…
The QCD corrections for the box diagrams are revisited for the case of a heavy top quark with $\mt = 174 \GeV$. We resolve first a longstanding discrepancy between two methods of calculation by showing that they give the same results when…