Related papers: Calculating the Two-photon Contribution to $\pi^0 …
We compute the decays ${B\to D^\ast_0}$ and ${B\to D^\ast_2}$ with finite masses for the $b$ and $c$ quarks. We first discuss the spectral properties of both the $B$ meson as a function of its momentum and of the $D^\ast_0$ and $D^\ast_2$…
We discuss the decay of a two-level system into an engineered reservoir of coupled harmonic oscillators in the single-excitation manifold and propose its optical simulation with an homogeneous chain of coupled waveguides where individual…
Using $6.32$ fb$^{-1}$ of $e^{+}e^{-}$ collision data collected at the center-of-mass energies between 4.178 and 4.226 GeV with the BESIII detector, we perform an amplitude analysis of the decay $D^+_s \to K^+\pi^+\pi^-$ and determine the…
Utilizing a data set corresponding to an integrated luminosity of 6.32~$\rm fb^{-1}$, recorded by the BESIII detector at center-of-mass energies between 4.178 and 4.226~GeV, we perform an amplitude analysis of the decay $D_{s}^{+} \to…
We derive the amplitude for the process $e^+e^-\to \pi^0\pi^0$ at large invariant energy. The process goes through the two-photon exchange and its amplitude is expressed in terms of the convolution integral which depends on the shape of the…
By employing a framework for the quasi-two-body decays in the perturbative QCD (PQCD) factorization approach, we calculate the branching ratios of the decays $B_{(s)} \to D (\rho(1450),\rho(1700))\to D \pi \pi$ with $D=(D_{(s)},…
We report the first calculation using physical light-quark masses of the electromagnetic form factor $V(z)$ describing the long-distance contributions to the $K^+\to\pi^+\ell^+\ell^-$ decay amplitude. The calculation is performed on a 2+1…
In view of the recent interest in the decays of mesons into a pair of light leptons, a computation of the QED radiative corrections to the decay of $\pi^{0}$ into an electron-positron pair is presented here. The results indicate that the…
After discussing the intrinsic ambiguity in determining the light quark mass ratio $m_u/m_d$, we reexamine the recent proposal that this ambiguity can be resolved by applying the QCD multipole expansion for the heavy quarkonium decays. It…
Using the Coulomb gauge formulation of QED we present a lattice QCD procedure to calculate the $\pi^+\pi^+$ scattering phase shift including the effects of the Coulomb potential which appears in this formulation. The approach described here…
A lattice calculation of the pseudoscalar decay constant of heavy-light mesons is reported. Results are obtained (in the quenched approximation) from lattices at $\beta=6.3$ through a procedure that interpolates between the static…
The first lattice QCD calculation of the form factors governing $\Lambda_c \to \Lambda \ell^+ \nu_\ell$ decays is reported. The calculation was performed with two different lattice spacings and includes one ensemble with a pion mass of…
Using $e^{+}e^{-}$ annihilation data corresponding to a total integrated luminosity of $6.32$ fb$^{-1}$ collected at the center-of-mass energies between 4.178 and 4.226 GeV with the BESIII detector, we perform an amplitude analysis of the…
We present the first amplitude analysis of the hadronic decay $D^+\to\pi^+\pi^0\pi^0$, using $e^{+}e^{-}$ collision data collected with the BESIII detector at a center-of-mass energy of 3.773~GeV, corresponding to an integrated luminosity…
We compute the two-loop QCD helicity amplitudes for the process e^+e^- --> q bar{q} g. The amplitudes are extracted in a scheme-independent manner from the coefficients appearing in the general tensorial structure for this process. The…
An amplitude analysis of the decay $D^0 \to K_S^0 \pi^0 \pi^0$ is performed to determine the relative magnitudes and phases of different intermediate processes. The analysis uses $e^+e^-$ collision data collected at the center-of-mass…
The Compton amplitude subtraction function is an essential component in work concerning both the proton radius puzzle and the proton-neutron mass difference. However, owing to the difficulty in determining the subtraction function, it…
A recently proposed approach to compute the inclusive semi-leptonic decay rate on the lattice allows for the calculation of various quantities (differential distributions and moments) in different subchannels. We systematically compare the…
We review the status of recent calculations by the RBC-UKQCD collaboration of the complex amplitude $A_2$, corresponding to the decay of a kaon to a two pion state with total isospin 2. In particular, we present preliminary results from two…
We present an amplitude analysis of the decay $D^{0} \rightarrow K^{-} \pi^{+} \pi^{+} \pi^{-}$ based on a data sample of 2.93 ${\mbox{\,fb}^{-1}}$ acquired by the BESIII detector at the $\psi(3770)$ resonance. With a nearly background free…