相关论文: Lepton Fluxes from Atmospheric Charm
We calculate the leading nonperturbative contributions to the effective Wilson coefficient of the four-fermion operators arising from the QCD penguin, and we demonstrate how the usual perturbative one loop contribution is augmented by…
The mass components of charmoniumlike states are investigated through the decomposition of QCD energy-momentum tensor (EMT) on lattice. The quark mass contribution $\langle H_m\rangle$ and the momentum fraction $\langle x\rangle$ of valence…
Opposite-sign lepton pairs ($ee$,$e\mu$ and $\mu\mu$) from open charm decay are proposed as a measure of nuclear shadowing effects. Via an approximate scaling the ratio of the dilepton spectra from $p+A$ to those from $pp$ reflects the…
We present the $x$-dependent nucleon and pion gluon distribution from lattice QCD using the pseudo-PDF approach, on lattice ensembles with $2+1+1$ flavors of highly improved staggered quarks (HISQ), generated by MILC Collaboration. We use…
Elliptic flow of charm hadrons is investigated based on the quark coalescence model. Due to the large difference between the charm quark and light quark masses, hadrons containing both light and charm quarks show a qualitatively different…
Recent experimental progress measuring the branching fractions of the heavy-baryon semileptonic decays $\Xi_c\to \Xi \ell \nu$ has stimulated theoretical interest and motivates precise lattice calculations of the form factors. Here we…
We argue that the strong jet quenching of heavy flavors observed in heavy-ion collisions is to a large extent due to binary scatterings in the quark-gluon plasma. It can be understood from first principles: the charm collision probability…
Studies of rare decays of charmed mesons into the final states containing leptons is an important vehicle in low-energy searches for new physics. I review theoretical implications of those studies involving transitions with and without…
We present the first study of the quark mass dependence of the heavy quark momentum and spatial diffusion coefficients using lattice QCD with light dynamical quarks corresponding to a pion mass of 320 MeV. We find that, for the temperature…
We study the perturbative QCD description of the HERA measurements of $F_2 (x, Q^2)$ using a gluon distribution that is obtained from an evolution incorporating angular ordering of the gluon emissions, and which embodies both GLAP and BFKL…
We report on our first set of results for charm physics, using a mixed-action setup with maximally twisted valence fermions on CLS $N_f=2+1$ ensembles. This setup avoids the need of improvement coefficients to subtract $O(am_c)$ effects.…
The role of the charm quark in the dynamics underlying the \Delta I = 1/2 rule for kaon decays can be understood by studying the dependence of kaon decay amplitudes on the charm quark mass using an effective \Delta S = 1 weak Hamiltonian in…
This is a summary of experimental results on photons, leptons, and heavy quarks presented at Quark Matter 2008. A first measurement of the bottom to charm contribution to the lepton spectrum has given experimental indication for the…
Analytic formulae are given for QCD corrections to the lepton spectra in decays of polarised up and down type heavy quarks. These formulae are much simpler than the published ones for the corrections to the spectra of charged leptons…
We discuss charm quark/antiquark and charmed meson production in association with one extra jet (gluon, quark, antiquark) at the LHC. The calculations are performed both in collinear and $k_T$-factorization approaches. Different…
In this paper we study the sensitivity of the flux of atmospheric muons to uncertainties in the primary cosmic ray spectrum and to the treatment of the geomagnetic field in a calculation. We use the air shower simulation program AIRES to…
We present our first set of results for charm physics, using the mixed-action setup introduced in a companion paper. Maximally twisted Wilson valence fermions are used on a sea of non-perturbatively $O(a)$-improved Wilson fermions, made up…
Charm production in pp collisions is considered in the framework of perturbative QCD. The values of two parameters, the charm quark mass $m_c$ and the QCD scale mu^2, are determined from the comparison of the theoretical calculations with…
We use a relativistic highly improved staggered quark action to discretize charm quarks on the lattice. We calculate the masses and the dispersion relation for heavy-heavy and heavy-light meson states, and show that for lattice spacings…
In this presentation, I discussed a) the charm total cross-section and its comparisons to measurements at other beam energies and pQCD calculations; b) the semileptonic decay of charmed hadrons and the sensitivity of non-photonic leptons to…