相关论文: Atmospheric neutrinos from charm
Updated standard model predictions for $D_{(s)} \to P l^+ l^-$, $l=e,\mu$, $P=\pi,K$ and inclusive decays are presented. Model-independent constraints on $|\Delta C|=|\Delta U|=1$ Wilson coefficients are worked out. New physics (NP)…
We determine the charm quark mass $\hat{m}_c$ from QCD sum rules of moments of the vector current correlator calculated in perturbative QCD at ${\cal O} (\hat\alpha_s^3)$. Only experimental data for the charm resonances below the continuum…
We point out the opportunity of tau neutrino astronomy for neutrino energies of the order of 10 GeV to 10$^{3}$ GeV. In this energy range, it is demonstrated that the flavor dependence in the background atmospheric neutrino flux leads to…
Ultrahigh energy neutrinos can provide important information about the distant astronomical objects and the origin of the Universe. Precise knowledge about their interactions and production rates is essential for estimating background,…
We present a strategy designed to separate several possible origins of the well-known enhancement of the Delta{I}=1/2 amplitude in non-leptonic kaon decays. In particular, we seek to disentangle the contribution of physics at the typical…
I briefly review the status and recent progress in the theoretical understanding of non-leptonic decays of beauty and charm hadrons. Focusing on a personal selection of topics, this covers perturbative calculations in quantum…
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…
The physics of charm has become one of the best laboratories exposing the limitations of the naive constituent quark model and also giving hints into a more mature description of hadron spectroscopy. Recent discoveries are a challenge that…
We study the relative contribution of partonic sub-processes to D meson production and D meson-triggered inclusive di-hadrons to lowest order in perturbative QCD. While gluon fusion dominates the creation of large angle DD-bar pairs, charm…
We perform a next-to-next-to-leading order (NNLO) QCD analysis of the charm-top-quark contribution eta_ct to the effective Delta S = 2 Hamiltonian in the Standard Model. eta_ct represents an important part of the short distance contribution…
Recent PHENIX Au+Au -> e- + X data from open charm decay are shown to be consistent with two extreme opposite dynamical scenarios of ultra-relativistic nuclear reactions. Perturbative QCD without final state interactions was previously…
We argue that the inclusion of the flavour-changing charged currents in the analysis of the Charm II data on neutrino- electron scattering could substantially change a fit of the effective couplings and makes impossible to draw any final…
The possibility of a (sizable) nonperturbative contribution to the charm parton distribution function (PDF) in a nucleon is investigated together with theoretical issues arising in its interpretation. Results from the global PDF analysis…
The kaon number density in nucleus+nucleus and p+p reactions is investigated for the first time as a function of the initial energy density $\epsilon$ and is found to exhibit a discontinuity around $\epsilon$=1.3 GeV/fm$^3$. This suggests a…
We present results of various searches for leptonic decays of charm mesons performed with the Belle detector. Also discussed are $D^0 \to \gamma\gamma$ decays.
It is well known that large nonfragmentational contributions to inclusive production of charmed particles appear at low energies. In the case of charm production in $B$-meson decays these contributions arise from the participation of the…
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…
Current experimental information on the charm meson decay observables in which the $c\to s\ell\nu_\ell$ transitions occur is well compatible with the Standard Model predictions. Recent precise lattice calculations of the $D_s$ meson decay…
We investigate the possibility of a (sizable) nonperturbative contribution to the charm parton distribution function (PDF) in a nucleon, theoretical issues arising in its interpretation, and its potential impact on LHC scattering processes.…
The drag and diffusion coefficients of a hot hadronic medium have been evaluated by using hidden charm mesons as probes. The matrix elements for the evaluation of these coefficients are calculated using an effective theory as well as from…