相关论文: D* Production in Two-Photon Collisions
The production of prompt D$^{0}$, D$^{+}$, and D$^{*+}$ mesons was measured at midrapidity (|y|< 0.5) in Pb-Pb collisions at the centre-of-mass energy per nucleon-nucleon pair $\sqrt{s_{\rm NN}}$ = 5.02 TeV with the ALICE detector at the…
We suggest that generalized parton distributions can be probed in charged current meson production process, $ep\to\nu_{e}\pi^{-}p$. In contrast to pion photoproduction, this process is sensitive to the unpolarized GPDs $H,\,E$, and for this…
We propose a new experimental method to probe the photon parton distribution function inside the proton (photon PDF) at LHC energies. The method is based on the measurement of dilepton production from the $\gamma p\rightarrow\ell^+\ell^-+X$…
We consider the exclusive photoproduction of a di-meson pair with large invariant mass, $\gamma N \rightarrow N' M_1M_2$, in the framework of collinear factorisation. The mesons considered $M_1$ and $M_2$ are either pions or rho mesons,…
We point out that the cross-section for the process $e^+ e^- \to e^+ e^- \tau^+ \tau^-$ at LEP is large enough to allow for a study of the anomalous electromagnetic couplings of the $\tau$ lepton. We show that the present bounds on the…
A global QCD analysis of the direct photon production process from both fixed target and collider experiments is presented. These data sets now completely cover the parton $x$ range from 0.01 to 0.6, thereby providing a stringent test of…
We calculate large mass diphoton exclusive photoproduction in the framework of collinear QCD factorization at next to leading order in {\alpha}s and at leading twist. Collinear divergences of the coefficient function are absorbed by the…
We propose a holographic model for dilepton production in proton-proton collisions based on the exchange of vector mesons. The holographic hard wall model is used to describe the dynamics and interactions of vector mesons and baryons. We…
We consider direct diphoton production in hadron collisions, and we compute the next-to-next-to-leading order (NNLO) QCD radiative corrections at the fully-differential level. Our calculation uses the $q_T$ subtraction formalism and it is…
We present new sets of nonperturbative fragmentation functions for D^*+- mesons, both at leading and next-to-leading order in the MS-bar factorization scheme with five massless quark flavors. They are determined by fitting the latest OPAL…
In these proceedings we present the latest results from ALICE on direct photon and light neutral meson production in p$-$Pb and Pb$-$Pb collisions. The direct photon excess ratio $R_{\gamma}$ in different charged particle multiplicity…
A remarkable number of studies have been performed at LEP in the field of two-photon physics in the last four years. These results represent a very important contribution to the understanding of strong interactions at low energies. In…
We present a fully relativistic and gauge invariant framework for calculating the cross sections of dilepton production in nucleon-nucleon ($NN$) collisions which is based on the meson-exchange approximation for the $NN$ scattering…
We estimate the differential and total cross sections for both the photoproduction of vector D*-meson and its yield in deep inelastic scattering at the HERA collider in the framework of model motivated by perturbative calculations in QCD.…
We report a measurement of $\phi$ meson production in central Pb+Au collisions at E$_{lab}$/A=158 GeV. For the first time in heavy-ion collisions, $\phi$ mesons were reconstructed in the same experiment both in the K$^+$K$^-$ and the…
In this work, we provide a comprehensive set of differential cross-section distributions for photon + di-jet production in proton-proton collisions with next-to-next-to-leading order precision in massless QCD. The event selection…
The process e+e- to 2 (or 3) gammas is studied using data recorded with the OPAL detector at LEP. The data sample taken at a centre-of-mass energy of 189 GeV corresponds to a total integrated luminosity of 178 pb-1. The measured…
The possibility to measure diffraction dissociation in collisions of real and virtual photons at LEP2 is pointed out.
The status of predictions for fermion-pair production at LEP is summarized with emphasis on LEP2 energies and on the physics interest there. Some numerical comparisons with other programs are performed. We also present first results of a…
The production of D*+-(2010) mesons in ep scattering in the range of exchanged photon virtuality 0.05 < Q^2 < 0.7 GeV^2 has been measured with the ZEUS detector at HERA using an integrated luminosity of 82 pb-1. The decay channels D*+ -> D0…