Related papers: Charm `in' the Photon
A study of the $\J$-meson photoproduction at large transverse momentum at HERA energies via the charm quark excitation in the photon is presented. Based on perturbative QCD, nonrelativistic quark model and photon structure function…
An overview is given of the ongoing measurement at HERA of the parton structure of the photon, as a function of its virtuality. Preliminary ZEUS results show disagreement with an NLO QCD calculation.
In the ZEUS experiment at HERA, photoproduction processes have been studied for photon-proton centre-of-mass energies in the range 100 < W_gamma p < 300 GeV and jet transverse energies extending to E_T^jet ~ 70 GeV. The data contribute to…
After the completion of data taking at HERA-2, a large data set is at hand to study the photoproduction of charm and beauty quarks in ep collisions. New measurements of charm production based on D^* meson tagging and beauty production based…
A number of ways are reviewed in which the study of charmed particles can answer corresponding questions about particles containing $b$ quarks. Topics include the properties of resonances, the magnitude of decay constants, the size of…
New high statistics, high resolution fixed target experiments producing $10^5$ - $10^6$ fully reconstructed charm particles are allowing a detailed study of the charm sector. Recent results on charm quark production from Fermilab fixed…
Two photon collisions offer a variety of physics studies that can be performed at the future electron-positron colliders. Using the planned CEPC parameters as a benchmark we consider several topics to be studied in the two-photon…
We review the present theoretical knowledge of the charm--strange contribution to charged--current DIS structure functions. In particular, the uncertainties arising from the choice of the factorization scale, of the massive QCD scheme, and…
LEP offers an excellent opportunity to measure two photon processes over a large kinematical range and thus study the complex nature of the photon. This article reviews the experimental status of ``Two Photon Physics'' at LEP. The recent…
Two recent results in ep physics using the ZEUS detector at HERA are discussed: a measurement of the prompt photon production cross section in photoproduction, and the first observation of Deeply Virtual Compton Scattering in DIS.
Production of muons and neutrinos in cosmic ray interactions with the atmosphere has been investigated with Monte Carlo models for hadronic interactions. The resulting conventional muon and neutrino fluxes (from $\pi$ and $K$ decays) agree…
We present the dependence of $D$ production on the charged particle multiplicity in proton-proton collisions at LHC energies. We show that, in a framework of source coherence, the open charm production exhibits a growth with the…
Open charm hadrons are excellent probe to study the dynamics of quarks and gluons inside hadrons. Because the mass of a charm quark is heavier than $\Lambda_{QCD}$, the so called heavy quark symmetry emerges in the hadron containing a charm…
Recent results on the study of the electromagnetic structure of nucleon resonances, the spin structure of proton and neutrons at small and intermediate photon virtualities, and the search for exotic pentaquark baryons are presented.
The electron and photon structure functions are compared. Advantages of the electron structure function are demonstrated. At very high momenta probabilistic (partonic) interpretation can be preserved despite strong $\gamma$-$Z$…
We study the properties of charmed hadrons in dense matter within a coupled-channel approach which accounts for Pauli blocking effects and meson self-energies in a self-consistent manner. We analyze the behaviour in this dense environment…
We possess convincing experimental evidence for the fact that the real photon has non-trivial parton structure. On the other hand, interactions of the cosmic microwave background photons with high energy particles propagating through the…
Charm photoproduction rates off nuclei below the nucleon threshold are estimated using the phenomenologically known structure functions both for x>1 and x<1. The rates rapidly fall below the threshold from values of the order 10 pb for Pb…
The predictions for the atmospheric neutrino flux at high energies strongly depend on the contribution of prompt neutrinos, which are determined by the production of charmed meson in the atmosphere at very forward rapidities. Here we…
Advances in manipulating the structure of optical beams enable the study of interaction between structured light and low-dimensional semiconductor systems. We explore the photocurrents in two-dimensional systems excited by such…