Related papers: Novel features in exclusive vector--meson producti…
In this Letter we explore the modelling of hadron production in electromagnetic ion dissociation (EMD) processes in high-energy ultraperipheral collisions at LHC energies. Since EMD can accompany exclusive particle production in these…
The energy-dependent hotspot model is used to predict cross sections for vector-meson diffractive photo-nuclear production off oxygen ($\gamma$O) and neon ($\gamma$Ne) that can be extracted from ultra-peripheral O--O and Ne--Ne collisions,…
We investigate exclusive electroproduction of vector and pseudoscalar mesons at large photon virtuality $Q^2$. These reactions were analyzed within the handbag approach where amplitudes factorize into hard subprocesses and generalized…
Screening of initial parton production due to the presence of on-shell partons in high-energy heavy-ion collisions is discussed. It is shown that the divergent cross sections in the calculation of parton production can be regulated…
In the framework of the QCD shock-wave approach, we review our results on the description of diffractive production of various final states (jets, meson) at next-to-leading order. This is applied to exclusive diffractive dijet…
New results on elastic electroproduction and proton-dissociative photoproduction at large t of rho, phi and J/psi mesons are presented. They are interpreted within perturbative QCD.
Exclusive electroproduction of $\omega$ mesons on unpolarized hydrogen and deuterium targets is studied in the kinematic region of Q$^2$>1.0 GeV$^2$, 3.0 GeV < W < 6.3 GeV, and -t'< 0.2 GeV$^2$. Results on the angular distribution of the…
We report the first observation of exclusive $\rho$ production in ultra-peripheral collisions at RHIC. The $\rho$ are produced electromagnetically at large impact parameters where no hadronic interactions occur. The produced $\rho$ have a…
We present model independent constraints on the masses and couplings to fermions of $B$ and $L$ conserving leptoquarks. Such vector or scalar particles could have masses below 100 GeV and be produced at HERA; we list the generation…
The exclusive electroproduction of omega mesons, ep -> e omega p, has been studied in the kinematic range 3<Q^2<20 GeV^2, 40<W<120 GeV and |t|<0.6 GeV^2 with the ZEUS detector at HERA using an integrated luminosity of 37.7 pb^{-1}. The…
Exclusive rho0 electroproduction at HERA has been studied with the ZEUS detector, using 120 pb{-1} integrated luminosity, in the kinematic range of photon virtuality of 2 < Q2 < 160 GeV2, and gamma* p center-of-mass energy of 32 < W < 180…
We summarise recent progress in the computation of helicity amplitudes for diffractive vector meson production at large momentum transfer and their comparison to data collected at the HERA collider.
The NA60 experiment has studied low-mass muon pair production in proton-nucleus collisions with a system of Be, Cu, In, W, Pb and U targets, using a 400 GeV proton beam at the CERN SPS. The transverse momentum spectra of the $\rho/\omega$…
At high energy, exclusive meson photo- and electro-production give access to the structure of hadronic matter. At low momentum transfers, the exchange of a few Regge trajectories leads to a comprehensive account of the cross-sections. Among…
The elastic electroproduction of rho mesons is studied at HERA with the H1 detector for a photon virtuality in the range 1 < Q^2 < 60 GeV^2 and for a hadronic centre of mass energy in the range 30 < W < 140 GeV. The shape of the pipi mass…
Exclusive diffractive photoproduction of heavy vector mesons (V=phi, J/psi and Upsilon) at HERA is studied in a model employing a dipole Pomeron exchange (P) with an inelastic gamma-P-V vertex. The model is fitted to the data on dsigma/dt,…
Exclusive production of $\rho^0$ and $J/\psi$ mesons in e^+ p collisions has been studied with the ZEUS detector in the kinematic range $0.25 < Q^2 < 50 GeV^2, 20 < W < 167 GeV$ for the $\rho^0$ data and $2 < Q^2 < 40 GeV^2, 50 < W < 150…
By using a Regge-pole model for vector meson production (VMP), successfully describing the HERA data, we analyse the correlation between VMP cross sections in photon-induced reactions at HERA and those in ultra-peripheral collisions at the…
Exclusive pi0 electroproduction from nucleons can be related to transversity, the tensor charge, and other quantities related to transversity. This process isolates C-parity odd and chiral odd combinations of t-channel exchange quantum…
We present the results of exclusive electroproduction of vector mesons on the proton at CLAS. We discuss the interpretation of these cross sections in terms of t-channel Reggeon exchanges and in terms of Generalized Parton Distributions…