相关论文: Upsilon photoproduction at HERA compared to estima…
The amplitude for photoproduction gamma p -> \Upsilon p is calculated in a pQCD k_\perp-factorization approach. The total cross section for diffractive \Upsilon's is compared to recent HERA data. The amplitude is used to predict the cross…
The forward photoproduction amplitude for gamma p to Upsilon p is calculated in a pQCD k_t-factorization approach with an unintegrated gluon distribution constrained by inclusive deep-inelastic structure functions. The total cross section…
The photoproduction reaction gamma p -> mu+ mu- p has been studied in ep interactions using the ZEUS detector at HERA. The data sample corresponds to an integrated luminosity of 43.2 pb^{-1}. The Upsilon meson has been observed in…
The cross section for exclusive $\Upsilon$ ultraperipheral photoproduction at present and future colliders is determined using the low $x$ gluon PDF extracted from an analysis of exclusive $J/\psi$ measurements performed at HERA and the…
The exclusive photoproduction reaction gamma p -> Upsilon(1S) p has been studied with the ZEUS detector in ep collisions at HERA using an integrated luminosity of 468 pb^-1. The measurement covers the kinematic range 60<W<220 GeV and Q^2<1…
Cross sections for the diffractive photoproduction of the Upsilon-family at HERA energies, within the framework of the analysis by Frankfurt, Koepf and Strikman, are presented. They compare well with the recent preliminary data from ZEUS…
We compute the rate for diffractive upsilon meson production at the Tevatron and the LHC. The upsilon is produced diffractively via the subprocess gamma + p -> upsilon + p where the initial photon is radiated off an incoming proton (or…
The exclusive photoproduction reaction gamma p --> Upsilon p has been studied with the ZEUS experiment in ep collisions at HERA using an integrated luminosity of 468 pb^{-1}. The measurement covers the kinematic range 60<W<220 GeV and Q^2<1…
The diffractive photoproduction of vector mesons is usually described considering the two-gluon (Pomeron) exchange, non-diagonal parton distributions and the contribution of the real part to the cross section. In this letter we analyze the…
Predictions for the diffractive photoproduction of the $\Upsilon$-family at HERA energies, within the framework of the analysis by Frankfurt, Koepf and Strikman, are presented. Two novel effects lead to a significant enhancement of the…
We present a dispersive analysis with the aim to extract the $\Upsilon$-p scattering length from $\gamma p \to \Upsilon p$ experiments. In this framework, the imaginary part of the $\Upsilon$-p forward scattering amplitude is obtained from…
We use perturbative QCD and parton-hadron duality to estimate the cross sections for the diffractive electroproduction of rhoprime(1-) and rho(3-) resonances which occur in the 1.3-1.8 GeV mass interval. We present the cross sections and…
At the electron-proton collider HERA the inclusive $D^{*\pm}$ meson photoproduction cross section has been measured with the H1 detector in two different, but partly overlapping, kinematical regions. For the first, where $<W_{\gamma p}>…
I discuss Upsilon production in pp collisions at RHIC, Tevatron and LHC energies, in particular the behaviour of the differential cross section in rapidity and the impact of QCD corrections on the P_T differential cross section. I also…
W bosons can be produced in the channels e+- p -> W+- + X at HERA thus allowing to probe for anomalous trilinear couplings among the gauge bosons. We discuss the NLO QCD corrections to the photoproduction of W bosons with finite transverse…
We explore QCD calculations for the process gamma p -> V X where V is a vector meson, in the region s >> -t and -t >> Lambda_QCD^2. We compare our calculations for the J/psi, phi and rho mesons with data from the ZEUS Collaboration at HERA…
The production of $\Upsilon$ mesons in fixed target $pN$ collisions is considered. It is shown that Non-Relativistic QCD predicts $\Upsilon$ states to be produced with sizeable transverse polarization. The possibility of a measurement of…
We calculate the next-to-leading order QCD corrections to the `direct' part of the spin-dependent cross section for single-inclusive charged-hadron photoproduction. This process could be studied experimentally in future polarized…
W bosons can be produced in the channels e+- p --> W+- + X at HERA thus allowing anomalous trilinear couplings among the gauge bosons to be probed. We discuss the next-to-leading order (NLO) QCD corrections to the photoproduction of W…
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,…