相关论文: The Transverse Cross Section in Exclusive Vector-M…
I present some results about transverse momentum dependent distribution and fragmentation functions. Firstly I illustrate a simple model, with predictive power about the energy behavior, for T-odd, chiral odd functions. Moreover I propose a…
We compute cross sections for incoherent and coherent diffractive J/Psi production in ultraperipheral nucleus-nucleus and proton-nucleus collisions using two different dipole models fitted to HERA data. We obtain a reasonably good…
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 investigate the transverse parton distribution of the proton through the t-dependence of the coherent J/psi differential cross section extracted from HERA measurements in the small-x regime. Employing a simple static Gaussian hot spot…
We present a study of the transverse size of parton showers and their diminishing interaction with the medium in the high virtuality stage of jet evolution. We consider the process of a hard quark produced in deep inelastic scattering off a…
A measurement is reported of differential top quark pair ($\mathrm{t\bar{t}}$) production cross sections, where top quarks are produced at large transverse momenta. The data collected with the CMS detector at the LHC are from pp collisions…
We report on our recent calculation for the off-shell ttA process and its potential for precision measurements by constructing ratios of total and differential cross sections. Precise theoretical predictions for these ratios can help to…
We study the possibility to produce single t-quarks both at LEP II and HERA. While within the Standard Model such reactions are not observable, the possibility exists in a wide class of dynamical models for the fermion mass generation.…
We investigate what can be learned at a linear collider about the sector of electroweak symmetry breaking from a precise measurement of the Higgs boson production cross section through the process e+e- -> hZ. We focus on deviations from the…
The t-channel exchange of a first generation leptoquark could contribute to the cross-section for q q-bar to e+e-. The leptoquark is off-shell, so this process can be sensitive to leptoquarks beyond the mass reach of pair production…
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…
Using methods from effective field theory, we develop a novel, systematic framework for the calculation of the cross sections for electroweak gauge-boson production at small and very small transverse momentum q_T, in which large logarithms…
The exclusive diffractive production of vector mesons and real photons in ep collisions has been studied at HERA in a wide kinematic range. Here the most recent experimental results are presented together with a Regge-type model and…
The production of prompt photons is measured in the photoproduction regime of electron-proton scattering at HERA. The analysis is based on a data sample corresponding to a total integrated luminosity of 340 pb^-1 collected by the H1…
Experimental results from HERA on diffractive vector meson production and their theoretical interpretation within microscopic QCD are reviewed with an emphasis on the BFKL color dipole and kt-factorization approaches.
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}>…
Since the start of HERA operation there has been considerable progress in the understanding of jet production in e p collisions. QCD calculations are now able to accommodate the hadronic structure of the virtual photon. The luminosities…
We present a measurement of the differential cross section for $t\bar{t}$ events produced in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV as a function of the transverse momentum ($p_T$) of the top quark. The selected events contain a…
The double-differential inclusive di-jet cross section in photoproduction processes is measured with the H1 detector at HERA. The cross section is determined as a function of the average transverse jet energy E_T^jets for ranges of the…
The normalised differential top quark-antiquark production cross section is measured as a function of the jet multiplicity. Using a procedure to associate jets to decay products of the top quarks, the differential cross section of the ttbar…