Related papers: A study on Delta u and Delta d in charged current …
Global polarizations ($P$) of $\Lambda$ ($\bar{\Lambda}$) hyperons have been observed in non-central heavy-ion collisions. The strong magnetic field primarily created by the spectator protons in such collisions would split the $\Lambda$ and…
A successful interpretation of the cross sections for elastic and inelastic vector meson production can be made if one assumes the underlying dynamics to be governed by hard partonic subprocesses. Extending these partonic approaches to…
The Spin Asymmetries of the Nucleon Experiment (SANE) performed inclusive, double-polarized electron scattering measurements of the proton at the Continuous Electron Beam Accelerator Facility at Jefferson Lab. A novel detector array…
In November 2010, the azimuthally symmetric WASA detector and the polarized proton beam of COSY, have been used to collect a high statistics sample of $\vec{p}p \rightarrow pp\eta$ reactions in order to determine the analyzing power as a…
We investigate the possibility to measure the spin content carried by the different quark flavors in a nucleon by means of polarized deep inelastic scattering with $W^\pm$ exchange at HERA. Such measurements require a polarized proton beam.…
We have substantially extended our analysis of the partonic content of the pomeron. Ambiguities in the normalization of the pomeron flux and the possiblity of a direct coupling of the pomeron to single quarks are discussed, yielding two…
We compare the parton distributions deduced in the framework of a quantum statistical approach for both the longitudinal and transverse degrees of freedom with the unpolarized distributions measured at Hera and with the polarized ones…
The production of $D^{*\pm}$ mesons in deep inelastic $ep$ scattering has been measured for exchanged photon virtualities $ 5<Q^2<1000 \gev^2 $, using an integrated luminosity of 363 pb$^{-1}$ with the ZEUS detector at HERA. Differential…
The luminosity of the electron-proton collider, HERA, will be increased by a factor of five during the long shutdown starting September 2000. At the same time longitudinal lepton beam polarisation will be provided for the collider…
Deep-inelastic ep scattering data, taken with the H1 and ZEUS detectors at HERA, are used to study the means and distributions of the event shape variables thrust, jet broadening, jet mass, C-parameter and two kinds of differential two-jet…
The distribution of the azimuthal angle for the charged hadrons has been studied in the hadronic centre-of-mass system for neutral current deep inelastic positron-proton scattering at HERA. Measurements of the dependence of the moments of…
Recent results from the ep (electron-proton) collider HERA are presented. Jet production and diffraction type reactions allow tests of predictions of Quantum Chromodynamics (QCD). Jet measurements are used to improve the combined H1-ZEUS…
Since its commissioning in 1991, the ep collider HERA has been running successfully for almost a decade without stopping improving its performance. In this report, the inclusive cross section and structure function measurements for the deep…
The H1 and ZEUS experiments are measuring diffractive interactions in ep collisions at HERA. Performing QCD fits of these data with NLO DGLAP, diffractive parton distribution functions can be calculated. These diffractive PDFs can be used…
A polarized, internal electron target gradually polarizes a proton beam in a storage ring. Here, we derive the spin-transfer cross section for $\vec e\,(p,\vec p\, )e$\ scattering. A recent measurement of the polarizing effect of a…
A detailed analysis is presented of the diffractive deep-inelastic scattering process $ep\to eXY$, where $Y$ is a proton or a low mass proton excitation carrying a fraction $1 - \xpom > 0.95$ of the incident proton longitudinal momentum and…
Measurements of charged particle distributions, sensitive to the underlying event, have been performed with the ATLAS detector at the LHC. The measurements are based on data collected using a minimum-bias trigger to select proton-proton…
Measurements of the production of events containing isolated high energy leptons (electrons and muons) produced in ep collisions have been performed with the H1 and ZEUS detectors at HERA, using data collected in the period 1994-2007.…
Standard parton distribution functions contain neither information on the correlations between partons nor on their transverse motion, then a vital knowledge about the three dimensional structure of the nucleon is lost. Hard exclusive…
The photoproduction of Drell-Yan lepton pairs at HERA is studied. We show that in the backward rapidity region the cross section is strongly sensitive to the small-$x$ behaviour of the quark distributions in the proton, and that with…