Related papers: Physics Updates from HERMES
Low energy Compton scattering allows the investigation of one of the fundamental properties of the nucleon -- how its internal structure deforms under an applied electromagnetic field. We review recent developments in the investigation of…
Latest results on structure functions, as available at the Lepton-Photon Symposium 1999, are presented. This report focusses on three experimental areas: new structure function measurements, in particular from HERA at low x and high Q2;…
Several experiments at the electron-proton ($ep$) collider HERA have collected high precision data on the spectrum of leading-proton and leading-neutron carrying a large fraction of the proton's energy. In this paper, we have analyzed…
The general structure of the cross section of $\gamma N$ scattering with polarized photon and/or nucleon in initial and/or final state is systematically described and exposed through invariant amplitudes. A low-energy expansion of the cross…
A review of recent jet measurements of the photon structure from the H1 experiment at HERA. The scale and the virtuality dependence of the effective parton distribution function of the photon is discussed.
This paper focuses on a measurement of deeply virtual Compton scattering (DVCS) performed at Jefferson Lab using a nearly-6-GeV polarized electron beam, two longitudinally polarized (via DNP) solid targets of protons (NH3) and deuterons…
In this contribution we present the main results of the investigation about double parton scattering (DPS) in quasi-real photon-proton interactions. We show the first evaluation of the DPS cross-section at leading-order for the four-jet…
We present work in a model used to describe semi-inclusive deep inelastic scattering off the deuteron. The model uses the virtual nucleon approximation to describe the interaction of the photon with the bound neutron and the generalized…
We discuss theoretical aspects of parton distribution functions for very high energy scattering in relation with upcoming measurements in DIS and hadron-hadron collisions.
Double-spin asymmetries in exclusive electroproduction of real photons from a transversely polarized hydrogen target are measured with respect to the product of target polarization with beam helicity and beam charge, and with respect to the…
We will describe the quantum statistical approach to parton distributions allowing to obtain simultaneously the unpolarized distributions and the helicity distributions. We will present some recent results, in particular related to the…
COMPASS, a new fixed target experiment at CERN, aimed at the study of nucleon spin structure and hadron spectroscopy, has started to collect physics data in Autumn 2001. This paper describes the COMPASS apparatus and the measurement of the…
The two photon exchange amplitude is investigated in frame of analytic properties of the virtual Compton scattering amplitude as a function of the invariant mass squared of the intermediate hadronic state. A sum rule is built, based on…
COMPASS is a fixed-target high energy physics experiment at the SPS at CERN \cite{Abbon:2007pq}. One of the important objectives of the experiment is the exploration of the transverse spin structure of the nucleon via spin dependent…
Neutral and charged current deep inelastic scattering cross sections and structure functions are presented. The review also discusses improvements to the parton density measurements using jet cross section data and recent high $Q^{2}$…
A multi-dimensional (x, y, z, P_{h\perp}) extraction of cos\phi_h and cos2\phi_h azimuthal asymmetries of unpolarized Semi-Inclusive Deep Inelastic Scattering at HERMES is discussed. The use of data taken with hydrogen and deuterium targets…
Recent experimental and theoretical ideas are laying the ground for a new era in the knowledge of the parton structure of nuclei. We report on two promising directions beyond inclusive deep inelastic scattering experiments, aimed at, among…
Physics perspectives are shown for future experiments in electron or positron scattering on nucleons, towards a deep and comprehensive understanding of the angular momentum structure of the nucleon in the context of Quantum Chromodynamics.…
Recent results on the Deeply Virtual Compton Scattering (DVCS) and prompt photon productions from H1 and ZEUS experiments on the $ep$ collider HERA are presented. A new DVCS cross section measurements of the H1 Collaboration, for photon…
In this prize talk, I recall some of the history surrounding the discovery of deeply virtual Compton scattering, and explain why it is an exciting experimental tool to obtain novel tomographic pictures of the nucleons at Jefferson Lab 12…