相关论文: Recent Physics results with the COMPASS Experiment

Double-spin asymmetries for production of charged pions and kaons in semi-inclusive deep-inelastic muon scattering have been measured by the COMPASS experiment at CERN. The data, obtained by scattering a 160 GeV muon beam off a…

These proceedings sketch how combining recent theoretical advances with data from the new generation of high-precision Compton scattering experiments on both the proton and few-nucleon systems offers fresh, detailed insight into the Physics…

We study the cross section for the photoproduction process $\gamma N\rightarrow h X$ where the incident photon and nucleon are longitudinally polarized and a hadron $h$ is observed at high transverse momentum. Specifically, we address the…

The first physics results of the HARP experiment are presented. We emphasize the high performance of the forward part of the apparatus. The differential raw pion yield and its efficiency correction up to polar angles of 250 mrad are shown.…

The Planck mission will permit measurements of the polarization of the cosmic microwave background and of polarized foregrounds such as our own Galaxy with an unprecedented combination of accuracy and completeness. This will provide…

Compton scattering from the proton was investigated at s=6.9 (GeV/c)**2 and \t=-4.0 (GeV/c)**2 via polarization transfer from circularly polarized incident photons. The longitudinal and transverse components of the recoil proton…

We provide an experimental and theoretical perspective on the behavior of unpolarized distribution functions for the nucleon and pion on the valence-quark domain; namely, Bjorken-x \gtrsim 0.4. This domain is key to much of hadron physics;…

The generalized parton distributions and the generalized distribution amplitudes give access to a deeper understanding of the quark and gluon content of hadrons. In this short review, we select some new developments of their interesting…

Parton distributions in impact parameter space, which are obtained by Fourier transforming GPDs, exhibit a significant deviation from axial symmetry when the target and/or quark are transversely polarized. Connections between this…

HERMES has measured azimuthal single-spin asymmetries of pions and charged kaons produced in deep-inelastic scattering of electrons and positrons off a transversely polarized hydrogen target. These asymmetries provide information about the…

A phenomenological description of single transverse spin effects in hadron-hadron inclusive processes is proposed, assuming a generalized factorization scheme and pQCD hard interactions. The transverse momentum, k_T, of the quarks inside…

Chiral perturbation theory makes definitive predictions for the extrinsic behavior of hadrons in external electric and magnetic fields. Near the chiral limit, the electric and magnetic polarizabilities of pions, kaons, and nucleons are…

Concerning new physics beyond the Standard Model we explore the discovery and analysis potentials of polarized (hadronic) experiments and we compare with the unpolarized case. For discovery, beam polarization is helpful in the case of…

This contribution to CIPANP 2012 highlights what we have learned about the asymmetric parton distributions of the nucleon over the past 20 years. These distributions include the transverse momentum dependent parton distributions describing…

The polarized distribution functions of mesons, including pion, kaon and eta, using the proton structure function, are calculated. We are looking for a relationship between the polarized distribution of mesons and the polarized structure of…

The COMPASS fixed-target experiment at the CERN-SPS studies the structure and spectrum of hadrons. One important goal using hadron beams is the search for new states, in particular spin-exotic mesons and glueballs. As a first input to the…

We present a fit to spin asymmetries which gives polarized quark distributions. These functions are closely related to the ones given by the newest Martin, Roberts and Stirling fit for unpolarized structure functions. The integrals of…

Polarized proton-proton collisions at the Relativistic Heavy Ion Collider (RHIC) provide unique opportunities to study the spin structure of the nucleon. We will highlight recent results on the nucleon spin structure from the STAR and…

An overview of the SMC data taking and the polarized deep inelastic scattering experiment is given. The new data on the deuteron extend the kinematic range and have considerably reduced statistical and systematic errors. The evaluation of…

Lattice simulations of hadronic structure are now reaching a level where they are able to not only complement, but also provide guidance to current and forthcoming experimental programmes at, e.g. Jefferson Lab, COMPASS/CERN and FAIR/GSI.…