Related papers: The Longitudinal Polarimeter at HERA
We give the results of an analysis of some 18 rise-time calibrations which are based on data collected in 1996/97. Such measurements are used to determine the absolute polarization scale of the transverse electron beam polarimeter (TPOL) at…
Results of inclusive measurements of inelastic electron and positron scattering from unpolarized protons and deuterons at the HERMES experiment are presented. The structure functions $F_2^p$ and $F_2^d$ are determined using a…
If a beam of unpolarized positrons (which is considered as a sum of two fractions with opposite helicities) passes through an intense circular polarized laser radiation these fractions may be separated. For high laser flash intensity each…
Synchrotron radiation facilities provide highly polarized X-ray beams across a wide energy range. However, the exact type and degree of polarization varies according to the beamline and experimental setup. To accurately determine the angle…
An easily constructed and operated polarimeter precisely determines the relative Stokes parameters that characterize the polarization of laser light. The polarimeter is calibrated in situ without removing or realigning its optical elements,…
The HERMES experiment has measured double spin asymmetries of inclusive and semi-inclusive cross sections for the production of charged hadrons in deep-inelastic scattering of polarised positrons on polarised hydrogen and deuterium targets,…
Precision measurements of diffraction have been performed by the H1 and ZEUS experiments at the HERA collider with high statistics for a wide kinematic range of photon virtuality $Q^2$. The diffractive parton densities are extracted by…
A combination of the inclusive diffractive cross section measurements made by the H1 and ZEUS Collaborations at HERA is presented. The analysis uses samples of diffractive deep inelastic ep scattering data at a centre-of-mass energy sqrt(s)…
To obtain full Stokes spectra in multi-wavelength windows simultaneously, we developed a new spectro-polarimeter on the Domeless Solar Telescope at Hida Observatory. The new polarimeter consists of a 60 cm aperture vacuum telescope on an…
We report on the experimental implementation of a polarimeter based on a scheme known to be optimal for obtaining the polarization vector of ensembles of spin-1/2 quantum systems, and the alignment procedure for this polarimeter is…
Spin-echo instruments are typically used to measure diffusive processes and the dynamics and motion in samples on ps and ns timescales. A key aspect of the spin-echo technique is to determine the polarisation of a particle beam. We present…
Deeply virtual Compton scattering has been measured in e^+p collisions at HERA with the ZEUS detector using an integrated luminosity of 61.1 pb^-1. Cross sections are presented as a function of the photon virtuality, Q^2, and photon-proton…
The production of photons at very small angles with respect to the proton beam direction is studied in deep-inelastic positron-proton scattering at HERA. The data are taken with the H1 detector in the years 2006 and 2007 and correspond to…
The first observation of an azimuthal cross--section asymmetry with respect to the charge of the incoming lepton beam is reported from a study of hard exclusive electroproduction of real photons. The data have been accumulated by the HERMES…
We report the first observation of an azimuthal asymmetry in the hard electroproduction of real photons with respect to the charge of the incoming lepton beam. The asymmetry is attributed to the interference between the Bethe-Heitler…
We demonstrated for the first time the production of highly polarized short-pulse positrons with a finite energy spread in accordance with a new scheme that consists of two-quantum processes, such as inverse Compton scatterings and…
We describe an apparatus used to measure the triple-correlation term (\D \hat{\sigma}_n\cdot p_e\times p_\nu) in the beta-decay of polarized neutrons. The \D-coefficient is sensitive to possible violations of time reversal invariance. The…
The physics scope of polarized nucleon-nucleon collisions originating from an internal polarized target in the HERA proton beam is summarized. Based on 240 pb^{-1} integrated luminosity at 40 GeV c.m. energy, statistical sensitivities are…
The process of deeply virtual Compton scattering will be shortly introduced, and the latest results from measurements at the HERA ep-collider at DESY will be given. In particular, the cross section has been measured with increased…
Handedness and a left-right asymmetry have been proposed as methods of probing the polarization of hard jets. If the analyzing powers for these observables are substantial they would provide useful tools for probing polarized hard…