相关论文: The Longitudinal Polarimeter at HERA
In view of the realistic possibility for operating high-energy polarized proton beams in future collider machines, it is highly desirable to propose for such beams, an absolute calibration allowing to measure accurately their degree of…
We study photoproduction reactions in a polarized ep collider mode of HERA at sqrt(s)=298 GeV. We examine the sensitivity of the cross sections and their asymmetries to the proton's polarized gluon distribution and to the completely unknown…
Parity is a key observable in nuclear spectroscopy. Linear polarization measurements of $\gamma$-rays are a probe to access the parities of energy levels. Utilizing the segmentation of detectors in the Segmented Germanium Array (SeGA) at…
Precision experiments in the parity violating electron scattering (PVES) sector is one the leading methods to probe physics beyond the standard model (SM). A large part of the physics program being envisioned for future facilities such as…
The value of accurately knowing the absolute calibration of the polarizing elements in the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) becomes especially important when conducting studies which require measuring degrees of…
A coherent optical spectrum analyzer is integrated with a rotating quarter wave plate polarimeter. The combined polarimeter optical spectrum analyzer (POSA) allows the extraction of the state of polarization with high spectral resolution.…
In recent years, Laser Plasma Acceleration (LPA) has become a promising alternative to conventional RF accelerators. However, so far, it has only been theoretically shown that generating polarized LPA beams is possible. The LEAP (Laser…
Through the simultaneous measurement of the transverse size as a function of longitudinal position, and the longitudinal distribution of luminosity, we are able to measure the $\beta_y^\ast$ (vertical envelope function at the collision…
The HERA luminosity upgrade is expected to generate two major problems in the current method of luminosity determination which is based on counting brehmsstrahlung photons: damage of the calorimeter monitor due to high primary synchrotron…
The production rates of lepton-photon and dimuon pairs at the HERA collider and the HERMES experiment are evaluated in the leading order equivalent photon approximation. It is shown that the production rates are sufficient to facilitate the…
We present a novel approach to precisely synthesize arbitrary polarization states of light with a high modulation bandwidth. Our approach consists of superimposing two laser light fields with the same wavelength, but with opposite circular…
We analyze the effects of Scalar and Vector Leptoquarks on various observables in electron (positron) - proton deep inelastic scattering. In view of the future program of the HERA collider, with a high luminosity and also with polarization,…
Our goal is to test the feasibility to obtain accurate measurements of the continuum polarization from high-resolution spectra using the spectropolarimetric mode of ESPaDOnS. We used the new pipeline OPERA to reduce recent and archived…
At a future linear collider, a polarized electron beam will play an important role in interpreting new physics signals. Backgrounds to a new physics reaction can be reduced by choice of the electron polarization state. The origin of a new…
Using the RHESSI satellite as a Compton polarimeter, a recent study claimed that the prompt emission of GRB021206 was almost fully linearly polarized. This was challenged by a subsequent reanalysis. We present an novel approach, applying…
We describe the Submillimeter Array (SMA) Polarimeter, a polarization converter and feed multiplexer installed on the SMA. The polarimeter uses narrow-band quarter-wave plates to generate circular polarization sensitivity from the…
A measurement is presented of elastic deeply virtual Compton scattering \gamma* p \to \gamma p made using e^+ p collision data corresponding to a luminosity of 46.5 pb^{-1}, taken with the H1 detector at HERA. The cross section is measured…
A coherent, short-length reference arm reflectometer, which utilizes a 76-MHz repetition rate mode-locked fiber laser, was investigated experimentally for long fiber links (> 10 km). The reflectometer combines the advantages of optical…
Evidence for a positive longitudinal double-spin asymmetry <A_1^rho> = 0.24 +-0.11 (stat) +-0.02 (syst) in the cross section for exclusive diffractive rho^0(770) vector meson production in polarised lepton-proton scattering was observed by…
The CERN Large Hadron Collider (LHC) is designed to collide proton beams of unprecedented energy, in order to extend the frontiers of high-energy particle physics. During the first very successful running period in 2010--2013, the LHC was…