74 research outputs found
QED radiative effects in the processes of exclusive photon electroproduction from polarized protons with the next-to-leading accuracy
Radiative effects in the electroproduction of photons in polarized
-scattering are calculated with the next-to-leading (NLO) accuracy. The
contributions of loops and two photon emission were presented in analytical
form. The covariant approach of Bardin and Shumeiko was used to extract the
infrared divergence. All contributions to the radiative correction were
presented in the form of the correction to the leptonic tensor thus allowing
for further applications in other experiments, e.g., deep inelastic scattering.
The radiative corrections (RC) to the cross sections and polarization
asymmetries were analyzed numerically for kinematical conditions of the current
measurement at Jefferson Lab. Specific attention was paid on analyzing
kinematical conditions for the process with large radiative effect when momenta
of two photons in the final state are collinear to momenta of initial and final
electrons, respectively.Comment: 22 pages, 7 figures, 4 appendice
Electroweak radiative corrections for polarized Moller scattering at future 11 GeV JLab experiment
We perform updated and detailed calculations of the complete NLO set of
electroweak radiative corrections to parity violating e- e- --> e- e- (gamma)
scattering asymmetries at energies relevant for the ultra-precise Moller
experiment coming soon at JLab. Our numerical results are presented for a range
of experimental cuts and relative importance of various contributions is
analyzed. We also provide very compact expressions analytically free from
non-physical parameters and show them to be valid for fast yet accurate
estimations.Comment: 15 pages, 5 tables and 5 figure
MERADGEN 1.0: Monte Carlo generator for the simulation of radiative events in parity conserving doubly-polarized Moller scattering
The Monte Carlo generator MERADGEN 1.0 for the simulation of radiative events
in parity conserving doubly-polarized Moller scattering has been developed.
Analytical integration wherever it is possible provides rather fast and
accurate generation. Some numerical tests and histograms are presented.Comment: 23 pages, 4 figure
One-loop chiral amplitudes of Moller scattering process
The high energy amplitudes of the large angles Moller scattering are
calculated in frame of chiral basis in Born and 1-loop QED level. Taking into
account as well the contribution from emission of soft real photons the compact
relations free from infrared divergences are obtained. The expressions for
separate chiral amplitudes contribution to the cross section are in agreement
with renormalization group predictions.Comment: 15 pages, 3 figure
Radiative effects in the processes of exclusive photon electroproduction from polarized protons
Radiative effects in the electroproduction of photons in polarized
ep-scattering are calculated in the leading log approximation and analyzed
numerically for kinematical conditions of current measurement at Jefferson Lab.
Radiative corrections to the cross sections, their azimuthal distributions and
Fourier coefficients are in particular focus. Kinematical regions where the
radiative corrections are considerable are identified.Comment: 11 pages, 8 figure
Lowest-order QED radiative corrections in unpolarized elastic electron-deuteron scattering beyond the ultra-relativistic limit for the proposed deuteron charge radius measurement at Jefferson Laboratory
Analogous to the well-known proton charge radius puzzle, a similar puzzle
exists for the deuteron charge radius, . There are discrepancies
observed in the results of , measured from electron-deuteron ()
scattering experiments, as well as from atomic spectroscopy. In order to help
resolve the charge radius puzzle of the deuteron, the PRad collaboration at
Jefferson Lab has proposed an experiment for measuring , named DRad.
This experiment is designed to measure the unpolarized elastic scattering
cross section in a low- region. To extract the cross section with a high
precision, having reliable knowledge of QED radiative corrections is important.
In this paper, we present complete numerical calculations of the lowest-order
radiative corrections in scattering for the DRad kinematics. The
calculations have been performed within a covariant formalism and beyond the
ultra-relativistic approximation (). Besides, we present a
systematic uncertainty on arising from higher-order radiative
corrections, estimated based on our cross-section results.Comment: 16 pages and 6 figure
Artificial Epitope-Based Immunogens in HIV-Vaccine Design
One of the promising approaches for designing HIV vaccines is construction of synthetic polyepitope HIV-1 immunogen using a wide range of conservative T- and B-cell epitopes of the main virus antigens. In theory this approach helps cope with HIV-1 antigenic variability, focuses immune responses on protective determinants and enables to exclude from the vaccine compound adverse regions of viral proteins that can induce autoantibodies or antibodies enhancing infectivity of virus. The paper presents the experience of our team in development of artificial polyepitope HIV-1 immunogens, which can induce both a humoral response, and responses of cytotoxic (CD8 + CTL) and helpers (CD4 + Th) T-cells. The design of HIV-immunogens has been done using our original software, TEpredict and PolyCTLDesigner. We describe development of the candidate HIV-1/AIDS vaccine – CombiHIVvac, which included two artificial polyepitope immunogens TBI and TCI for stimulating humoral and cellular responses. The results of the specific activity and safety of CombiHIVvac vaccine, obtained during preclinical and clinical trials, are presented
SIDIS-RC EvGen: a Monte-Carlo event generator of semi-inclusive deep inelastic scattering with the lowest-order QED radiative corrections
SIDIS-RC EvGen is a C++ standalone Monte-Carlo event generator for studies of
semi-inclusive deep inelastic scattering (SIDIS) processes at medium to high
lepton beam energies. In particular, the generator contains binary and library
components for generating SIDS events and calculating cross sections for
unpolarized or longitudinally polarized beam and unpolarized, longitudinally or
transversely polarized target. The structure of the generator incorporates
transverse momentum-dependent parton distribution and fragmentation functions,
whereby we obtain multi-dimensional binned simulation results, which will
facilitate the extraction of important information about the three-dimensional
nucleon structure from SIDIS measurements. In order to build this software, we
have used recent elaborate QED calculations of the lowest-order radiative
effects, applied to the leading order Born cross section in SIDIS. In this
paper, we provide details on the theoretical formalism as well as the
construction and operation of SIDIS-RC EvGen, e.g., how we handle the event
generation process and perform multi-dimensional integration. We also provide
example programs, flowcharts, and numerical results on azimuthal transverse
single-spin asymmetries.Comment: 53 pages, 10 figures, and 3 listing
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