16 research outputs found
Precision electron polarimetry
A new generation of precise Parity-Violating experiments will require a sub-percent accuracy of electron beam polarimetry. Compton polarimetry can provide such accuracy at high energies, but at a few hundred MeV the small analyzing power limits the sensitivity. M{\o}ller polarimetry provides a high analyzing power independent on the beam energy, but is limited by the properties of the polarized targets commonly used. Options for precision polarimetry at ~300 MeV will be discussed, in particular a proposal to use ultra-cold atomic hydrogen traps to provide a 100\%-polarized electron target for M{\o}ller polarimetry
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
Is the LHCb plausible in the GlueX total cross sections ?
New high-statistics total cross section data for from
the GLUonic EXcitation (GlueX) experiment are fitted in a search for the exotic
state observed by the Large Hadron Collider beauty (LHCb)
collaboration. The integrated luminosity of this GlueX experiment was about
. The fits show that destructive interference involving
an -wave resonance and associated non-resonance background produces a sharp
dip structure about below the LHCb mass, in the same location
as a similar structure is seen in the data. Limitations of the employed model
and the need for improved statistics are discussed.Comment: 4 pages, 3 figures, 2 table
The GlueX DIRC Project
The GlueX experiment was designed to search for and study the pattern of
gluonic excitations in the meson spectrum produced through photoproduction
reactions at a new tagged photon beam facility in Hall D at Jefferson
Laboratory. The particle identification capabilities of the GlueX experiment
will be enhanced by constructing a DIRC (Detection of Internally Reflected
Cherenkov light) detector, utilizing components of the decommissioned BaBar
DIRC. The DIRC will allow systematic studies of kaon final states that are
essential for inferring the quark flavor content of both hybrid and
conventional mesons. The design for the GlueX DIRC is presented, including the
new expansion volumes that are currently under development.Comment: 8 pages, 6 figure
Conceptual Design of Beryllium Target for the KLF Project
The Kaon Production Target (KPT) is an important component of the proposed
K-Long facility which will be operated in JLab Hall~D, targeting strange baryon
and meson spectroscopy. In this note we present a conceptual design for the
Be-target assembly for the planned K-Long beam line, which will be used along
with the GlueX spectrometer in its standard configuration for the proposed
experiments. The high quality 12-GeV CEBAF electron beam enables production of
a K flux at the GlueX target on the order of , which
exceeds the K flux previously attained at SLAC by three orders of
magnitude. An intense K beam would open a new window of opportunity not
only to locate "missing resonances" in the strange hadron spectrum, but also to
establish their properties by studying different decay channels systematically.
The most important and radiation damaging background in K production is due
to neutrons. The Monte Carlo simulations for the proposed conceptual design of
KPT show that the resulting neutron and gamma flux lead to a prompt radiation
dose rate for the KLF experiment that is below the JLab Radiation Control
Department radiation dose rate limits in the experimental hall and at the site
boundary, and will not substantially affect the performance of the
spectrometer.Comment: 9 pages, 9 figure
Precision measurements of A1N in the deep inelastic regime
We have performed precision measurements of the double-spin virtual-photon asymmetry A1A1 on the neutron in the deep inelastic scattering regime, using an open-geometry, large-acceptance spectrometer and a longitudinally and transversely polarized 3He target. Our data cover a wide kinematic range 0.277≤x≤0.5480.277≤x≤0.548 at an average Q2Q2 value of 3.078 (GeV/c)2, doubling the available high-precision neutron data in this x range. We have combined our results with world data on proton targets to make a leading-order extraction of the ratio of polarized-to-unpolarized parton distribution functions for up quarks and for down quarks in the same kinematic range. Our data are consistent with a previous observation of anA1n zero crossing near x=0.5x=0.5. We find no evidence of a transition to a positive slope in(Δd+Δd¯)/(d+d¯) up to x=0.548x=0.548
Jefferson Lab Report
Jefferson Laboratory is finishing a major upgrade and has already started operations with the 12 GeV continuous electron beam. The main research direction is the study of the structure of hadrons, including a search for gluon excitations in the spectra of light mesons and baryons, and studies of multidimensional images of the nucleon. Studied of certain properties of atomic nuclei are also ongoing. There is also an active program of searching for effects beyond the Standard Model in parity-violating electron scattering, as well as a search for new particles
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High-rate Precision Experiments
A new generation of experiments for studies of the nucleon structure with electromagnetic probes is under consideration by the physics community interested in hadron physics. One of the main goals of these projects is studying the Generalized Parton Distributions (GPD), which typically requires detecting several particles in the final state, high luminosity, large acceptance and good missing mass resolution of the spectrometers. The combination of these requirements is challenging and pushes the detectors involved to the limits. In this paper a review of the proposed experiments is presented and their feasibility is evaluated taking into account the recent progress of the detector technique