8 research outputs found
Target and double spin asymmetries of deeply virtual pi(0) production with a longitudinally polarized proton target and CLAS
The target and double spin asymmetries of the exclusive pseudoscalar channel
were measured for the first time in the
deep-inelastic regime using a longitudinally polarized 5.9 GeV electron beam
and a longitudinally polarized proton target at Jefferson Lab with the CEBAF
Large Acceptance Spectrometer (CLAS). The data were collected over a large
kinematic phase space and divided into 110 four-dimensional bins of ,
, and . Large values of asymmetry moments clearly indicate a
substantial contribution to the polarized structure functions from transverse
virtual photon amplitudes. The interpretation of experimental data in terms of
generalized parton distributions (GPDs) provides the first insight on the
chiral-odd GPDs and , and complement previous measurements
of unpolarized structure functions sensitive to the GPDs and .
These data provide necessary constraints for chiral-odd GPD parametrizations
and will strongly influence existing theoretical handbag models
First measurement of the polarization observable E in the p→(γ→,π<sup>+</sup>)n reaction up to 2.25 GeV
First results from the longitudinally polarized frozen-spin target (FROST)
program are reported. The double-polarization observable E, for the reaction
, has been measured using a circularly polarized
tagged-photon beam, with energies from 0.35 to 2.37 GeV. The final-state pions
were detected with the CEBAF Large Acceptance Spectrometer in Hall B at the
Thomas Jefferson National Accelerator Facility. These polarization data agree
fairly well with previous partial-wave analyses at low photon energies. Over
much of the covered energy range, however, significant deviations are observed,
particularly in the high-energy region where high-L multipoles contribute. The
data have been included in new multipole analyses resulting in updated nucleon
resonance parameters. We report updated fits from the Bonn-Gatchina, J\"ulich,
and SAID groups.Comment: 6 pages, 3 figure
Semi-inclusive pi(0) target and beam-target asymmetries from 6 GeV electron scattering with CLAS
We present precision measurements of the target and beam-target spin
asymmetries from neutral pion electroproduction in deep-inelastic scattering
(DIS) using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. We
scattered 6-GeV, longitudinally polarized electrons off longitudinally
polarized protons in a cryogenic NH target, and extracted double and
single target spin asymmetries for in
multidimensional bins in four-momentum transfer ( GeV),
Bjorken- (), hadron energy fraction (), transverse
pion momentum ( GeV), and azimuthal angle between the
lepton scattering and hadron production planes. We extracted asymmetries as a
function of both and , which provide access to transverse-momentum
distributions of longitudinally polarized quarks. The double spin asymmetries
depend weakly on . The moments are zero within
uncertainties, which is consistent with the expected suppression of the Collins
fragmentation function. The observed moments suggest that quark
gluon correlations are significant at large .Comment: 18 preprint pages, 3 figure
Proposal for a candidate core set of fitness and strength tests for patients with childhood or adult idiopathic inflammatory myopathies
OBJECTIVE: Currently there are no evidence-based recommendations regarding fitness and strength tests for patients with childhood or adult idiopathic inflammatory myopathies (IIM). This hinders clinicians and researchers in choosing the appropriate fitness- or muscle strength-related outcome measures for these patients. Through a Delphi survey, we aimed to identify a candidate core set of fitness and strength tests for children and adults with IIM.
METHODS: Fifteen experts participated in a Delphi survey that consisted of 5 stages to achieve a consensus. Using an extensive search of published literature and through the work of experts, a candidate core set based on expert opinion and clinimetrics properties was developed. Members of the International Myositis Assessment and Clinical Studies Group were invited to review this candidate core set during the final stage, which led to a final candidate core set.
RESULTS: A core set of fitness- and strength-related outcome measures was identified for children and adults with IIM. For both children and adults, different tests were identified and selected for maximal aerobic fitness, submaximal aerobic fitness, anaerobic fitness, muscle strength tests, and muscle function tests.
CONCLUSION: The core set of fitness- and strength-related outcome measures provided by this expert consensus process will assist practitioners and researchers in deciding which tests to use in patients with IIM. This will improve the uniformity of fitness and strength tests across studies, thereby facilitating the comparison of study results and therapeutic exercise program outcomes among patients with IIM
