1,244 research outputs found
Neutron Structure Functions From Nuclear Data
The spin-averaged structure function of the neutron, F_2^n, is extracted from
recent deuteron data, taking into account the small but significant corrections
due to nuclear effects in the deuteron. At small x, the F_2D/F_2p ratio
measured by the New Muon and Fermilab E665 Collaborations is interpreted to
suggest a small amount of shadowing in deuterium, which acts to enhance F_2^n
for x < 0.1. A careful treatment of Fermi motion, binding and nucleon off-shell
effects in the deuteron also indicates that the neutron/proton structure
function ratio as x -> 1 is consistent with the perturbative QCD expectation of
3/7, but larger than the traditional value of 1/4.Comment: 16 pages RevTeX, 5 postscript figures, presented at 2nd. Cracow
Epiphany Conference on Proton Structure, Jan. 199
Deuteron spin structure functions in the resonance and DIS regions
We derive relations between spin-dependent nuclear and nucleon g_1 and g_2
structure functions within the nuclear impulse approximation, which are valid
at all Q^2, and in both the resonance and deep inelastic regions. We apply the
formalism to the specific case of the deuteron, which is often used as a source
of neutron structure information, and compare the size of the nuclear
corrections calculated using exact kinematics and using approximations
applicable at large Q^2.Comment: 22 pages, 7 figures, Fig. 1 correcte
Spin structure functions of 3He at finite Q^2
Using recently derived relations between spin-dependent nuclear and nucleon
g_1 and g_2 structure functions at finite Q^2, we study nuclear effects in 3He
in the nucleon resonance and deep inelastic regions. Comparing the finite-Q^2
results with the standard convolution formulas obtained in the large-Q^2 limit,
we find significant broadening of the effective nucleon momentum distribution
functions, leading to additional suppression of the nuclear g_1 and g_2
structure functions around the resonance peaks.Comment: 33 pages, 6 figures, to appear in Phys. Rev.
Deep inelastic scattering from light nuclei
We review recent developments in the study of deep inelastic scattering from
light nuclei, focusing in particular on deuterium, helium, and lithium.
Understanding the nuclear effects in these systems is essential for the
extraction of information on the neutron structure function.Comment: 11 pages, 5 figures; talk given by W. Melnitchouk at the Workshop on
Testing QCD through Spin Observables in Nuclear Targets, University of
Virginia, April 200
Subjective skeletal discomfort measured using a comfort questionnaire following a load carriage exercise
Objective: Limited research has been conducted into the effect of load carriage on discomfort and injuries. This study aimed to determine the skeletal discomfort for part-time soldiers who completed a 1-hour field march carrying 24 kg.
Methods: A postmarch comfort questionnaire was completed by 127 participants, with exercise withdrawals and postmarch injuries also recorded.
Results: The foot was subjectively rated as the most uncomfortable skeletal region. Females reported hip discomfort to be significantly greater than males. The military experience of participants had no difference on the mean perceived comfort ratings of any of the measured regions. Finally, only one participant withdrew from the exercise, with no participants reporting a load carriage injury in the 2 to 3 days proceeding the exercise Conclusions: This study concludes that although a 1-hour period of load carriage causes noteworthy discomfort it is not sufficient to result in noncompletion of a military exercise or cause injury
Precise Determination of Electroweak Parameters in Neutrino-Nucleon Scattering
A systematic error in the extraction of from nuclear deep
inelastic scattering of neutrinos and antineutrinos arises from higher-twist
effects arising from nuclear shadowing. We explain that these effects cause a
correction to the results of the recently reported significant deviation from
the Standard Model that is potentially as large as the deviation claimed, and
of a sign that cannot be determined without an extremely careful study of the
data set used to model the input parton distribution functions.Comment: 3pages, 0 figures, version to be published by IJMP
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