1,483 research outputs found
Parton distribution function for quarks in an s-channel approach
We use an s-channel picture of hard hadronic collisions to investigate the
parton distribution function for quarks at small momentum fraction x, which
corresponds to very high energy scattering. We study the renormalized quark
distribution at one loop in this approach.
In the high-energy picture, the quark distribution function is expressed in
terms of a Wilson-line correlator that represents the cross section for a color
dipole to scatter from the proton. We model this Wilson-line correlator in a
saturation model. We relate this representation of the quark distribution
function to the corresponding representation of the structure function
F_T(x,Q^2) for deeply inelastic scattering
Hard diffraction from small-size color sources
We describe diffractive hard processes in the framework of QCD factorization and discuss what one can learn from the study of hadronic systems with small transverse size
Diagnostic Evaluation of Pelvic Inflammatory Disease
Pelvic inflammatory disease (PID) is a serious public health and reproductive health problem in the United States.
An early and accurate diagnosis of PID is extremely important for the effective management of the acute illness and for
the prevention of long-term sequelae. The diagnosis of PID is difficult, with considerable numbers of false-positive and
false-negative diagnoses. An abnormal vaginal discharge or evidence of lower genital tract infection is an important
and predictive finding that is often underemphasized and overlooked. This paper reviews the clinical diagnosis and
supportive laboratory tests for the diagnosis of PID and outlines an appropriate diagnostic plan for the clinician and
the researcher
Recursive numerical calculus of one-loop tensor integrals
A numerical approach to compute tensor integrals in one-loop calculations is
presented. The algorithm is based on a recursion relation which allows to
express high rank tensor integrals as a function of lower rank ones. At each
level of iteration only inverse square roots of Gram determinants appear. For
the phase-space regions where Gram determinants are so small that numerical
problems are expected, we give general prescriptions on how to construct
reliable approximations to the exact result without performing Taylor
expansions. Working in 4+epsilon dimensions does not require an analytic
separation of ultraviolet and infrared/collinear divergences, and, apart from
trivial integrals that we compute explicitly, no additional ones besides the
standard set of scalar one-loop integrals are needed.Comment: Typo corrected in formula 79. 22 pages, Latex, 1 figure, uses
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