7,972 research outputs found
QCD Predictions for the Transverse Energy Flow in Deep-Inelastic Scattering in the Small x HERA Regime
The distribution of transverse energy, , which accompanies
deep-inelastic electron-proton scattering at small , is predicted in the
central region away from the current jet and proton remnants. We use BFKL
dynamics, which arises from the summation of multiple gluon emissions at small
, to derive an analytic expression for the flow. One interesting
feature is an increase of the distribution with
decreasing , where . We perform a
numerical study to examine the possibility of using characteristics of the
distribution as a means of identifying BFKL dynamics at HERA.Comment: 16 pages, REVTEX 3.0, no figures. (Hardcopies of figures available on
request from Professor A.D. Martin, Department of Physics, University of
Durham, DH1 3LE, England.) Durham preprint : DTP/94/0
Properties of the BFKL equation and structure function predictions for HERA
The general properties of the Lipatov or BFKL equation are reviewed.
Modifications to the infrared region are proposed. Numerical predictions for
the deep-inelastic electron-proton structure functions at small are
presented and confronted with recent HERA measurements.Comment: 21 pages, 11 figures, Latex file, Durham preprint DTP 92/2
Deep inelastic events containing a forward photon as a probe of small dynamics
We calculate the rate of producing deep inelastic events containing an
energetic isolated forward photon at HERA. We quantify the enhancement arising
from the leading gluon emissions with a view to using such events to
identify the underlying dynamics.Comment: 11 pages, Latex, 7 ps figure
BFKL versus HERA
The BFKL equation and the kT-factorization theorem are used to obtain
predictions for F2 in the small Bjorken-x region over a wide range of Q**2. The
dependence on the parameters, especially on those concerning the infrared
region, is discussed. After a background fit to recent experimental data
obtained at HERA and at Fermilab (E665 experiment), we find that the predicted,
almost Q**2 independent BFKL slope lambda >= 0.5 appears to be too steep at
lower Q**2 values. Thus there seems to be a chance that future HERA data can
distinguish between pure BFKL and conventional field theoretic renormalization
group approaches.Comment: 26 pages, 6 eps figures, LaTeX2e using epsfig.sty and amssymb.st
The description of F2 at small x incorporating angular ordering
We study the perturbative QCD description of the HERA measurements of using a gluon distribution that is obtained from an evolution
incorporating angular ordering of the gluon emissions, and which embodies both
GLAP and BFKL dynamics. We compare the predictions with recent HERA data for
. We present estimates of the charm component and of .Comment: 8 LaTeX pages + 4 uuencoded figure
THE GLUON DISTRIBUTION AT SMALL x OBTAINED FROM A UNIFIED EVOLUTION EQUATION.
We solve a unified integral equation to obtain the and
dependence of the gluon distribution of a proton in the small regime; where
and are the longitudinal momentum fraction and the transverse
momentum of the gluon probed at a scale . The equation generates a gluon
with a steep behaviour, with , and a
distribution which broadens as decreases. We compare our solutions with, on
the one hand, those that we obtain using the double-leading-logarithm
approximation to Altarelli-Parisi evolution and, on the other hand, to those
that we determine from the BFKL equation.Comment: LaTeX file with 10 postscript figures (uuencoded
A unified BFKL and GLAP description of data
We argue that the use of the universal unintegrated gluon distribution and
the (or high energy) factorization theorem provides the natural framework
for describing observables at small x. We introduce a coupled pair of evolution
equations for the unintegrated gluon distribution and the sea quark
distribution which incorporate both the resummed leading BFKL
contributions and the resummed leading GLAP contributions. We solve
these unified equations in the perturbative QCD domain using simple parametic
forms of the nonperturbative part of the integrated distributions. With only
two (physically motivated) input parameters we find that this
factorization approach gives an excellent description of the measurements of
at HERA. In this way the unified evolution equations allow us to
determine the gluon and sea quark distributions and, moreover, to see the x
domain where the resummed effects become significant. We use
factorization to predict the longitudinal structure function and
the charm component of .Comment: 25 pages, LaTeX, 9 figure
When a patient\u27s ethnicity is declared, medical students\u27 decision-making processes are affected
Background: Disparity in health status and healthcare outcomes is widespread and well known. This holds true for Indigenous peoples in many settings including Australia and Hawaii. While multi-factorial, there is increasing evidence of health practitioner contribution to this disparity. This research explored senior medical studentsâ clinical decision-making processes.
Methods: A qualitative study was conducted in 2014 with 30 final year medical students from The University of Melbourne, Australia, and The John Burns Medical School, Hawaii, USA. Each student responded to questions about a paper-based case, first in writing and elaborated further in an interview. Half the students were given a case of a patient whose ethnicity was not declared; the other half considered the patient who was Native Hawaiian or Australian Aboriginal. A systematic thematic analysis of the interview transcripts was conducted.
Results: The study detected subtle biases in studentsâ ways of talking about the Indigenous person and their anticipation of interacting with her as a patient. Four main themes emerged from the interview transcripts: the patient as a person; constructions of the person as patient; patientâstudent/doctor interactions; and the value of various education settings. There was a strong commitment to the patientâs agenda and to the element of trust in the doctorâpatient interaction.
Conclusion: These findings will help to advance medical curricula so that institutions graduate physicians who are increasingly able to contribute to equitable outcomes for all patients in their care. The study also draws attention to subtle biases based on ethnicity that may be currently at play in physiciansâ practices
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