1,143 research outputs found
Partons and Jets at the LHC
I review some issues related to short distance QCD and its relation to the
experimental program of the Large Hadron Collider (LHC) now under construction
in Geneva.Comment: Talk at the conference QCD2002 at IIT Kanpur, India, November 2002.
Ten pages with 12 figure
Liquid-liquid coexistence in the phase diagram of a fluid confined in fractal porous materials
Multicanonical ensemble sampling simulations have been performed to calculate
the phase diagram of a Lennard-Jones fluid embedded in a fractal random matrix
generated through diffusion limited cluster aggregation. The study of the
system at increasing size and constant porosity shows that the results are
independent from the matrix realization but not from the size effects. A
gas-liquid transition shifted with respect to bulk is found. On growing the
size of the system on the high density side of the gas-liquid coexistence curve
it appears a second coexistence region between two liquid phases. These two
phases are characterized by a different behaviour of the local density inside
the interconnected porous structure at the same temperature and chemical
potential.Comment: 5 pages, 4 figures. To be published in Europhys. Letter
Cervicitis as a Clinical Indicator of Gonococcal and Chlamydial Infections in Pregnancy
Objective: We undertook the present study to attempt to apply clinical indicators predictive of cervical infection in nongravid populations with either Neisseria gonorrhoeae or Chlamydia trachomatis to our pregnant population and to determine the significance of the clinical diagnosis of “cervicitis.
Spin operator and spin states in Galilean covariant Fermi field theories
Spin degrees of freedom of the Galilean covariant Dirac field in (4+1)
dimensions and its nonrelativistic counterpart in (3+1) dimensions are
examined. Two standard choices of spin operator, the Galilean covariant and
Dirac spin operators, are considered. It is shown that the Dirac spin of the
Galilean covariant Dirac field in (4+1) dimensions is not conserved, and the
role of non-Galilean boosts in its nonconservation is stressed out. After
reduction to (3+1) dimensions the Dirac field turns into a nonrelativistic
Fermi field with a conserved Dirac spin. A generalized form of the Levy-Leblond
equations for the Fermi field is given. One-particle spin states are
constructed. A particle-antiparticle system is discussed.Comment: Minor corrections in the text; journal versio
Color transparency in deeply inelastic diffraction
We suggest a simple physical picture for the diffractive parton distributions
that appear in diffractive deeply inelastic scattering. In this picture,
partons impinging on the proton can have any transverse separation, but only
when the separation is small can they penetrate the proton without breaking it
up. By comparing the predictions from this picture with the diffractive data
from HERA, we determine rough values for the small separations that dominate
the diffraction process.Comment: 10 pages, 2 figures; v2: citations added, two comments revised and
expanded, results unchange
Efficiency improvements for the numerical computation of NLO corrections
In this paper we discuss techniques, which lead to a significant improvement
of the efficiency of the Monte Carlo integration, when one-loop QCD amplitudes
are calculated numerically with the help of the subtraction method and contour
deformation. The techniques discussed are: holomorphic and non-holomorphic
division into sub-channels, optimisation of the integration contour,
improvement of the ultraviolet subtraction terms, importance sampling and
antithetic variates in loop momentum space, recurrence relations.Comment: 34 pages, version to be publishe
Does the Robotic Platform Reduce Morbidity Associated With Combined Radical Surgery and Adjuvant Radiation for Early Cervical Cancers?
Open radical hysterectomy followed by adjuvant radiation for cervical cancer has been associated with significant rates of morbidity. Radical hysterectomy is now often performed robotically. We sought to examine if the robotic platform decreased the morbidity associated with radical hysterectomy followed by adjuvant radiation
From 'River Cottage' to 'Chicken Run': Hugh Fearnley-Whttingstall and the class politics of ethical consumption
Lifestyle television provides a key site through which to explore the dilemmas of ethical consumption, as the genre shifts to consider the ethics of different consumption practices and taste cultures. UK television cook Hugh Fearnley-Whittingstall's TV programmes offer fertile ground not only for thinking about television personalities as lifestyle experts and moral entrepreneurs, but also for thinking about how the meanings and uses of their television image are inflected by genre. In this article we explore how the shift from the lifestyled downshifting narrative of the River Cottage series to the 'campaigning culinary documentary' Hugh's Chicken Run exposes issues of celebrity, class and ethics. While both series are concerned with ethical consumption, they work in different ways to reveal a distinction between 'ethical' and 'unethical' consumption practices and positions - positions that are inevitably classed
Intrinsic transverse momentum and the polarized Drell-Yan process
In this paper we study the cross section at leading order in for
polarized Drell-Yan scattering at measured lepton-pair transverse momentum
. We find that for a hadron with spin the quark content at leading
order is described by six distribution functions for each flavor, which depend
on both the lightcone momentum fraction , and the quark transverse momentum
\bbox{k}_T^2. These functions are illustrated for a free-quark ensemble. The
cross sections for both longitudinal and transverse polarizations are expressed
in terms of convolution integrals over the distribution functions.Comment: 25 pages, REVTEX 3.0 (3 figures included in separate LATEX file using
feynman.tex), NIKHEF-94-P1 (Revised version
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