5,649 research outputs found
N=(1,1) super Yang--Mills theory in 1+1 dimensions at finite temperature
We present a formulation of N=(1,1) super Yang-Mills theory in 1+1 dimensions
at finite temperature. The partition function is constructed by finding a
numerical approximation to the entire spectrum. We solve numerically for the
spectrum using Supersymmetric Discrete Light-Cone Quantization (SDLCQ) in the
large-N_c approximation and calculate the density of states. We find that the
density of states grows exponentially and the theory has a Hagedorn
temperature, which we extract. We find that the Hagedorn temperature at
infinite resolution is slightly less than one in units of (g^(2) N_c/pi)^(1/2).
We use the density of states to also calculate a standard set of thermodynamic
functions below the Hagedorn temperature. In this temperature range, we find
that the thermodynamics is dominated by the massless states of the theory.Comment: 16 pages, 8 eps figures, LaTe
D^+ \to K^- \p^+ \p^+ : the low-energy sector
An effective chiral lagrangian, which includes scalar
resonances, is used to describe the process D^+ \rar K^- \p^+ \p^+ at
low-energies. Our main result is a set of five -wave amplitudes, suited to
be used in analyses of production data.Comment: Talk given at SCADRON 70 - Workshop on Scalar Mesons and Related
Topics - Lisbon - February 200
Beam profile measurements at 40 MHz in the PS to SPS transfer channel
Bunch to bunch beam profile measurements provide a valuable tool to control the injection lines to the SPS. A fast profile monitor based on a 2.5 ”m Mylar coated with Aluminium Optical Transition Radiation (OTR) radiator, has been developed, installed and tested in the transfer line between the PS and SPS. The OTR beam image is focused onto a fast Linear Multianode Photo Multiplier Tube and the associated electronics sample and store profiles every 25 ns. The paper describes the detector design, the electronic processing, and presents the results of different measurements made with bunches of 109-1011 protons at 26 GeV, and bunches of 106 Pb82 ions at 5.11 GeV/u
The Supersymmetric Ward-Takahashi Identity in 1-Loop Lattice Perturbation Theory. I. General Procedure
The one-loop corrections to the lattice supersymmetric Ward-Takahashi
identity (WTi) are investigated in the off-shell regime. In the Wilson
formulation of the N=1 supersymmetric Yang-Mills (SYM) theory, supersymmetry
(SUSY) is broken by the lattice, by the Wilson term and is softly broken by the
presence of the gluino mass. However, the renormalization of the supercurrent
can be realized in a scheme that restores the continuum supersymmetric WTi
(once the on-shell condition is imposed). The general procedure used to
calculate the renormalization constants and mixing coefficients for the local
supercurrent is presented. The supercurrent not only mixes with the gauge
invariant operator . An extra mixing with other operators coming from
the WTi appears. This extra mixing survives in the continuum limit in the
off-shell regime and cancels out when the on-shell condition is imposed and the
renormalized gluino mass is set to zero. Comparison with numerical results are
also presented.Comment: 16 pages, 2 figures. Typos error correcte
Nuclear magnetic resonance measurements reveal the origin of the Debye process in monohydroxy alcohols
Monohydroxy alcohols show a structural relaxation and at longer time scales a
Debye-type dielectric peak. From spin-lattice relaxation experiments using
different nuclear probes an intermediate, slower-than-structural dynamics is
identified for n-butanol. Based on these findings and on diffusion
measurements, a model of self-restructuring, transient chains is proposed. The
model is demonstrated to explain consistently the so far puzzling observations
made for this class of hydrogen-bonded glass forming liquids.Comment: 4 pages, 4 figure
Sonoluminescing air bubbles rectify argon
The dynamics of single bubble sonoluminescence (SBSL) strongly depends on the
percentage of inert gas within the bubble. We propose a theory for this
dependence, based on a combination of principles from sonochemistry and
hydrodynamic stability. The nitrogen and oxygen dissociation and subsequent
reaction to water soluble gases implies that strongly forced air bubbles
eventually consist of pure argon. Thus it is the partial argon (or any other
inert gas) pressure which is relevant for stability. The theory provides
quantitative explanations for many aspects of SBSL.Comment: 4 page
To , or not to : Recent developments and comparisons of regularization schemes
We give an introduction to several regularization schemes that deal with
ultraviolet and infrared singularities appearing in higher-order computations
in quantum field theories. Comparing the computation of simple quantities in
the various schemes, we point out similarities and differences between them.Comment: 61 pages, 12 figures; version sent to EPJC, references update
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