1,005 research outputs found
Extended Gaussian ensemble or q-statistics in hadronic production processes?
The extended Gaussian ensemble introduced recently as a generalization of the
canonical ensemble, which allows to treat energy fluctuations present in the
system, is used to analyze the inelasticity distributions in high energy
multiparticle production processes.Comment: Presented at NEXT2005 (News, Expectations and Trends in Statistical
Physics, NEXT-SigmaPhi 3rd International Conference) 13-18 August 2005,
Kolymbari CRETE, minor corrections, to be published in Europ. Phys. J. B
(2006
Diffusion approximation for equilibrium Kawasaki dynamics in continuum
A Kawasaki dynamics in continuum is a dynamics of an infinite system of
interacting particles in which randomly hop over the space. In
this paper, we deal with an equilibrium Kawasaki dynamics which has a Gibbs
measure as invariant measure. We study a diffusive limit of such a
dynamics, derived through a scaling of both the jump rate and time. Under weak
assumptions on the potential of pair interaction, , (in particular,
admitting a singularity of at zero), we prove that, on a set of smooth
local functions, the generator of the scaled dynamics converges to the
generator of the gradient stochastic dynamics. If the set on which the
generators converge is a core for the diffusion generator, the latter result
implies the weak convergence of finite-dimensional distributions of the
corresponding equilibrium processes. In particular, if the potential is
from and sufficiently quickly converges to zero
at infinity, we conclude the convergence of the processes from a result in
[Choi {\it et al.}, J. Math. Phys. 39 (1998) 6509--6536]
Analysis of Bose-Einstein correlations in e+e- -> W+W- events including final state interactions
Recently DELPHI Collaboration reported new data on Bose-Einstein correlations
(BEC) measured in e+e- -> W^+W^- events. Apparently no enhancement has been
observed. We have analyzed these data including final state interactions (FSI)
of both Coulomb and strong (s-wave) origin and found that there is enhancement
in BEC but it is overshadowed by the FSI which are extremely important for
those events. We have found the following values for the size of the
interaction range beta and the degree of coherence lambda: beta=0.87 +/- 0.31fm
and lambda=1.19 +/- 0.48, respectively.Comment: 7pages, 4 figure
Sensitivity of the interlayer magnetoresistance of layered metals to intralayer anisotropies
Many of the most interesting and technologically important electronic
materials discovered in the past two decades have two common features: a
layered crystal structure and strong interactions between electrons. Two of the
most fundamental questions about such layered metals concern the origin of
intralayer anisotropies and the coherence of interlayer charge transport. We
show that angle dependent magnetoresistance oscillations (AMRO) are sensitive
to anisotropies around an intralayer Fermi surface. Hence, AMRO can be a probe
of intralayer anisotropies that is complementary to angle-resolved
photoemission spectroscopy (ARPES) and scanning tunneling microscopy (STM).
However, AMRO are not very sensitive to the coherence of the interlayer
transport. We illustrate this with comparisons to recent AMRO experiments on an
overdoped cuprate.Comment: 7 pages, 3 figure
The Bose-Einstein distribution functions and the multiparticle production at high energies
The evolution properties of propagating particles produced at high energies
in a randomly distributed environment are studied. The finite size of the phase
space of the multiparticle production region as well as the chaoticity can be
derived.Comment: 18 pages, LaTeX, no figures, no table
The Fractal Properties of the Source and BEC
Using simple space-time implementation of the random cascade model we
investigate numerically influence of the possible fractal structure of the
emitting source on Bose-Einstein correlations between identical particles. The
results are then discussed in terms of the non-extensive Tsallis statistics.Comment: LaTeX file and 2 PS files with figures, 8 pages altogether. Talk
presented at the 12th Indian Summer School "Relativistic Heavy Ion Physics,
Prague, Czech Republic, 30 August-3 Sept. 1999; to be published in Czech J.
Phys. (1999). Some typos correcte
Magic angle effects of the one-dimensional axis conductivity in quasi-one dimensional conductors
In quasi-one-dimensional conductors, the conductivity in both one-dimensional
axis and interchain direction shows peaks when magnetic field is tilted at the
magic angles in the plane perpendicular to the conducting chain. Although there
are several theoretical studies to explain the magic angle effect, no
satisfactory explanation, especially for the one-dimensional conductivity, has
been obtained. We present a new theory of the magic angle effect in the
one-dimensional conductivity by taking account of the momentum-dependence of
the Fermi velocity, which should be large in the systems close to a spin
density wave instability. The magic angle effect is explained in the
semiclassical equations of motion, but neither the large corrugation of the
Fermi surface due to long-range hoppings nor hot spots, where the relaxation
time is small, on the Fermi surface are required.Comment: 4 pages, 3 figure
Highly anisotropic interlayer magnetoresistance in ZrSiS nodal-line Dirac semimetal
We instigate the angle-dependent magnetoresistance (AMR) of the layered
nodal-line Dirac semimetal ZrSiS for the in-plane and out-of-plane current
directions. This material has recently revealed an intriguing butterfly-shaped
in-plane AMR that is not well understood. Our measurements of the polar
out-of-plane AMR show a surprisingly different response with a pronounced
cusp-like feature. The maximum of the cusp-like anisotropy is reached when the
magnetic field is oriented in the - plane. Moreover, the AMR for the
azimuthal out-of-plane current direction exhibits a very strong four-fold
- plane anisotropy. Combining the Fermi surfaces calculated from first
principles with the Boltzmann's semiclassical transport theory we reproduce and
explain all the prominent features of the unusual behavior of the in-plane and
out-of-plane AMR. We are also able to clarify the origin of the strong
non-saturating transverse magnetoresistance as an effect of imperfect
charge-carrier compensation and open orbits. Finally, by combining our
theoretical model and experimental data we estimate the average relaxation time
of ~s and the mean free path of ~nm at 1.8~K in our
samples of ZrSiS.Comment: 8 pages, 4 figure
Prenylcysteine oxidase 1, a pro-oxidant enzyme of low density lipoproteins
Elevated levels of low density lipoproteins (LDLs) cause atherosclerotic disease, and proteomic analyses have found that these lipoproteins are endowed with prenylcysteine lyase. This systematic review summarizes current understanding of this enzyme, now known as prenylcysteine oxidase 1 (PCYOX1), which hydrolyzes the thioether bond of prenylcysteines in the nal step in the degradation of prenylated proteins, releasing hydrogen peroxide, cysteine and the isoprenoid aldehyde. Despite the high variability of the PCYOX1 gene, no polymorphism
has yet been associated with any disease. The liver, which is responsible for vehiculization of the enzyme in lipoproteins, is one of the main organs responsible for its expression, together with the gastrointestinal tract, kidney, male reproductive tissue and muscle. Moreover, although hepatic mRNA expression is sensitive to diet and hormones, the repercussion of these changes in LDLs containing PCYOX1 has not been addressed. One consequence of its elevated activity could be an increase in hydrogen peroxide, which might help to propagate the oxidative burden of LDLs, thus making PCYOX1 a potential pharmacological target and a new biomarker in cardiovascular disease
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