8,460 research outputs found
ICANOE and OPERA experiments at the LNGS/CNGS
We discuss two experiments ICANOE and OPERA that have been proposed within
the context of long-baseline and atmospheric neutrino experiments in Europe.
The joint ICANOE/OPERA program aims at further improving our understanding of
the effect seen in atmospheric neutrinos. This program is based on (1) a
continuation of the observation of atmospheric neutrinos with the improved
technique of ICANOE/ICARUS (2) a sensitive numu->nue and numu->nutau appearance
program with the accelerator neutrinos coming from CERN (CNGS) from a distance
of 730 km.Comment: 8 pages; Invited talk at the XIX International Conference on Neutrino
Physics and Astrophysics (Neutrino 2000), Sudbury, Canada, June 16-21, 2000;
new version fix typo
A three-dimensional wavelet based multifractal method : about the need of revisiting the multifractal description of turbulence dissipation data
We generalize the wavelet transform modulus maxima (WTMM) method to
multifractal analysis of 3D random fields. This method is calibrated on
synthetic 3D monofractal fractional Brownian fields and on 3D multifractal
singular cascade measures as well as their random function counterpart obtained
by fractional integration. Then we apply the 3D WTMM method to the dissipation
field issue from 3D isotropic turbulence simulations. We comment on the need to
revisiting previous box-counting analysis which have failed to estimate
correctly the corresponding multifractal spectra because of their intrinsic
inability to master non-conservative singular cascade measures.Comment: 5 pages, 3figures, submitted to Phys. Rev. Let
Nuclear Parton Distributions - a DGLAP Analysis
Nuclear parton distributions are studied within a framework of
the DGLAP evolution. Measurements of in deep inelastic
collisions, and Drell--Yan dilepton cross sections measured in collisions
are used as constraints. Also conservation of momentum and baryon number is
required. It is shown that the calculated evolution of agrees very well with the recent NMC data, and that the ratios
are only moderately sensitive to the choice of a specific modern
set of free parton distributions. For general use, we offer a numerical
parametrization of for all parton flavours in , and at
and .Comment: Talk in Quark Matter '99, 5 pages, includes 3 eps-figure
Diffraction for non-believers
Diffractive reactions involving a hard scale can be understood in terms of
quarks and gluons. These reactions have become a valuable tool for
investigating the low-x structure of the proton and the behavior of QCD in the
high-density regime, and they may provide a clean environment to study or even
discover the Higgs boson at the LHC. In this paper we give a brief introduction
to the description of diffraction in QCD. We focus on key features studied in
ep collisions at HERA and outline challenges for understanding diffractive
interactions at the LHC.Comment: 23 pages, 26 figures. Contributed to the Proceedings of the Workshop
on HERA and the LHC, DESY and CERN, 2004-200
Nuclear modification difference between u_v and d_v distributions and its relation to NuTeV sin^2 theta_W anomaly
We investigate a possible nuclear correction to the NuTeV measurement of the
weak-mixing angle sin^2 theta_W. In particular, a nuclear modification
difference between u_v and d_v distributions contributes to the NuTeV
measurement with the iron target. First, the modification differenceis
determined by a chi^2 analysis so as to reproduce nuclear data on the structure
function F_2 and Drell-Yan processes. Then, taking the NuTeV kinematics into
account, we calculate a contribution to the sin^2 theta_W determination. In
addition, its uncertainty is estimated by the Hessian method. Although the
uncertainty becomes comparable to the NuTeV deviation, the effect is not large
enough to explain the whole NuTeV sin^2 theta_W anomaly at this stage. However,
it is difficult to determine such a nuclear modification difference, so that we
need further investigations on the difference and its effect on the NuTeV
anomaly.Comment: 6 pages,3 figure
Structure function results from H1
New structure function results from H1 are presented. The measurements cover
a huge kinematical range for Q^2, the four momentum transfer squared, from
0.35, GeV^2 to 30,000, GeV^2, and for Bjorken x between \sim 5\cdot 10^{-6} and
0.65. At Q^2>100, GeV^2, full HERA, I data have been analyzed. The data are
compared with a new QCD analysis. The impact of the HERA, I data on the parton
density functions is discussed.Comment: 8 page
A Spectrometer to Study Elastic and Diffractive Physics at LHC
The possibility to study elastic and diffractive physics in pp collisions at
LHC is investigated. For this purpose we have considered detectors close to the
beam in conjunction with the magnetic elements of the accelerator to provide a
high precision spectrometer for very forward final state protons. The
geometrical acceptance is given and momentum resolution is calculated for
different spatial resolution detectors.Comment: 26 pages, 13 figures, Latex, submitted in International Journal of
Modern Physics
A Systematic Study of Power Corrections from World Deep Inelastic Scattering Measurements
By performing an analysis in moment space using high statistics DIS world
data, we extract the values of both the QCD parameter
up to NLO and of the power corrections to the proton
structure function, . At variance with previous analyses, the use of
moments allows us to extend the kinematical range to larger values of ,
where we find that power corrections are quantitatively more important. Our
results are consistent with the dependence predicted by IR renormalon
calculations. We discuss preliminary results on nuclear targets with the intent
of illustrating a possible strategy to disentangle power corrections ascribed
to IR renormalons from the ones generated dynamically e.g. from rescattering in
the final state. The latter appear to be modified in nuclear targets.Comment: 4 pages, 2 figures, LateX with espcrc2 and epsfi
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