540 research outputs found
An Antiproton Event
During the systematic scaling for double stars in nuclear emulsions
exposed to 3 Gev. Pion beam an event was recorded and from analysis it can be interpreted
as due to the annihilation of an anti proton produced in the emulsion. The details of the
event along with a micro photograph are given below
Fractal Inspired Models of Quark and Gluon Distributions and Longitudinal Structure Function FL(x, Q2) at small x
In recent years, Fractal Inspired Models of quark and gluon densities at
small x have been proposed. In this paper, we investigate longitudinal
structure function F-L (x, Q2) within this approach. We make predictions using
the QCD based approximate relation between the longitudinal structure function
and the gluon density. As the Altarelli-Martinelli equation for the
longitudinal structure function cannot be applied to Model I due to the
presence of a singularity in the Bjorken x-space we consider Model II only. The
qualitative feature of the prediction of Model II is found to be compatible
with the QCD expectation.Comment: 11 pages, 4 figures, Accepted for publication on 10-07-2010 in Indian
Journal of Physic
Affine crystal structure on rigged configurations of type D_n^(1)
Extending the work arXiv:math/0508107, we introduce the affine crystal action
on rigged configurations which is isomorphic to the Kirillov-Reshetikhin
crystal B^{r,s} of type D_n^(1) for any r,s. We also introduce a representation
of B^{r,s} (r not equal to n-1,n) in terms of tableaux of rectangular shape r x
s, which we coin Kirillov-Reshetikhin tableaux (using a non-trivial analogue of
the type A column splitting procedure) to construct a bijection between
elements of a tensor product of Kirillov-Reshetikhin crystals and rigged
configurations.Comment: 26 pages, 3 figures. (v3) corrections in the proof reading. (v2) 26
pages; examples added; introduction revised; final version. (v1) 24 page
Antifungal activity and chemical composition of Citrus reticulata Blanco essential oil against phytopathogens from North East India
The essential oil (EO) isolated by hydro-distillation from the peel of fully matured ripen fruits of Citrus
reticulata Blanco were analyzed by GC and GC 13MS. Thirty seven different components were identified
constituting approximatel
Cryo-capacitation changes during cryopreservation of swamp buffalo spermatozoa
Cryopreservation of sperm cells induces cryo-capacitation like changes. These changes are associated with reduced survival of sperm cells in the female reproductive tract that ultimately associate with poor fertility. The present study was designed with the objective to investigate the cryo-capacitation changes in relation to acrosomal status, transaminases activities, sperm membrane protein and cholesterol content in swamp buffalo spermatozoa. Results revealed that the total mean incidences of acrosome reacted spermatozoa and the mean activity of ALT and AST were significantly higher after equilibration and freezing. The mean level of sperm membrane protein and cholesterol was significantly lower after equilibration and freezing. It may be concluded from the present study that cryopreservation induces capacitation-like changes in swamp buffalo spermatozoa
Moments of Nucleon's Parton Distribution for the Sea and Valence Quarks from Lattice QCD
We extend the study of lowest moments, , of the parton
distribution function of the nucleon to include those of the sea quarks; this
entails a disconnected insertion calculation in lattice QCD. This is carried
out on a quenched lattice with Wilson fermion. The quark loops
are calculated with noise vectors and unbiased subtractions, and multiple
nucleon sources are employed to reduce the statistical errors. We obtain
5 signals for for the $u,d,$ and $s$ quarks, but is
consistent with zero within errors. We provide results for both the connected
and disconnected insertions. The perturbatively renormalized for the
strange quark at $\mu = 2$ GeV is $_{s+\bar{s}} = 0.027 \pm 0.006$ which is
consistent with the experimental result. The ratio of for vs.
in the disconnected insertion with quark loops is calculated to be . This is about twice as large as the phenomenologically fitted
from
experiments where and include both the connected and
disconnected insertion parts. We discuss the source and implication of this
difference.Comment: 50 Pages 58 Figure
Structure Functions of the Nucleon and their Interpretation
The current status of measurements of the nucleon structure functions and
their understanding is reviewed. The fixed target experiments E665, CCFR and
NMC and the HERA experiments H1 and ZEUS are discussed in some detail. The
extraction of parton momentum distribution functions from global fits is
described, with particular attention paid to much improved information on the
gluon momentum distribution. The status of alpha_s measurements from deep
inelastic data is reviewed. Models and non-perturbative approaches for the
parton input distributions are outlined. The impact on the phenomenology of QCD
of the data at very low values of the Bjorken x variable is discussed in
detail. Recent advances in the understanding of the transition from deep
inelastic scattering to photoproduction are summarised. Some brief comments are
made on the recent HERA measurements of the ep NC and CC cross-sections at very
high Q2.Comment: 196 pages, 79 figures, uses ijmpa.sty and psfig.tex (included
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