11 research outputs found
Investigation of the nuetralino pair production at LHC
In this article, we investigate the Drell-Yan process of the light neutralino
pair () productions
at proton-proton collisions and we present the general formulate for the
differential cross sections. We conduct an extensive examination of the
dependence of the total cross section of the subprocesses on the beam energy, on the mass
of the squarks and also on the gaugino for the three extremely different
scenarios. For all three cases, the outcomes are as follows. The dependence of
the total cross section of the subprocesses on the beam energy is dominated by one of
the subprocesses, . On the other hand, the dependence of the total cross section of
the subprocesses
on the mass of the squarks is dominated by one of the subprocesses, . We derive there from that
our findings may lead to new insights relating to experimental investigations
and these dependencies may be used as bases of an experimental research for the
neutralino pair at LHC.Comment: 38pp, 22 figures, ReVTeX4, (Baku State University, Azerbaijan, and
Erciyes University, Kayseri, Turkey
Inclusive production of meson in proton-proton collisions at BNL RHIC
Inclusive cross sections for production in proton-proton collisions
were calculated in the -factorization approach for the RHIC energy.
Several mechanisms were considered, including direct color-singlet mechanism,
radiative decays of mesons, decays of , open-charm associated
production of as well as weak decays of B mesons. Different
unintegrated gluon distributions from the literature were used. We find that
radiative decays and direct color-singlet contributions constitute the
dominant mechanism of production. These process cannot be consistently
treated within collinear-factorization approach. The results are compared with
recent RHIC data. The new precise data at small transverse momenta impose
stringent constraints on UGDFs. Some UGDFs are inconsistent with the new data.
The Kwieci\'nski UGDFs give the best description of the data. In order to
verify the mechanism suggested here we propose -- jet correlation
measurement and an independent measurement of meson production in
and/or decay channels. Finally, we address the issue of
\J spin alignment.Comment: 26 pages, 20 figures, the text was slightly modified, the title was
modified, more discussion was added, one figure was removed, one was adde
Prompt photon hadroproduction at high energies in the k_T-factorization approach
We consider the prompt photon production at high energy hadron colliders in
the framework of k_T-factorization approach. The unintegrated quark and gluon
distributions in a proton are determined using the Kimber-Martin-Ryskin
prescription. The conservative error analisys is performed. We investigate both
inclusive prompt photon and prompt photon and associated muon production rates.
In Standard Model such events come mainly due to Compton scattering process
where the final heavy (charm or bottom) quark produces a muon. The theoretical
results are compared with recent experimental data taken by the D0 and CDF
collaborations at Fermilab Tevatron. Our analysis also covers the azimuthal
correlations between produced prompt photon and muon which can provide an
important information about non-collinear parton evolution in a proton.
Finally, we extrapolate the theoretical predictions to CERN LHC energies.Comment: 27 pages, 13 figure
Possible experiment for determination of the role of microscopic vortex rings in the \lambda-transition in He-II
It is suggested that microscopic vortex rings (MVR) play an important role in
the \lambda-transition in helium-II and substantially determine the value of
T_{\lambda}. For very thin films of He-II, with thickness d less than the size
of the smallest MVR, the rings do not fit in and, therefore, do not exist in
such films. Consequently, for superfluid films of He-II, a peculiarity in the
form of a smoothed-out jump should be observed in the curve T_{m}(d) at the
values of thickness approximately equal to the size of the smallest MVR, d= 3 -
9 A (T_{m} is the temperature of the maximum of the broad peak on the curve of
the dependence of the specific heat on temperature). The absence of a similar
peculiarity will be an evidence that MVR do not influence the values of
T_{\lambda} and T_{m}, and do not play any key role in the \lambda-transition.
The currently available experimental data are insufficient for revealing the
predicted peculiarity.Comment: 6 pages, 2 figure
Deep inelastic production at HERA in the -factorization approach and its consequences for the nonrelativistic QCD
In the framework of the -factorization approach, we analyse the
inclusive and inelastic production of particles in deep inelastic
scattering. We take into account both colour-singlet and colour-octet
production channels. We inspect the sensitivity of theoretical predictions to
the choice of model parameters. Our theoretical results agree reasonably well
with recent experimental data collected by the collaboration H1 at HERA.Comment: 14 pages, 6 figure
Relevance of nucleon spin in amplitude analysis of reactions pi(-)p->pi(0)pi(0)n and pi(-)p->eta eta n
The measurements of reactions and on polarized targets at CERN found a strong dependence of pion
production amplitudes on nucleon spin. Analyses of recent measurements of
reaction on unpolarized targets by GAMS
Collaboration at 38 GeV/c and BNL E852 Collaboration at 18 GeV/c use the
assumption that pion production amplitudes do not depend on nucleon spin, in
conflict with the CERN results on polarized targets. We show that measurements
of and on unpolarized
targets can be analysed in a model independent way in terms of 4 partial-wave
intensities and 3 independent interference phases in the mass region where -
and -wave dominate. We also describe model-independent amplitude analysis of
reaction measured on polarized target, both in the
absence and in the presence of -wave amplitudes. We suggest that high
statistics measurements of reactions and be made on polarized targets at Protvino IHEP and at BNL, and
that model-independent amplitude analyses of this polarized data be performed
to advance hadron spectroscopy on the level of spin dependent production
amplitudes.Comment: 54 page