401 research outputs found
Identified Particle Production in d+Au and p+p collisions at RHIC
The BRAHMS experiment at RHIC has measured the transverse momentum spectra of
charged pions, kaons and (anti-)protons over a wide range of rapidity in d+Au
and p+p collisions at GeV. The nuclear modification factor
at forward rapidities shows a clear suppression for . The
measured net-proton yields in p+p collisions are compared to PYTHIA and
HIJING/B and seem to be better described by the latter.Comment: 4 pages, 3 figures, presented at the 19th International Conference on
Ultra-Relativistic Nucleus-Nucleus Collisions, "Quark Matter 2006", Shanghai,
China, November 14-20, 2006. to appear in the proceedings of Quark Matter
2006 as a special issue of Journal of Physics G: Nuclear and Particle Physic
Cavity spin optodynamics
The dynamics of a large quantum spin coupled parametrically to an optical
resonator is treated in analogy with the motion of a cantilever in cavity
optomechanics. New spin optodynamic phenonmena are predicted, such as
cavity-spin bistability, optodynamic spin-precession frequency shifts, coherent
amplification and damping of spin, and the spin optodynamic squeezing of light.Comment: 4 pages, 3 figure
Formation of van der Waals molecules in buffer gas cooled magnetic traps
We show that a large class of helium-containing cold polar molecules form
readily in a cryogenic buffer gas, achieving densities as high as 10^12 cm^-3.
We explore the spin relaxation of these molecules in buffer gas loaded magnetic
traps, and identify a loss mechanism based on Landau-Zener transitions arising
from the anisotropic hyperfine interaction. Our results show that the recently
observed strong T^6 thermal dependence of spin change in buffer gas trapped
silver (Ag) is accounted for by the formation and spin change of AgHe, thus
providing evidence for molecular formation in a buffer gas trap.Comment: 4 pages, 4 figure
Organization of Core Spliceosomal Components U5 snRNA Loop I and U4/U6 Di-snRNP within U4/U6.U5 Tri-snRNP as Revealed by Electron Cryomicroscopy
CGC, QCD Saturation and RHIC data (Kharzeev-Levin-McLerran-Nardi point of view)
This is the talk given at the Workshop:"Focus on Multiplicitioes", Bari,
Italy, 17-19 June,2004.. In this talk, we are going to discuss ion-ion and
deuteron - nucleus RHIC data and show that they support, if not more, the idea
of the new QCD phase: colour glass condensate with saturated parton density. .Comment: 26 pages with 33 figure
The C-terminal RG dipeptide repeats of the spliceosomal Sm proteins D 1 and D 3 contain symmetrical dimethylarginines which form a major B-cell epitope for anti-Sm autoantibodies.
Elliptical Flow in Relativistic Ion Collisions at s^(1/2)= 200 A GeV
A consistent picture of the Au+Au and D+Au, s^1/2 = 200 A GeV measurements at
RHIC obtained with the PHENIX, STAR, PHOBOS and BRAHMS detectors including both
the rapidity and transverse momentum spectra was previously developed with the
simulation LUCIFER. The approach was modeled on the early production of a fluid
of pre-hadrons after the completion of an initial, phase of high energy
interactions. The formation of pre-hadrons is discussed here, in a perturbative
QCD approach as advocated by Kopeliovich, Nemchik and Schmidt. In the second
phase of LUCIFER, a considerably lower energy hadron-like cascade ensues. Since
the dominant collisions occurring in this latter phase are meson-meson in
character while the initial collisions are between baryons, i.e. both involve
hadron sized interaction cross-sections, there is good reason to suspect that
the observed elliptical flow will be produced naturally, and this is indeed
found to be the case.Comment: 7 pages, 6 figure
Correlations and fluctuations studied with ALICE
The measurement of particle correlations and event-by-event fluctuations of
physical observables allows to study a large variety of properties of the
matter produced in ultra relativistic heavy-ion collisions. We will present
results for two-particle correlations, mean transverse momentum fluctuations,
and net charge fluctuations in Pb-Pb collisions at 2.76 TeV.Comment: 7 pages, 5 figures, Proceedings submitted for the 28th Winter
Workshop on Nuclear Dynamics, Puerto Rico, April 7-14, 2012; corrected typo
Strangeness and heavy flavor at RHIC: Recent results from PHENIX
We report recent results of strangeness and heavy flavor measurements from
PHENIX.
The topics are: Elliptic flow of strangeness and heavy flavor electron
production comparing to the other hadrons, meson production, and an
exotic particle search.Comment: 8 pages, 6 figures, 1 table. Submitted to J. Phys. G (Proceedings of
the 8th International Conference on Strangeness in Quark Matter, Cape Town,
South Africa, September 15-20, 2004
Suppression of High Transverse Momentum Spectra in Au+Au Collisions at RHIC
Au+Au, A GeV measurements at RHIC, obtained with the PHENIX,
STAR, PHOBOS and BRAHMS detectors, have all indicated a suppression of neutral
pion production, relative to an appropriately normalized NN level. For central
collisions and vanishing pseudo-rapidity these experiments exhibit suppression
in charged meson production, especially at medium to large transverse momenta.
In the PHENIX experiment similar behavior has been reported for
spectra.
In a recent work on the simpler D+Au interaction, to be considered perhaps as
a tune-up for Au+Au, we reported on a pre-hadronic cascade mechanism which
explains the mixed observation of moderately reduced suppression at
higher pseudo-rapidity as well as the Cronin enhancement at mid-rapidity. Here
we present the extension of this work to the more massive ion-ion collisions.
Our major thesis is that much of the suppression is generated in a late stage
cascade of colourless pre-hadrons produced after an initial short-lived
coloured phase. We present a pQCD argument to justify this approach and to
estimate the time duration of this initial phase. Of essential
importance is the brevity in time of the coloured phase existence relative to
that of the strongly interacting pre-hadron phase. The split into two phases is
of course not sharp in time, but adequate for treating the suppression of
moderate and high mesons.Comment: 19 pages, 10 figure
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