1,593 research outputs found
Search for a Ridge Structure Origin with Shower Broadening and Jet Quenching
We investigate the role of jet and shower parton broadening by the strong
colour field in the - correlation of high
particles. When anisotropic momentum broadening () is
given to jet and shower partons in the initial stage, a ridge-like structure is
found to appear in the two hadron correlation. The ratio of the peak to the
pedestal yield is overestimated.Comment: Talk given at 20th Int. Conf. on Ultra-Relativistic Nucleus-Nucleus
Collisions, Jaipur, India, Feb.4-10, 200
Jet-fluid string formation and decay in high-energy heavy-ion collisions
We propose a new hadronization mechanism, jet-fluid string (JFS) formation
and decay, to understand observables in intermediate to high- regions
comprehensively. In the JFS model, hard partons produced in jet lose their
energy in traversing the QGP fluid, which is described by fully
three-dimensional hydrodynamic simulations. When a jet parton escapes from the
QGP fluid, it picks up a partner parton from a fluid and forms a color singlet
string, then it decays to hadrons. We find that high- values in JFS
are about two times larger than in the independent fragmentation model.Comment: 6 pages, 2 figures; Proceeding for poster sessions at Quark Matter
2006, Shanghai, China, 14-20 November 2006; to appear in Int. J. of Mod.
Phys.
Forward particle productions at RHIC and the LHC from CGC within local rcBK evolution
In order to describe forward hadron productions in high-energy nuclear
collisions, we propose a Monte-Carlo implementation of
Dumitru-Hayashigaki-Jalilian-Marian formula with the unintegrated gluon
distribution obtained numerically from the running-coupling BK equation. We
discuss influence of initial conditions for the BK equation by comparing a
model constrained by global fit of small-x HERA data and a newly proposed one
from the running coupling MV model.Comment: Talk given at conference Quark Matter 2011, 4 page
Jet broadening in unstable non-Abelian plasmas
We perform numerical simulations of the QCD Boltzmann-Vlasov equation
including both hard elastic particle collisions and soft interactions mediated
by classical Yang-Mills fields. We provide an estimate of the coupling of jets
to a hot plasma which is independent of infrared cutoffs. For weakly-coupled
anisotropic plasmas the local rotational symmetry in momentum space is broken.
The fields develop unstable modes, forming configurations where B_t>E_t and
E_z>B_z. This provides a possible explanation for the experimental observation
that high-energy jets traversing the plasma perpendicular to the beam axis
experience much stronger broadening in rapidity than in azimuth.Comment: 6 pages, 7 figures, version accepted for publication in Phys.Rev.C,
typos fixed, more detailed discussion of q-ha
Back-to-back correlations of high p_T hadrons in relativistic heavy ion collisions
We investigate the suppression factor and the azimuthal correlation function
for high hadrons in central Au+Au collisions at GeV
by using a dynamical model in which hydrodynamics is combined with explicitly
traveling jets. We study the effects of parton energy loss in a hot medium,
intrinsic of partons in a nucleus, and broadening of jets on
the back-to-back correlations of high hadrons. Parton energy loss is
found to be a dominant effect on the reduction of the away-side peaks in the
correlation function.Comment: 4 pages, 4 figures; version to appear in Phys. Rev. Let
Structure of longitudinal chromomagnetic fields in high energy collisions
Creative Commons License (CC BY 3.0)Peer reviewe
Pumilio binds para mRNA and requires nanos and brat to regulate sodium current in drosophila motoneurons
Homeostatic regulation of ionic currents is of paramount importance during periods of synaptic growth or remodeling. Our previous work has identified the translational repressor Pumilio (Pum) as a regulator of sodium current (INa) and excitability in Drosophila motoneurons. In this current study, we show that Pum is able to bind directly the mRNA encoding the Drosophila voltage-gated sodium channel paralytic (para). We identify a putative binding site for Pum in the 3' end of the para open reading frame (ORF). Characterization of the mechanism of action of Pum, using whole-cell patch clamp and real-time reverse transcription-PCR, reveals that the full-length protein is required for translational repression of para mRNA. Additionally, the cofactor Nanos is essential for Pum-dependent para repression, whereas the requirement for Brain Tumor (Brat) is cell type specific. Thus, Pum-dependent regulation of INa in motoneurons requires both Nanos and Brat, whereas regulation in other neuronal types seemingly requires only Nanos but not Brat. We also show that Pum is able to reduce the level of nanos mRNA and as such identify a potential negative-feedback mechanism to protect neurons from overactivity of Pum. Finally, we show coupling between INa (para) and IK (Shal) such that Pum-mediated change in para results in a compensatory change in Shal. The identification of para as a direct target of Pum represents the first ion channel to be translationally regulated by this repressor and the location of the binding motif is the first example in an ORF rather than in the canonical 3'-untranslated region of target transcripts
Re-Hardening of Hadron Transverse Mass Spectra in Relativistic Heavy-Ion Collisions
We analyze the spectra of pions and protons in heavy-ion collisions at
relativistic energies from 2 A GeV to 65+65 A GeV by using a jet-implemented
hadron-string cascade model. In this energy region, hadron transverse mass
spectra first show softening until SPS energies, and re-hardening may emerge at
RHIC energies. Since hadronic matter is expected to show only softening at
higher energy densities, this re-hardening of spectra can be interpreted as a
good signature of the quark-gluon plasma formation.Comment: 10 pages, 3 figures, 1 table, Poster presentation at QM2001, Revised
to correct latex error in citation on April 6, 200
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