2,466 research outputs found
Di-Jet Conical Correlations Associated with Heavy Quark Jets in anti--de Sitter Space/Conformal Field Theory Correspondence
We show that far zone Mach and diffusion wake ``holograms'' produced by
supersonic strings in anti--de Sitter space/conformal field theory (AdS/CFT)
correspondence do not lead to observable conical angular correlations in the
strict supergravity limit if Cooper-Frye hadronization is
assumed. However, a special {\em nonequilibrium} ``neck'' zone near the jet is
shown to produce an apparent sonic boom azimuthal angle distribution that is
roughly independent of the heavy quark's velocity. Our results indicate that a
measurement of the dependence of the away-side correlations on the velocity of
associated identified heavy quark jets at the BNL Relativistic Heavy Ion
Collider and CERN LHC will provide a direct test of the nonperturbative
dynamics involved in the coupling between jets and the strongly-coupled
Quark-Gluon Plasma (sQGP) implied by AdS/CFT correspondence.Comment: 4 pages, 2 figures, version published in Physical Review Letter
Kinin-B1 receptors in ischaemia-induced pancreatitis: Functional importance and cellular localisation
In this study we compare the role of kininB1 and B2 receptors during ischaemia/reperfusion of rat pancreas. Our investigations were prompted by the observation that infusion of a kininB2 receptor antagonist produced significant improvement in acute experimental pancreatitis. In an acute model with two hours of ischaemia/two hours of reperfusion, application of the kininB1 receptor antagonist (CP-0298) alone, or in combination with kininB2 receptor antagonist (CP-0597), significantly reduced the number of adherent leukocytes in postcapillary venules. In a chronic model with five days of reperfusion, the continuous application of kininB1 receptor antagonist or a combination of kininB1 and B2 receptor antagonists markedly reduced the survival rate. In kininreceptor binding studies kininB1 receptor showed a 22-fold increase in expression during the time of ischaemia/ reperfusion. Carboxypeptidase M activity was upregulated 10-fold following two hours of ischaemia and two hours of reperfusion, provided the appropriate specific ligand, desArg10-kallidin and/or desArg9-bradykinin, was used. The occurrence of kininB1 receptor binding sites on acinar cell membranes was demonstrated by microautoradiography. With a specific antibody, the localisation of kininB1 receptor protein was confirmed at the same sites. In conclusion, we have demonstrated the upregulation of the pancreatic acinar cell kininB1 receptors during ischaemia/reperfusion. The novel functional finding was that antagonism of the kininB1 receptors decreased the survival rate in an experimental model of pancreatitis
Cherenkov gluons at RHIC and LHC
The coherent hadron production analogous to Cherenkov radiation of photons
gives rise to the ring-like events. Being projected on the ring diameter they
produce the two-bump structure recently observed for the away-side jets at
RHIC. The position of the peaks and their height determine such properties of
the hadronic medium as its nuclear index of refraction, the parton density, the
free path length and the energy loss of Cherenkov gluons. Beside comparatively
low energy gluons observed at RHIC, there could be high energy gluons at LHC,
related to the high energy region of positive real part of the forward
scattering amplitude and possessing different characteristics.Comment: 6 pages, talk at QM2006 modified with new reference
Event-by-Event Fluctuations at 40, 80, and 158 AGeV/c in Pb+Au Collisions
Event-by-event fluctuations of mean pt and net charge in 40, 80, and 158
AGeV/c Pb+Au collisions are presented. The observed dynamical mean pt
fluctuations in central events of about 1 % are very similar to results from
RHIC. The centrality dependence of mean pt fluctuations at 158 AGeV/c shows a
peculiar non-monotonic pattern with respect to the extrapolation from the
fluctuations measured in p+p collisions. Dynamical net charge fluctuations
smaller than the charge conservation limit are observed. After correction for
charge conservation, the measured fluctuation signal in central events is
comparable to RHIC results.Comment: 4 pages, 6 figures, proceedings of the Quark Matter 2004, in Oakland,
USA, to be published in Journal of Physics G: Nuclear and Particle Physic
Quark Matter 2006: high-pT and jets
An overview of new experimental results on high-\pT{} particle production and
jets in heavy ion collisions from the Quark Matter 2006 conference is
presented.Comment: Presented at Quark Matter 200
Freeze-out dynamics via charged kaon femtoscopy in √ sNN = 200 GeV central Au + Au collisions
We present measurements of three-dimensional correlation functions of like-sign, low-transverse-momentum kaon pairs from √sNN=200 GeV Au+Au collisions. A Cartesian surface-spherical harmonic decomposition technique was used to extract the kaon source function. The latter was found to have a three-dimensional Gaussian shape and can be adequately reproduced by Therminator event-generator simulations with resonance contributions taken into account. Compared to the pion one, the kaon source function is generally narrower and does not have the long tail along the pair transverse momentum direction. The kaon Gaussian radii display a monotonic decrease with increasing transverse mass mT over the interval of 0.55≤mT≤1.15 GeV/c2. While the kaon radii are adequately described by the mT -scaling in the outward and sideward directions, in the longitudinal direction the lowest mT value exceeds the expectations from a pure hydrodynamical model prediction
Mach Cones in Quark Gluon Plasma
The experimental azimuthal dihadron distributions at RHIC show a double peak
structure in the away side ( rad.) for intermediate
particles. A variety of models have appeared trying to describe this
modification. We will review most of them, with special emphasis in the Conical
Flow scenario in which the observed shape is a consequence of the emission of
sound by a supersonic high momentum particle propagating in the Quark Gluon
Plasma.Comment: 8 pages, 3 figures, Invited plenary talk given at the 19th
International Conference on Ultrarelativistic Nucleus-Nucleus Collisions:
Quark Matter 2006 (QM 2006), Shanghai, China, 14-20 Nov 200
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