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[en] Logarithmic representations of the conformal Galilean algebra (CGA) and the Exotic Conformal Galilean algebra (ECGA) are constructed. This can be achieved by non-decomposable representations of the scaling dimensions or the rapidity indices, specific to conformal Galilean algebras. Logarithmic representations of the non-exotic CGA lead to the expected constraints on scaling dimensions and rapidities and also on the logarithmic contributions in the co-variant two-point functions. On the other hand, the ECGA admits several distinct situations which are distinguished by different sets of constraints and distinct scaling forms of the two-point functions. Two distinct realisations for the spatial rotations are identified as well. This is the first concrete example of a reducible, but non-decomposable representation, without logarithmic terms. Such cases had been anticipated before
[en] We describe a Chandra X-ray target-of-opportunity project designed to isolate the site of TeV flaring in the radio galaxy M87. To date, we have triggered the Chandra observations only once (2010 April) and by the time of the first of our nine observations, the TeV flare had ended. However, we found that the X-ray intensity of the unresolved nucleus was at an elevated level for our first observation. Of the more than 60 Chandra observations we have made of the M87 jet covering nine years, the nucleus was measured at a comparably high level only three times. Two of these occasions can be associated with TeV flaring, and at the time of the third event, there were no TeV monitoring activities. From the rapidity of the intensity drop of the nucleus, we infer that the size of the emitting region is of order a few light days x the unknown beaming factor; comparable to the same sort of estimate for the TeV emitting region. We also find evidence of spectral evolution in the X-ray band which seems consistent with radiative losses affecting the non-thermal population of the emitting electrons within the unresolved nucleus.
[en] The early parton momentum distribution is extracted by using the STAR collaboration data of ridge particles associated with a near-side jet in central A uAu collisions at √sNN = 200 GeV. The ridge particles are identified as medium partons kicked by the jet near the surface and they carry direct information on the parton momentum distribution at the moment of jet-parton collisions. The extracted parton momentum distribution has a thermal-like transverse momentum distribution but a rapidity plateau structure with a relatively flat rapidity distribution at mid-rapidities with sharp kinematic boundaries at large rapidities that depend on the transverse momentum.
[en] We present the NLO corrections for the quark induced forward production of a jet with an associated rapidity gap. We make use of Lipatov's QCD high energy effective action to calculate the real emission contributions to the so-called Mueller–Tang impact factor. We combine them with the previously calculated virtual corrections and verify ultraviolet and collinear finiteness of the final result
[en] Starting from the past experimental results on multiplicity distributions in intervals of rapidity and of their analysis in terms of the superposition of events of soft and semi-hard type (see the talk of A. Giovannini) three possible scenarios for hh collisions in the TeV energy region are discussed. (author)
[en] Experiment of relativistic heavy ion collider (RHIC) has created a nearly perfect fluid, where shear viscosity to entropy density (η/s) ratio is so small that it almost reaches the lower bound (η/s = 1/4π). In the high temperature domain however, the theoretical calculations using perturbative methods surprisingly do not lead to such small value of η/s. There it behaves as weakly interacting gas, having relatively large value (10-20 times larger than lower bound). To resolve this discrepancy between experimental and theoretical values, different alternative calculations, based on effective QCD models and hadronic models have been studied in recent times. Some estimations are also done from the direction of transport simulations and Lattice QCD calculations. These analysis were carried out for infinite size systems. Effects of finiteness in system volumes have not however been considered which we are studying in this work
[en] In these proceedings, we highlight experimental data (published and preliminary) related to jet quenching and the response of the medium to this deposited energy. Signatures in two- and three-particle hadron correlations indicate interesting structures near the trigger particle in azimuth and over a broad range in pseudo-rapidity, often termed 'the ridge', and conical-like structures separated in azimuth opposite to the trigger particle. We review numerous theoretical interpretations of the ridge in particular with a critical eye for the key properties that allow one to discriminate between, or rule out, certain physical pictures and models (and hopefully learn something in the process).
[en] We report the measurement of charged hadron production at different pseudo-rapidity values in deuteron+gold as well as proton-proton collisions at √(sNN) = 200GeV at RHIC. The nuclear modification factors RdAU and Rcp are used to investigate new behaviors in the deuteron+gold system as function of rapidity and the centrality of the collisions respectively
[en] A new sampling type electromagnetic calorimeter, FOrward CALorimeter (FOCAL), has been proposed for the ALICE experiment at CERN to boost its physics capabilities in the forward pseudorapidity region (2.5≤η≤5.5). A detailed GEANT-4 simulation was performed and an optimised geometry, with depth 20 XR and transverse size with inner and outer radii of 6 cm and 80 cm respectively, at 8 m away from the interaction point was obtained. A new ASIC, ANUINDRA with large dynamic range (∼ 2.6 pC) has been designed to overcome the saturation in data taking for higher energies. This ASIC has been tested in the laboratory as well as with the full-depth prototype at the SPS beam line facility at CERN
[en] The G moments of horizontal analysis of rapidity fluctuations are usually averaged over all events before multifractal analysis. Two methods are suggested to improve the vertical analysis so that the characteristics of highly fluctuating events can be probed more effectively. The multifractal spectrum f(α) should become broader. Relevance to analyses of experimental data is stressed at all stages of this study