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There are two type of scales present simultaneously in the space-like as well as in the time-like directions in a model-class describing a cylindrically symmetric, finite, three-dimensionally expanding boson source. One type of the scales is related to the finite lifetime or geometrical size of the system, the other type is governed by the rate of change of the local momentum distribution in the considered temporal or spatial direction. The parameters of the Bose-Einstein correlation function may obey an M t -scaling, as observed in S + P b and P b + P b reactions at CERN SPS. This M t -scaling may imply that the Bose-Einstein correlation functions view only a small part of a big and expanding system. The full sizes of the expanding system at the last interaction are shown to be measurable with the help the invariant momentum distribution of the emitted particles. A vanishing duration parameter can also be generated, with a specific M t dependence, in the considered model-class.

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Pseudorapidity (η) distributions of charged particles produced in proton-proton collisions at a centre-of-mass energy of 8 TeV are measured in the ranges |η| < 2.2 and 5.3 < |η| < 6.4 covered by the CMS and TOTEM detectors, respectively. The data correspond to an integrated luminosity of L = 45 µb −1 . Measurements are presented for three event categories. The most inclusive category is sensitive to 91-96 % of the total inelastic proton-proton cross section. The other two categories are disjoint subsets of the inclusive sample that are either enhanced or depleted in single diffractive dissociation events. The data are compared to models used to describe high-energy hadronic interactions. None of the models considered provide a consistent description of the measured distributions.

%'e calculate two-pion correlation functions from a dynamical string model situation and from a Bjorken-scaling solution. The effects of hadronic decays and final-state Coulomb and strong interactions are included. Correlation functions are shown to depend strongly on both the total transverse momenta and the direction of the relative momentum of the pairs.

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We discuss Bose-Einstein correlation functions and momentum distributions which describe boson-emitting systems containing a central part surrounded The results are applied to high energy heavy ion data taken at CERN SPS.New insights are obtained for the description of low transverse momentum enhancement of pions. Z. Phys. C in press *

The PHENIX experiment at the BNL Relativistic Heavy Ion Collider (RHIC) has measured electrons with 0:3 < p T < 9 GeV=c at midrapidity (jyj < 0:35) from heavy-flavor (charm and bottom) decays in Au Au collisions at s NN p 200 GeV. The nuclear modification factor R AA relative to p p collisions shows a strong suppression in central Au Au collisions, indicating substantial energy loss of heavy quarks in the medium produced at RHIC energies. A large azimuthal anisotropy v 2 with respect to the reaction plane is observed for 0:5 < p T < 5 GeV=c indicating substantial heavy-flavor elliptic flow. Both R AA and v 2 show a p T dependence different from those of neutral pions. A comparison to transport models which simultaneously describe R AA p T and v 2 p T suggests that the viscosity to entropy density ratio is close to the conjectured quantum lower bound, i.e., near a perfect fluid.