The Multi-Purpose Detector (MPD) is to be installed at the Nuclotron Ion Collider fAcility (NICA) of the Joint Institute for Nuclear Research (JINR). Its main goal is to study the phase diagram of ...the strongly interacting matter produced in heavy-ion collisions. These studies, while providing insight into the physics of heavy-ion collisions, are relevant for improving our understanding of the evolution of the early Universe and the formation of neutron stars. In order to extend the MPD trigger capabilities, we propose to include a high granularity beam-beam monitoring detector (BE-BE) to provide a level-0 trigger signal with an expected time resolution of 30 ps. This new detector will improve the determination of the reaction plane by the MPD experiment, a key measurement for flow studies that provides physics insight into the early stages of the reaction. In this work, we use simulated Au+Au collisions at NICA energies to show the potential of such a detector to determine the event plane resolution, providing further redundancy to the detectors originally considered for this purpose namely, the Fast Forward Detector (FFD) and the Hadron Calorimeter (HCAL). We also show our results for the time resolution studies of two prototype cells carried out at the T10 beam line at the CERN PS complex.
A large number of atmospheric muon events were recorded during 2009 for the calibration, alignment and commissioning of most of the ALICE (A Large Ion Collider Experiment at the CERN LHC) detectors. ...Specific triggers, not used during the LHC collisions, were implemented to take these data. Some triggers select atmospheric muons, with zenith angle between 0° and 60°, crossing the central barrel of ALICE and reconstructed with the TPC (Time Projection Chamber). The muon multiplicity of the event, and for each muon the momentum, the sign, the direction and the spatial coordinates are measured. We present a first analysis of these events with correlations between some observables. Another trigger selects horizontal muons with zenith angle between 65° and 85°. These muons are detected and reconstructed with the Forward Muon Spectrometer. The angular distribution and some characteristics of these rare events are discussed.
We compute the Lambda and anti-Lambda global polarization in semi-central heavy-ion collisions modeling the source as consisting of a high-density core and a less dense corona. We show that when more ...Lambdas than anti-Lambdas are produced in the corona, and this is combined with a smaller number of Lambdas coming from the core, as compared to those coming from the corona, an amplification effect for the anti-Lambda with respect to that of Lambda polarization can occur. This amplification becomes more important for lower collision energies and quantitatively accounts for the Lambda and anti-Lambda polarizations measured by the STAR beam energy scan.
