Coulomb interaction on pion production in Au+Au collisions at relativistic energies

Coulomb effects on charged pion transverse momentum spectra produced in Au+Au collisions at RHIC-BES energies are investigated. From these spectra the {\pi}-/{\pi}+ ratios as a function of transverse momentum are obtained and used to extract the Coulomb kick (a momentum change due to Coulomb interaction) and initial pion ratio for three different collision energies and various centrality classes. The Coulomb kick shows a decrease with the increase of beam energy and a clear centrality dependence, with larger values for the most central collisions. The results are connected with the kinetic freeze-out dynamics and discussed

A mobile detector for measurements of the atmospheric muon flux in underground sites

Muons comprise an important contribution of the natural radiation dose in air (approx. 30 nSv/h of a total dose rate of 65-130 nSv/h), as well as in underground sites even when the flux and relative contribution are significantly reduced. The flux of the muons observed in underground can be used as an estimator for the depth in mwe (meter water equivalent) of the underground site. The water equivalent depth is an important information to devise physics experiments feasible for a specific site. A mobile detector for performing measurements of the muon's flux was developed in IFIN-HH, Bucharest. Consisting of 2 scintillator plates (approx. 0.9 m2) which measure in coincidence, the detector is installed on a van which facilitates measurements at different locations at surface or underground. The detector was used to determine muon fluxes at different sites in Romania. In particular, data were taken and the values of meter water equivalents were assessed for several locations from the salt mine from Slanic Prahova, Romania. The measurements have been performed in 2 different galleries of the Slanic mine at different depths. In order to test the stability of the method, also measure- ments of the muon flux at surface at different elevations were performed. The results were compared with predictions of Monte-Carlo simulations using the CORSIKA and MUSIC codes

Study of Monte Carlo event generators for proton-proton collisions at LHC energies in the forward region *

Abstract In this paper we present a comparative study between PYTHIA, EPOS, QGSJET, and SIBYLL generators. The global event observables considered are the charged energy flow, charged particle distributions, charged hadron production ratios and V 0 ratios. The study is performed in the LHCb and TOTEM fiducial phase spaces on minimum bias simulated data samples for pp collisions at = 7 TeV , using the reference measurements from these experiments. In the majority of cases, the measurements are within a band defined by the most extreme predictions. The observed differences between the predictions and the measurements seem to be, in most part, caused by extrapolation from the central pseudorapidity region (|η| 2.5), in which the generators were mainly tuned. </jats:p

Interactive whiteboards in Romania

AbstractThe utilization of the interactive whiteboard is a challenge for Romanian teachers. The education methods involving this device can vary because they depend on the components involved in this process: the teacher, the students, the computer, as basic tool, and software, including applications developed for education in different programming languages. The results of a preliminary study involving 54 Romanian teachers about the experience referring to this subject are presented

Strange particle effective temperatures in relativistic nuclear collisions

The energy dependence of the effective temperatures of charged kaons, [Formula: see text] and [Formula: see text] produced in Au[Formula: see text]Au collisions at the Relativistic Heavy Ion Collider (RHIC) Beam Energy Scan (BES) energies are presented. At energies around [Formula: see text][Formula: see text]GeV, there is a sudden change in the energy dependence of [Formula: see text] and [Formula: see text] effective temperatures, while at higher energies a slower, continuous rise up to [Formula: see text][Formula: see text]TeV is observed. This behavior is similar with previous SPS results and could indicate the onset of deconfinement in this energy range. The [Formula: see text] effective temperatures increase with energy and no plateau-like behavior is evidenced by the data. </jats:p

Coulomb Interaction Effects on Pion Production in Au+Au Collisions at Relativistic Energies

Coulomb effects on charged pion transverse momentum spectra measured in Au+Au collisions at RHIC-BES energies are investigated. From these spectra the π-/π+ ratios as a function of transverse momentum are obtained and used to extract the “Coulomb kick”, pc (a momentum change due to the Coulomb interaction), and initial pion ratio for three different collision energies and various centrality classes. The Coulomb kick shows a decrease with the increase of beam energy and a clear centrality dependence, with larger values for the most central collisions. The results are connected with the kinetic freeze-out dynamics

Rapidity dependence of charged pion production at relativistic energies using Tsallis statistics

Transverse momentum distributions of charged pions produced in Au+Au collisions at 62.4GeV, 130GeV, 200GeV, Cu+Cu and d+Au collisions at 200GeV, p+p collisions at 62.4 and 200GeV and Pb+Pb collisions at 17.3GeV are studied using the Tsallis distribution as a parametrization. The non-extensivity parameter and Tsallis volume increase with energy, while the Tsallis temperature shows a decrease at higher energies. Using BRAHMS $p_T$ spectra obtained in Au+Au collisions at 62.4GeV and 200GeV, Tsallis fit parameters are obtained on a very wide rapidity range. Results are compared with p+p and Cu+Cu data and changes of Tsallis parameters with rapidity and energy are investigated. We found that non-extensivity parameter q shows a decrease from midrapidity to forward rapidities for all the studied systems. Tsallis volume, V , increases with the system size from p+p, Cu+Cu to Au+Au, both in central rapidity region and at forward rapidities. The values of temperatures increase with rapidity, but the $T/\cosh(y)$ ratio is constant as a function of rapidity