First results on the longitudinal asymmetry and its effect on the pseudorapidity distributions in Pb–Pb collisions at = 2.76 TeV at the Large Hadron Collider are obtained with the ALICE detector. The longitudinal asymmetry arises because of an unequal number of participating nucleons from the two colliding nuclei, and is estimated for each event by measuring the energy in the forward neutron-Zero-Degree-Calorimeters (ZNs). The effect of the longitudinal asymmetry is measured on the pseudorapidity distributions of charged particles in the regions , and by taking the ratio of the pseudorapidity distributions from events corresponding to different regions of asymmetry. The coefficients of a polynomial fit to the ratio characterise the effect of the asymmetry. A Monte Carlo simulation using a Glauber model for the colliding nuclei is tuned to reproduce the spectrum in the ZNs and provides a relation between the measurable longitudinal asymmetry and the shift in the rapidity () of the participant zone formed by the unequal number of participating nucleons. The dependence of the coefficient of the linear term in the polynomial expansion, , on the mean value of is investigated.

Longitudinal asymmetry and its effect on pseudorapidity distributions in Pb–Pb collisions at sNN=2.76 TeV

Boca, G.;Costanza, S.;Rotondi, A.;
2018-01-01

Abstract

First results on the longitudinal asymmetry and its effect on the pseudorapidity distributions in Pb–Pb collisions at = 2.76 TeV at the Large Hadron Collider are obtained with the ALICE detector. The longitudinal asymmetry arises because of an unequal number of participating nucleons from the two colliding nuclei, and is estimated for each event by measuring the energy in the forward neutron-Zero-Degree-Calorimeters (ZNs). The effect of the longitudinal asymmetry is measured on the pseudorapidity distributions of charged particles in the regions , and by taking the ratio of the pseudorapidity distributions from events corresponding to different regions of asymmetry. The coefficients of a polynomial fit to the ratio characterise the effect of the asymmetry. A Monte Carlo simulation using a Glauber model for the colliding nuclei is tuned to reproduce the spectrum in the ZNs and provides a relation between the measurable longitudinal asymmetry and the shift in the rapidity () of the participant zone formed by the unequal number of participating nucleons. The dependence of the coefficient of the linear term in the polynomial expansion, , on the mean value of is investigated.
2018
Applied Physics/Condensed Matter/Materials Science encompasses the resources of three related disciplines: Applied Physics, Condensed Matter Physics, and Materials Science. The applied physics resources are concerned with the applications of topics in condensed matter as well as optics, vacuum science, lasers, electronics, cryogenics, magnets and magnetism, acoustical physics and mechanics. The condensed matter physics resources are concerned with the study of the structure and the thermal, mechanical, electrical, magnetic and optical properties of condensed matter. They include superconductivity, surfaces, interfaces, thin films, dielectrics, ferroelectrics and semiconductors. The materials science resources are concerned with the physics and chemistry of materials and include ceramics, composites, alloys, metals and metallurgy, nanotechnology, nuclear materials, adhesion and adhesives. Resources dealing with polymeric materials are listed in the Organic Chemistry/Polymer Science category.
Esperti anonimi
Inglese
Internazionale
STAMPA
781
20
32
13
Nuclear and High Energy Physics
http://www.sciencedirect.com/science/journal/03702693
1039
info:eu-repo/semantics/article
262
Acharya, S.; Adam, J.; Adamová, D.; Adolfsson, J.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmad, N.; Ahn, S. U.;...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11571/1237787
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