scholarly journals Antimatter production in proton-proton and heavy-ion collisions at ultrarelativistic energies

2011 ◽  
Vol 84 (5) ◽  
Author(s):  
J. Cleymans ◽  
S. Kabana ◽  
I. Kraus ◽  
H. Oeschler ◽  
K. Redlich ◽  
...  
2011 ◽  
Vol 20 (07) ◽  
pp. 1545-1550
Author(s):  
◽  
MARTIN SPOUSTA

We present the measurement of jet production performed with the ATLAS detector in proton-proton collisions at center-of-mass energy of 7 TeV, using an integrated luminosity of 17 nb−1. We show the inclusive jet cross sections and jet shapes. The expected performance and strategy for the jet reconstruction in heavy ion collisions is also discussed.


2018 ◽  
Vol 172 ◽  
pp. 05006
Author(s):  
Ivan Vitev

In these proceedings, we report on recent results related to vector boson-tagged jet production in heavy ion collisions and the related modification of jet substructure, such as jet shapes and jet momentum sharing distributions. Z0-tagging and γ-tagging of jets provides new opportunities to study parton shower formation and propagation in the quark-gluon plasma and has been argued to provide tight constrains on the energy loss of reconstructed jets. We present theoretical predictions for isolated photon-tagged and electroweak boson-tagged jet production in Pb+Pb collisions at √sNN = 5.02 TeV at the LHC, addressing the modification of their transverse momentum and transverse momentum imbalance distributions. Comparison to recent ATLAS and CMS experimental measurements is performed that can shed light on the medium-induced radiative corrections and energy dissipation due to collisional processes of predominantly quark-initiated jets. The modification of parton splitting functions in the QGP further implies that the substructure of jets in heavy ion collisions may differ significantly from the corresponding substructure in proton-proton collisions. Two such observables and the implication of tagging on their evaluation is also discussed.


Author(s):  
Wen Yi Song ◽  
Wendy Taylor

Abstract We describe pair-production models of spin-0 and spin-½ magnetic monopoles and high-electric-charge objects in proton-proton and heavy-ion collisions, considering both the Drell-Yan and the photon-fusion processes. In particular, we extend the Drell-Yan production model of spin-½ high-electric-charge objects to include Z0-boson exchange for proton-proton collisions. Furthermore, we explore spin-½ and, for the first time, spin-0 production in ultraperipheral heavy-ion collisions. With matrix element calculations and equivalent photon fluxes implemented in MadGraph5_aMC@NLO, we present leading-order production cross sections of these mechanisms in √s = 14 TeV proton-proton collisions and √sNN = 5.5 TeV ultraperipheral lead-lead collisions at the LHC. While the mass range accessible in ultraperipheral lead-lead collisions is much lower than that in proton-proton collisions, we find that the theoretical production cross sections are significantly enhanced in the former for masses below 82 GeV.


2020 ◽  
Vol 235 ◽  
pp. 05004
Author(s):  
Hai Tao Li

Jet quenching effects have been widely used to study the properties of strongly-interacting matter, quark-gluon plasma, in heavy-ion collisions. Flavor tagging in heavy-ion collisions plays an important role to reveal the medium parton showers for quark and gluon evolution. Combining with kinematic information, the average jet charge can be used to separate the contribution of different jet flavors, which is defined as the momentum- weighted sum of the charges of hadrons inside a given jet. Using soft-collinear effective theory with medium interactions, we investigate the factorization of the jet charge in QCD medium. We provide predictions for jet charge distributions and their modifications compared to the ones in proton-proton collisions.


2020 ◽  
Vol 56 (11) ◽  
Author(s):  
Benjamin Dönigus

AbstractThe production of light (anti-)nuclei and (anti-)hypernuclei in ultra-relativistic heavy-ion collisions, but also in more elementary collisions as proton–proton and proton–nucleus collisions, became recently a focus of interest. In particular, the fact that these objects are all loosely bound compared to the temperature and energies, e.g. the kinetic energies involved, is often stressed out to be special for their production. The binding energies of these (anti-)nuclei is between 130 keV ($${\mathrm {\Lambda }}$$ Λ separation energy in the hypertriton) and about 8 MeV per nucleon. Whereas the connected temperatures are of the order of 100 to 160 MeV. This lead to some difficulties in the interpretation of the usually discussed production models, i.e. coalescence and statistical-thermal models, as will be discussed here. In this brief review we discuss selected highlights of the production of light (anti-)nuclei, such as (anti-)deuteron, (anti-)helium and (anti-)alpha nuclei. In addition, we will discuss the current status of the highly debated lifetime of the (anti-)hypertriton and connected measurements and model results.


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