Search results for "Heavy Ion"

Production of Σ(1385)± and Ξ(1530)0 in proton–proton collisions at √s = 7 TeV

2015

The production of the strange and double-strange baryon resonances ((1385)±, (1530)0) has been measured at mid-rapidity (|y|< 0.5) in proton–proton collisions at √s = 7 TeV with the ALICE detector at the LHC. Transverse momentum spectra for inelastic collisions are compared to QCD-inspired models, which in general underpredict the data. A search for the φ(1860) pentaquark, decaying in the π channel, has been carried out but no evidence is seen. peerReviewed

Measurement of J/ψ at forward and backward rapidity in p+p, p+Al, p+Au, and 3He+Au collisions at √sNN=200 GeV

2020

Charmonium is a valuable probe in heavy-ion collisions to study the properties of the quark gluon plasma, and is also an interesting probe in small collision systems to study cold nuclear matter effects, which are also present in large collision systems. With the recent observations of collective behavior of produced particles in small system collisions, measurements of the modification of charmonium in small systems have become increasingly relevant. We present the results of J/Psi measurements at forward and backward rapidity in various small collision systems, p + p, p + Al, p + Au, and He-3+Au, at root s(NN) = 200 GeV. The results are presented in the form of the observable RAB, the nuc…

Centrality and pseudorapidity dependence of the charged-particle multiplicity density in Xe–Xe collisions at √sNN = 5.44 TeV

2019

In this Letter, the ALICE Collaboration presents the first measurements of the charged-particle multiplicity density, dNch/dη, and total charged-particle multiplicity, Ntot ch , in Xe–Xe collisions at a centre-of-mass energy per nucleon–nucleon pair of √sNN = 5.44 TeV. The measurements are performed as a function of collision centrality over a wide pseudorapidity range of −3.5 < η < 5. The values of dNch/dη at mid-rapidity and Ntot ch for central collisions, normalised to the number of nucleons participating in the collision (Npart) as a function of √sNN follow the trends established in previous heavy-ion measurements. The same quantities are also found to increase as a function of Npart, a…

Relative particle yield fluctuations in Pb--Pb collisions at √sNN = 2.76 TeV

2019

First results on K/π, p/π and K/p fluctuations are obtained with the ALICE detector at the CERN LHC as a function of centrality in Pb–Pb collisions at √sNN = 2.76 TeV. The observable νdyn, which is defined in terms of the moments of particle multiplicity distributions, is used to quantify the magnitude of dynamical fluctuations of relative particle yields and also provides insight into the correlation between particle pairs. This study is based on a novel experimental technique, called the Identity Method, which allows one to measure the moments of multiplicity distributions in case of incomplete particle identification. The results for p/π show a change of sign in νdyn from positive to neg…

Measurement of two-particle correlations with respect to second- and third-order event planes in Au+Au collisions at √sNN = 200 GeV

2019

We present measurements of azimuthal correlations of charged hadron pairs in √sNN = 200 GeV Au + Au collisions for the trigger and associated particle transverse-momentum ranges of 1 4 GeV/c) correlations is suppressed compared with that of correlations measured in p + p collisions. At the lowest associated particle pT (0.5 < pa T < 1 GeV/c), the away-side shape and yield are modified relative to those in p + p collisions. These observations are consistent with the scenario of radiative-jet energy loss. For the low-pT trigger correlations (2 < pt T < 4 GeV/c), a finite away-side yield exists and we explore the dependence of the shape of the away-side within the context of an underlying-even…

Multiparticle azimuthal correlations for extracting event-by-event elliptic and triangular flow in Au + Au collisions at √sNN = 200 GeV

2019

The rare isotope beams production at the Texas A&M university Cyclotron Institute

2013

The Cyclotron Institute at Texas A&M is currently configuring a scheme for the production of radioactive-ion beams that incorporates a light-ion guide and a heavy-ion guide coupled with an electron-cyclotron-resonance ion source constructed for charge-breeding. This scheme is part of an upgrade to the facility and is intended to produce radioactive beams suitable for injection into the K500 superconducting cyclotron. The current status of the project and details on the ion sources used in the project is presented. peerReviewed

Jet-like correlations with neutral pion triggers in pp and central Pb–Pb collisions at 2.76 TeV

2016

Physics letters / B B763, 238 - 250 (2016). doi:10.1016/j.physletb.2016.10.048

Flow dominance and factorization of transverse momentum correlations in Pb-Pb collisions at the LHC

2017

Physical review letters 118(16), 162302 (2017). doi:10.1103/PhysRevLett.118.162302

Features of W production in p-p, p-Pb and Pb-Pb collisions

2017

We consider the production of inclusive W bosons in variety of high-energy hadronic collisions: p--p, p--$\overline{\rm p}$, p--Pb, and Pb--Pb. In particular, we focus on the resulting distributions of charged leptons from W decay that can be measured with relatively low backgrounds. The leading-order expressions within the collinearly factorized QCD indicate that the center-of-mass energy dependence at forward/backward rapidities should be well approximated by a simple power law. The scaling exponent is related to the small-$x$ behaviour of the quark distributions, which is largely driven by the parton evolution. An interesting consequence is the simple scaling law for the lepton charge as…