Search results for "Heavy-ion"
showing 10 items of 119 documents
Dipole picture and the nonrelativistic expansion
2022
We study exclusive quarkonium production in the dipole picture at next-to-leading order (NLO) accuracy, using the non-relativistic expansion for the quarkonium wavefunction. This process offers one of the best ways to obtain information about gluon distributions at small $x$, in ultraperipheral heavy ion collisions and in deep inelastic scattering. The quarkonium light cone wave functions needed in the dipole picture have typically been available only at tree level, either in phenomenological models or in the nonrelativistic limit. In this paper, we discuss the compatibility of the dipole approach and the non-relativistic expansion and compute NLO relativistic corrections to the quarkonium …
Scattering and gluon emission in a color field : a light-front Hamiltonian approach
2021
We develop a numerical method to nonperturbatively study scattering and gluon emission of a quark from a colored target using a light-front Hamiltonian approach. The target is described as a classical color field, as in the color glass condensate effective theory. The Fock space of the scattering system is restricted to the |q⟩+|qg⟩ sectors, but the time evolution of this truncated system is solved exactly. This method allows us to study the interplay between coherence and multiple scattering in gluon emission. It could be applied both to studying subeikonal effects in high-energy scattering and to understanding jet quenching in a hot plasma.
High-precision mass measurements and production of neutron-deficient isotopes using heavy-ion beams at IGISOL
2019
An upgraded ion-guide system for the production of neutron-deficient isotopes with heavy-ion beams has been commissioned at the IGISOL facility with an $^{36}\mathrm{Ar}$ beam on a $^{\mathrm{nat}}\mathrm{Ni}$ target. It was used together with the JYFLTRAP double Penning trap to measure the masses of $^{82}\mathrm{Zr}, ^{84}\mathrm{Nb}, ^{86}\mathrm{Mo}, ^{88}\mathrm{Tc}$, and $^{89}\mathrm{Ru}$ ground states and the isomeric state $^{88}\mathrm{Tc}^{m}$. Of these, $^{89}\mathrm{Ru}$ and $^{88}\mathrm{Tc}^{m}$ were measured for the first time. The precision of measurements of $^{82}\mathrm{Zr}, ^{84}\mathrm{Nb}$, and $^{88}\mathrm{Tc}$ was significantly improved. The literature value for $^…
Radiation effects in nitride read-only memories
2010
Abstract We report on the influence of different types of radiation on the nitride read-only memories (NROM®). The memory cells were irradiated by light ions (Boron), X-rays and γ-rays. Memory transistor parameters, such as threshold voltage and subthreshold drain leakage were studied as a function of the accumulated radiation dose and compared to the as-programmed (-erased) devices parameters. Their time evolution was registered in the range from few hours up to 5 months after the irradiation. The NROM® cells showed good radiation robustness up to high accumulated doses. Sufficient program margin (difference of threshold voltage in the programmed state and the read-out voltage level) remai…
Two-particle azimuthal correlations in photonuclear ultraperipheral Pb+Pb collisions at 5.02 TeV with ATLAS
2021
We thank CERN for the very successful operation of the LHC, as well as the support staff from our institutions without whom ATLAS could not be operated efficiently. We acknowledge the support of ANPCyT, Argentina, YerPhI, Armenia, ARC, Australia, BMWFW and FWF, Austria, ANAS, Azerbaijan, SSTC, Belarus, CNPq and FAPESP, Brazil, NSERC, NRC, and CFI, Canada, CERN and ANID, Chile, CAS, MOST, and NSFC, China, COLCIENCIAS, Colombia, MSMT CR, MPO CR, and VSC CR, Czech Republic, DNRF and DNSRC, Denmark, IN2P3-CNRS and CEA-DRF/IRFU, France, SRNSFG, Georgia, BMBF, HGF, and MPG, Germany, GSRT, Greece, RGC and Hong Kong SAR, China, ISF and Benoziyo Center, Israel, INFN, Italy, MEXT and JSPS, Japan, CNR…
Evidence for thermal equilibration in multifragmentation reactions probed with bremsstrahlung photons
2001
The production of nuclear bremsstrahlung photons (E$_{\gamma}>$ 30 MeV) has been studied in inclusive and exclusive measurements in four heavy-ion reactions at 60{\it A} MeV. The measured photon spectra, angular distributions and multiplicities indicate that a significant part of the hard-photons are emitted in secondary nucleon-nucleon collisions from a thermally equilibrated system. The observation of the thermal component in multi-fragment $^{36}$Ar+$^{197}$Au reactions suggests that the breakup of the thermalized source produced in this system occurs on a rather long time-scale.
Kaon-proton strong interaction at low relative momentum via femtoscopy in Pb-Pb collisions at the LHC
2021
Physics letters / B 822, 136708 (2021). doi:10.1016/j.physletb.2021.136708
Charge-dependent flow and the search for the chiral magnetic wave in Pb-Pb collisions at √sNN = 2.76 TeV
2016
We report on measurements of a charge-dependent flow using a novel three-particle correlator with ALICE in Pb-Pb collisions at the CERN Large Hadron Collider (LHC), and discuss the implications for observation of local parity violation and the chiral magnetic wave (CMW) in heavy-ion collisions. Charge-dependent flow is reported for different collision centralities as a function of the event charge asymmetry. While our results are in qualitative agreement with expectations based on the CMW, the nonzero signal observed in higher harmonics correlations indicates a possible significant background contribution. We also present results on a differential correlator, where the flow of positive and …
Temperature dependence of η / s of strongly interacting matter: Effects of the equation of state and the parametric form of ( η / s ) ( T )
2020
We investigate the temperature dependence of the shear viscosity to entropy density ratio η/s using a piecewise linear parametrization. To determine the optimal values of the parameters and the associated uncertainties, we perform a global Bayesian model-to-data comparison on Au+Au collisions at √sNN=200 GeV and Pb+Pb collisions at 2.76 TeV and 5.02 TeV, using a 2+1D hydrodynamical model with the Eskola-Kajantie-Ruuskanen-Tuominen (EKRT) initial state. We provide three new parametrizations of the equation of state (EoS) based on contemporary lattice results and hadron resonance gas, and use them and the widely used s95p parametrization to explore the uncertainty in the analysis due to the c…
β and γ bands in N = 88, 90, and 92 isotones investigated with a five-dimensional collective Hamiltonian based on covariant density functional theory…
2019
A comprehensive systematic study is made for the collective β and γ bands in even-even isotopes with neutron numbers N=88 to 92 and proton numbers Z=62(Sm) to 70 (Yb). Data, including excitation energies, B(E0) and B(E2) values, and branching ratios from previously published experiments are collated with new data presented for the first time in this study. The experimental data are compared to calculations using a five-dimensional collective Hamiltonian (5DCH) based on the covariant density functional theory (CDFT). A realistic potential in the quadrupole shape parameters V(β,γ) is determined from potential energy surfaces (PES) calculated using the CDFT. The parameters of the 5DCH are fixe…