Scientific Open-access Literature Archive and Repository
Not a member yet
16397 research outputs found
Sort by
Femtoscopy with Lévy sources at NA61/SHINE
Get PDFIn the recent decades of high-energy physics research, it was demonstrated that strongly interacting quark-gluon plasma (sQGP) is created in ultrarelativistic nucleus-nucleus collisions. Investigation and understanding of the properties of the hadronic matter are among the most important goals of the NA61/SHINE collaboration at CERN SPS. Mapping of the phase diagram is achieved by varying the collision energy (5 GeV √s NN <17 GeV) and by changing the collision system (p+p, p+Pb, Be+Be, Ar+Sc, Xe+La, Pb+Pb). Femtoscopic correlations reveal the space-time structure of the hadron emitting source. In this article, we report on the measurement of femtoscopic correlations in small to intermediate systems. Comparing the measurements to calculations based on symmetric Lévy sources, we discuss the results on Lévy source parameters as a function of average pair transverse mass. One of the physical parameters is of particular importance, the Lévy exponent α, which describes the shape of the source and may be related to the critical exponent η in the proximity of the critical point. Therefore, measuring it may shed light on the location of the critical endpoint of the QCD phase diagram
Femtoscopic correlation studies between D0 mesons and charged kaons in Au+Au collisions at √s NN=200 GeV by STAR
Get PDFHeavy quarks are produced in hard partonic scatterings at the very early stage of heavy-ion collisions and they experience the whole evolution of the Quark-Gluon Plasma medium. Femtoscopic correlation is defined as two particle
correlation at low relative momentum which is sensitive to the final-state interaction as well as to the extent of the region from which the correlated particles emit. Study of such correlations between charmed mesons and identified charged hadrons could shed light on their interactions in the hadronic phase and the interaction of charm quarks with the medium. We report the first measurement of femtoscopic
correlations between D0 and kaon pairs at mid-rapidity in Au+Au collisions at √s NN = 200 GeV by the STAR experiment. The physics implications are discussed by comparing to theory calculations
Production of resonances in Partial Chemical Equilibrium
Get PDFWithin the model of Partial Chemical Equilibrium (PCE) we calculate the multiplicity ratios of selected unstable resonances to given stable species. We focus on those ratios that have been measured either in Pb+Pb collisions at the LHC or in Au+Au collisions at the top RHIC energy. The model provides an interpretation how in an expanding hadronic fireball with decreasing temperature the final numbers of stable hadrons after decays of all resonances remain unchanged. Each stable species acquires its own chemical potential and the resonances are kept in equilibrium with them. Multiplicities of unstable resonances provide a test of this scenario. We observe that the ratios of K∗/K and ρ0/π fit reasonably well into the picture of single kinetic freeze-out of the single-particle spectra, but the φ-meson
and hyperon resonances are not reproduced by this model
Preface
Get PDFThis volume includes most of the contributions presented at the fifth edition of the IWM-EC International Workshop on Multi facets of EoS and Clustering, held in May 2024 at INFN, Laboratori Nazionali del Sud and Sezione di Catania and at Department of Physics and Astronomy “Ettore Majorana” in Catania, Italy
Quantifying neutron-proton equilibration using molecular dynamics codes
Get PDFPrevious studies have quantified neutron-proton equilibration experimentally in dynamically deformed nuclei in heavy ion collisions (Jedele A. et al., Phys. Rev. Lett., 118 (2017) 062501; Rodriguez Manso A. et al., Phys. Rev. C, 95 (2017) 044604). The results showed the composition of the two heaviest fragments from the excited projectile-like fragment evolve exponentially with respect to its angle of rotation. Simulations using constrained molecular dynamics and anti-symmetrized molecular dynamics were utilized for different slope parameterizations to compare the experimental results. The results indicate better agreement with a softer interaction
Searching nuclear EoS from isospin transport in heavy-ion reactions around the Fermi energy domain
Get PDFThe isospin transport of the quasi-projectile formed in the
64,58Ni+64,58Ni reactions around the Fermi energy domain is studied in the framework of the Boltzmann-Uehling-Uhlenbeck transport model. Isospin transport ratio is investigated, with the aim of ensuring an optimal comparison between experimental data and theoretical calculations and reducing the present uncertainties in the extraction of empirical equation of state parameters. We show that isospin transport ratio calculated from the neutron to proton ratio of the quasi-projectile as well as forward emitted free nucleons are not identical but both are sensitive to the symmetry energy at saturation, its slope and curvature. The sensitivity of the nuclear EoS to isospin transport ratios is greater for the quasi-projectile than for the free
nucleon
Performance of the AMD model for the low-energy reaction 18O+12C at 16.7 MeV/nucleon
Get PDFThis study investigates the performance of the antisymmetrized molecular dynamics (AMD) transport model in simulating the low-energy nuclear reactions 18O+12C at 16.7 MeV/nucleon. The experimental data, gathered using the GARFIELD+RCo detector at Laboratori Nazionali di Legnaro, are compared with the AMD model coupled with the GEMINI++ decay code. The study found that the model accurately predicts the behaviour of fragments with Z ≥ 10, while discrepancies were pointed out in the production of fragments with 4 <Z<10
Le scienze umane e sociali nel XXI secolo: comprendere e trasformare la società
Get PDFQuesta pubblicazione raccoglie le relazioni presentate dai ricercatori del
Dipartimento di Scienze Umane e Sociali Patrimonio Culturale (DSU)
in occasione della Conferenza di Dipartimento intitolata “Le Scienze Umane
e Sociali nel XXI secolo: Comprendere e Trasformare la Società”, che si è
tenuta il 9 novembre 2023 a Roma, nella sede centrale del CNR. L’iniziativa
si è svolta in continuità con la prima Conferenza di Dipartimento che aveva
avuto luogo il 30 giugno e il 1 luglio 2022 nella stessa sede. Da questa prima
conferenza, infatti, era scaturito l’interesse a proseguire e approfondire
le discussioni dei gruppi di lavoro tematici che avevano visto una ampia
partecipazione di ricercatori appartenenti a diversi istituti del Dipartimento.\ud
In entrambi i casi i contributi presentati e discussi nel corso delle conferenze
hanno ribadito l’importanza dell’approccio multi ed interdisciplinare ai temi
di studio e il fatto che tale approccio costituisce un elemento distintivo delle
ricerche del DSU e del CNR in generale
Recent results in VBS and VBF measurement performed with the CMS experiment
Get PDFThe study of vector boson scattering (VBS) and vector boson fusion (VBF) processes is crucial for testing the Standard Model (SM). This report focuses on two analyses: the electroweak production of opposite-sign W±W∓ bosons in the fully leptonic decay channel and the electroweak WV production in the semileptonic decay channel. Additionally, it briefly covers the ongoing single W boson electroweak
production analysis. The data sample analyzed corresponds to an integrated luminosity of 138 fb−1 of proton-proton collisions at √s = 13 TeV collected by the CMS detector. The VBS W±W∓ signal is observed with a significance of 5.6 standard deviations (5.2 expected) and a measured fiducial cross-section of 10.2±2.0 fb, consistent with the SM prediction of 9.1 ± 0.6 fb. The VBS WV process shows the
first evidence with a significance of 4.4 standard deviations observed (5.1 expected) and a measured fiducial cross-section of 1.9±0.5 fb, matching the SM prediction of
2.2 ±0.1 fb. Finally, the VBF W analysis is expected to have a 15% uncertainty on the fiducial cross-section measurement
Unconventional search and long-lived particles at LHC: Signature and experimental challenges
Get PDFThe search for long-lived and unconventional particles at collider experiments presents a unique set of experimental challenges and opportunities. This contribution delves into their distinctive signatures and the innovative strategies
employed to detect them at the LHC. A brief overview of the theoretical motivations together with the main experimental challenges to face are addressed highlighting the vast variety of searches aimed at exploiting the full potential of the existing detectors together with the commissioning and prospects of future dedicated experiments