arXiv subjects

Roberta Arnaldi

Publications and source records attributed to Roberta Arnaldi.

9 recordsLinked to original sources

arXiv2025

Physics Briefing Book: Input for the 2026 update of the European Strategy for Particle Physics

The European Strategy for Particle Physics (ESPP) reflects the vision and presents concrete plans of the European particle physics community for advancing human knowledge in fundamental physics. The ESPP is updated every five-to-six years through a community-driven process. It commences with the submission of specific proposals and other input from the community at large, outlining projects envisioned for the near-, mid-, and long-term future. All submitted contributions are evaluated by the Physics Preparatory Group (PPG), and a preliminary analysis is presented at a Symposium meant to foster a broad community discussion on the scientific value and feasibility of the various ideas proposed. The outcomes of the analysis and the deliberations at the Symposium are synthesized in the current Briefing Book, which provides an important input in the deliberations of the Strategy recommendations by the European Strategy Group (ESG).

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arXiv2025

Future facilities: the CERN SPS

The Super Proton Synchrotron (SPS) at CERN has played a pioneering role in the study of heavy-ion collisions since 1986 and nowadays remains central to the exploration of the Quark Gluon Plasma. This document summarizes the present status and future prospects of the SPS physics program with particular focus on hard and electromagnetic probes, highlighting the results and goals of NA61/SHINE and the proposed NA60+ experiment.

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arXiv2023

Prospects for open heavy-flavour and quarkonium measurements with NA60+

The high-intensity beams provided by the CERN SPS in a large range of energies offer a unique opportunity to investigate the region of the QCD phase diagram at high baryochemical potential. The NA60+ experiment, proposed for taking data with heavy-ion collisions at the SPS in the next years, is in an ideal position to provide new insights into the QCD phase diagram, measuring rare probes via a Pb-Pb and p-A beam-energy scan, in the collisions energy interval $\sqrt{s_{NN}}$= 6-17 GeV. NA60+ plans to measure the production of hidden and open charm hadrons and prospects on these measurements will be discussed. Open charm hadrons will be measured from their decays into charged hadrons, reconstructed from the tracks in the silicon detectors of the vertex telescope. This will enable high-precision measurements of the yield of D$^{0}$, D$^{+}$, and D$^{+}_{s}$ mesons, and of $\Lambda_{c}^{+}$ baryons, thus allowing us to constrain the transport properties of the QGP and the charm-quark hadronisation. Charmonium states, J/$\psi$ and $\psi$(2S), will be measured through dimuon decays reconstructed with the muon spectrometer. Hence, by measuring the charmonium yield in p-A and Pb-Pb collisions at different collision energies, NA60+ will have a unique opportunity to study the threshold energy for the onset of deconfinement.

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arXiv2016

Experimental overview on quarkonium production

Quarkonium production in heavy-ion collisions is a well-known signature of the formation of a plasma of quarks and gluons (QGP). After thirty years from the first measurements at SPS energies, a large wealth of results is now accessible from high-energy experiments at RHIC and LHC, and these new data are contributing to sharpen the picture of the quarkonium behaviour in A-A collisions. In this paper, an overview of the main results on both charmonium and bottomonium production in p-A and A-A collisions is presented, focussing on the most recent achievements from the RHIC and LHC experiments.

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arXiv2014

Inclusive Psi(2S) production in p-Pb collisions with ALICE

The ALICE Collaboration has studied the inclusive $\psi(\rm 2S)$ production in p-Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV at the CERN LHC. Measurements are performed, in the $\mu^{+}\mu^{-}$ decay channel, in a forward (2.03$<y_{\rm cms}<$3.53) and in a backward (-4.46$<y_{\rm cms}<$-2.96) centre of mass rapidity ranges, as a function of transverse momentum or event activity. The $\psi(\rm 2S)$ production is compared to the $\rm J/\psi$ one through the double ratio $[\sigma_{\psi(\rm 2S)}/\sigma_{\rm J/\psi}]_{\rm pPb}/[\sigma_{\psi(\rm 2S)}/\sigma_{\rm J/\psi}]_{\rm pp}$ between the cross sections evaluated in p-Pb and pp collisions and by calculating the $\rm J/\psi$ and $\psi(\rm 2S)$ nuclear modification factors. Results indicate that the $\psi(\rm 2S)$ production is suppressed with respect to pp and, in particular in the backward rapidity region, the suppression is stronger than the $\rm J/\psi$ one. This unexpected difference between the $\rm J/\psi$ and $\psi(\rm 2S)$ behaviour, not accounted for by theoretical models based on nuclear parton shadowing and coherent energy loss mechanisms, indicates the presence of sizeable final state effects on the $\psi(\rm 2S)$ production.

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arXiv2012

J/Psi and Psi(2S) production in Pb-Pb collisions with the ALICE Muon Spectrometer at the LHC

Charmonium states are considered important signatures of the strongly interacting medium created in heavy-ion collisions. In the ALICE experiment, these probes can be investigated in the mu^+mu^- decay channel, in the forward rapidity region (2.5<y<4) down to zero transverse momentum. Results on charmonia production in Pb-Pb collisions at sqrt(s_NN)=2.76 TeV are presented. The centrality and transverse momentum dependence of the inclusive J/Psi nuclear modification factor are shown and compared with theoretical models. Finally, first ALICE results on the Psi(2S) production in Pb-Pb collisions are also discussed.

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arXiv2011

Measurement of J/Psi production in pp collisions at sqrt(s)=2.76 and 7 TeV with ALICE

We present results from the ALICE experiment on the inclusive J/Psi production in pp collisions at sqrt(s)=2.76 and 7 TeV. The integrated and differential cross sections are evaluated down to pT=0 in two rapidity ranges, |y|<0.9 and 2.5<y<4, in the dielectron and dimuon decay channel respectively. The measurement at sqrt(s)=2.76 TeV, the same energy as Pb-Pb collisions, provides a crucial reference for the study of hot nuclear matter effects on J/Psi production. The J/Psi yield in pp collisions at sqrt(s)=7 TeV has also been studied as a function of the charged particle multiplicity and first results are presented.

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arXiv2009

J/psi production in p-A and A-A collisions at fixed target experiments

Charmonia suppression is one of the main signatures for the formation of a deconfined medium. However, also nuclear effects, not related to the production of a hot medium, can affect the J/psi yield. The determination, from the study of p-A collisions, of the J/psi behaviour in nuclear matter is, therefore, extremely important to correctly quantify the amount of charmonia suppression induced by the deconfined medium. In this paper the new NA60 results collected at 158 GeV incident energy, i.e. under the same kinematical conditions as the In-In (NA60) and Pb-Pb (NA50) data, are presented and compared with p-A measurements from other fixed target experiments. Results on A-A collisions are also reviewed taking into account the new available information on the influence of cold nuclear matter on the J/psi production yield. Finally, results on the J/psi polarization are shown for p-A and A-A collisions.

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arXiv2001

The onset of the anomalous J/psi suppression in Pb-Pb collisions at the CERN SPS

The J/psi suppression observed by the NA50 experiment is one of the most striking signatures for quark gluon plasma formation in Pb-Pb collisions at 158 AGeV. The J/psi production has been studied as a function of the centrality of the collision estimated via the forward energy EZDC released in a zero degree calorimeter (ZDC). The study of the correlation between the number of participant nucleons in the collisions, Npart, and EZDC allows to check whether the J/psi suppression pattern vs. EZDC is compatible with a sudden J/psi suppression mechanism expressed as a function of Npart.

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