相关论文: Coherent J/$\psi$ photoproduction and polarization…

Ultra-relativistic heavy ions generate strong electromagnetic fields which offer the possibility to study $\gamma$-nucleus and $\gamma$-proton interactions at the LHC in the so called ultra-peripheral collisions (UPC). Here we report ALICE…

In heavy-ion collisions at the LHC, the ALICE Collaboration is studying Quantum Chromodynamics (QCD) matter at very high energy density where the formation of a Quark Gluon Plasma (QGP) is expected. Quarkonium production is an important…

We present recent results from the ALICE Collaboration on the study of coherent and incoherent J/$\psi$ photoproduction in ultra-peripheral Pb-Pb collisions, including results from exclusive and dissociate J/$\psi$ mesons in…

The intense photon fluxes of relativistic nuclei provide a possibility to study photonuclear and two-photon interactions in ultra-peripheral collisions (UPC) where the nuclei do not overlap and no strong nuclear interactions occur. The…

The first measurement of the cross section for coherent J/$\psi$ photoproduction as a function of $|t|$, the square of the momentum transferred between the incoming and outgoing target nucleus, is presented. The data were measured with the…

Ultra-peripheral Pb-Pb collisions, in which the two nuclei pass close to each other, but at an impact parameter greater than the sum of their radii, provide information about the initial state of nuclei. In particular, heavy vector meson…

Photoproduction of $\rho^0$ mesons in ultra-peripheral Pb+Pb collisions has been studied by the ALICE Collaboration at the CERN LHC. The strong photon flux associated with relativistic charged nuclei leads to a very large cross section for…

Incoherent and dissociative J/$\psi$ photoproduction is sensitive to fluctuations of the gluonic structure of the target. Thus, the measurement of J/$\psi$ photoproduction of the colliding hadron sheds light on the initial state of QCD and…

ALICE has measured quarkonium production in p-Pb collisions at backward ($-$4.46 $<$ $y_{\rm cms}$ $<$ $-$2.96), mid ($-$1.37 $<$ $y_{\rm cms}$ $<$ 0.43) and forward (2.03 $<$ $y_{\rm cms}$ $<$ 3.53) rapidity ($y$) regions down to zero…

ALICE (A Large Ion Collider Experiment) aims at studying the behaviour of nuclear matter at high energy densities and the transition to the Quark Gluon Plasma (QGP), expected to occur in ultra-relativistic heavy ion collisions. Quarkonia…

We report on the first measurement of an excess in the yield of J/$\psi$ at very low transverse momentum ($p_{\rm T}< 0.3$ GeV/$c$) in peripheral hadronic Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV, performed by ALICE at the CERN…

Ultra-peripheral collisions (UPCs), studied using the ALICE detector, allow us to investigate the low-$x$ behavior of the gluon distribution of the colliding particles. Two new measurements of coherent J/$\psi$ photoproduction cross section…

In this new energy regime, quarkonium provides a unique probe to study the properties of the high-density, strongly interacting system formed in the early stages of high-energy heavy-ion collisions. In ALICE, quarkonium states are…

The study of quarkonia, bound states of heavy (charm or bottom) quark-antiquark pairs such as the J/psi or the Upsilon?, provides insight into the earliest and hottest stages of high-energy nucleus-nucleus collisions where the formation of…

The ALICE detector provides excellent capabilities to study quarkonium production at the Large Hadron Collider (LHC). Heavy quarkonia, bound states of charm or beauty quark anti-quark pairs such as the $\mathrm{J/\psi}$, are expected to be…

Quarkonium production has long been regarded as a potential signature of deconfinement in nucleus-nucleus collisions. Recently, the production of J/$\psi$ via regeneration within the quark-gluon plasma (QGP) or at the phase boundary has…

High energy photons originating from the electromagnetic field of ultrarelativistic lead nuclei can interact with the other lead ion. These reactions are studied in the ultra-peripheral heavy ion collisions to probe the physics of strong…

We present the first measurement at the LHC of exclusive J/$\psi$ photoproduction off protons, in ultra-peripheral proton-lead collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV. Events are selected with a dimuon pair produced either in the…

The ALICE experiment has measured quarkonium production in Pb-Pb collisions at \sqrt{sNN} = 2.76 TeV and in p-Pb collisions at \sqrt{sNN} = 5.02 TeV. The measurements are performed in the dielectron de- cay channel at mid-rapidity (|yLAB| <…

The strong electromagnetic fields surrounding the Pb-ions accelerated at the CERN Large Hadron Collider (LHC) allow two-photon and photonuclear interactions to be studied in a so far unexplored kinematic regime. Exclusive photoproduction of…