A. Andronic

Heavy ions at the Future Circular Collider

The Future Circular Collider (FCC) Study is aimed at assessing the physics potential and the technical feasibility of a new collider with centre-of-mass energies, in the hadron-hadron collision mode, seven times larger than the nominal LHC energies. Operating such machine with heavy ions is an option that is being considered in the accelerator design studies. It would provide, for example, Pb-Pb and p-Pb collisions at sqrt{s_NN} = 39 and 63 TeV, respectively, per nucleon-nucleon collision, with integrated luminosities above 30 nb^-1 per month for Pb-Pb. This is a report by the working group on heavy-ion physics of the FCC Study. First ideas on the physics opportunities with heavy ions at the FCC are presented, covering the physics of the Quark-Gluon Plasma, of gluon saturation, of photon-induced collisions, as well as connections with other fields of high-energy physics.

Inclusive photon production at forward rapidities in proton–proton collisions at √s = 0.9, 2.76 and 7 TeV - eScholarship

The multiplicity and pseudorapidity distributions of inclusive photons have been measured at forward rapidities (2.3 < η < 3.9) in proton–proton collisions at three center-of-mass energies, √ s = 0.9, 2.76 and 7 TeV using the ALICE detector. It is observed that the increase in the average photon multiplicity as a function of beam energy is compatible with both a logarithmic and a power-law dependence. The relative increase in average photon multiplicity produced in inelastic pp collisions at 2.76 and 7 TeV center-of-mass energies with respect to 0.9 TeV are 37.2 ± 0.3 % (stat) ± 8.8 % (sys) and 61.2 ± 0.3 % (stat) ± 7.6 % (sys), respectively. The photon multiplicity distributions for all center-of-mass energies are well described by negative binomial distributions. The multiplicity distributions are also presented in terms of KNO variables. The results are compared to model predictions, which are found in general to underestimate the data at large photon multiplicities, in particular at the highest center-of-mass energy. Limiting fragmentation behavior of photons has been explored with the data, but is not observed in the measured pseudorapidity range.

Transverse Momentum Distribution and Nuclear Modification Factor of Charged Particles in p plus Pb Collisions at root(NN)-N-s=5.02 TeV

The transverse momentum (p(T)) distribution of primary charged particles is measured in minimum bias (non-single-diffractive) p+Pb collisions at sqrt[s(NN)]=5.02 TeV with the ALICE detector at the LHC. The p(T) spectra measured near central rapidity in the range 0.5<p(T) <20 GeV/c exhibit a weak pseudorapidity dependence. The nuclear modification factor R(pPb) is consistent with unity for p(T) above 2 GeV/c. This measurement indicates that the strong suppression of hadron production at high p(T) observed in Pb+Pb collisions at the LHC is not due to an initial-state effect. The measurement is compared to theoretical calculations.

Production of Σ (1385)±and Ξ (1530)0in p–Pb collisions at √sNN=5.02 TeV

The transverse momentum distributions of the strange and double-strange hyperon resonances ([Formula: see text], [Formula: see text]) produced in p-Pb collisions at [Formula: see text] TeV were measured in the rapidity range [Formula: see text] for event classes corresponding to different charged-particle multiplicity densities, [Formula: see text]d[Formula: see text]/d[Formula: see text]. The mean transverse momentum values are presented as a function of [Formula: see text]d[Formula: see text]/d[Formula: see text], as well as a function of the particle masses and compared with previous results on hyperon production. The integrated yield ratios of excited to ground-state hyperons are constant as a function of [Formula: see text]d[Formula: see text]/d[Formula: see text]. The equivalent ratios to pions exhibit an increase with [Formula: see text]d[Formula: see text]/d[Formula: see text], depending on their strangeness content.The transverse momentum distributions of the strange and double-strange hyperon resonances (

Centrality dependence of ψ(2S) suppression in p-Pb collisions at √sNN= 5.02 TeV - eScholarship

\Sigma (1385)^{\pm }

Event-by-event mean pT fluctuations in pp and Pb–Pb collisions at the LHC - eScholarship

Σ(1385)±,

pi(0) and eta reconstruction from photon conversions in ALICE for first p-p collisions at the LHC

\Xi (1530)^{0}