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A. Accardi

Publications and source records attributed to A. Accardi.

43 records · Page 3Linked to original sources

Hard probes in heavy ion collisions at the LHC: PDFs, shadowing and $pA$ collisions

This manuscript is the outcome of the subgroup ``PDFs, shadowing and $pA$ collisions'' from the CERN workshop ``Hard Probes in Heavy Ion Collisions at the LHC''. In addition to the experimental parameters for $pA$ collisions at the LHC, the issues discussed are factorization in nuclear collisions, nuclear parton distributions (nPDFs), hard probes as the benchmark tests of factorization in $pA$ collisions at the LHC, and semi-hard probes as observables with potentially large nuclear effects. Also, novel QCD phenomena in $pA$ collisions at the LHC are considered. The importance of the $pA$ program at the LHC is emphasized.

hep-ph↗

Jet and Dijet Rates in pA Collisions

Jet and dijet rates in pA collisions at LHC energies are computed using a NLO Monte Carlo code. Uncertainties due to the choice of scale, jet-finding algorithm, nucleon parton densities and nuclear modifications of nucleon parton densities are analyzed. Predictions for different pA collisions at LHC energies are presented.

hep-ph↗

Jet and Dijet Rates in AB Collisions

Jet and dijet rates in AB collisions at LHC energies are computed using a NLO Monte Carlo code. Uncertainties due to nuclear modifications of nucleon parton densities are analyzed. Predictions for different AB collisions at LHC energies are presented.

hep-ph↗

Minijet transverse spectrum in high-energy hadron-nucleus collisions

Hadron-nucleus collisions at LHC energies are studied by including explicitly semi-hard parton rescatterings in the collision dynamics. Under rather general conditions, we obtain explicit formulae for the semi-hard cross-section and the inclusive minijet transverse spectrum. As an effect of the rescatterings the spectrum is lowered at small $p_t$ and is enhanced at relatively large transverse momenta, the deformation being more pronounced at increasing rapidity. Its study allows to test the proposed interaction mechanisms and represents an important baseline to examine nucleus-nucleus collisions.

hep-ph↗

Semi-hard scatterings at RHIC and LHC: initial conditions and charged multiplicities

Minijet production in ultra-relativistic heavy-ion collisions is discussed by taking semi-hard parton rescatterings explicitly into account. At both RHIC and LHC energies we find sizable effects on global characteristics of the nuclear collision like the initial multiplicity and transverse energy of the minijets. The dependence of these quantities on the cutoff that separates soft and hard interactions becomes much smoother after the inclusion of the rescatterings. This allows to define an energy and centrality dependent saturation cutoff and to push perturbative computations to rather low values of the cutoff. As an application we compute the charged multiplicity at mid rapidity and compare it to the recent RHIC data.

hep-ph↗

Hard Parton Rescatterings and Minijets in Nuclear Collisions at LHC

The average number of minijets and the corresponding transverse energy produced in heavy ion collisions are evaluated by including explicitly semi-hard parton rescatterings in the dynamics of the interaction. At the LHC semi-hard rescatterings have a sizable effect on global characteristics of the typical inelastic event. An interesting feature is that the dependence on the cutoff which separates soft and hard parton interactions becomes less critical after taking rescatterings into account.

hep-ph↗

Topological Yang-Mills cohomology in pure Yang-Mills Theory

Using the first order formalism (BFYM) of the Yang-Mills theory we show that it displays an embedded topological sector corresponding to the field content of the Topological Yang-Mills theory (TYM). This picture arises after a proper redefinition of the fields of BFYM and gives a clear representation of the non perturbative part of the theory in terms of the topological sector. In this setting the calculation of the $vev$ of a YM observable is translated into the calculation of a corresponding (non topological) quantity in TYM. We then compare the topological observables of TYM with a similar set of observables for BFYM and discuss the possibility of describing topological observables in YM theory.

hep-th↗