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I. Melo

Publications and source records attributed to I. Melo.

6 recordsLinked to original sources

Multistrangeness in Heavy-Ion Collisions

We discuss strangeness production in heavy-ion collisions in the broad energy range --- from SIS energies through AGS-SPS-RHIC and upto LHC energies. On several examples we demonstrate how the strange particle production can reveal information about the collision dynamics and about possible modifications of particle properties in medium. In particular the production of hadrons containing two and more strange quarks, like $Ξ$ and $Ω$ baryons, or a $ϕ$ meson is of interest. We conduct our discussion in the framework of the minimal statistical model, in which the total strangeness yield is fixed by the $K^+$ multiplicity. It is emphasized that in collisions with a small number of produced strange particles, the exact strangeness conservation in each collision event must be explicitly preserved.

nucl-th

Probing the strong electroweak symmetry breaking in a model with a vector resonance

We systematically study the possibility to probe the physics behind the electroweak symmetry breaking at the LHC assuming new strong interactions being responsible for the effect. The new physics is described by the Higgs-less effective Lagrangian with a vector resonance in the particle spectrum, in addition to the Standard Model fields. We analyze signals of the resonance in the mixing-induced LHC processes pp-> abX, ab=t\bar{t},b\bar{b},t\bar{b},W^+Z,W^+W^-. At this level of our calculations we do not consider further decays of the quarks and of the gauge bosons.

hep-ph

Non-equilibrium Phase Transitions in Ultrarelativistic Nuclear Collisions

Highly excited nuclear matter created in ultrarelativistic heavy-ion collisions possibly reaches the phase of quark deconfinement. It quickly cools down and hadronises. We explain that the process of hadronisation may likely be connected with disintegration into fragments. Observable signals of such a scenario are proposed.

nucl-th

Study of event-by-event fluctuations in heavy ion collisions

We propose Kolmogorov-Smirnov test as a means for recognising event-by-event fluctuations of rapidity distributions in relativistic heavy ion collisions. Such fluctuations may be induced by the spinodal decomposition of the rapidly expanding system during the 1st order quark-hadron phase transition.

nucl-th

Some constraints on neutral heavy leptons from flavor-conserving decays of the Z boson

Small neutrino masses can arise in some grand unified models or superstring theories. We consider a model with an enhanced fermion sector containing Dirac neutral heavy leptons. The dependence on the mass and mixing parameters of these new fermions is investigated for several measurable quantities. We study the flavor-conserving leptonic decays of the Z boson and universality breaking in these decays. We also consider the W boson mass dependence on neutral heavy lepton parameters.

hep-ph