P. Castorina

Noncommutative gravitational quantum well

We study noncommutative geometry at the quantum mechanics level by means of a model where noncommutativity of both configuration and momentum spaces is considered. We analyze how this model affects the problem of the two-dimensional gravitational quantum well and use the latest experimental results for the two lowest energy states of neutrons in the Earths gravitational field to establish an upper bound on the fundamental momentum scale introduced by noncommutativity, namely, {radical}({eta}) < or approx. 1 meV/c, a value that can be improved in the future by up to 3 orders of magnitude. We show that the configuration space noncommutativity has, in leading order, no effect on the problem. We also analyze some features introduced by the model, especially a correction to the presently accepted value of Plancks constant to 1 part in 10{sup 24}.

Thermal Hadronization and Hawking-Unruh Radiation in QCD

We conjecture that, because of color confinement, the physical vacuum forms an event horizon for quarks and gluons, which can be crossed only by quantum tunneling, i.e., through the QCD counterpart of Hawking radiation at black holes. Since such radiation cannot transmit information to the outside, it must be thermal, of a temperature determined by the chromodynamic force at the confinement surface, and it must maintain color neutrality. We explore the possibility that the resulting process provides a common mechanism for thermal hadron production in high energy interactions, from e+e- annihilation to heavy ion collisions.

The thermal production of strange and non-strange hadrons in e+e− collisions

The thermal multihadron production observed in different high energy collisions poses two basic problems. (1) Why do even elementary collisions with comparatively few secondaries (e+e−xa0annihilation) show thermal behavior? (2) Why is there in such interactions a suppression of strange particle production? We show that the recently proposed mechanism of thermal hadron production through Hawking–Unruh radiation can naturally account for both. The event horizon of color confinement leads to thermal behavior, but the resulting temperature depends on the strange quark content of the produced hadrons, causing a deviation from full equilibrium and hence a suppression of strange particle production. We apply the resulting formalism to multihadron production in e+e− annihilation over a wide energy range and make a comprehensive analysis of the data in the conventional statistical hadronization model and the modified Hawking–Unruh formulation. We show that this formulation provides a very good description of the measured hadronic abundances, fully determined in terms of the string tension and the bare strange quark mass; it contains no adjustable parameters.

A comparative analysis of statistical hadron production

We perform a systematic comparison of the statistical model parametrization of hadron abundances observed in high-energy pp, AA and e+e− collisions. The basic aim of the study is to test if the quality of the description depends on the nature of the collision process. In particular, we want to see if nuclear collisions, with multiple initial interactions, lead to “more thermal” average multiplicities than elementary pp collisions or e+e− annihilation. Such a comparison is meaningful only if it is based on data for the same or similar hadronic species and if the analyzed data has quantitatively similar errors. When these requirements are maintained, the quality of the statistical model description is found to be the same for the different initial collision configurations.

Nonuniform symmetry breaking in noncommutative λ Φ 4 theory

Spontaneous symmetry breaking in noncommutative cutoff

Scaling of variables and the relation between noncommutative parameters in noncommutative quantum mechanics

ensuremath{lambda}{ensuremath{Phi}}^{4}

Quark matter in neutron stars within the Nambu-Jona-Lasinio model and confinement

theory has been analyzed by using the formalism of the effective action for composite operators in the Hartree-Fock approximation. It turns out that there is no phase transition to a constant vacuum expectation of the field and the broken phase corresponds to a nonuniform background. By considering

Vacuum instability as the origin of asymptotic freedom

〈ensuremath{varphi}(x)〉=Amathrm{cos}(stackrel{ensuremath{rightarrow}}{Q}ensuremath{cdot}stackrel{ensuremath{rightarrow}}{x})

Trace Anomaly and Quasi-Particles in Finite Temperature SU(N) Gauge Theory

the generated mass gap depends on the angles among the momenta

Exact string black hole behind the hadronic Rindler horizon

stackrel{ensuremath{rightarrow}}{k}