Papers by Joséluis Cortés
International Journal of Modern Physics A, 1994
The nonrelativistic quantum-field-theoretic Lagrangian which describes an anyon system in the pre... more The nonrelativistic quantum-field-theoretic Lagrangian which describes an anyon system in the presence of an electromagnetic field is identified. A nonminimal magnetic coupling to the Chern–Simons statistical field as well as to the electromagnetic field together with a direct coupling between both fields are the nontrivial ingredients of the Lagrangian obtained from the nonrelativistic limit of the fermionic relativistic formulation. The results, an electromagnetic gyromagnetic ratio 2 for any spin together with a nontrivial dynamical spin-dependent contact interaction between anyons as well as the spin dependence of the electromagnetic effective action, agree with the quantum-mechanical formulation.
It is demonstrated that the recently proposed pseudoclassical model for Weyl particles [1] (D.M. ... more It is demonstrated that the recently proposed pseudoclassical model for Weyl particles [1] (D.M. Gitman, A.E. Gonçalves and I.V. Tyutin, Phys. Rev. D 50 (1994) 5439) is classically inconsistent. A possible way of removing the classical inconsistency of the model is proposed.
A reinterpretation of noncommutativity as a mapping of paths is proposed at the level of quantum ... more A reinterpretation of noncommutativity as a mapping of paths is proposed at the level of quantum mechanics.
Physical Review D, 1981
The inclusive semileptonic decays of flavored heavy particles are investigated in detail. The inc... more The inclusive semileptonic decays of flavored heavy particles are investigated in detail. The inclusive decay rate is in agreement with the standard quark-parton-model estimation.
Physical Review D, 1983
We study the polarization amplitudes for the production of a weak boson (W) and a photon from qua... more We study the polarization amplitudes for the production of a weak boson (W) and a photon from quark-antiquark annihilation in the standard model minimally extended by giving the W an arbitrary anomalous magnetic moment κ. We find that in the cm frame the amplitude ...
Zeitschrift für Physik C Particles and Fields, 1985
Physical Review D, 1982
Mass effects in weak-decay rates of heavy particles are computed. A natural explanation of the ex... more Mass effects in weak-decay rates of heavy particles are computed. A natural explanation of the experimental D+ semileptonic branching ratio arises when mass and quantum-chromodynamic corrections are both taken into account. The experimental results on semileptonic branching ratio of b-flavored 8 mesons allows the prediction of the lifetime ratio r (B)/r(B') (3.5 in a model-independent way.
Astroparticle Physics, 2014
We consider a particular effect which can be expected in scenarios of deviations from Special Rel... more We consider a particular effect which can be expected in scenarios of deviations from Special Relativity induced by Planckian physics: the loss of additivity in the total energy of a system of particles. We argue about the necessity to introduce a length scale to control the effects of nonadditivity for macroscopic objects and consider white dwarfs as an appropriate laboratory to test this kind of new physics. We study the sensitivity of the mass-radius relation of the Chandrasekhar model to these corrections by comparing the output of a simple phenomenological model to observational data of white dwarfs.
Physics Letters B, 1997
We show that it is possible to find an extension of the matter content of the standard model with... more We show that it is possible to find an extension of the matter content of the standard model with a unification of gauge and Yukawa couplings reproducing their known values. The perturbative renormalizability of the model with a single coupling and the requirement to accomodate the known properties of the standard model fix the masses and couplings of the additional particles. The implications on the parameters of the standard model are discussed.
A recently conjectured relashionship between UV and IR cutoffs in an effective field theory witho... more A recently conjectured relashionship between UV and IR cutoffs in an effective field theory without quantum gravity is generalized in the presence of large extra dimensions. Estimates for the corrections to the usual calculation of observables within quantum field theory are used to put very stringent limits, in some cases, on the characteristic scale of the additional compactified dimensions. Implications for the cosmological constant problem are also discussed.
We present a way of protecting a Dirac fermion interacting with a scalar (Higgs) field from getti... more We present a way of protecting a Dirac fermion interacting with a scalar (Higgs) field from getting a mass from the vacuum. It is obtained through an implementation of translational symmetry when the theory is formulated with a momentum cutoff, which forbids the usual Yukawa term. We consider that this mechanism can help to understand the smallness of neutrino masses without a tuning of the Yukawa coupling. The prohibition of the Yukawa term for the neutrino forbids at the same time a gauge coupling between the right-handed electron and neutrino. We prove that this mechanism can be implemented on the lattice.
In this paper the implications of a recently proposed phenomenological model of cosmology, the As... more In this paper the implications of a recently proposed phenomenological model of cosmology, the Asymptotic Cosmological Model (ACM), on the behavior of scalar perturbations are studied. Firstly we discuss new fits of the ACM at the homogeneous level, including fits to the Type Ia Supernovae UNION dataset, first CMB peak of WMAP5 and BAOs. The linearized equations of scalar perturbations in the FRW metric are derived. A simple model is used to compute the CMB temperature perturbation spectrum. The results are compared with the treatment of perturbations in other approaches to the problem of the accelerated expansion of the universe.
A new formulation of fermions on the lattice based on a discretization of a second order formalis... more A new formulation of fermions on the lattice based on a discretization of a second order formalism is proposed. A comparison with the first order formalism in connection with the U(1) anomaly and the doubling problem is presented. The new formulation allows to eliminate half of the degrees of freedom which can be important in non-perturbative calculations and it can open new possibilities to the formulation of chiral gauge theories.
A new approach to the path integral over fermionic fields, based on the extension of a reformulat... more A new approach to the path integral over fermionic fields, based on the extension of a reformulation of the adiabatic approximation to some quantum mechanical systems, is presented. A novel non-analytic contribution to the efective fermionic action for a fermion field coupled to a non-Abelian vector field is identified. The possible interpretation of this contribution as a violation of the decoupling theorem in Quantum Field Theory (QFT) is discussed. The generalization of the approach to the case of finite temperature and density suggests the possibility to apply it to the understanding of non-perturbative properties in QFT and their dependence on temperature and density.
An interpretation of neutrino oscillations based on a modification of relativistic quantum field ... more An interpretation of neutrino oscillations based on a modification of relativistic quantum field theory at low energies, without the need to introduce a neutrino mass, is seen to be compatible with all observations.
The symmetry properties of a proposal to go beyond relativistic quantum field theory based on a m... more The symmetry properties of a proposal to go beyond relativistic quantum field theory based on a modification of the commutation relations of fields are identified. Poincaré invariance in an auxiliary spacetime is found in the Lagrangian version of the path integral formulation. This invariance is contrasted with the idea of Doubly (or Deformed) Special Relativity (DSR). This analysis is then used to go from the free theory of a complex field to an interacting field theory.
A quantization condition due to the boundary conditions and the compatification of the light cone... more A quantization condition due to the boundary conditions and the compatification of the light cone space-time coordinate x − is identified at the level of the classical equations for the right-handed fermionic field in two dimensions. A detailed analysis of the implications of the implementation of this quantization condition at the quantum level is presented. In the case of the Thirring model one has selection rules on the excitations as a function of the coupling and in the case of the Schwinger model a double integer structure of the vacuum is derived in the light-cone frame. Two different quantized chiral Schwinger models are found, one of them without a θ-vacuum structure. A generalization of the quantization condition to theories with several fermionic fields and to higher dimensions is presented.
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Papers by Joséluis Cortés