113 documents found, page 1 of 12
Pion structure in the instanton liquid model
Anikin, I. V.; Dorokhov, A. E.; Tomio, Lauro [UNESP]Made available in DSpace on 2022-04-28T19:55:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2000-12-01; The covariant quark model of the pion based on the effective nonlocal quark-hadron Lagrangian involving nonlocality induced by instanton fluctuations of the QCD vacuum is reviewed. Explicit gauge invariant formalism allows us to construct the conserved vector and axial currents and to demonstrate their ...
Model independence of scattering of three identical bosons in two dimensions
Adhikari, Sadhan K. [UNESP]; Delfino, A.; Frederico, T.; Tomio, Lauro [UNESP]Made available in DSpace on 2022-04-28T19:59:54Z (GMT). No. of bitstreams: 0 Previous issue date: 1993-01-01; Within the framework of scattering integral equations in momentum space, we present numerical results of scattering of three identical bosons at low energies in two dimensions for short-range separable potentials. An analysis of the present numerical results reveals the three-particle scattering observa...
Stability of trapped Bose-Einstein condensates
Abdullaev, F. Kh [UNESP]; Gammal, A. [UNESP]; Tomio, Lauro [UNESP]; Frederico, T.Made available in DSpace on 2022-04-28T20:00:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2001-01-01; In three-dimensional trapped Bose-Einstein condensate (BEC), described by the time-dependent Gross-Pitaevskii-Ginzburg equation, we study the effect of initial conditions on stability using a Gaussian variational approach and exact numerical simulations. We also discuss the validity of the criterion for...
Long range local effective potential for a three-particle system
Delfino, A.; Frederico, T.; Tomio, Lauro [UNESP]Made available in DSpace on 2022-04-28T20:01:33Z (GMT). No. of bitstreams: 0 Previous issue date: 1988-01-01; We derive the long- range behavior of an effective interaction for a system with three identical particles. We start our derivation from the zero range theory in configuration space and we show that the asymptotic effective potential, in the relative distance of the subsystem to the third particle, goes...
Relativistic three-particle scattering equations
Adhikari, Sadhan K. [UNESP]; Tomio, Lauro [UNESP]; Frederico, T.Made available in DSpace on 2022-04-28T20:01:34Z (GMT). No. of bitstreams: 0 Previous issue date: 1993-01-01; We derive a set of relativistic three-particle scattering equations in the three-particle c.m. frame employing a relativistic three-particle propagator suggested long ago by Ahmadzadeh and Tjon in the c.m. frame of a two-particle subsystem. We make the coordinate transformation of this propagator from t...
Neutron-neutron correlation in the halo dissociation of light exotic nuclei
Yamashita, M. T. [UNESP]; Frederico, T.; Tomio, Lauro [UNESP]Made available in DSpace on 2022-04-28T20:01:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-07-01; We present model results for the two-halo-neutron correlation functions, Cnn, for the dissociation process of light exotic nuclei modelled as two neutrons and a core. A minimum is predicted for Cnn as a function of the relative momentum of the two neutrons, pnn, due to the coherence of the neutrons in t...
Inclusive annihilation of antiprotons on deuterium
Frederico, T.; Carlson, B. V.; Mastroleo, R. C.; Tomio, Lauro [UNESP]; Hussein, M. S.Made available in DSpace on 2022-04-28T20:03:09Z (GMT). No. of bitstreams: 0 Previous issue date: 1990-01-01; The inclusive annihilation of antiprotons on deuterium is calculated within a three-body model. At very low antiproton energies (Ep»<2.2 MeV), structure is observed in the energy spectra of emerging protons at forward angles. The theory can be easily extended to higher antiproton energies. © 1990 The Am...
The kaon electromagnetic form factor in the light-front formalism
Pereira, F. P. [UNESP]; De Melo, J. P.B.C. [UNESP]; Frederico, T.; Tomio, Lauro [UNESP]Made available in DSpace on 2022-04-28T20:06:48Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-12-27; Numerical calculations are performed and compared to the experimental data for the electromagnetic form factor of the kaon, extracted from both components of the electromagnetic current, J+ and J-, with a pseudo-scalar coupling of the quarks to the kaon. In the case of J+, there is no pair term contribu...
Bose-Einstein condensates with inhomogeneous scattering length in one and two d...
Abdullaev, F. Kh; Filho, Victo S. [UNESP]; Gammal, A.; Tomio, Lauro [UNESP]Made available in DSpace on 2022-04-28T20:06:49Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-12-27; We report on investigations of the properties of bright solitons in Bose-Einstein condensates in the presence of point-like spatial inhomogeneities, in one and two dimensions. By considering an analytical variational approach and full numerical simulations, we describe such processes due to interactions...
Nonlinear Schrödinger equation with power-law confining potential
Holz, Sheila M. [UNESP]; Filho, Victo S. [UNESP]; Tomio, Lauro [UNESP]; Gammal, A.Made available in DSpace on 2022-04-28T20:08:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-07-26; Critical limits of a stationary nonlinear three-dimensional Schrödinger equation with confining power-law potentials (∼ rα) are obtained using spherical symmetry. When the nonlinearity is given by an attractive two-body interaction (negative cubic term), it is shown how the maximum number of particles N...