Navegação Ciências Exatas e da Terra por Assunto "Física nuclear"
Resultados 1-20 de 34
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Charge commutator for any momentum
(1969) [Artigo de periódico]The nucleon matrix elements of the charge commutation relations are considered for arbitrary momentum. The resulting expression is exact. The high-momentum limit reduces to the Alder-Weisberger sum rule. For zero momentum ... -
Charm and bottom production in inclusive double Pomeron exchange in heavy-ion collisions at energies available at the CERN Large Hadron Collider
(2011) [Artigo de periódico]The inclusive double Pomeron exchange cross section for heavy-quark pair production is calculated for nucleus-nucleus collisions at the Large Hadron Collider. The present estimate is based on hard diffractive factorization, ... -
Comparison of quasifree (p, 2p) with (p, pn) scattering as a check of the impulse approximation
(1979) [Artigo de periódico]It is shown that the ratio o f the cross sections o f quasifree (p ,Zp) and (p ,pn) reactions in complex nuclei for identical and suitable geometries can be reliably calculated in the distorted wave impulse approximation. ... -
Compatibility of the nuclear shell and nucleon bag models
(1987) [Artigo de periódico]It is shown that the standard self-consistency argument, reconciling the nuclear independentparticle model with the large low-energy nucleon-nucleon cross sections, loses its validity for nucleon bags with a radius larger ... -
Degrees of symmetry in quantum field theories
(1972) [Artigo de periódico]A hierarchy of possible symmetries in quantum field theory is defined, which reaches from a purely mathematical invariance to the conventional physical invariance, including the commonly discussed type of spontaneously ... -
A dependence of hadron-nucleus massive lepton pair production
(1994) [Artigo de periódico]Nuclear effects in the small x region of hadron-nucleus Drell-Yan processes at 800 GeV are analyzed. We employ the parton recombination model to describe the suppression in the RpA DY(x₂)ratio and we compare it with REMC(x), ... -
Double-photon exclusive processes with heavy-quark–heavy-antiquark pairs in high-energy Pb-Pb collisions at energies available at the CERN Large Hadron Collider
(2011) [Artigo de periódico]The cross section for exclusive heavy-quark and heavy-antiquark pair (Q¯Q) production in peripheral ultrarelativistic heavy-ion collisions is calculated at an energy available at the CERN Large Hadron Collider, i.e., √ sNN ... -
Effective polarization in quasi-free scattering
(1980) [Artigo de periódico]A simple relation, involving only experimental quantmes, for the effective polarizations m quasi-free (p, 2p) scattering on closed shell nuclei IS tested for recent TRIUMF (p, 2p) experiments with 200 MeV polanzed protons. -
Effects of geometric constraints on the nuclear multifragmentation process
(2007) [Artigo de periódico]We include in statistical model calculations the facts that in the nuclear multifragmentation process the fragments are produced within a given volume and have a finite size. The corrections associated with these constraints ... -
Electrofission of (sup 239) pu in the energy range 7-12 mev
(1997) [Artigo de periódico]The electrofission cross section of ²³⁹Pu(e,f) is measured between 7 and 12 MeV. The data are analyzed by means of the virtual photon formalism, assuming that E1, E2 (T=0), and M1 transitions are involved. Using known ... -
Exclusive glueball production in high-energy nucleus-nucleus collisions
(2011) [Artigo de periódico]The cross sections for the glueball candidates in quasireal photon-photon collisions and on central diffraction processes (i.e., double Pomeron exchange) in heavy-ion interactions at the Relativistic Heavy-Ion Collider ... -
Finite-size effects in isobaric ratios
(2012) [Artigo de periódico]The properties of isobaric ratios, between nuclei produced in the same reaction, are investigated using the canonical and grand-canonical statistical ensembles. Although the grand-canonical formulas furnish a means to ... -
Implementación y evaluación de una propuesta de enseñanza para el tópico física de partículas en una disciplina de estructura de la materia basada en la teoría de los campos conceptuales de Vergnaud
(2009) [Artigo de periódico]En este trabajo presentase resultados de una investigación respecto a la enseñanza de conceptos de la Física de Partículas en una asignatura de Estructura de la Materia en un curso de formación inicial de profesores de ... -
Investigation of medium and heavy nuclei by quasi-free-proton scattering
(1960) [Artigo de periódico] -
Investigation of nuclear structure by quasi-free scattering with polarized protons
(1981) [Artigo de periódico]Quasi-free scattering with polarized protons can be a sensitive method to probe certain spin correlations in the nuclear wave function. This is demonstrated by the comparison of the effective polarizations following from ... -
Isospin effects and the density dependence of the nuclear symmetry energy
(2009) [Artigo de periódico]The density dependence of the nuclear symmetry energy is inspected using the statistical multifragmentation model with Skyrme effective interactions. The model consistently considers the expansion of the fragments' volumes ... -
J/(psi) suppression in electro-and hadroproduction : a conventional physics explanation
(1994) [Artigo de periódico]Having in mind the importance of the phenomenon for the search for the quark-gluon plasma in the collision of heavy nuclei, we study the suppression of J/Ψ production in leptoproduction and hadroproduction on heavy nuclear ... -
Kn scattering in the cloudy bag model : s, p and d waves
(1985) [Artigo de periódico]s-, p-, and d-wave KN phase shifts are calculated with the cloudy bag model (CBM). The results are in qualitative agreement with phase-shift analysis, except in those partial waves where exotic resonances are claimed to ... -
Medium effects on spin observables of proton knockout reactins
(1995) [Artigo de periódico]Medium modifications of the properties of bound nucleons and mesons are investigated by means of intermediate energy quasifree proton knockout reactions with polarized incident protons, by comparison of quantities which ... -
Nonlocality of the propagation and the effective nucleos spinorbit interaction
(1982) [Artigo de periódico]The imaginary central and spin-orbit components of the .1.-nucleus optical potential are investigated in a 11'-exchange model. It is found that the effective spin-orbit interaction of the isobar reflects lárge nonlocalities ...
