122196529
QUANTUM FIELD THEORETICAL ELECTROMAGNETIC AND GRAVITATIONAL TWO PARTICLE POTENTIALS
The fourth-order static electromagnetic and gravitational two-particle potentials are derived from the scattering operator by using the techniques of the standard field theory. Integrals over four-vector variables are evaluated in a covariant manner, while in earlier treatments such integrals are usually converted to noncovariant forms. Our treatment is more direct, and we are able to carry out regularization and renormalization of divergent integrals unambiguously where necessary. Moreover, calculations of multiple parameter integrals are reduced to elementary integrations in the static and long-range approximations. Our quantum field-theoretical results are in complete agreement with the classical potentials.
122167852
MULTIPLE PHOTON PRODUCTION IN QUANTUM ELECTRODYNAMICS
Multiple production of photons in high-energy processes in quantum electrodynamics is investigated, and the electron-positron annihilation is specially discussed in detail. It is found that at very high energies in cosmic rays, multiple production of up to four or five observable photons can easily take place. But, the probability, according to quantum electrodynamics, for the multiple production of a larger number of observable photons is quite small.
6552264
Nonsingular potential model for heavy quarkonia.
A nonsingular potential model for heavy quarkonia is described which does not require recourse to an illegitimate perturbative treatment for the investigation of quarkonium spectra. Our overall results for the energy levels, the leptonic widths, and the E1 transition widths are in very good agreement with the experimental data for bb-bar and they are reasonably good for cc-bar. We also find that the confining part of the quarkonium potential is scalar-vector exchange rather than the currently favored scalar exchange.
120383870
Higgs model with ghost-field formalism
The Higgs model for the interaction of vector and scalar fields is treated by means of the ghost-field formalism, which preserves the unitarity of the scattering operator as well as simplifies the renormalization procedure. Our ghost-field formalism has some similarity to the ${R}_{\ensuremath{\xi}}$ formalism with $\ensuremath{\xi}=1$, but it does not require the introduction of the so-called gauge-compensating terms. Applications to the second-order self-energy of a scalar particle and to the fourth-order scattering of vector particles are discussed.
121663425
Quantum-chromodynamic potential model for light and heavy quarkonia
Our earlier treatment for the investigation of the cc-bar, bb-bar, and tt-bar spectra is extended to other p quarkonia with u, d, s, c, and b quarks. We find that it is possible to account fully for the observed ground-state hyperfine splittings of light as well as heavy quarkonia provided that the perturbative quantum-chromodynamic potential is supplemented not only by the nonperturbative confining potential but also by a nonperturbative annihilation potential which rapidly decreases with increase in the quark mass. We also give our predictions for the experimentally interesting bu-bar, bs-bar, and bc-bar systems with unknown mass splittings.
122156675
Relativistic Hadron Model with Intrinsic Mass Splittings
A simple mechanism for the $\mathrm{SU}(3)$-symmetry breaking in strong interactions is introduced by using the formalism of the multispinor field equations, which avoids the use of physical quarks but has resemblance to the quark model. The resulting treatment leads to the Gell-Mann-Okubo mass formula for baryons, but not for mesons. It yields approximate values of -19.5\ifmmode^\circ\else\textdegree\fi{} and 33\ifmmode^\circ\else\textdegree\fi{} for the $\ensuremath{\eta}\ensuremath{-}{\ensuremath{\eta}}^{\ensuremath{'}}$ and $\ensuremath{\varphi}\ensuremath{-}\ensuremath{\omega}$ mixing angles, respectively, and also provides a reasonable explanation for the intermultiplet meson mass formula $m_{K}^{}{}_{}{}^{2}\ensuremath{-}m_{\ensuremath{\pi}}^{}{}_{}{}^{2}=m_{{K}^{*}}^{}{}_{}{}^{2}\ensuremath{-}m_{\ensuremath{\rho}}^{}{}_{}{}^{2}$.
94214864
Theoretical study of cold nuclear fusion using barrier penetration approach
118396346
Isoscaling, symmetry energy and thermodynamic models
Abstract The isoscaling parameter usually denoted by α depends upon both the symmetry energy coefficient and the isotopic contents of the dissociating systems. We compute α in theoretical models: first in a simple mean field model and then in thermodynamic models using both grand canonical and canonical ensembles. For finite systems the canonical ensemble is much more appropriate. The model values of α are compared with a much used standard formula. Next we turn to cases where in experiments, there are significant deviations from isoscaling. We show that in such cases, although the grand canonical model fails, the canonical model is capable of explaining the data.
119924547
Volume integrals of real part of nucleon optical potentials
Volume integrals of the real part of the proton and neutron optical potentials are computed using the existing phenomenological analyses for $A=10\ensuremath{-}238$. These results are in good agreement with the Jeukenne-Lejeune-Mahaux model which employs Reid's hard core nucleon-nucleon interaction. An empirical expression having an isovector dependence has been used to fit the volume integrals and the isovector component of the real potential has been estimated.
123618858
An experimental system for detection of high energy cosmic gamma ray bursts
Abstract While bursts of cosmic gamma rays of energies 0.1–10 MeV can be detected and studied only with satellite-borne detectors, bursts of gamma rays at GeV energies can be detected using sensitive ground-based detectors. An experimental system to detect these high energy gamma ray bursts is being operated at the mountain altitude laboratory at Ootacamund, India. The design features and the experimental details related to this system are described.
118614091
Study of Cosmic Ray Short Term Variations Using GRAPES-3 Muon Telescopes