122095360
Gauge theories of massive vector fields without scalar fields
We show that it is possible to formulate gauge theories of massive vector fields without introducing physical scalar fields. Examples of such gauge theories are provided by applications of our treatment to the massive Yang-Mills field, a charged vector field interacting with the photon field, and a model of weak and electromagnetic interactions. One-loop renormalizability of each of these systems is discussed. It is suggested that instead of postulating the existence of hypothetical particles to obtain renormalizable gauge theories, it might be worthwhile to construct gauge theories with limited renormalizability by using the formalism described here.
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 $m_{K}^{}{}_{}{}^{2}\ensuremath{-}m_{\ensuremath{\pi}}^{}{}_{}{}^{2}=m_{{K}^{*}}^{}{}_{}{}^{2}\ensuremath{-}m_{\ensuremath{\rho}}^{}{}_{}{}^{2}$.
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.
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.
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.
118650256
Absolutely anticommuting (anti-)BRST symmetry transformations for topologically massive Abelian gauge theory
We demonstrate the existence of the nilpotent and absolutely anticommuting Becchi–Rouet–Stora–Tyutin (BRST) and anti-BRST symmetry transformations for the four (3+1)-dimensional (4D) topologically massive Abelian U(1) gauge theory that is described by the coupled Lagrangian densities (which incorporate the celebrated (B∧F) term). The absolute anticommutativity of the (anti-) BRST symmetry transformations is ensured by the existence of a Curci–Ferrari type restriction that emerges from the superfield formalism as well as from the equations of motion which are derived from the above coupled Lagrangian densities. We show the invariance of the action from the point of view of the symmetry considerations as well as superfield formulation. We discuss, furthermore, the topological term within the framework of superfield formalism and provide the geometrical meaning of its invariance under the (anti-)BRST symmetry transformations.
14798493
Effects of momentum-dependent symmetry potential on heavy-ion collisions induced by neutron-rich nuclei
Abstract Using an isospin- and momentum-dependent transport model we study effects of the momentum-dependent symmetry potential on heavy-ion collisions induced by neutron-rich nuclei. It is found that symmetry potentials with and without the momentum-dependence but corresponding to the same density-dependent symmetry energy E sym ( ρ ) lead to significantly different predictions on several E sym ( ρ )-sensitive experimental observables especially for energetic nucleons. The momentum- and density-dependence of the symmetry potential have to be determined simultaneously in order to extract the E sym ( ρ ) accurately. The isospin asymmetry of midrapidity nucleons at high transverse momenta is particularly sensitive to the momentum-dependence of the symmetry potential. It is thus very useful for investigating accurately the equation of state of dense neutron-rich matter.
120893061
Models of the proton spin structure
A phenomenological model of spin sharing by the constituents of a proton is constructed, based on the recent EMC measurement of the spin dependent structure function and knowledge of the unpolarized parton densities.
118643338
An Interacting Gauge Field Theoretic Model for the Hodge Theory: Basic Canonical Brackets
We derive the basic canonical brackets amongst the creation and annihilation operators for a two (1 + 1)-dimensional (2D) gauge field theoretic model of an interacting Hodge theory where a U(1) gauge field (A_\mu) is coupled with the fermionic Dirac fields (\psi and \bar \psi). In this derivation, we exploit the spin-statistics theorem, normal ordering and the strength of the underlying six infinitesimal continuous symmetries (and the concept of their generators) that are present in the theory. We do not use the definition of the canonical conjugate momenta (corresponding to the basic fields of the theory) anywhere in our whole discussion. Thus, we conjecture that our present approach provides an alternative to the canonical method of quantization for a class of gauge field theories that are physical examples of Hodge theory where the continuous symmetries (and corresponding generators) provide the physical realizations of the de Rham cohomological operators of differential geometry at the algebraic level.
120592867
Double parton scattering contribution toW+jets
We investigate the double parton scattering production ofW±+jets in proton colliders. At high energies an observable signal is expected from double parton collisions when events with small transverse momentumW together with two jets balancing inpT are selected. Double parton scattering is also a potentially serious background to several rare processes whose signal is aW++W−(→ev+jets) final state. A simplepTW cut seems to be sufficient to separate the genuineW-pair events from the double scattering background.