Off-shell variation in the binding energy of triton

Phase-shift-equivalent potentials are used to study the sensitivity of triton binding energy (E _T) to the off-shell behaviour of two-nucleonT matrix in a translationally-invariant basis of harmonic oscillator wavefunction. For a smaller value of inverse range parameterλ (1.95 fm⁻¹), which is close to the attractive range of our model potential, a 21% variation in the triton binding energy is obtained. For the other value ofλ an off-shell variation of about 28% inE _T is obtained.     

Higher-Order Kinetic Term for Controlling Photon Mass in Off-Shell Electrodynamics

In relativistic classical and quantum mechanics with Poincaré-invariant parameter, particle worldlines are traced out by the evolution of spacetime events. The formulation of a covariant canonical framework for the evolving events leads to a dynamical theory in which mass conservation is demoted from a priori constraint to the status of conserved Noether current for a certain class of interactions. In pre-Maxwell electrodynamics—the local gauge theory associated with this framework —events induce five local off-shell fields, which mediate interactions between instantaneous events, not between the worldlines which represent entire particle histories. The fifth field, required to compensate for dependence of gauge transformations on the evolution parameter, enables the exchange of mass between particles and fields. In the equilibrium limit, these pre-Maxwell fields are pushed onto the zero-mass shell, but during interactions there is no mechanism regulating the mass that photons may acquire, even when event trajectories evolve far into the spacelike region. This feature of the off-shell formalism requires the application of some ad hoc mechanism for controlling the photon mass in two opposite physical domains: the low energy motion of a charged event in classical Coulomb scattering, and the renormalization of off-shell quantum electrodynamics. In this paper, we discuss a nonlocal, higher derivative correction to the photon kinetic term, which provides regulation of the photon mass in a manner which preserves the gauge invariance and Poincaré covariance of the original theory. We demonstrate that the inclusion of this term is equivalent to an earlier solution to the classical Coulomb problem, and that the resulting quantum field theory is renormalized.     

Two-potential formula continued off-the-energy-shell

We derive an off-energy-shell generalization of the two-potential formula by using a coordinate-space approach and apply the formalism to construct algorithms for studying spatial behaviour of the fully off-shellT matrix. We also suggest some future applications of the proposed theory.     

Ground state of liquid helium-3: off-shell effects due to non-local potentials

It is shown that by incorporating the off-shell effects through the introduction of phase equivalent nonlocal potentials, (that are essentially equivalent so far as two-body properties are concerned) one could obtain a much better agreement regarding the important properties of the ground state of liquid helium-3, in lowest order Brueckner-Goldstone theory. The binding energy, equilibruim density and the convergence character of Brueckner-Goldstone series improve drastically.     

Wave functions from an off-energy-shell generalisation of the Gordon’s method

An ansatz is introduced in the Gordon’s method for nonlocal separable potentials to construct expressions for off-shell wave functions associated with the physical, regular and standing wave boundary conditions. This method has certain calculational advantages and is particularly suitable for dealing with potentials of higher rank. Results obtained for the Mongan case IV potential agree with those derived by the complicated techniques.     

Temperature-Dependent Imaginary Part of the Off-Shell Nucleon Self-Energy and the Second Order Correction of Real Part of the Nucleon Self-Energy

The imaginary part of the off-shell nucleon self-energy at finite temperature in nuclear matter, where the polarization and correlation contributions of exchanges of the meson are taken into account, is investigated based on Walecka's meson-nucleon model and thermofield dynamics. The second order correction of temperature-dependent real part of the nucleon self-energy is calculated in terms of the dispersion relation. The Schrodinger equivalent potential of relativistic microscopic optical potential of a nucleon at finite temperature in nuclear medium is also studied.     

Off-Shell Propagat ion in a Quark-Gluon Plasma

The off-shell propagation in a quark-gluon plasma is estimated from a quantum transport model beyond the quasi-particle approach. While our ansatz is crude concerning the properties of real quarks and gluons, it nevertheless takes very serious the basic principles of quantum field theory for non-equilibrium states.     

Are operators describing b →sγ?

The operators of b→sγ,b→sl+l-are usually regarded as being sufficient to describe b→sγγ,b→sl+l-γwith the statement that contributions from diagrams without an effective vertex b→sγ to processes b→sγγand b→sl+l-γ are negligible.In this work we present a comprehensive analysis of the transition b→sγγand find that 1)Effects due to off-shell quarks in vertex b→sγ on b→sγγ are large; 2)Contributions from diagrams without an effective vertex b→sγ to b→sγγare not negligible compared with others; 3)These effects cancel each other out exactly,so the operators of b→sγ can safely be used to describe b→sγγ.     

On the integral representations of the Jost function and Coulomb off-shell Jost solution

The integral representations of the Jost function (on- and off-shell) are rederived by the judicious use of the transposed operator relation on the particular integrals for Jost solution and using one of these particular integrals an analytical expression for the Coulomb off-shell Jost solution is presented in the maximal reduced form.