arXiv subjects

W. G. Love

Publications and source records attributed to W. G. Love.

4 recordsLinked to original sources

arXiv2007

An in-medium full-folding model approach to quasielastic (p,n) charge-exchange reactions

A microscopic description of the quasielastic (p,n) charge-exchange reaction (here, charge-exchange scattering between analogue states) is presented and discussed. Emphasis is focused on the spin-isospin structure of the projectile-target coupling. The model is a coupled-channel extension of the full-folding optical model approach (OMP) developed for nucleon elastic scattering, where emphasis is placed on retaining the genuine off-shell behavior of realistic effective interactions in the nuclear medium. The resulting non-local optical potentials are applied to the calculation of (p,n) differential cross sections, with particular emphasis on small-angle Fermi ($ΔS=0$) cross-sections to isobaric analog states. These parameter-free results provide a reasonable description of the $^{14}$C(p,n)-data at proton energies above $\sim$100 MeV, but deteriorate for heavier targets. These shortcomings are analyzed and possible ways to correct them are discussed.

nucl-th↗

arXiv2005

Spin structure of spin-1/2 baryon and spinless meson production amplitudes in photo and hadronic reactions

The most general spin structures of the spin-1/2 baryon and spinless meson production operator for both photon and nucleon induced reactions are derived from the partial-wave expansions of these reaction amplitudes. The present method provides the coefficients multiplying each spin operator in terms of the partial-wave matrix elements. The result should be useful in studies of these reactions based on partial-wave analyses, especially, when spin observables are considered.

nucl-th↗

arXiv2005

Nuclear halo structure from quasielastic charge-exchange reactions

Neutron and proton densities in the nuclear periphery are investigated within (p,n) charge-exchange isobar transitions. For this purpose we have developed parameter-free optical potentials with a detailed treatment of the in-medium $t_τ$ part of the effective interaction. Non local coupled-channel Lane equations are solved to obtain the scattering observables. The use of conventional proton and neutron densities significantly underestimates Fermi (forward-angle) cross-sections in agreement with findings by various other groups. However, we have found model-independent densities which provide a remarkable improvement in the description of the quasielastic scattering data.The densities obtained are consistent with recent measurements at CERN in studies of the neutron-to-proton halo factor f(r)=Z$ρ_n/Nρ_p$ with antiprotons. These findings provide an alternative way to investigate the nuclear periphery, and may also help to solve the long-standing puzzle of the underestimated Fermi cross section in (p,n) charge-exchange phenomena.

nucl-th↗

arXiv2004

Spin observables and the determination of the parity of $Θ^+$ in photoproduction reactions

Spin observables in the photoproduction of the $Θ^+$ are explored for the purpose of determining the parity of the $Θ^+$. Based on reflection symmetry in the scattering plane, we show that certain spin observables in the photoproduction of the $Θ^+$ can be related directly to its parity. We also show that measurements of both the target nucleon asymmetry and the $% Θ^+$ polarization may be useful in determining the parity of $Θ^+$ in a model-independent way. Furthermore, we show that no combination of spin observables involving only the polarization of the photon and/or nucleon in the initial state can determine the parity of $Θ^+$ unambiguously.

hep-ph↗