William & Mary ScholarWorks

Welcome! William & Mary ScholarWorks preserves and provides access to the research and creative output of William & Mary's faculty, staff, and students.

UPDATE 18th JUNE 2025: Our repository has migrated from Digital Commons to Open Repository DSpace as of this summer. Additional updates and improvements will continue through the Fall semester. Thank you for your patience during this transition.

Recent Submissions

Open Access
High-precision covariant one-boson-exchange potentials for 𝑛𝑝 scattering below 350 MeV
(2007) Gross, Franz; Stadler, Alfred; Data science
All realistic potential models for the two-nucleon interaction are to some extent based on boson exchange. However, in order to achieve an essentially perfect fit to the scattering data, characterized by a χ2/Ndata ∼ 1, previous potentials have abandoned a pure one boson-exchange mechanism (OBE). Using a covariant theory, we have found a OBE potential that fits the 2006 world np data below 350 MeV with a χ2/Ndata = 1.06 for 3788 data. Our potential has fewer adjustable parameters than previous high-precision potentials, and also reproduces the experimental triton binding energy without introducing additional irreducible three-nucleon forces.
Open Access
Quark mass function from a one-gluon-exchange-type interaction in Minkowski space
(2018-12-27) Biernat, Elmar; Gross, Franz; Peña, M. T.; Stadler, Alfred; Leitão, Sofia; Data science
We present first results for the quark mass function in Minkowski space in both the spacelike and timelike regions calculated from the same quark-antiquark interaction kernel used in the latest meson calculations using the Gross equation. This kernel consists of a Lorentz vector effective one-gluon- exchange-type interaction, a vector constant, and a mixed scalar-pseudoscalar covariant linear confining interaction that does not contribute to the mass function. We analyze the gauge dependence of our results, prove the gauge independence of the constituent quark mass and mass gap equation, and identify the Yennie gauge as the appropriate gauge to be used in CST calculations. We compare our results in the spacelike region to lattice QCD data and find good agreement. Funded by SCOAP3.
Open Access
Quark Mass Function from an OGE-Type Interaction in Minkowski Space
(2021) Biernat, Elmar; Gross, Franz; Peña, M. T.; Stadler, Alfred; Leitão, Sofia; Data science
We present results for the quark mass function in Minkowski space calculated from an interaction kernel that consists of an effective one-gluonexchange and a constant interaction. We analyze the gauge dependence of our results and compare them in the spacelike region to the available lattice QCD data.
Open Access
Removal of singularities from the covariant spectator theory
(American Physical Society, 2021-09-16) Gross, Franz; Data science
A modification of the one boson exchange (OBE) kernel for the covariant spectator theory (CST) is presented and discussed. When applied to the scattering of two identical particles, the previously used kernels either introduced spurious singularities, or removed them in an ad-hoc way. The new modification not only removes these singularities, but also maintains the convergence of the two-body CST equation (sometimes called the Gross equation) when used to describe the scattering of two identical scalar particles. Funded by SCOAP3.
Open Access
Is there an A(y) problem in low-energy neutron–proton scattering?
(2008) Gross, Franz; Stadler, Alfred; Data science
We calculate Ay in neutron–proton scattering for the interactions models WJC-1 and WJC-2 in the Covariant Spectator Theory. We find that the recent 12 MeV measurements performed at TUNL are in better agreement with our results than with the Nijmegen Phase Shift Analysis of 1993, and after reviewing the low-energy data, conclude that there is no Ay problem in low-energy np scattering.