@article{llanes-estrada_cotanch_szczepaniak_swanson_2004, title={Hyperfine meson splittings: chiral symmetry versus transverse gluon exchange}, volume={70}, ISSN={["1089-490X"]}, DOI={10.1103/physrevc.70.035202}, abstractNote={Meson spin splittings are examined within an effective Coulomb gauge QCD Hamiltonian incorporating chiral symmetry and a transverse hyperfine interaction necessary for heavy quarks. For light and heavy quarkonium systems the pseudoscalar-vector meson spectrum is generated by approximate BCS-RPA diagonalizations. This relativistic formulation includes both S and D waves for the vector mesons which generates a set of coupled integral equations. A smooth transition from the heavy to the light quark regime is found with chiral symmetry dominating the pi-rho mass difference. A reasonable description of the observed meson spin splittings and chiral quantities, such as the quark condensate and the pi mass, is obtained. Similar comparisons with TDA diagonalizations, which violate chiral symmetry, are deficient for light pseudoscalar mesons indicating the need to simultaneously include both chiral symmetry and a hyperfine interaction. The eta_b mass is predicted to be around 9400 MeV consistent with other theoretical expectations and above the unconfirmed 9300 MeV candidate. Finally, for comparison with lattice results, the J reliability parameter is also evaluated.}, number={3}, journal={PHYSICAL REVIEW C}, author={Llanes-Estrada, FJ and Cotanch, SR and Szczepaniak, AP and Swanson, ES}, year={2004}, month={Sep} }
 @article{swanson_szczepaniak_1999, title={Heavy hybrids with constituent gluons - art. no. 014035.}, volume={5901}, number={1}, journal={Physical Review. D, Particles and Fields}, author={Swanson, E. S. and Szczepaniak, A. P.}, year={1999}, pages={4035-} }
 @article{page_swanson_szczepaniak_1999, title={Hybrid meson decay phenomenology - art. no. 034016}, volume={5903}, number={3}, journal={Physical Review. D, Particles and Fields}, author={Page, P. R. and Swanson, E. S. and Szczepaniak, A. P.}, year={1999}, pages={4016} }
 @article{robertson_swanson_szczepaniak_ji_cotanch_1999, title={Renormalized effective QCD Hamiltonian: Gluonic sector}, volume={59}, ISSN={["2470-0029"]}, DOI={10.1103/physrevd.59.074019}, abstractNote={Extending previous QCD Hamiltonian studies, we present a new renormalization procedure which generates an effective Hamiltonian for the gluon sector. The formulation is in the Coulomb gauge where the QCD Hamiltonian is renormalizable and the Gribov problem can be resolved. We utilize elements of the Glazek and Wilson regularization method but now introduce a continuous cut-off procedure which eliminates non-local counterterms. The effective Hamiltonian is then derived to second order in the strong coupling constant. The resulting renormalized Hamiltonian provides a realistic starting point for approximate many-body calculations of hadronic properties for systems with explicit gluon degrees of freedom.}, number={7}, journal={PHYSICAL REVIEW D}, author={Robertson, DG and Swanson, ES and Szczepaniak, AP and Ji, CR and Cotanch, SR}, year={1999}, month={Apr} }
 @article{szczepaniak_ji_radyushkin_1998, title={Consistent analysis of O(alpha(s)) corrections to the pion elastic form factor}, volume={57}, ISSN={["0556-2821"]}, DOI={10.1103/physrevd.57.2813}, abstractNote={We examine the role of $O({\ensuremath{\alpha}}_{s})$ perturbative corrections to the pion elastic form factor ${F}_{\ensuremath{\pi}}{(Q}^{2})$. We express the quark current three-point function in terms of light cone variables and use Borel transformation to simultaneously model the Feynman mechanism contribution determined by the soft part of the pion light cone wave function and the hard term involving one gluon exchange. We find that for ${Q}^{2}\ensuremath{\sim}4{\mathrm{GeV}}^{2}$ the total $O({\ensuremath{\alpha}}_{s})$ contribution may reach $30%$ of the soft contribution, even though its hard, factorization scale dependent part remains rather small.}, number={5}, journal={PHYSICAL REVIEW D}, author={Szczepaniak, A and Ji, CR and Radyushkin, A}, year={1998}, month={Mar}, pages={2813–2822} }
 @article{ji_kaminski_lesniak_szczepaniak_williams_1998, title={Coupled channel analysis of S-wave pi pi and (K)over-barK photoproduction}, volume={58}, ISSN={["1089-490X"]}, DOI={10.1103/physrevc.58.1205}, abstractNote={We present a coupled channel partial wave analysis of nondiffractive $S$-wave ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ and ${K}^{+}{K}^{\ensuremath{-}}$ photoproduction focusing on the $K\overline{K}$ threshold. Final state interactions are included. We calculate total cross sections and angular and effective mass distributions in both $\ensuremath{\pi}\ensuremath{\pi}$ and $K\overline{K}$ channels. Our results indicate that these processes are experimentally measurable and valuable information on the ${f}_{0}$(980) resonance structure can be obtained.}, number={2}, journal={PHYSICAL REVIEW C}, author={Ji, CR and Kaminski, R and Lesniak, L and Szczepaniak, A and Williams, R}, year={1998}, month={Aug}, pages={1205–1217} }
 @article{swanson_szczepaniak_1997, title={Decays of hybrid mesons}, volume={56}, number={9}, journal={Physical Review. D, Particles and Fields}, author={Swanson, E. S. and Szczepaniak, A. P.}, year={1997}, pages={5692–5695} }
 @article{szczepaniak_swanson_1997, title={From current to constituent quarks: a renormalization-group-improved Hamiltonian-based description of hadrons}, volume={55}, number={3}, journal={Physical Review. D, Particles and Fields}, author={Szczepaniak, A. P. and Swanson, E. S.}, year={1997}, pages={1578–1591} }
 @article{szczepaniak_swanson_1997, title={On the DIRAC structure of confinement}, volume={55}, number={7}, journal={Physical Review. D, Particles and Fields}, author={Szczepaniak, A. P. and Swanson, E. S.}, year={1997}, pages={3987–3993} }