@article{wang_cotanch_general_2008, title={Meson and tetra-quark mixing}, volume={55}, ISSN={["1434-6044"]}, DOI={10.1140/epjc/s10052-008-0605-7}, abstractNote={The mixing between q-qbar meson and qqbar-qqbar tetra-quark states is examined within an effective QCD Coulomb gauge Hamiltonian model. Mixing matrix elements of the Hamiltonian are computed and then diagonalized yielding an improved prediction for the low-lying J^{PC} = 0^{+/- +}, 1^{--} isoscalar spectra. Mixing effects were found significant for the scalar hadrons but not for the 1^{--} states, which is consistent with the ideal mixing of vector mesons. A perturbative assessment of the exact QCD kernel is also reported.}, number={3}, journal={EUROPEAN PHYSICAL JOURNAL C}, author={Wang, Ping and Cotanch, Stephen R. and General, Ignacio J.}, year={2008}, month={Jun}, pages={409–415} } @article{general_llanes-estrada_cotanch_2007, title={Coulomb gauge approach to (qqg)over-bar hybrid mesons}, volume={51}, ISSN={["1434-6052"]}, DOI={10.1140/epjc/s10052-007-0298-3}, abstractNote={An effective Coulomb gauge Hamiltonian, H_eff, is used to calculate the light (u-ubar-g), strange (s-sbar-g) and charmed (c-cbar-g) hybrid meson spectra. For the same two parameter H_eff providing glueball masses consistent with lattice results and a good description of the observed u,d,s and c quark mesons, a large-scale variational treatment predicts the lightest hybrid has J^{PC}=0^{++} and mass 2100 MeV. The lightest exotic 1^{-+} state is just above 2200 MeV, near the upper limit of lattice and Flux Tube predictions. These theoretical formulations all indicate the observed 1^{-+} pi_1(1600) and, more clearly, pi_1(1400) are not hybrid states. The Coulomb gauge approach further predicts that in the strange and charmed sectors, respectively, the ground state hybrids have 1^{+-} with masses 2125 and 3830 MeV, while the first exotic 1^{-+} states are at 2395 and 4020 MeV. Finally, using our hybrid wavefunctions, dimensional counting rules and the Franck-Condon principle, novel experimental signatures are presented to assist light and heavy hybrid meson searches.}, number={2}, journal={EUROPEAN PHYSICAL JOURNAL C}, author={General, I. J. and Llanes-Estrada, F. J. and Cotanch, S. R.}, year={2007}, month={Jul}, pages={347–358} } @article{general_wang_cotanch_llanes-estrada_2007, title={Light 1(-+) exotics: Molecular resonances}, volume={653}, ISSN={["1873-2445"]}, DOI={10.1016/j.physletb.2007.08.015}, abstractNote={Highlights in the search for nonconventional (non qqbar) meson states are the pi_1(1400) and pi_1(1600) exotic candidates. Should they exist, mounting theoretical arguments suggest that they are tetraquark molecular resonances excitable by meson rescattering. We report a new tetraquark calculation within a model field theory approximation to Quantum Chromodynamics in the Coulomb gauge supporting this conjecture. We also strengthen this claim by consistently contrasting results with exotic state predictions for hybrid (q qbar g) mesons within the same theoretical framework. Our findings confirm that molecular-like configurations involving two color singlets (a resonance, not a bound state) are clearly favored over hybrid or color-exotic tetraquark meson (q qbar q qbar atoms) formation. Finally, to assist needed further experimental searches we document a useful off-plane correlator for establishing the structure of these exotic systems along with similar, but anticipated much narrower, states that should exist in the charmonium and bottomonium spectra.}, number={2-4}, journal={PHYSICS LETTERS B}, author={General, Ignacio J. and Wang, Ping and Cotanch, Stephen R. and Llanes-Estrada, Felipe J.}, year={2007}, month={Sep}, pages={216–223} } @article{cotanch_general_wang_2007, title={QCD Coulomb gauge approach to exotic hadrons}, volume={31}, ISSN={["1434-6001"]}, DOI={10.1140/epja/i2006-10234-2}, abstractNote={The Coulomb gauge Hamiltonian model is used to calculate masses for selected JPC states consisting of exotic combinations of quarks and gluons: ggg glueballs (oddballs), q¯g hybrid mesons and q¯q¯ tetraquark systems. An odderon Regge trajectory is computed for the J- glueballs with intercept much smaller than the pomeron, explaining its nonobservation. The lowest 1-+ hybrid-meson mass is found to be just above 2.2GeV while the lightest tetraquark state mass with these exotic quantum numbers is predicted around 1.4GeV consistent with the observed π(1400).}, number={4}, journal={EUROPEAN PHYSICAL JOURNAL A}, author={Cotanch, S. R. and General, I. J. and Wang, P.}, year={2007}, month={Mar}, pages={656–661} } @article{general_cotanch_2004, title={Goldberger-Treiman constraint criterion for hyperon coupling constants}, volume={69}, ISSN={["1089-490X"]}, DOI={10.1103/physrevc.69.035202}, abstractNote={After a half century of investigating meson-baryon interactions, it is somewhat surprising that there are still several important coupling constants not accurately known. While theN coupling constant, gNN, has been determined to within a few percent, significant un- certainty in the two hyperon couplings, gK(Y =�,�)N, re- mains and even recently published values for both vary by more than a factor of four. This large variance is due to limited experimental information and also shortcom- ings in theoretical models. Further, analyses of purely hadronic processes typically yield larger couplings than those obtained from hyperon electromagnetic production studies. Fortunately, with the advent of new accelerator facilities, such as Jefferson Lab and SPring-8, more ac- curate and abundant data are now becoming available. Related, the recently reported (1) discovery of the ex- otic strangeness +1 pentaquark resonance, � + , is also attracting attention which should spawn additional KN measurements.}, number={3}, journal={PHYSICAL REVIEW C}, author={General, IJ and Cotanch, SR}, year={2004}, month={Mar} }