On the radiative decays of light vector and axial-vector mesons
| dc.creator | Lutz, M. F. M. | |
| dc.creator | Leupold, S. | |
| dc.date | 2008-01-24 | |
| dc.date | 2008-03-12 | |
| dc.date.accessioned | 2026-07-07T11:55:32Z | |
| dc.date.available | 2026-07-07T11:55:32Z | |
| dc.description | We study the light vector and axial-vector mesons. According to the hadrogenesis conjecture the nature of the two types of states is distinct. The axial-vector mesons are generated dynamically by coupled-channel interactions based on the chiral Lagrangian written down in terms of the Goldstone bosons and the light vector mesons. We propose a novel counting scheme that arises if the chiral Lagrangian is supplemented by constraints from large-N_c QCD in the context of the hadrogenesis conjecture. The counting scheme is successfully tested by a systematic study of the properties of vector mesons. The spectrum of light axial-vector mesons is derived relying on the leading order interaction of the Goldstone bosons with the vector mesons supplemented by a phenomenology for correction terms. The f_1(1282), b_1(1230), h_1(1386), a_1(1230) and K_1(1272) mesons are recovered as molecular states. Based on those results the one-loop contributions to the electromagnetic decay amplitudes of axial-vector molecules into pseudo-scalar or vector mesons are evaluated systematically. In order to arrive at gauge invariant results in a transparent manner we choose to represent the vector particles by anti-symmetric tensor fields. It is emphasized that there are no tree-level contributions to a radiative decay amplitude of a given state if that state is generated by coupled-channel dynamics. The inclusion of the latter would be double counting. At present we restrict ourselves to loops where a vector and a pseudo-scalar meson couple to the axial-vector molecule. We argue that final and predictive results require further computations involving intermediate states with two vector mesons. The relevance of the latter is predicted by our counting rules. | |
| dc.description | added appendix concerning double-counting issues | |
| dc.identifier | https://arxiv.org/abs/0801.3821 | |
| dc.identifier | http://arxiv.org/abs/0801.3821 | |
| dc.identifier | Nucl.Phys.A813:96-170,2008 | |
| dc.identifier | doi:10.1016/j.nuclphysa.2008.09.005 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/205274 | |
| dc.subject | Nuclear Theory | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.title | On the radiative decays of light vector and axial-vector mesons | |
| dc.type | text |