s-wave charmed baryon resonances from a coupled-channel approach with heavy quark symmetry

Abstract

We study charmed baryon resonances which are generated dynamically within a unitary mesonbaryon coupled channel model that treats the heavy pseudoscalar and vector mesons on equal footing as required by heavy-quark symmetry. It is an extension of recent SU(4) models with tchannel vector meson exchanges to an SU(8) spin-flavor scheme, but differs considerably from the SU(4) approach in how the strong breaking of the flavor symmetry is implemented. Some of our dynamically generated states can be readily assigned to recently observed baryon resonances, while others do not have a straightforward identification and require the compilation of more data as well as an extension of the model to d-wave meson-baryon interactions and p-wave coupling in the neglected s-and u-channel diagrams. Of several novelties, we find that the Λc(2595), which emerged as a N D quasi-bound state within the SU(4) approaches, becomes predominantly a N D * quasi-bound state in the present SU(8) scheme.

Single electrons from heavy-flavor mesons in relativistic heavy-ion collisions

“…In the low-energy limit the interaction provides a generalized Weinberg-Tomozawa contact interaction as worked out in Refs. [62,64,66,67]. The effective Lagrangian obeys SU(6) spin-flavor symmetry in the light sector, plus HQSS in the heavy sector (which is preserved either the heavy quark is contained in the meson or in the baryon).…”

“…We refer the reader to Refs. [62,64,[66][67][68][69] for technical details. The unitarization procedure allows for the possibility of generating resonant states as poles of the scattering amplitude T ij .…”

“…A description of their interactions has been developed in Refs. [62][63][64][65][66][67][68][69][70] using effective field theory. Moreover, after the application of an effective theory, one should implement to the scattering amplitudes a unitarization method to better control the behavior of the cross sections at moderates energies.…”

Charmed baryonic resonances in medium

“…The poles of the scattering amplitudes are the dynamicallygenerated charmed baryonic resonances. Dynamically generated states in different charm and strange sectors are predicted within our model [23][24][25]. We restrict our study to those states stemming from the most attractive representations of our SU(6) × HQSS model.…”

“…HQSS is a proper QCD symmetry that appears when the quark masses become larger than a e-mail: tolos@ice.csic.es the typical confinement scale. Thus, we have developed a model that incorporates HQSS constraints [23][24][25][26][27][28]. Nuclear medium modifications have been then incorporated in order to study how charmed baryonic resonances are modified in matter and, consequently, to analyze the properties of charmed mesons in nuclear matter, and the influence of these modifications in the charmonium production rhythm at finite baryon densities.…”