Molecular components in D^*_s0(2317) and D_s1(2460) mesons

¹ CERN (European Organization for Nuclear Research), CH-1211 Geneva, Switzerland
² Technische Universität München, D-85748 Garching bei München, Germany
³ Universidad de Salamanca, E-37008 Salamanca, Spain

^* Currently at Instituto de Física Corpuscular (IFIC), CSIC-Universidad de Valencia, E-46071 Valencia, Spain
^** speaker, e-mail: jorge.segovia@tum.dem

Published online: 29 November 2016

Abstract

Different experiments have confirmed that the D^*_s0(2317) and D_s1(2460) mesons are very narrow states located, respectively, below the DK and D^*K thresholds. This is markedly in contrast with the expectations of naive quark models and heavy quark symmetry. We address the mass shifts of the cs̄ ground states with quantum numbers J^P = 0⁺ (D^*_s0(2317)) and J^P = 1⁺ (D_s1(2460)) using a nonrelativistic constituent quark model in which quark-antiquark and meson-meson degrees of freedom are incorporated. The quark model has been applied to a wide range of hadronic observables and thus the model parameters are completely constrained. We observe that the coupling of the 0⁺ (1⁺) meson sector to the DK (D^*K) threshold is a key feature in lowering the masses of the corresponding D^*_s0(2317) and D_s1(2460) states predicted by the naive quark model, but also in describing the D_s1(2536) meson as the 1⁺ state of the j^P_q = 3/2⁺ doublet predicted by heavy quark symmetry and thus reproducing its strong decay properties. Two features of our formalism cannot be address nowadays by other approaches: the coupling of the D-wave D^*K threshold in the J^P = 1⁺ cs̄ channel and the computation of the probabilities associated with different Fock components in the physical state.