Identifying the t-channel exchange of vector mesons as the driving force for the s-wave scattering of pseudo-scalar mesons off the baryon ground states, a surprisingly rich spectrum of molecules is formed. We argue that chiral symmetry and large- N_c considerations determine that part of the interaction which generates the spectrum. All channels that are required by the existence of (u,d,s,c) quarks are considered. A bound state with exotic quantum numbers is predicted at mass 2.78 GeV. It couples strongly to the (bar D_s N),(bar D Lambda),(bar D Sigma) channels. A further charm minus-one system is predicted at mass 2.84 GeV as a result of (bar D_s Lambda), (bar D Xi) interactions. We suggest the existence of strongly bound crypto-exotic baryons, which contain a charm-anti-charm pair. Such states are narrow since they can decay only via OZI-violating processes. A narrow nucleon resonance is found at mass 3.52 GeV. It is a coupled-channel bound state of the (eta_c N), (bar D Sigma_c) system, which decays dominantly into the (eta' N) channel. Furthermore two isospin singlet hyperon states at mass 3.23 GeV and 3.58 GeV are observed as a consequence of coupled-channel interactions of the (bar D_s Lambda_c), (bar D Xi_c) and (eta_c Lambda),(bar D Xi_c') states. Most striking is the small width of about 1 MeV of the lower state. The upper state may be significantly broader due to a strong coupling to the (eta' Lambda) state. The two so far observed s-wave baryons with charm one are recovered. We argue that the Lambda_c(2880) is not a s-wave state. In addition to those states we predict the existence of about ten narrow s-wave baryon states with masses below 3 GeV.Comment: 51 pages, 3 figures, 25 tables some misprints are corrected, a few more references are adde

We study heavy-light meson resonances with quantum numbers J^P=0^+ and J^P=1^+ in terms of the non-linear chiral SU(3) Lagrangian. Adjusting the free parameters that arise at subleading order to reproduce the mass of the D(2420) resonance as well as the new states established recently by the BABAR, CLEO and BELLE collaborations we obtain refined masses for the anti-triplet and sextet states. Bound states of antikaons at the D(1867) and D(2008) mesons are predicted at 2352 MeV (J^P=0^+) and 2416 MeV (J^P=1^+). In addition we anticipate a narrow scalar state of mass 2389 MeV with (I,S)=(1/2,0)Comment: 12 pages, 3 figure

Identifying the zero-range exchange of vector mesons as the driving force for the s-wave scattering of pseudo-scalar mesons off the baryon ground states, the spectrum of 3 2 − molecules is computed.We predict a strongly bound 15-plet of C = −1 states. A narrow crypto-exotic octet of charm-zero states is foreseen. In the C = +1 sector a sextet of narrow resonances is formed due to the interaction of D mesons with the baryon decuplet. A strongly bound triplet of double-charm states is a consequence of coupled-channel dynamics driven by the D mesons.

No abstract

No abstract