Baryon states with open beauty in the extended local hidden gauge approach

In this paper we examine the interaction of \bar B N, \bar B \Delta, \bar B^* N and \bar B^* \Delta states, together with their coupled channels, using a mapping from the light meson sector. The assumption that the heavy quarks act as spectators at the quark level automatically leads us to the results of the heavy quark spin symmetry for pion exchange and reproduces the results of the Weinberg Tomozawa term, coming from light vector exchanges in the extended local hidden gauge approach. With this dynamics we look for states dynamically generated from the interaction and find two states with nearly zero width, which we associate to the \Lambda_b(5912) and \Lambda_b(5920) states. The states couple mostly to \bar B^* N, which are degenerate with the Weinberg Tomozawa interaction. The difference of masses between these two states, with J=1/2, 3/2 respectively, is due to pion exchange connecting these states to intermediate \bar B N states. In addition to these two \Lambda_b states, we find three more states with I=0, one of them nearly degenerate in two states of J=1/2,3/2. Furthermore we also find eight more states in $I=1$, two of them degenerate in J=1/2, 3/2, and other two degenerate in J=1/2, 3/2, 5/2.Comment: 26 pages, 9 figures, 24 table

J/ψ(ηc)NJ/\psi (\eta_c) N and Υ(ηb)N\Upsilon (\eta_b) N cross sections

Inspired by the recent findings of the two $P_c^+$ states in the $J/\psi p$ mass spectrum at LHCb, we investigate the elastic and inelastic cross sections of the $J/\psi N$, $\eta_c N$, $\Upsilon N$ and $\eta_b N$ channels within the constraints from heavy quark spin and flavour symmetry. The $\bar{D}^{(*)} \Sigma_c^{(*)}$ ($B^{(*)} \Sigma_b^{(*)}$) bound states predicted in earlier works should be accessible in elastic and/or inelastic processes of the $J/\psi N$ and/or $\eta_c N$ ($\Upsilon N$ and/or $\eta_b N$) interactions.Comment: Minor correction

Heavy quark spin symmetric molecular states from Dˉ(∗)Σc(∗){\bar D}^{(*)}\Sigma_c^{(*)} and other coupled channels in the light of the recent LHCb pentaquarks

We consider the ${\bar D}^{(*)}\Sigma_c^{(*)}$ states, together with $J/\psi N$ and other coupled channels, and take an interaction consistent with heavy quark spin symmetry, with the dynamical input obtained from an extension of the local hidden gauge approach. By fitting only one parameter to the recent three pentaquark states reported by the LHCb collaboration, we can reproduce the three of them in base to the mass and the width, providing for them the quantum numbers and approximate molecular structure as $1/2^-$ $\bar{D} \Sigma_c$, $1/2^-$ $\bar{D}^* \Sigma_c$, and $3/2^-$ $\bar{D}^* \Sigma_c$, and isospin $I=1/2$. We find another state around 4374 MeV, of $3/2^-$ $\bar{D} \Sigma_c^*$ structure, for which indications appear in the experimental spectrum. Two other near degenerate states of $1/2^-$ $\bar{D}^* \Sigma_c^*$ and $3/2^-$ $\bar{D}^* \Sigma_c^*$ nature are also found around 4520 MeV, which although less clear, are not incompatible with the observed spectrum. In addition, a $5/2^-$ $\bar D^* \Sigma_c^*$ state at the same energy appears, which however does not couple to $J/\psi p$ in $S-$wave, and hence it is not expected to show up in the LHCb experiment.Comment: 8 page

Baryon states with open charm in the extended local hidden gauge approach

In this paper we examine the interaction of $D N$ and $D^* N$ states, together with their coupled channels, by using an extension of the local hidden gauge formalism from the light meson sector, which is based on heavy quark spin symmetry. The scheme is based on the use of the impulse approximation at the quark level, with the heavy quarks acting as spectators, which occurs for the dominant terms where there is the exchange of a light meson. The pion exchange and the Weinberg-Tomozawa interactions are generalized and with this dynamics we look for states generated from the interaction, with a unitary coupled channels approach that mixes the pseudoscalar-baryon and vector-baryon states. We find two states with nearly zero width which are associated to the $\Lambda_c(2595)$ and $\Lambda_c(2625)$. The lower state, with $J^P = 1/2^-$, couples to $D N$ and $D^* N$, and the second one, with $J^P = 3/2^-$, to $D^* N$. In addition to these two $\Lambda_c$ states, we find four more states with $I=0$, one of them nearly degenerate in two states of $J=1/2,\ 3/2$. Furthermore we find three states in $I=1$, two of them degenerate in $J=1/2, 3/2$.Comment: v3: version to appear in Eur.Phys.J.

Description of ρ(1700)\rho (1700) as a ρKKˉ\rho K \bar{K} system with the fixed center approximation

We study the $\rho K\bar{K}$ system with an aim to describe the $\rho (1700)$ resonance. The chiral unitary approach has achieved success in a description of systems of the light hadron sector. With this method, the $K \bar{K}$ system in the isospin sector $I=0$, is found to be a dominant component of the $f_0 (980)$ resonance. Therefore, by regarding the $K\bar{K}$ system as a cluster, the $f_0 (980)$ resonance, we evaluate the $\rho K\bar{K}$ system applying the fixed center approximation to the Faddeev equations. We construct the $\rho K$ unitarized amplitude using the chiral unitary approach. As a result, we find a peak in the three-body amplitude around 1739 MeV and a width of about 227 MeV. The effect of the width of $\rho$ and $f_0 (980)$ is also discussed. We associate this peak to the $\rho (1700)$ which has a mass of $1720 \pm 20$ MeV and a width of $250 \pm 100$ MeV

Growth of single-crystal columns of CoSi2 embedded in epitaxial Si on Si(111) by molecular beam epitaxy

The codeposition of Si and Co on a heated Si(111) substrate is found to result in epitaxial columns of CoSi2 if the Si:Co ratio is greater than approximately 3:1. These columns are surrounded by a Si matrix which shows bulk-like crystalline quality based on transmission electron microscopy and ion channeling. This phenomenon has been studied as functions of substrate temperature and Si:Co ratio. Samples with columns ranging in average diameter from approximately 25 to 130 nm have been produced

NDKNDK, KˉDN\bar{K} DN and NDDˉND\bar{D} molecules

We investigate theoretically baryon systems made of three hadrons which contain one nucleon and one D meson, and in addition another meson, $\bar{D}, K$ or $\bar{K}$. The systems are studied using the Fixed Center Approximation to the Faddeev equations. The study is made assuming scattering of a $K$ or a $\bar{K}$ on a $DN$ cluster, which is known to generate the $\Lambda_c(2595)$, or the scattering of a nucleon on the $D\bar{D}$ cluster, which has been shown to generate a hidden charm resonance named X(3700). We also investigate the configuration of scattering of $N$ on the $KD$ cluster, which is known to generate the $D_{s0}^*(2317)$. In all cases we find bound states, with the $NDK$ system, of exotic nature, more bound than the $\bar{K} DN$.Comment: 9 figure

Study of charm and beauty mass spectra, semileptonic decays of B(s,c)B_{(s,c)} and Bc→J/ψ(ηc)+P(V){B_c} \to J/\psi ({\eta _c}) + P(V) in a phenomenological potential model

Using a non-relativistic potential model, we obtain the mass spectra, leptonic decay constants, and parameters of the Isgur-Wise function for the beauty and charm mesons. With the calculated quantities, we investigate purely leptonic decays of $B^+$, $B^{*}$, $B_c^+$, semileptonic decay modes ${B_{(s)}} \to {D_{(s)}}l\nu$ and ${B_c} \to {\eta _c}\ell \bar \nu$ for three lepton channels $e,\mu ,\tau$, and obtain the corresponding branching fractions. $\bar B_{(s)}^{} \to D_{(s)}^*l\bar \nu$ transitions are also studied. Next, we apply the form factors for spin zero and spin one transitions of $B_c$ to calculate the nonleptonic branching ratios of ${B_c} \to J/\psi ({\eta _c}) + P(V)$, where $P$ and $V$ stand for the $D_q^{* - }$ vector meson and the $D_q$ pseudoscalar meson, respectively. Our results are found to be in agreement with those obtained in the experimental and theoretical results

A narrow DNNDNN quasi-bound state

The energies and widths of $DNN$ quasi-bound states with isospin I=1/2 are evaluated in two methods, the fixed center approximation to the Faddeev equation and the variational method approach to the effective one-channel Hamiltonian. The $DN$ interactions are constructed so that they dynamically generate the $\Lambda_c(2595)$ (I=0, $J^{\pi} =1/2^-$) resonance state. We find that the system is bound by about 250 MeV from the $DNN$ threshold, $\sqrt{s} \sim 3500$ MeV. Its width including both the mesonic decay and the $D$ absorption, is estimated to be about 20-40 MeV. The I=0 $DN$ pair in the $DNN$ system is found to form a cluster that is similar to the $\Lambda_c(2595)$.Comment: 17 pages, 18 figures, 3 table