Related papers: BABAR Resonance and Four-quark Mesons
We discuss the behavior of dynamically-generated charmed baryonic resonances in matter within a unitarized coupled-channel model consistent with heavy-quark spin symmetry. We analyze the implications for the formation of $D$-meson bound…
The models for the internal structure of the newly found four-quark charmonium-like resonance $Z_c(3900)$ are discussed: the molecular model as well as the hadro-charmonium and tetraquark schemes. It is argued that it would be possible to…
The $D_s(2320)$ state recently observed by BaBar in the $D_s^+\pi^0$ channel may be the first of a host of $cq\bar q\bar q$ four-quark states. We give a phenomenological account of the masses and decay modes. The isosinglet $D_s(2320)$…
We propose that there coexist two scalar mesons of different structures (a conventional meson and a four-quark meson) in the recently observed broad bumps just below the large peak of the tensor meson in the D-pi mass distribution. We base…
The BaBar Collaboration has recently reported branching fractions for semileptonic decays of the $B$ meson into final states with charged and neutral $D_{1}(2420)$ and $D_{2}^{\ast}(2460)$, two narrow orbitally excited charmed mesons. We…
The production of wrong sign charmed mesons b -> \bar D_{(s)} X, D_{(s)}=(D0,D+,D_s), is studied using the data collected by the DELPHI experiment in the years 1994 and 1995. Charmed mesons in Z -> b bbar events are exclusively…
We report a measurement of the branching fractions of Bbar -> D** l^- nubar_l decays based on 417 fb-1 of data collected at the Upsilon(4S) resonance with the BaBar detector at the PEP-II e+e- storage rings. Events are selected by fully…
We study charmed and strange baryon resonances that are generated dynamically within a unitary meson-baryon coupled-channel model which incorporates heavy-quark spin symmetry. This is accomplished by extending the SU(3) Weinberg-Tomozawa…
Masses of open- and hidden-charm tetra-quark scalar mesons are studied in a new approach. As the result, newly estimated masses of hidden-charm sector are significantly lower than our earier ones by a naive quark counting. In particular,…
While the charmonium model has been effective in describing ccbar bound mesons, there have been many recently discovered charmonium-like states it cannot accommodate. Here I provide a review of recent results from the B-factories including…
The chromomagnetic interaction, with full account for flavour-symmetry breaking, is applied to S-wave configurations containing two quarks and two antiquarks. Phenomenological implications are discussed for light, charmed, charmed and…
We suggest a new point of view according to which baryon resonances can be understood as collective excitations about intrinsic one-quark excitations in a mean field of definite symmetry. This approach is justified in the limit of large…
We assume that the two hidden charm pentaquark discovered at $LHCb$ are built by the three light quarks and the $c \bar{c}$ pair, both colour octets. in relative P-wave for the $\frac{5}{2}^+$ state and by the eigenvectors of the…
This paper provides a short review of new states carrying a charm quark(s) which were observed in the recent few years at B factories. The following new particles are discussed: X(3872), Y(3940), X(3940), \chi_c^{\prime}(3930), Y(4260),…
The model dependence of the predictions of nucleon resonances with hidden charm is investigated. We consider several coupled-channel models which are derived from relativistic quantum field theory by using (1) a unitary transformation…
Two recent OPAL publications dealing with spectroscopy of heavy-light mesons will be discussed. In the charm sector, a search for a narrow radial excitation of the D*+- is performed. No signal is seen, and an upper limit of the production…
We present several searches for charmless hadronic two-body and three-body decays of B mesons from electron-positron annihilation data collected by the BABAR detector near the Upsilon(4S) resonance. We report the preliminary branching…
We discuss some new aspects of charm production trigerred by recent observations of the LHCb collaboration. The LHCb collaboration measured small asymmetries in production of $D^+ D^-$ mesons as well as $D_s^+ D_s^-$ mesons. Is this related…
The meson-baryon coupled channel unitary approach with the local hidden gauge formalism is extended to the hidden beauty sector. A few narrow $N^*$ and $\Lambda^*$ resonances around 11 GeV are predicted as dynamically generated states from…
The recent observation by the D0 collaboration of a narrow structure X(5568) consisting of four different quark flavors bdus, has not been confirmed by LHCb. More data and dedicated analyses are needed to cover a larger mass range. In the…