Triangle singularities in B−→K−π−D+s0 and B−→K−π−D+s1

We study the appearance of structures in the decay of the B− into K−π−D+s0(2317) and K−π−D+s1(2460) final states by forming invariant mass distributions of π−D+s0 and π−D+s1 pairs, respectively. The structure in the distribution is associated to the kinematical triangle singularity that appears when the B−→K−K∗0D0 ( B−→K−K∗0D∗0 ) decay process is followed by the decay of the K∗0 into π−K+ and the subsequent rescattering of the K+D0 ( K+D∗0 ) pair forming the D+s0(2317) ( D+s1(2460) resonance. We find this type of non-resonant peaks at 2850MeV in the invariant mass of π−Ds0 pairs from B−→K−π−D+s0(2317) decays and around 3000MeV in the invariant mass of π−D+s1 pairs from B−→K−π−D+s1(2460) decays. By employing the measured branching ratios of the B−→K−K∗0D0 and B−→K−K∗0D∗0 decays, we predict the branching ratios for the processes B− into K−π−D+s0(2317) and K−π−D+s1(2460) , in the vicinity of the triangle singularity peak, to be about 8×10−6 and 1×10−6 , respectively. The observation of this reaction would also give extra support to the molecular picture of the D+s0(2317) and D+s1(2460)

A hidden-charm S=-1 pentaquark from the decay of Λb into J/ψηΛ states

The hidden-charm pentaquark Pc(4450) observed recently by the LHCb collaboration may be of molecular nature, as advocated by some unitary approaches that also predict pentaquark partners in the strangeness S=−1 sector. In this work we argue that a hidden-charm strange pentaquark could be seen from the decay of the Λb, just as in the case of the non-strange Pc(4450), but looking into the J/ψηΛ decay mode and forming the invariant mass spectrum of J/ψΛ pairs. In the model presented here, which assumes a standard weak decay topology and incorporates the hadronization process and final-state interaction effects, we find the J/ψηΛ final states to be populated with similar strength as the J/ψK−p states employed for the observation of the non-strange pentaquark. This makes the Λb→J/ψηΛ decay to be an interesting process to observe a possible strange partner of the Pc(4450). We study the dependence of the J/ψΛ mass spectra on various model ingredients and on the unknown properties of the strange pentaquark

Weak decays of heavy hadrons into dynamically generated resonances

In this paper, we present a review of recent works on weak decay of heavy mesons and baryons with two mesons, or a meson and a baryon, interacting strongly in the final state. The aim is to learn about the interaction of hadrons and how some particular resonances are produced in the reactions. It is shown that these reactions have peculiar features and act as filters for some quantum numbers which allow to identify easily some resonances and learn about their nature. The combination of basic elements of the weak interaction with the framework of the chiral unitary approach allow for an interpretation of results of many reactions and add a novel information to different aspects of the hadron interaction and the properties of dynamically generated resonances Read More: http://www.worldscientific.com/doi/10.1142/S021830131630001