Triangle singularities in B−→K−π−Ds0+B^-\rightarrow K^-\pi^-D_{s0}^+ and B−→K−π−Ds1+B^-\rightarrow K^-\pi^-D_{s1}^+

We study the appearance of structures in the decay of the $B^-$ into $K^- \pi^- D_{s0}^+(2317)$ and $K^- \pi^- D_{s1}^+(2460)$ final states by forming invariant mass distributions of $\pi^- D_{s0}^+$ and $\pi^- D_{s1}^+$ pairs, respectively. The structure in the distribution is associated to the kinematical triangle singularity that appears when the $B^- \to K^- K^{*\,0} D^0$ ($B^- \to K^- K^{*\,0} D^{*\,0}$) decay process is followed by the decay of the $K^{*\,0}$ into $\pi^- K^+$ and the subsequent rescattering of the $K^+ D^0$ ($K^+ D^{*\,0}$) pair forming the $D_{s0}^+(2317)$ ($D_{s1}^+(2460)$) resonance. We find this type of non-resonant peaks at 2850 MeV in the invariant mass of $\pi^- D_{s0}$ pairs from $B^- \to K^- \pi^- D_{s0}^+(2317)$ decays and around 3000 MeV in the invariant mass of $\pi^- D_{s1}^+$ pairs from $B^- \to K^- \pi^- D_{s1}^+(2460)$ decays. By employing the measured branching ratios of the $B^- \to K^- K^{*\,0} D^0$ and $B^- \to K^- K^{*\,0} D^{*\,0}$ decays, we predict the branching ratios for the processes $B^-$ into $K^- \pi^-D_{s0}^+(2317)$ and $K^- \pi^- D_{s1}^+(2460)$, in the vicinity of the triangle singularity peak, to be about $8\times10^{-6}$ and $1\times 10^{-6}$, respectively. The observation of this reaction would also give extra support to the molecular picture of the $D_{s0}^+(2317)$ and $D_{s1}^+(2460)$.Comment: 18 pages, 15 figures, accepted version for publication in Eur. Phys. J.

Modeling Three and Four Coupled Phase Qubits

The Josephson junction phase qubit has been shown to be a viable candidate for quantum computation. In recent years, the two coupled phase system has been extensively studied theoretically and experimentally. We have analyzed the quantum behavior of three and four capacitively-coupled phase qubits with different possible configurations, using a two-level system model. Energy levels and eigenstates have been calculated as a function of bias current and detuning. The properties of these simple networks are discussed

An analysis of the Lattice QCD spectra for Ds0∗(2317)D^*_{s0}(2317) and Ds1∗(2460)D^*_{s1}(2460)

In this talk I present the results obtained using effective field theories in a finite volume from a reanalysis of lattice data on the $KD^{(*)}$ systems, where bound states of $KD$ and $KD^*$ are found and associated with the states $D^*_{s0}(2317)$ and $D^*_{s1}(2460)$, respectively. We confirm the presence of such states on the lattice data and determine the weight of the $KD$ channel in the wave function of $D^*_{s0}(2317)$ and that of $KD^*$ in the wave function of $D^*_{s1}(2460)$. Our results indicate a large meson-meson component in both cases.Comment: Conference Proceedings, Hadron 2017, Salamanca, Spai

Evidence for the two pole structure of the Lambda(1405) resonance

The K^- p --> pi^0 pi^0 Sigma^0 reaction is studied within a chiral unitary model. The distribution of pi^0 Sigma^0 states forming the Lambda(1405) shows, in agreement with a recent experiment, a peak at 1420 MeV and a relatively narrow width of Gamma = 38 MeV. The mechanism for the reaction is largely dominated by the emission of a pi^0 prior to the K^- p interaction leading to the Lambda(1405). This ensures the coupling of the Lambda(1405) to the K^- p channel, thus maximizing the contribution of the second state found in chiral unitary theories, which is narrow and of higher energy than the nominal Lambda(1405). This is unlike the pi^- p --> K^0 \pi Sigma reaction, which gives more weight to the pole at lower energy and with a larger width. The data of these two experiments, together with the present theoretical analysis, provides a firm evidence of the two pole structure of the Lambda(1405).Comment: 4 pages, 6 figure