32,068 research outputs found

    Polarization amplitudes in τ−→ντVP\tau^- \to \nu_{\tau} V P decay beyond the standard model

    Full text link
    We use a recent formalism of the weak hadronic reactions τ−→ντM1M2\tau^- \to \nu_{\tau} M_1 M_2 to study the helicity amplitudes in τ−→ντVP\tau^- \to \nu_{\tau} V P decay. This recent formalism maps the transition matrix elements at the quark level into hadronic matrix elements, and finally writes the weak matrix elements in terms of easy analytical formulas evaluated by means of an elaborate angular momentum algebra. The formalism provides directly the amplitudes for the different spin third components of the vector mesons involved. We extend the formalism to a general case, with the operator γμ−αγμγ5\gamma^\mu -\alpha\gamma^\mu \gamma_5, that can account for different models beyond the standard model and study in detail the τ−→ντK∗0K−\tau^- \to \nu_{\tau} K^{*0} K^{-} reaction for the different helicities of the K∗0K^{*0}. The results are shown in terms of the α\alpha parameter that differs for each model. We find that dΓdMinv(K∗0K−)\frac{d \Gamma}{d M_{\rm inv}^{(K^{*0} K^{-} )}} is very different for the different components M=±1,0M=\pm 1, 0 and in particular the magnitude dΓdMinv(K∗0K−)∣M=+1−dΓdMinv(K∗0K−)∣M=−1\frac{d \Gamma}{d M_{\rm inv}^{(K^{*0} K^{-} )}}|_{M=+1} -\frac{d \Gamma}{d M_{\rm inv}^{(K^{*0} K^{-} )}}|_{M=-1} is very sensitive to the α\alpha parameter, which makes the investigation of this magnitude a most welcome initiative to test different models beyond the standard model.Comment: 20 pages, 6 figures, add some discussion

    Helicity amplitudes in B→D∗νˉlB \to D^{*} \bar{\nu} l decay

    Full text link
    We use a recent formalism of the weak hadronic reactions that maps the transition matrix elements at the quark level into hadronic matrix elements, evaluated with an elaborate angular momentum algebra that allows finally to write the weak matrix elements in terms of easy analytical formulas. In particular they appear explicitly for the different spin third components of the vector mesons involved. We extend the formalism to a general case, with the operator γμ−αγμγ5\gamma^\mu -\alpha\gamma^\mu \gamma_5, that can accommodate different models beyond the standard model and study in detail the B→D∗νˉlB \to D^{*} \bar{\nu} l reaction for the different helicities of the D∗D^*. The results are shown for each amplitude in terms of the α\alpha parameter that is different for each model. We show that dΓdMinv(νl)\frac{d \Gamma}{d M_{\rm inv}^{(\nu l)}} is very different for the different components M=±1,0M=\pm 1, 0 and in particular the magnitude dΓdMinv(νl)∣M=−1−dΓdMinv(νl)∣M=+1\frac{d \Gamma}{d M_{\rm inv}^{(\nu l)}}|_{M=-1} -\frac{d \Gamma}{d M_{\rm inv}^{(\nu l)}}|_{M=+1} is very sensitive to the α\alpha parameter, which suggest to use this magnitude to test different models beyond the standard model. We also compare our results with the standard model and find very similar results, and practically identical at the end point of Minv(νl)=mB−mD∗M_{\rm inv}^{(\nu l)}= m_B- m_{D^*}.Comment: 25 pages, 10 figure

    B0→D0Dˉ0K0B^0 \to D^0 \bar D^0 K^0, B+→D0Dˉ0K+B^+ \to D^0 \bar D^0 K^+ and the scalar DDˉD \bar D bound state

    Get PDF
    We study the B0B^0 decay to D0Dˉ0K0D^0 \bar D^0 K^0 based on the chiral unitary model that generates the X(3720) resonance, and make predictions for the D0Dˉ0D^0 \bar D^0 invariant mass distribution. From the shape of the distribution, the existence of the resonance below threshold could be induced. We also predict the rate of production of the X(3720) resonance to the D0Dˉ0D^0 \bar D^0 mass distribution with no free parameters.Comment: 9 pages, 17 figure

    Radiative decay of the dynamically generated open and hidden charm scalar meson resonances D_{s0}^*(2317) and X(3700)

    Get PDF
    We present the formalism for the decay of dynamically generated scalar mesons with open- or hidden-charm and give results for the decay of D^*_{s0} (2317) to \gamma D_s^* plus that of a hidden charm scalar meson state predicted by the theory around 3700 MeV decaying into \gamma J/\psi.Comment: Appendix adde
    • …
    corecore