4,708 research outputs found

    Branching Fractions and CP Asymmetries of the Quasi-Two-Body Decays in Bsβ†’K0(Kβ€Ύ0)KΒ±Ο€βˆ“B_{s} \to K^0(\overline K^0)K^\pm \pi^\mp within PQCD Approach

    Full text link
    Motivated by the first untagged decay-time-integrated amplitude analysis of Bsβ†’KSKβˆ“Ο€Β±B_s \to K_SK^{\mp}\pi^{\pm} decays performed by LHCb collaboration, where the decay amplitudes are modeled to contain the resonant contributions from intermediate resonances Kβˆ—(892)K^*(892), K0βˆ—(1430)K_0^*(1430) and K2βˆ—(1430)K_2^*(1430), we comprehensively investigate the quasi-two-body Bsβ†’K0/Kβ€Ύ0KΒ±Ο€βˆ“B_{s} \to K^0/\overline{\kern -0.2em K}^0 K^{\pm}\pi^{\mp} decays, and calculate the branching fractions and the time-dependent CPCP asymmetries within the perturbative QCD approach based on the kTk_T factorization. In the quasi-two-body space region the calculated branching fractions with the considered intermediate resonances are in good agreement with the experimental results of LHCb by adopting proper KΟ€K\pi pair wave function, describing the interaction between the kaon and pion in the KΟ€K\pi pair. Furthermore,within the obtained branching fractions of the quasi-two-body decays, we also calculate the branching fractions of corresponding two-body decays, and the results consist with the LHCb measurements and the earlier studies with errors. For these considered decays, since the final states are not flavour-specific, the time-dependent CPCP could be measured. We calculate six CPCP-violation observables, which can be tested in the ongoing LHCb experiment.Comment: 20 page

    Cabibbo-Kobayashi-Maskawa-favored BB decays to a scalar meson and a DD meson

    Full text link
    Within the perturbative QCD approach, we investigated the Cabibbo-Kobayashi-Maskawa-favored Bβ†’Dβ€ΎSB \to \overline{D} S ("SS" denoting the scalar meson) decays on the basis of the two-quark picture. Supposing the scalar mesons are the ground states or the first excited states, we calculated the the branching ratios of 72 decay modes. Most of the branching ratios are in the range 10βˆ’410^{-4} to 10βˆ’710^{-7}, which can be tested in the ongoing LHCb experiment and the forthcoming Belle-II experiment. Some decays, such as B+β†’Dβ€Ύ(βˆ—)0a0+(980/1450)B^+ \to \overline{D}^{(*)0} a_0^+(980/1450) and B+β†’D(βˆ—)βˆ’a0+(980/1450)B^+ \to D^{(*)-} a_0^+(980/1450), could be used to probe the inner structure and the character of the scalar mesons, if the experiments are available. In addition, the ratios between the Br(B0β†’Dβ€Ύ(βˆ—)0Οƒ)Br(B^0\to \overline{D}^{(*)0}\sigma) and Br(B0β†’Dβ€Ύ(βˆ—)0f0(980))Br(B^0\to \overline{D}^{(*)0}f_0(980)) provide a potential way to determine the mixing angle between Οƒ\sigma and f0(980)f_0(980). Moreover, since in the standard model these decays occur only through tree operators and have no CPCP asymmetries, any deviation will be signal of the new physics beyond the standard model.Comment: 2 figures, 6 table

    Kinetic Ballooning Mode Under Steep Gradient: High Order Eigenstates and Mode Structure Parity Transition

    Get PDF
    The existence of kinetic ballooning mode (KBM) high order (non-ground) eigenstates for tokamak plasmas with steep gradient is demonstrated via gyrokinetic electromagnetic eigenvalue solutions, which reveals that eigenmode parity transition is an intrinsic property of electromagnetic plasmas. The eigenstates with quantum number l=0l=0 for ground state and l=1,2,3…l=1,2,3\ldots for non-ground states are found to coexist and the most unstable one can be the high order states (lβ‰ 0l\neq0). The conventional KBM is the l=0l=0 state. It is shown that the l=1l=1 KBM has the same mode structure parity as the micro-tearing mode (MTM). In contrast to the MTM, the l=1l=1 KBM can be driven by pressure gradient even without collisions and electron temperature gradient. The relevance between various eigenstates of KBM under steep gradient and edge plasma physics is discussed.Comment: 6 pages, 6 figure

    Simultaneous observation of small- and large-energy-transfer electron-electron scattering in three dimensional indium oxide thick films

    Full text link
    In three dimensional (3D) disordered metals, the electron-phonon (\emph{e}-ph) scattering is the sole significant inelastic process. Thus the theoretical predication concerning the electron-electron (\emph{e}-\emph{e}) scattering rate 1/τφ1/\tau_\varphi as a function of temperature TT in 3D disordered metal has not been fully tested thus far, though it was proposed 40 years ago [A. Schmid, Z. Phys. \textbf{271}, 251 (1974)]. We report here the simultaneous observation of small- and large-energy-transfer \emph{e}-\emph{e} scattering in 3D indium oxide thick films. In temperature region of T≳100T\gtrsim100\,K, the temperature dependence of resistivities curves of the films obey Bloch-Gr\"{u}neisen law, indicating the films possess degenerate semiconductor characteristics in electrical transport property. In the low temperature regime, 1/τφ1/\tau_\varphi as a function of TT for each film can not be ascribed to \emph{e}-ph scattering. To quantitatively describe the temperature behavior of 1/τφ1/\tau_\varphi, both the 3D small- and large-energy-transfer \emph{e}-\emph{e} scattering processes should be considered (The small- and large-energy-transfer \emph{e}-\emph{e} scattering rates are proportional to T3/2T^{3/2} and T2T^2, respectively). In addition, the experimental prefactors of T3/2T^{3/2} and T2T^{2} are proportional to kFβˆ’5/2β„“βˆ’3/2k_F^{-5/2}\ell^{-3/2} and EFβˆ’1E_F^{-1} (kFk_F is the Fermi wave number, β„“\ell is the electron elastic mean free path, and EFE_F is the Fermi energy), respectively, which are completely consistent with the theoretical predications. Our experimental results fully demonstrate the validity of theoretical predications concerning both small- and large-energy-transfer \emph{e}-\emph{e} scattering rates.Comment: 5 pages and 4 figure
    • …
    corecore