4,838 research outputs found
Branching Fractions and CP Asymmetries of the Quasi-Two-Body Decays in within PQCD Approach
Motivated by the first untagged decay-time-integrated amplitude analysis of
decays performed by LHCb collaboration, where the
decay amplitudes are modeled to contain the resonant contributions from
intermediate resonances , and , we
comprehensively investigate the quasi-two-body decays, and calculate the branching fractions and
the time-dependent asymmetries within the perturbative QCD approach based
on the 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 pair
wave function, describing the interaction between the kaon and pion in the
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 could
be measured. We calculate six -violation observables, which can be tested
in the ongoing LHCb experiment.Comment: 20 page
Cabibbo-Kobayashi-Maskawa-favored decays to a scalar meson and a meson
Within the perturbative QCD approach, we investigated the
Cabibbo-Kobayashi-Maskawa-favored ("" 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 to , which can be tested in the ongoing LHCb
experiment and the forthcoming Belle-II experiment. Some decays, such as and , 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 and provide a potential way to determine the mixing
angle between and . Moreover, since in the standard model
these decays occur only through tree operators and have no 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
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 for ground state and for
non-ground states are found to coexist and the most unstable one can be the
high order states (). The conventional KBM is the state. It is
shown that the KBM has the same mode structure parity as the
micro-tearing mode (MTM). In contrast to the MTM, the 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
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 as a function of temperature 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
\,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, as a function of for each film can not
be ascribed to \emph{e}-ph scattering. To quantitatively describe the
temperature behavior of , 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 and , respectively). In addition, the
experimental prefactors of and are proportional to
and ( is the Fermi wave number,
is the electron elastic mean free path, and 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
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