10,272 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
Observing muon neutrino to electron neutrino oscillations in the NOvA Experiment
Neutrino oscillations offers an insight on new physics beyond the Standard Model. The three mixing angles (, and ) and the two mass splittings ( and ) have been measured by different neutrino oscillation experiments. Some other parameters including the mass ordering of different neutrino mass eigenstates and the CP violation phase are still unknown.
\nova~is a long-baseline accelerator neutrino experiment, using neutrinos from the NuMI beam at Fermilab. The experiment is equipped with two functionally identical detectors about 810 kilometers apart and 14 mrad off the beam axis. In this configuration, the muon neutrinos from the NuMI beam reach the disappearance maximum in the far detector and a small fraction of that oscillates into electron neutrinos.
The sensitivity to the mass ordering and CP violation phase determination is greately enhanced. This thesis presents the \nue appearance analysis using the neutrino data collected with the \nova~experiment between February 2014 and May 2015, which corresponds to 3.45 protons-on-target (POT). The appearance analysis is performed by comparing the observed \nuecc-like events to the estimated background at the far detector. The total background is predicted to be 0.95 events with 0.89 originated from beam events and 0.06 from cosmic ray events. The beam background is obtained by extrapolating near detector data through different oscillation channels, while the cosmic ray background is calculated based on out-of-time NuMI trigger data. A total of 6 electron neutrino candidates are observed in the end at the far detector which represents 3.3 excess over the predicted background. The \nova~ result disfavors inverted mass hierarchy for at C.L
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