6,095 research outputs found
Possible large violation in three body decays of heavy baryon
We propose a new mechanism which can introduce large asymmetries in the
phase spaces of three-body decays of heavy baryons. In this mechanism, a large
asymmetry is induced by the interference of two intermediate resonances,
which subsequently decay into two different combinations of final particles. We
apply this mechanism to the decay channel , and
find that the differential asymmetry can reach as large as , while
the regional asymmetry can reach as large as in the interference
region of the phase space.Comment: 7 pages, 2 figures, 2nd version accepted by Phys. Lett.
Localized direct CP violation in
We study the localized direct CP violation in the hadronic decays
,
including the effect caused by an interesting mechanism involving the charge
symmetry violating mixing between and . We calculate the
localized integrated direct CP violation when the low invariant mass of
[] is near . For five models of
form factors investigated, we find that the localized integrated direct CP
violation varies from -0.0170 to -0.0860 in the ranges of parameters in our
model when \,GeV. This result, especially the
sign, agrees with the experimental data and is independent of form factor
models. The new experimental data shows that the signs of the localized
integrated CP asymmetries in the regions \,GeV
and \,GeV are positive and negative,
respectively. We find that - mixing makes the localized
integrated CP asymmetry move towards the negative direction, and therefore
contributes to the sign change in those two regions. This behavior is also
model independent. We also calculate the localized integrated direct CP
violating asymmetries in the regions \,GeV and
\,GeV and find that they agree with the
experimental data in some models of form factors.Comment: 22 pages, 2 figures. arXiv admin note: text overlap with
arXiv:hep-ph/0602043, arXiv:hep-ph/0302156 by other author
Normal modes and time evolution of a holographic superconductor after a quantum quench
We employ holographic techniques to investigate the dynamics of the order
parameter of a strongly coupled superconductor after a perturbation that drives
the system out of equilibrium. The gravity dual that we employ is the Soliton background at zero temperature. We first analyze the normal
modes associated to the superconducting order parameter which are purely real
since the background has no horizon. We then study the full time evolution of
the order parameter after a quench. For sufficiently a weak and slow
perturbation we show that the order parameter undergoes simple undamped
oscillations in time with a frequency that agrees with the lowest normal model
computed previously. This is expected as the soliton background has no horizon
and therefore, at least in the probe and large limits considered, the
system will never return to equilibrium. For stronger and more abrupt
perturbations higher normal modes are excited and the pattern of oscillations
becomes increasingly intricate. We identify a range of parameters for which the
time evolution of the order parameter become quasi chaotic. The details of the
chaotic evolution depend on the type of perturbation used. Therefore it is
plausible to expect that it is possible to engineer a perturbation that leads
to the almost complete destruction of the oscillating pattern and consequently
to quasi equilibration induced by superposition of modes with different
frequencies.Comment: 10 pages, 7 figures, corrected typos, expanded section on chaotic
oscillations and new results for other quenc
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