6,817 research outputs found
Study of Radiative Leptonic D Meson Decays
We study the radiative leptonic meson decays of D^+_{(s)}\to
\l^+\nu_{\l}\gamma (\l=e,\mu,\tau), and D^0\to
\l^+\l^-\gamma () within the light front quark model. In the standard
model, we find that the decay branching ratios of , and
are (), (), and
(), and that of D^0\to\l^+\l^-\gamma (\l=e,\mu) and
are and ,
respectively.Comment: 23 pages, 6 Figures, LaTex file, a reference added, to be published
in Mod. Phys. Lett.
Direct CP and T Violation in Baryonic B Decays
We review the direct CP and T violation in the three-body baryonic B decays
in the standard model. In particular, we emphasize that the direct CP violating
asymmetry in is around 22% and the direct
violating asymmetry in \bar B^0 \ra \Lambda \bar p \pi^+ can be as large as
12%, which are accessible to the current B factories at KEK and SLAC as well as
SuperB and LHCb.Comment: 6 pages, Talk given at 4th International Conference on Flavor Physics
(ICFP 2007), Beijing, China, 24-28 Sep 200
A systematic study of Zr and Sn isotopes in the Relativistic Mean Field theory
The ground-state properties of Zr and Sn isotopes are studied within the
relativistic mean field theory. Zr and Sn isotopes have received tremendous
attention due to various reasons, including the predicted giant halos in the
neutron-rich Zr isotopes, the unique feature of being robustly spherical in the
region of Sn Sn and the particular interest of Sn
isotopes to nuclear astrophysics. Furthermore, four (semi-) magic neutron
numbers, 40, 50, 82 and 126, make these two isotopic chains particularly
important to test the pairing correlations and the deformations in a
microscopic model. In the present work, we carry out a systematic study of Zr
and Sn isotopes from the proton drip line to the neutron drip line with
deformation effects, pairing correlations and blocking effects for nuclei with
odd number of neutrons properly treated. A constrained calculation with
quadrupole deformations is performed to find the absolute minimum for each
nucleus on the deformation surface. All ground-state properties, including the
separation energies, the odd-even staggerings, the nuclear radii, the
deformations and the single-particle spectra are analyzed and discussed in
detail.Comment: the final version to appear in Modern Physics Letters A. more
figures, discussions, and references added. the data remain unchange
CP Violation in Fermion Pair Decays of Neutral Boson Particles
We study CP violation in fermion pair decays of neutral boson particles with
spin 0 or 1. We study a new asymmetry to measure CP violation in decays and discuss the possibility of measuring it
experimentally. For the spin-1 particles case, we study CP violation in the
decays of to octet baryon pairs. We show that these decays can
be used to put stringent constraints on the electric dipole moments of
, and .Comment: 14p, OZ-93/22, UM-93/89, OITS 51
Electromagnetically induced transparency and four-wave mixing in a cold atomic ensemble with large optical depth
We report on the delay of optical pulses using electromagnetically induced
transparency in an ensemble of cold atoms with an optical depth exceeding 500.
To identify the regimes in which four-wave mixing impacts on EIT behaviour, we
conduct the experiment in both rubidium 85 and rubidium 87. Comparison with
theory shows excellent agreement in both isotopes. In rubidium 87, negligible
four-wave mixing was observed and we obtained one pulse-width of delay with 50%
efficiency. In rubidium 85, four-wave-mixing contributes to the output. In this
regime we achieve a delay-bandwidth product of 3.7 at 50% efficiency, allowing
temporally multimode delay, which we demonstrate by compressing two pulses into
the memory medium.Comment: 8 pages, 6 figure
Large-scale magnetic fields from inflation due to Chern-Simons-like effective interaction
We discuss the generation of large-scale magnetic fields due to the breaking
of the conformal invariance in the electromagnetic field through the -even
dimension-six Chern-Simons-like effective interaction with a fermion current in
inflationary cosmology. It is shown that the magnetic fields on 1Mpc scale with
the field strength of G at the present time can be generated even
for the scale of the effective interaction being the Planck scale.Comment: 13 pages, 2 figures, additional explanations include
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