5,571 research outputs found
Gold-plated Mode of CP-Violation in Decays of B_c Meson from QCD Sum Rules
The model-independent method based on the triangle ideology is implemented to
extract the CKM-matrix angle gamma in the decays of doubly heavy long-lived
meson B_c. We analyze a color structure of diagrams and conditions to
reconstruct two reference-triangles by tagging the flavor and CP eigenstates of
D^0 meson in the fixed exclusive channels. The characteristic branching ratios
are evaluated in the framework of QCD sum rules.Comment: 11 pages, RevTeX4 file, 4 eps-figure
Two-particle decays of B_c meson into charmonium states
The factorization of hard and soft contributions into the hadronic decays of
B_c meson at large recoils is explored in order to evaluate the decay rates
into the S, P and D-wave charmonia associated with rho and pi. The constraints
of approach applicability and uncertainties of numerical estimates are
discussed. The mode with the J/psi in the final state is evaluated taking into
account the cascade radiative electromagnetic decays of excited P-wave states,
that enlarges the branching ratio by 20-25%.Comment: 13 pages, LaTeX axodraw-style, 1 figure, 2 table
A prohibition of equilibrium spin currents in multi-terminal ballistic devices
We show that in the multi-terminal ballistic devices with intrinsic
spin-orbit interaction connected to normal metal contacts there are no
equilibrium spin currents present at any given electron energy. Obviously, this
statement holds also after the integration over all occupied states. Based on
the proof of this fact, a number of scenarios involving nonequilibrium spin
currents is identified and further analyzed. In particular, it is shown that an
arbitrary two-terminal device cannot polarize transient current. The same is
true for the output terminal of an N-terminal device when all N-1 inputs are
connected in parallel.Comment: 3 pages, 1 figure; presented at the DARPA SPinS review (#Th-19), San
Francisco, CA, October 25-28, 200
- …