13,884,070 research outputs found
The process at a Collider
The helicity amplitudes for the process are
studied to 1-loop order in the minimal SUSY (MSSM) model, where is the
CP-odd Higgs particle.
Simple exact analytic formulae are obtained, in terms of the and
Passarino-Veltman functions; in spite of the fact that the loop-diagrams often
involve different particles running along their sides. For a usual mSUGRA set
of parameters, is
expected. If SUSY is realized in Nature, these expressions should be useful for
understanding the Higgs sector.Comment: Misprints in typos corrected, 1 reference added e-mail:
[email protected]
An Unrestricted Hartree-Fock Self-consistent Huckel-like Procedure. Application to the Magnetic Properties of Radicals and Metallic Clusters
The Huckel method, which can be considered an SCF method
on the orthogonalized Lowdin basis, is extended to the UHF model.
Some applications to :re-radicals and to metallic clusters are given.
A strong magnetization can appear, even in small size clusters.
Correlation with the Hund rule is discussed. A calculation carried
out on a tetrahedral cluster explains the origin of the strong
magnetization in elements located in the middle of the transition
elements period. Examples of antiferro- and ferrimagnetic clusters
are given
Search for the rare decays B^0 → D_s^((*)+)a-_(0(2))
We have searched for the decays B^0 → D_s^+a^-_0, B^0 → D_s^(*+)a^-_0, B^0 → D_s^+a^-_2 and B^0 → D_s^(*+)a^-_2 in a sample of about 230 × 10^6 Υ(4S) → BB̅ decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We find no evidence for these decays and set upper limits at 90% C.L. on the branching fractions: B(B^0 → D_s^+a^-_0)<1.9 × 10^(-5), B(B^0 → D_s^(*+)a^-_0)<3.6 × 10^(-5), B(B^0 → D_s^+a^-_2)<1.9 × 10^(-4), and B(B^0 → D_s^(*+)a^-_2)<2.0 × 10^(-4)
A Test of CPT Symmetry in K^0 vs \bar{K}^0 to \pi^+\pi^-\pi^0 Decays
I show that the CP-violating asymmetry in K^0 vs \bar{K}^0 \to
\pi^+\pi^-\pi^0 decays differs from that in K_L \to \pi^+\pi^-, K_L \to
\pi^0\pi^0 or the semileptonic K_L transitions, if there exists CPT violation
in K^0-\bar{K}^0 mixing. A delicate measurement of this difference at a super
flavor factory (e.g., the \phi factory) will provide us with a robust test of
CPT symmetry in the neutral kaon system.Comment: 4 pages, 1 figure. To appear in the Proceedings of the International
PHIPSI09 Workshop, October 2009, Beijing, Chin
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