959 research outputs found
Two-photon Exchange Corrections to Single Spin Asymmetry of Neutron and He
In a simple hadronic model, the two-photon exchange contributions to the
single spin asymmetries for the nucleon and the He are estimated. The
results show that the elastic contributions of two-photon exchange to the the
single spin asymmetries for the nucleon are rather small while those for the
He are relatively large. Besides the strong angular dependence, the
two-photon contributions to the single spin asymmetry for the He are very
sensitive to the momentum transfer.Comment: 11 pages, 8 figure
Photon Polarization in the b->s gamma processes in the Left-Right Symmetric Model
The circular-polarization of the photon in the radiative B decays is
dominantly left-handed in the Standard Model (SM), but the right-handed
polarization may be enhanced in some new physics models with right-handed
currents, such as the Left-Right Symmetric Model (LRSM). In this article, we
investigate how large this wrong polarization could be within the allowed
parameter space of the LRSM. We show that in LRSM, the right-handed
polarization of the photon in the processes could be largely
enhanced by the mixing contributions because of the helicity flip on
the internal top quark line of the penguin diagrams and the enhancement by the
CKM factor . We discuss the sensitivity of the proposed
methods to determine the photon polarization to the LRSM as well
as their complementary role compared to the direct search of right-handed
charged gauge bosons at LHC.Comment: 30pages, 5 figures, published version; references adde
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