Triple product correlations in top squark decays

We propose several T-odd asymmetries in the decay chains of the top squarks $\tilde t_m \to t \tilde \chi^0_k$ and $t\to bW^+\to bl\nu$ and $\tilde\chi^0_k \to l^\pm\tilde l_n^\mp \to l^\pm l^\mp\tilde\chi^0_1$, for $l =e,\mu,\tau$. We calculate the asymmetries within the Minimal Supersymmetric Standard Model with complex parameters $M_1$, $\mu$ and $A_t$. We give the analytic formulae for the decay distributions. We present numerical results for the asymmetries and estimate the event rates necessary to observe them. The largest T-odd asymmetry can be as large as 40%.Comment: 26 pages, 5 figures; misprints corrected; reference adde

Consistency tests for the extraction of the Boer-Mulders and Sivers functions

At present, the Boer-Mulders (BM) function for a given quark flavor is extracted from data on semi-inclusive deep inelastic scattering (SIDIS) using the simplifying assumption that it is proportional to the Sivers function for that flavor. In a recent paper, we suggested that the consistency of this assumption could be tested using information on so-called difference asymmetries i.e. the difference between the asymmetries in the production of particles and their antiparticles. In this paper, using the SIDIS COMPASS deuteron data on the ⟨ cos ϕ h ⟩ , ⟨ cos 2 ϕ h ⟩ and Sivers difference asymmetries, we carry out two independent consistency tests of the assumption of proportionality, but here applied to the sum of the valence-quark contributions. We find that such an assumption is compatible with the data. We also show that the proportionality assumptions made in the existing parametrizations of the BM functions are not compatible with our analysis, which suggests that the published results for the Boer-Mulders functions for individual flavors are unreliable. The ⟨ cos ϕ h ⟩ and ⟨ cos 2 ϕ h ⟩ asymmetries receive contributions also from the, in principle, calculable Cahn effect. We succeed in extracting the Cahn contributions from experiment (we believe for the first time) and compare with their calculated values, with interesting implications

Complete 1-Loop Calculation of the T-violating D-Parameter in Neutron Decay in the MSSM

We investigate the violation of time reversal invariance in the decay of the free neutron in the framework of the Minimal Supersymmetric Standard Model (MSSM). The coefficient of the triple product of the neutron spin and the momenta of electron and neutrino, the so called D parameter, is computed at one loop order including all diagrams. We find that D is mainly sensitive to the trilinear A coupling in the squark sector and to the phase of the coefficient \mu which mixes the two Higgs superfields. The maximal MSSM contribution using parameters still allowed by experiment is however at D \approx 10^{-7}, while QED final state interactions give a value of D_{fsi} = - 2.3 * 10^{-5}. Explicit expressions for all relevant diagrams are given in an Appendix.Comment: 24 pages, 14 figures; Improved scanning of parameter space leads to some numerical change, but the basic conclusion remains unchange

CP violating asymmetry in H±→W±h1H^\pm\to W^\pm h_1 decays

The CP violating asymmetry from the decay rates $H^\pm\to W^\pm h_1$ of charged Higgs bosons into the lightest neutral Higgs boson and a $W^\pm$ boson is calculated and discussed in the complex MSSM. The contributions from all complex phases are considered, especially from the top-squark trilinear coupling, which induces a large contribution to the CP asymmetry.Comment: 19 pages, 10 figures, version published in JHE