Thursday, May 24, 2012

1205.5170 (B. C. Allanach et al.)

A Supersymmetric Explanation for High A_{FB}(t tbar) Via R-Parity
Violation
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B. C. Allanach, Sridhar
We propose a supersymmetric explanation for the anomalously high forward backward asymmetry in top pair production measured by CDF and D0. We suppose that it is due to the t-channel exchange of a right-handed sbottom which couples to d_R and t_R, as is present in the R-parity violating minimal supersymmetric standard model. We show that all Tevatron and LHC experiments' t tbar constraints may be respected for a sbottom mass between 300 and 1300 GeV, and a large Yukawa coupling >2, yielding A_{FB} up to 0.16. The non Standard Model contribution to the LHC charge asymmetry parameter is Delta A_C^y=0.005-0.06, small enough to be consistent with current measurements but non-zero and positive, allowing for LHC confirmation in the future. A small additional contribution to the LHC t tbar production cross-section is also predicted, allowing a further test.
View original: http://arxiv.org/abs/1205.5170

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