Limits on scalar leptoquark interactions and consequences for GUTs

作者：Dorsner Ilja^*; Drobnak Jure; Fajfer Svjetlana; Kamenik Jernej F; Kosnik Nejc

来源：The Journal of High Energy Physics, 2011, 2011(11): 002.

DOI：10.1007/JHEP11(2011)002

• Beyond Standard Model
• Rare Decays
• GUT
• Quark Masses and SM Parameters

A colored weak singlet scalar state with hypercharge 4/3 is one of the possible candidates for the explanation of the unexpectedly large forward-backward asymmetry in a production as measured by the CDF and DO experiments. We investigate the role of this state in a plethora of flavor changing neutral current processes and precision observables of down-quarks and charged leptons. Our analysis includes tree- and loop-level mediated observables in the K and B systems, the charged lepton sector, as well as the Z -> b (b) over bar decay width. We perform a global fit of the relevant scalar couplings. This approach can explain the (g-2)mu anomaly while tensions among the CP violating observables in the quark sector, most notably the nonstandard CP phase (and width difference) in the B-s system cannot be fully relaxed. The results are interpreted in a class of grand unified models which allow for a light colored scalar with a mass below 1 TeV. We find that the renormalizable SU(5) scenario is not compatible with our global fit, while in the SO(10) case the viability requires the presence of both the 126- and 120-dimensional representations.

• 出版日期2011-11