Abstract
In top-pair events where at least one of the tops decays semileptonically, the identification of the lepton charge allows us to tag not only the top quark charge but also that of the subsequent b quark. In cases where the b also decays semileptonically, the charge of the two leptons can be used to probe CP violation in heavy flavor mixing and decays. This strategy to measure CP violation is independent of those adopted so far in experiments, and can already constrain non standard model sources of CP violation with current and near future LHC data. To demonstrate the potential of this method we construct two CP asymmetries based on same-sign and opposite-sign leptons and estimate their sensitivities. This proposal opens a new window for doing precision measurements of CP violation in b and c quark physics via high p(T) processes at ATLAS and CMS.
Highlights
Introduction.—The copious production of top quarks at the LHC is usually exploited to explore various top properties or search for new heavy resonances
All existing analyses of CP violation (CPV) in B physics rely on a coherent production of bb" pairs, either from the decay of a bb" resonance or from gluon splitting, where the total b flavor charge at production vanishes
In cases where the b decays semileptonically, we can construct two CP asymmetries, one in which the latter lepton and the one from the W are of the same sign, and the other with opposite signs
Summary
In cases where the b decays semileptonically, the charge of the two leptons can be used to probe CP violation in heavy flavor mixing and decays. This strategy to measure CP violation is independent of those adopted so far in experiments, and can already constrain non standard model sources of CP violation with current and near future LHC data. Top physics gives another source of b’s, and due to the large top mass and small width, to a good approximation, a top decay yields a definite nonzero b flavor charge This charge can be unambiguously tagged at the time of decay by the charge of the lepton daughter of the W (originating from the top). The CP asymmetries.—The following CP asymmetries related to Bq-B"q mixing are defined
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
