1,725 research outputs found
More Flavor SU(3) Tests for New Physics in CP Violating B Decays
The recent LHCb measurements of the and
rates and CP asymmetries are in agreement with U-spin expectations from and results. We derive the complete set of
isospin, U-spin, and SU(3) relations among the CP asymmetries in two-body
charmless and decays, some of which are novel. To go
beyond the unbroken SU(3) limit, we present relations which are properly
defined and normalized to allow incorporation of SU(3) breaking in the simplest
manner. We show that there are no CP relations beyond first order in SU(3) and
isospin breaking. We also consider the corresponding relations for charm
decays. Comparing parametrizations of the leading order sum rules with data can
shed light on the applicability and limitations of both the flavor symmetry and
factorization-based descriptions of SU(3) breaking. Two factorization relations
can already be tested, and we show they agree with current data.Comment: 30 pages, 1 figur
Right-handed Neutrinos and
We explore scenarios where the anomalies arise from semitauonic
decays to a right-handed sterile neutrino. We perform an EFT study of all five
simplified models capable of generating at tree-level the lowest dimension
electroweak operators that give rise to this decay. We analyze their
compatibility with current data and other relevant hadronic
branching ratios, and show that one simplified model is excluded by this
analysis. The remainder are compatible with collider constraints on the
mediator semileptonic branching ratios, provided the mediator mass is of order
TeV. We also discuss the phenomenology of the sterile neutrino itself, which
includes possibilities for displaced decays at colliders and direct searches,
measurable dark radiation, and gamma ray signals.Comment: 30 pages, 13 figures. Updated collider constraints and discussions.
Matches published version in JHE
Model independent analysis of semileptonic decays to for arbitrary new physics
We explore semileptonic decays to the four lightest excited charm mesons,
, for nonzero charged lepton mass
and for all four-Fermi interactions, including calculation
of the and
corrections to the heavy quark limit for all form factors. In the heavy quark
limit some form factors are suppressed at zero recoil, therefore, the corrections can be very important. The
rates exhibit sensitivities to new physics in mediated
decays complementary to the and modes. Since they are also important
backgrounds to , the correct interpretation of future
semitauonic rate measurements requires consistent treatment of
both the backgrounds and the signals. Our results allow more precise
and more reliable calculations of these decays, and
are systematically improvable by better data on the and modes. As an
example, we show that the rates are more sensitive to a new tensor interaction than the rates.Comment: 17 pages, 4 figures, 5 tables; published versio
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