Electroweak constraints on flavorful effective theories

We derive model-independent constraints arising from the Z and W boson observables on dimension six operators in the effective theory beyond the Standard Model. In particular, we discuss the generic flavor structure for these operators as well as several flavor patterns motivated by simple new physics scenarios.Comment: 31 pages; v2: SILH basis constraints added, comments and clarifications added or remove

Υ\Upsilon and ψ\psi leptonic decays as probes of solutions to the RD(∗)R_D^{(*)} puzzle

Experimental measurements of the ratios $R(D^{(*)})\equiv\frac{\Gamma(B\to D^{(*)}\tau\nu)}{\Gamma(B\to D^{(*)}\ell\nu)}$ ($\ell=e,\mu$) show a $3.9\sigma$ deviation from the Standard Model prediction. In the absence of light right-handed neutrinos, a new physics contribution to $b\to c\tau\nu$ decays necessarily modifies also $b\bar b\to\tau^+\tau^-$ and/or $c\bar c\to\tau^+\tau^-$ transitions. These contributions lead to violation of lepton flavor universality in, respectively, $\Upsilon$ and $\psi$ leptonic decays. We analyze the constraints resulting from measurements of the leptonic vector-meson decays on solutions to the $R(D^{(*)})$ puzzle. Available data from BaBar and Belle can already disfavor some of the new physics explanations of this anomaly. Further discrimination can be made by measuring $\Upsilon(1S,2S,3S)\to\tau\tau$ in the upcoming Belle II experiment.Comment: Version published in JHEP, 17 pages, 7 figure

Asymmetric Higgsino Dark Matter

In the supersymmetric framework, a higgsino asymmetry exists in the universe before the electroweak phase transition. We investigate whether the higgsino is a viable asymmetric dark matter candidate. We find that this is indeed possible. The gauginos, squarks and sleptons must all be very heavy, such that the only electroweak-scale superpartners are the higgsinos. The temperature of the electroweak phase transition must be in the (1-10) GeV range.Comment: 5 pages, 2 figure