arXiv subjects

Alex Kagan

Publications and source records attributed to Alex Kagan.

3 recordsLinked to original sources

arXiv2001

Flavor-Change with Ultra-Light Sbottom and Gluinos

Implications of a 2 - 5.5 GeV sbottom and 12 - 16 GeV gluino masses for rare B decay phenomenology are discussed. An effective Hamiltonian is constructed in which the gluinos are integrated out and a \tilde{b} squark remains among the light flavor degrees of freedom. Restrictive constraints come from $b \to s γand b \to sg, but they allow a substantially enhanced inclusive b decay rate into charmless hadronic final states, and {\cal O}(10%) direct CP asymmetries in $B \to X_s γand B^\pm \to K^0 π^\pm decays, which are an order of magnitude larger than in the Standard Model. New contributions to B_s mixing are negligible but significant effects in B_d mixing may be possible.

hep-ph↗

arXiv1998

Z-induced FCNCs and their effects on Neutrino Oscillations

Adding singlet neutrinos to the standard model spectrum in general gives rise to Z-induced flavor-changing neutral currents. We study the impact of these currents on matter-induced neutrino oscillations in the sun and in supernovae. While the effects for solar neutrinos are negligible, dramatic effects are possible for supernova neutrinos.

hep-ph↗

arXiv1994

Constraining Anomalous Top Quark Couplings at the Tevatron

We explore the influence of an anomalous chromomagnetic moment, $κ$, onthe production characteristics of top quark pairs at the Tevatron. We find that for top quarks in the 170 GeV mass range, present searches are probing values of $κ$ of order ${1 \over 3}$. For $κ$'s in this range we find that significant enhancements in the both the $q \bar q,~gg \to t \bar t$ production cross sections are obtained. Once top has been verified and QCD uncertainties are under control, future high statistics measurements at the Tevatron will eventually be sensitive to values of $κ$ with magnitudes smaller than 0.10-0.15. We discuss a class of scalar technicolor models which may produce large values of $κ$ in conjunction with generation of $m_t$.

hep-ph↗