0000000000138650
AUTHOR
Mª Concepción González García
Before and after: how has the SNO neutral current measurement changed things?
We present Before and After global oscillation solutions, as well as predicted Before and After values and ranges for ten future solar neutrino observables (for BOREXINO, KamLAND, SNO, and a generic p-p neutrino detector). The 'Before' case includes all solar neutrino data (and some theoretical improvements) available prior to April 20, 2002 and the After case includes, in addition, the new SNO data on the CC, NC, and day-night asymmetry. We have performed global analyses using the full SNO day-night energy spectrum and, alternatively, using just the SNO NC and CC rates and the day-night asymmetry. The LMA solution is the only currently allowed MSW oscillation solution at similar to99% CL. …
Searching for an invisibly decaying Higgs boson in e+ e-, e gamma and gamma gamma collisions
Higgs bosons can have a substantial ``invisible'' branching ratio in many extensions of the Standard Model, such as models where the Higgs bosons decay predominantly into light or massless weakly interacting Goldstone bosons. In this work, we examine the production mechanisms and backgrounds for invisibly decaying Higgs bosons at the Next Linear e+e− Collider operating in the modes e+e−, eγ, and γγ. We demonstrate that such machine is much more efficient to survey for invisibly decaying Higgs bosons than the Large Hadron Collider at CERN.
Constraints on additional Z' gauge bosons from a precise measurement of the Z mass
We analyze the constraints on the mass and mixing of superstring-inspired E6 Z' neutral gauge boson that follow from the recent precise Z mass measurements and show that they depend very sensitively on the assumed value of the W mass and also, to a lesser extent, on the top-quark mass.