Particle theory

Abstract:

We discuss experimental implications of extending the gauge structure of the standard model to include an additional U(1) interaction broken at or near the weak scale. We work with the most general, renormalizable Lagrangian for the SU(2)x U(1)x U(1) sector, with emphasis on the phenomenon of gauge kinetic mixing between the two U(1) gauge fields, and do not restrict ourselves to any of the "canonical" Z' models often discussed in the literature. Low-energy processes and Z(0)-pole precision measurements an specifically addressed.

Abstract:

Results are presented on structure functions and final state properties within the CCFM approach. Traditionally used forms of the CCFM equation have difficulty fitting the F_2 data, predicting too fast a growth at small x. A solution can be found in a particular treatment of formally subleading (1-z) terms, which dampens very considerably the small-x growth. Preliminary results are shown for the transverse energy flow, and future prospects and plans are discussed.

Abstract:

This talk discusses and explains the two-loop corrections, also known as the Milan factor, for power corrections to jet-shape observables.

Abstract:

It is attractive to suppose for several astrophysical reasons that the universe has close to the critical density in light (~30 eV) neutrinos which decay radiatively with a lifetime of ~10^{23} sec. In such a cosmology the universe is reionized early and the last scattering surface of the cosmic microwave background significantly broadened. We calculate the resulting angular power spectrum of temperature fluctuations in the cosmic microwave background. As expected the acoustic peaks are significantly damped relative to the standard case. This would allow a definitive test of the decaying neutrino cosmology with the forthcoming MAP and PLANCK surveyor missions.