118473824
Proton stability from a fourth family
The possibility to violate baryon or lepton number without introducing any new flavor structures, beyond those needed to account for the known fermion masses and mixings, is analyzed. With four generations, but only three colors, this minimality requirement is shown to lead to baryon number conservation, up to negligible dimension-18 operators. In a supersymmetric context, this same minimality principle allows only superpotential terms with an even number of flavored superfields, hence effectively enforcing R parity both within the minimal supersymmetric standard model and in a grand unified theory context.
119335059
Radiative kaon decays and the penguin contribution to the Delta I = 1/2 rule
A consistent census of penguins in the Delta I = 1/2 rule is taken from the eta0 pole contribution to the radiative KL to gamma gamma, KS to pi0 gamma gamma and K+ to pi+ gamma gamma decay modes. We briefly comment on its impact for KL to pi0 pi0 gamma gamma, KL to pi+ pi- gamma and check its compatibility with the KL - KS mass difference and the CP violating epsilon-prime / epsilon parameter. Comment: 37 pages, 16 figures
117809651
Rare K decays in the standard model
The very clean theoretical predictions for the rare decays K --> pi nu nu_bar and KL --> pi0 l+ l- are reviewed, and their various theoretical inputs summarized. The less favorable situation for KL --> mu+ mu- is also commented.
809980
Long-distance effects in rare K decays
Rare K decays provide for very clean tests of the Standard Model, and are especially suited to search for New Physics signal. In this talk, recent progresses in the estimation of long-distance effects induced by light quarks in KL to pi0 mu+ mu- and K+ to pi+ nu nu are reported.
118649028
Tree-level contributions to the rare decays B+ ---> pi+ nu anti-nu, B+ ---> K+ nu anti-nu, and B+ ---> K*+ nu anti-nu in the Standard Model
The tree-level contributions to the rare decays B+ --> pi+ nu anti-nu, B+ --> K+ nu anti-nu, and B+ --> K*+ nu anti-nu are analyzed and compared to those occurring in K+ --> pi+ nu anti-nu, D+ --> pi+ nu anti-nu, and Ds+ --> pi+ nu anti-nu. It is shown that these purely long-distance contributions, arising from the exchange of a charged lepton, can be significant in B+ decays for an intermediate tau, potentially blurring the distinction between the modes used to extract B --> tau nu and those used to probe the genuine short-distance b --> (s,d) nu anti-nu FCNC transitions. Numerically, the tree-level contributions are found to account for 97%, 12% and 14% of the total B+ --> pi+ nu anti-nu, B+ --> K+ nu anti-nu, and B+ --> K*+ nu anti-nu rates, respectively.
17438804
What could be learnt from positronium for quarkonium
In order to fulfill Low's theorem requirements, a new lowest order basis for bound state decay computations is proposed, in which the binding energy is treated non-perturbatively. The properties of the method are sketched by reviewing standard positronium decay processes. Then, it is shown how applying the method to quarkonia sheds new light on some longstanding puzzles. Comment: 12 pages, 10 figures. Talk given at the ETH Workshop on Positronium Physics, May 30-31, 2003, Zurich, Switzerland
125682886
Calibration of the MINOS detectors and extraction of neutrino oscillation parameters
120652887
STATUS OF THE MINOS EXPERIMENT
The MINOS experiment is designed to search for neutrino oscillations. A neutrino beam from Fermilab is observed by the Near and Far detectors, separated by 735km. A comparison of the observed neutrino events at the two locations allows a measurement of the oscillation parameters to be made. Commissioning of the Near detector is underway and the Far detector is collecting cosmic ray and atmospheric neutrino data. Analysis of the atmospheric neutrino events has begun and neutrino, antineutrino event separation has been achieved. Data collection with the NuMI beam will begin in December 2004.