14th International Symposium on Particles, Strings and Cosmology (PASCOS '08)
In the last years, the NA48/2 experiment at the CERN SPS has recorded an unprecedented sample of charged kaon decays. From this, we report very precise measurements of fundamental parameters of Chiral Perturbation Theory (ChPT) and the study of low energy pi-pi scattering. Several rare and very rare decays have been studied. From more than 10^6 K+- -> pi+ pi0 gamma decays, a first measurement of the interference between Bremsstrahlung and Direct Emission amplitudes and a stringent limit on direct CP violation in this channel is presented.
We study observables in a conformal field theory which are very closely related to the ones used to describe hadronic events at colliders. We focus on the correlation functions of the energies deposited on calorimeters placed at a large distance from the collision. We consider initial states produced by an operator insertion and we study some general properties of the energy correlation functions for conformal field theories. We argue that the small angle singularities of energy correlation functions are controlled by the twist of non-local light-ray operators with a definite spin.
Astrophysical evidence indicates that the universe consists to about 25% of non-baryonic, cold Dark Matter, compared to merely ~4% of \'regular\' matter, composed of quarks and electrons. The existence of Dark Matter and Dark Energy is striking evidence for physics beyond the Standard Model, and understanding their nature ranks among the foremost questions in science today. If the bulk of matter in the universe consists of relic massive particles moving at non-relativistic speeds, we may be able to detect these particles in direct searches with low background experiments.
We present the results from the MiniBooNE neutrino oscillations search in which no significant excess of events is observed above background in the energy range from 475 MeV to 3000 MeV. For lower energies an excess of events that is not consistent with a two neutrino oscillation model is observed. We present recent advances in the understanding of this excess, including a study of muon and electron neutrinos from the nearby NuMI neutrino source.
We comment on several points concerning unparticles which have been overlooked in the literature. One regards Mack\'s unitarity constraint lower bounds on CFT operator dimensions,e.g,. d>= 3 for primary, gauge invariant, vector unparticle operators. We correct the results in the literature to account for this, and also for a needed correction in the form of the propagator for vector and tensor unparticles.
The sensitivity of inflationary models to Planck-suppressed operators motivates modeling inflation in string theory. The case of high-scale inflation is particularly interesting both theoretically and observationally. Observationally it yields a gravity wave (B mode polarization) signature, and theoretically it requires a large field excursion which is particularly sensitive to UV physics. I\'ll present a simple mechanism derived recently in collaboration with A. Westphal for obtaining large-field inflation, and hence a gravitational wave signature, from string theory.