Multi-Beam Strategy for Neutrino-Nucleus Cross-Sections

Neutrino oscillation experiments rely on the knowledge of neutrino-nucleus cross-sections. Generally, just one scattering process is used to model these cross-sections. However, it is not sufficient to describe the cross-sections by only one scattering process. In the region of momentum transfers Q^2 < 10^5 MeV, there are two dominant processes, charged-current quasi-elastic scattering and charged-current whole-nucleus scattering. Both of these processes must be accounted for in the analysis. Determining the neutrino cross-sections experimentally is difficult. In most experiments, only the scattering angle and energy of the charged lepton in the final state are known, although neither the recoiled target nor the energy of the incoming neutrino are measured. The Multi-Beam Strategy presented in this dissertation is a novel data-based analysis tool. It can incorporate several nuclear processes in the analysis and simultaneously reduce the model-dependence of the analysis

The Greisen Equation Explained and Improved

Analytic description of the evolution of cosmic ray showers is dominated by the Greisen equation nearly five decades old. We present an alternative approach with several advantages. Among the new features are a prediction of the differential distribution, replacing Greisen's form which fails to be positive definite. Explicit comparison with Monte Carlo simulations shows excellent agreement after a few radiation lengths of development. We find a clear connection between Monte Carlo adjustment of Greisen's form and underlying physics, and present a concise derivation with all steps explicit. We also reconstruct the steps needed to reproduce Greisen's approximate formula, which appears not to have been published previously.Comment: 8 pages, 7 figures, revised version, accepted for publication in Phys. Rev.

Light-cone distribution amplitudes of the baryon octet

We present results of the first ab initio lattice QCD calculation of the normalization constants and first moments of the leading twist distribution amplitudes of the full baryon octet, corresponding to the small transverse distance limit of the associated S-wave light-cone wave functions. The P-wave (higher twist) normalization constants are evaluated as well. The calculation is done using $N_f=2+1$ flavors of dynamical (clover) fermions on lattices of different volumes and pion masses down to 222 MeV. Significant SU(3) flavor symmetry violation effects in the shape of the distribution amplitudes are observed.Comment: Update to the version published in JHE

A Pionic Hadron Explains the Muon Magnetic Moment Anomaly

A significant discrepancy exists between experiment and calculations of the muon's magnetic moment. We find that standard formulas for the hadronic vacuum polarization term have overlooked pionic states known to exist. Coulomb binding alone guarantees $\pi^+ \pi^-$ states that quantum mechanically mix with the $\rho$ meson. A simple 2-state mixing model explains the magnetic moment discrepancy for a mixing angle of order $\alpha \sim 10^{-2}$. The relevant physical state is predicted to give a tiny observable bump in the ratio R(s) of $e^+ e^-$ annihilation at a low energy not previously searched. The burden of proof is reversed for claims that conventional physics cannot explain the muon's anomalous moment.Comment: 14 pages, 2 figures, revised version, accepted for publication in Physics Letters