Long-baseline neutrino oscillation experiments and CP violation in the lepton sector

We discuss possibilities to investigate the effects of CP (and T) violation in the lepton sector in neutrino oscillation experiments. We consider the effects of CP violation in the framework of two schemes of mixing of four massive neutrinos that can accommodate the results of all neutrino oscillation experiments. Using the constraints on the mixing parameters that follow from the results of short-baseline neutrino oscillation experiments, we derive rather strong upper bounds on the effects of CP violation in nu_munu_e transitions in long-baseline neutrino oscillation experiments. We show that the effects of CP violation in nu_munu_tau transitions in long-baseline oscillation experiments can be as large as is allowed by the unitarity of the mixing matrix. The matter effects, which complicate the problem of searching for CP violation in long-baseline experiments, are discussed in detail. We consider the T-odd asymmetries whose measurement could allow to reveal T and CP violation in the lepton sector independently from matter effects.Comment: 31 pages, including 5 figure

A competing risks approach to the two-sex problem

The measurement of nuptiality rates is complicated by the fact that a marriage can be attributed both to the woman and the man involved. This is an example of the so called two-sex problem of mathematical demography. Several theoretical solutions have been proposed, but none has found universal acceptance. We introduce an individual level stochastic model based on competing risks ideas. The model shows explicitly how behavioral factors influence the accuracy of the various models. Although the product model is shown to be the only one that is invariant with respect to the units in which time and age are measured, different behavioral considerations may lead to different definitions of the population at risk. We show that the marriage models are only expected to differ empirically, if the numbers of marriageables vary abruptly in close ages. In an attempt to use data analysis to determine the best fitting risk population, we apply moving averages, approximately polynomial models, and subspace fitting models to Finnish age-specific marriage data, mostly from 1989. The results are conflicting. Depending on the criterium used, different models provide the best fit. We also study the role of the models in the forecasting of marriages. In some circumstances, an erroneous choice of the population at risk model can be compensated by a particular forecasting method.

Persistent age distributions for an age-structured two-sex population model

In this paper we formulate an age-structured two-sex population model which takes into account a monogamous marriage rule and the duration of marriage. We are mainly concerned with the existence of exponential solutions with a persistent age distribution. First we provide a semigroup method to deal with the time-evolution problem of our two-sex population model. Next, by constructing a fixed point mapping, we prove the existence of exponential solutions under homogeneity conditions.Two-Sex Population Dynamics, Marriage Model, Exponential Solutions, Persistent Age Distributions, Fixed Point Theorem, Semigroups,