title: Naturalness of CP violation in the standard model.
abstract: We construct a natural measure on the space of Cabibbo-Kobayashi-Maskawa matrices in the standard model, assuming the fermion mass matrices are randomly selected from a distribution which incorporates the observed quark mass hierarchy. This measure allows us to assess the likelihood of Jarlskog's CP violation parameter J taking its observed value J approximately 3 x 10(-5). We find that the observed value, while well below the mathematically allowed maximum, is in fact typical once the observed quark masses are assumed.
authors.affiliation: Centre for Mathematical Sciences, Cambridge University, Cambridge, CB3 0WA, UK.
authors.forename: Gary W
authors.initials: GW
authors.lastname: Gibbons
authors.forename: Steffen
authors.initials: S
authors.lastname: Gielen
authors.forename: C N
authors.initials: CN
authors.lastname: Pope
authors.forename: Neil
authors.initials: N
authors.lastname: Turok