On stochastic realism and CP bias in diffractive dissociations

Abstract

CP bias in proton--antiproton diffractive dissociation can be viewed from several philosophical perspectives, notably stochastic realism and stochastic epistemicism. When combined with the presumption of temporal symmetry, stochastic realism suggests that the laws of physics allow the possibility of thermodynamic antisystems, although whether antisystemic characteristics can be physically realised in nature remains an open question. Here, this bias is interpreted as apparent, indicating significant non-unitary contributions and a distinction from fundamental CP violations arising from unitary Hamiltonian dynamics. Such apparent effects may arise from intrinsic stochasticity, from environmental interactions, or from interference between the two. This work investigates the relevant mechanisms and determines conditions for creating, transmitting, or screening a CP bias. In the environmental branch, an equilibrated radiation bath may transmit a CP bias from matter-dominated surroundings, although causality constraints may limit this possibility. In the intrinsic branch, the observed bias is consistent with subleading antisystemic effects required by CPT invariance. Further experiments are needed to distinguish between these mechanisms.