Nonextensive statistics in stringy space-time foam models and entangled meson states

The possibility of generation of nonextensive statistics, in the sense of Tsallis, due to space-time foam is discussed within the context of a particular kind of foam in string/brane theory, the D-particle foam model. The latter involves pointlike brane defects (D-particles), which provide the topologically nontrivial foamy structures of space-time. A stochastic Langevin equation for the velocity recoil of D-particles can be derived from the pinched approximation for a sum over genera in the calculation of the partition function of a bosonic string in the presence of heavy D-particles. The string coupling in standard perturbation theory is related to the exponential of the expectation of the dilaton. Inclusion of fluctuations of the dilaton itself and uncertainties in the string background will then necessitate fluctuations in gs. The fluctuation in the string coupling in the sum over genera typically leads to a generic structure of the Langevin equation where the coefficient of the noise term fluctuates owing to dependence on the string coupling gs. The positivity of gs leads naturally to a stochastic modeling of its distribution with a χ distribution. This then rigorously implies a Tsallis-type nonextensive or, more generally, a superstatistics distribution for the recoil velocity of D-particles. As a concrete and physically interesting application, we provide a rigorous estimate of an ω-like effect, pertinent to CPT violating modifications of the Einstein-Podolsky-Rosen correlators in entangled states of neutral kaons. In the case of D-particle foam fluctuations, which respect the Lorentz symmetry of the vacuum on average, we find that the ω effect may be within the range of sensitivity of future meson factories.