Models of $n\bar{n}$ transition in medium

Abstract

The present state of the $n\bar{n}$ transition problem is briefly outlined. The models based on the diagram technique for direct reactions, potential description of $\bar{n}$-medium interaction and field-theoretical approach are considered. It is shown that for the $n\bar{n}$ transition in medium field-theoretical approach should be used. The lower limit on the free-space $n\bar{n}$ oscillation time ${\tau }_{\min }$ is found to be: $10^{16}\mathrm{yr}>{\tau }_{\min }>1.2\cdot 10^9\mathrm{s}$.

Comments: 10 pages, 2 figures. arXiv admin note: substantial text overlap with arXiv:1101.2310 and arXiv:1003.4360