Screened Casimir force at finite temperatures: A possible role in nuclear interactions

We derive a simple asymptotic expression for the screened Casimir free energy that is valid in both the high-temperature limit and in the large-separation limit. Any finite (i.e., nonzero) plasma density fundamentally alters the long-range interaction. The similarity of the derived expression with the Yukawa potential of nuclear interactions encourages us to investigate the Casimir free energy between two nuclear particles in a sea of electrons and positrons. We use simple estimates to explore the possible role of screened Casimir interactions for nuclear interactions. The magnitude of the force and of the coupling constant indicates an intriguing possible interpretation in which the nuclear force is a screened Casimir force and the mesons can be viewed as plasmons in the electron-positron sea.