On a possible method of Casimir pressure renormalization in a ball
  We propose a method of Casimir pressure renormalization for massive scalar field in a ball. This method is slightly different from the generally accepted. An alternative way of choosing the normalization point leads to an exponential pressure dependence on the mass of the field instead of an inverse polynomial dependence. The method proposed does not use the scalar quantized field in the exterior domain. This allows us to bypass the difficulties that appear when one uses the standard approach. 
A.I. Dubikovsky, P.K. Silaev, O.D. Timofeevskaya
hep-th