Comment on “On the quantum Zeno effect” by Nakazato et al.

Recently, using a specific example involving neutron spin, Nakazato et al. [Phys. Lett A 199 (1995) 27] argued that the uncertainty principle would impose a remarkable limitation on the mathematical limit involved in the quantum Zeno effect. In this paper we show that it is impossible for Nakazato et al. to obtain this limitation by the uncertainty relation, because an unsuitable assumption has been used in their deduction process.     

Comment on “Noncommutation of Pauli spin operators in neutron polarimetry” by Y. Hasegawa et al

I place the work of Hasegawa et al. [Phys. Lett. A 234 (1997) 322] in the proper perspective.     

Comment on “On the Barut-Vigier model of the hydrogen atom” by Samsonenko et al.

Contrary to the claim of Samsonenko, Tahti and Ndahayo [Phys. Lett. A 220 (1996) 297], it is found that the ground state energy for a hydrogen atom in the Barut-Vigier potential is E = 13.6 eV.