Robert G. Sachs

The Physics of Time Reversal

A filler for a continuous cigarette filter rod is formed by feeding a wide band of filaments of filter material on to a slower moving surface, to which suction is applied so that the band is axially shrunk and the filaments crimped. The band is then narrowed to the desired width of the filler whilst retaining the crimp in the filaments, preferably by the use of a plasticiser.

Interference phenomena of neutral K mesons

Abstract A systematic theoretical treatment of various interference phenomena of the neutral K mesons is presented. The phenomena are treated for the extreme case that CPT, CP, and T invariance are all violated. Consequences of these invariances are then derived. Section II gives the relationships imposed on the propagators by the invariance conditions and Section III presents the general analysis of the K1, K2 problem in terms of the propagator. In Section IV the space-time development of a K0 beam is treated and this is applied to the general problem of K0 decay in Section V. Section V also contains a discussion of the 2π decay mode while the leptonic modes are treated in Section VI. Finally, in Section VII the scattering and regeneration of K1 and K2 mesons is discussed with particular reference to regenerative forward scattering.

The Transformations T, CP and CPT in the Presence of Vacuum Degeneracy

On etudie les effets de la degenerescence du vide sur des concepts relies aux transformations impropres CP et T. On considere deux types de degenerescence

Reflections on the ZGS: Terwilliger’s contributions

The early history of the ZGS is recalled, with emphasis on Kent Terwilliger’s contributions. The role of the Users Advisory Committee in the design of the accelerator is detailed.(AIP)

QCD Vacuum in the Early Universe

The thermal equilibrium value of the number density of the vacuum fluctuations (instantons) in QCD has been determined by Gross, Pisarski, and Yaffe for the high temperature of the early Universe. It is shown that, in coming to thermal equilibrium, all {vert_bar}{theta},vac{r_angle} states are suppressed except those with {theta}={plus_minus}({pi}/2). The instanton contribution to the electric dipole moment of the neutron is found to depend only on the chiral phase of the quark mass matrix and is no larger than its experimental upper limit so that the {open_quotes}strong {bold {ital CP}} problem{close_quotes} appears to be eliminated by this identification of the vacuum state. {copyright} {ital 1997} {ital The American Physical Society}

A question about the CPT theorem

Abstract A question has been raised concerning the proof of the CPT theorem in theories for which the fundamental vacuum state is degenerate. The question is elaborated further here and the issue is rephrased in terms of initial and boundary conditions on the “original” theory (e.g., in the early universe). In this connection, it is suggested that the “strong CP violation” of QCD is due to T violation of the boundary conditions and that these conditions do not violate CP. It is suggested that the answer to the question lies in the choice of “standing wave” rather than “running wave” linear combinations of the vacuum states as the basis for the physical vacuum. Such a choice not only resolves the degeneracy question relating to the CPT theorem but also would appear to eliminate strong CP violation as an issue.