In a recent paper [1], we consider a collection of N atoms prepared by a pulse of one photon of wave vector. The N atoms are well described by an entangled Dicke-like state, which yields anomalous spontaneous rates proportional to the number of atoms, i.e., the emission rate is enhanced. That paper stimulated spirited discussions and debate. For example, it was argued at the 2006 Volga River conference on quantum control that the important conclusion that follows from the nuclear physics ?-ray studies of this problem was the prediction of a suppressed (not enhanced) radiation rate. In further work [2], I prove that there is no radiative suppression associated with the Dicke state given in [1]. However, the interplay between quantum optics (Dicke super and subradiant states) and nuclear physics (forward scattering of ? radiation) suggests several interesting problems [3] and open questions.

[1] "Directed Spontaneous Emission from an Extended Ensemble of N atoms: Timing is Everything," PRL, 010501 (2006), M.O. Scully, E.S. Fry, C.H.R. Ooi, and K. Wódkiewicz.
[2] "Correlated Spontaneous Emission on the Volga," Laser Physics, 2007, Vol. 17, No. 5, pp. 635?646, M. Scully.
[3] "Cooperative Spontaneous Emission as an N-body Eigenvalue Problem," A. Svidzinsky, M. Scully, and R. Glauber, to be published.