No abstract available

[en] Nonlinear dynamical systems involving small populations of individuals may sustain oscillations in the population densities arising from discrete changes in population numbers due to random events. By applying these ideas to nanolasers operating with small numbers of emitting dipoles and photons at threshold, we show that such lasers should display photon and dipole population cycles above threshold, which should be observable as a periodic modulation in the second-order correlation function of the nanolaser output. Such a modulation was recently reported in a single-mode vertical-cavity surface-emitting semiconductor laser. (paper)

[en] Spin-isospin excitations in nuclei have been investigated via the (³He,t) reaction at 450 MeV. The volume integrals of the effective interactions J_στ and J_τ for the (³He,t) reaction at 450 MeV have been empirically determined to be 172±17 MeV fm³ and 53±5 MeV fm³, respectively. These values are consistent with those obtained for the (p,n) reaction at the same bombarding energy per nucleon. The Gamow-Teller strength can be deduced with the same reliability as the (p,n) reaction at the bombarding energy above 100 MeV. The neutrino absorption cross sections by ⁷¹Ga is obtained on basis of the present (³He,t) measurement. The new SNU value obtained for ⁷¹Ga is 130.3±1.6(stat.)±16.8(syst.). The spin-isospin responses for the Sn isotopes, ¹¹⁶Cd and ¹⁰⁰Mo are presented and are discussed in relation with double β-decay. A measurement of decay protons from the spin-isospin resonances in ¹³N is presented. A new possibility of studying the spin-isospin responses on the β⁺ side via the (t,³He) reaction using a dispersion matching technique is discussed. (orig.)