We investigate the kinetics of systems in which particles of one species undergo binary fragmentation and pair annihilation. In the latter, non-linear process, fragments react at collision to produce an inert species, causing loss of mass. We analyse these systems in the reaction-limited regime by solving a continuous model within the mean-field approximation. The rate of fragmentation, for a p...

The neutralino, the lightest stable supersymmetric particle, is a strong theoretical candidate for the missing astronomical ”dark matter”. Depending on their annihilation cross section, relic neutralinos from early formation of the Universe trapped in orbits around massive objects may currently be annihilating at measurable rates. The Minimal Supersymmetric extension of the Standard Model predi...

A rigorous QCD analysis of the inclusive annihilation decay rates of heavy quarkonium states is presented. The effective-field-theory framework of nonrelativistic QCD is used to separate the short-distance scale of annihilation, which is set by the heavy quark massM , from the longer-distance scales assoOn leave from Dept. of Physics and Astronomy, Northwestern University, Evanston, IL 60208.

We used radio observations of the neighbor galaxy M31 in order to put constraints on the dark matter particle mass and annihilation cross section. Dark matter annihilation in M31 halo produces highly energetic leptons, which emit synchrotron radiation on radio frequencies in the galactic magnetic field. We predicted expected radio fluxes for the two annihilation channels: ! b b and ! þ . We the...

Graph games with an annihilation rule, as introduced by Conway, Fraenkel and Yesha, are studied under the midre play rule for progressively finite graphs that satisfy a condition on the reversibility of non-terminal Sprague-Grundy zeros to Spragu+Grundy ones. Two general theorems on the Spragu+Grundy zeros and ones are given, followed by two theorems characterizing the set of P-positions under ...

Creation and annihilation operators are used in many-body quantum physics because they provide a less awkward notation than symmetrized or antisymmetrized wave functions, and a convenient language for perturbation theory, etc. These notes are not intended to give anything but an introduction. For a much more extended discussion see books on many-body theory, such as Fetter and Walecka, Quantum ...

We investigate experimentally the interaction of two-dimensional solitary beams in photorefractive strontium barium niobate crystal. We show that simultaneous collision of many solitons can result in complete annihilation of some of them. This effect depends on the relative phases of the solitons and may be useful for application in the formation of multiport waveguide junctions.