We present a geometric interpretation of the so-called annihilation range in reactions of the type p̄p → two light mesons based upon Lorentz effects in the highly relativistic final states (γ = Ecm/2mc ≃ 6.8 − 8.0). Lorentz-boosted meson wave functions, within the framework of the constituent quark model, result in a richer angular dependence of the annihilation amplitudes and thus in higher par...

We review the prospects for probing new physics with neutrino astrophysics. High energy neutrinos provide an important means of accessing physics beyond the electroweak scale. Neutrinos have a number of advantages over conventional astronomy and, in particular, carry information encoded in their flavor degree of freedom which could reveal a variety of exotic neutrino properties. We also outline...

In this note, we introduce a graph invariant called the annihilation number and show that it is a sharp upper bound on the independence number. While the invariant does not distinguish between different graphs with the same degree sequence – since it is determined solely by the degrees – it still outperforms many well known upper bounds on independence number. The process which leads to the ann...

Recent studies have considered modifications to the standard weakly interacting massive particle scenario in which the pair annihilation cross section (times relative velocity v) is enhanced by a factor 1/upsilon to approximately 10(-3) in the Galaxy, enough to explain several puzzling Galactic radiation signals. We show that in these scenarios a burst of weakly interacting massive particle ann...

Dilepton production from both pion-pion and kaon-antikaon annihilation in heavy-ion collisions is studied using the relativistic transport model. The formation of a rho meson from pion-pion annihilation and a phi meson from kaon-antikaon annihilation, their propagation in the medium, and their decay into dileptons are explicitly treated. Including the medium modifications of the masses and widt...

From the relic density measurement by WMAP the WIMP annihilation cross section can be determined in a model independent way. If the WIMPS are postulated to be the neutralinos of Supersymmetry, then only a limited region of the supersymmetric parameter space matches this annihilation cross section. It is shown that the resulting positrons, antiprotons and gamma rays from the neutralino annihilat...

Hadronic annihilation rate of 1 heavy quarkonium is given to next-to-leading order in αs and leading order in v using a recently developed factorization formalism which is based on NRQCD. The result includes both the annihilation of P-wave color-singlet QQ̄ component, and the annihilation of S-wave color-octet QQ̄ component of the quarkonium. The notorious infrared divergences due to soft gluons,...

We sketch some recent ideas proposed as the mechanism behind the puzzling experimental results on baryon-antibaryon production in e+e− annihilation close to threshold. The essential new point in the proposed mechanism is that it is a two-stage process, with a coherent state of pions serving as an intermediary between e+e− and the baryon-antibaryon system. Skyrmion-antiskyrmion annihilation is p...

We consider the effects of Galactic substructure on energetic neutrinos from annihilation of weakly interacting massive particles that have been captured by the Sun and Earth. Substructure gives rise to a time-varying capture rate and thus to time variation in the annihilation rate and resulting energetic-neutrino flux. However, there may be a time lag between the capture and annihilation rates...

An accurate method to compute the annihilation rate in positronic systems by means of quantum Monte Carlo simulations is tested and compared with previously proposed methods using simple model systems. This method can be applied within all the quantum Monte Carlo techniques, just requiring to accumulate the positron-electron distribution function. The annihilation rate of eLiH as a function of ...