منابع مشابه
Irrational constants in positronium decays
Most of the multi-loop analytical calculations in quantum field theories have been dine for socalled single-scale problems. This means that the evaluated integrals are basicaly expressed as numerical constants up to a trivial scale factor. Examples of such problems include almost all renormalization group calculations, evaluations of the critical exponents, anomalous magnetic moments of the ele...
متن کاملDecays of Positronium
We briefly review the theoretical and experimental results concerning decays of positronium. Possible solutions of the “orthopositronium lifetime puzzle” are discussed. Positronium annihilation into neutrinos is examined and disagreement is found with previously published results.
متن کاملBinding energy corrections in positronium decays
Positronium annihilation amplitudes that are computed by assuming a factorization approximation with on-shell intermediate leptons, do not exhibit good analytical behavior. We propose an ansatz which allows to include binding energy corrections and obtain the correct analytical and gauge invariance behavior of these QED amplitudes. As a consequence of these non-perturbative corrections, the par...
متن کاملSearch for CPT-odd decays of positronium.
We have limited a CPT-violating correlation in annihilations of polarized ortho-positronium. We searched for an asymmetry in the triple correlation s-->.(k-->(1)xk-->(2)), where k-->(1) and k-->(2) are the two largest photon momenta, and s--> is the spin of the positronium. Using the Gammasphere array of Compton-suppressed high-purity germanium detectors, we detected 2.65x10(7) events of ortho-...
متن کاملAn Improved Limit on Invisible Decays of Positronium
The results of a new search for positronium decays into invisible final states are reported. Convincing detection of this decay mode would be a strong evidence for new physics beyond the Standard Model (SM): for example the existence of extra–dimensions, of milli-charged particles, of new light gauge bosons or of mirror particles. Mirror matter could be a relevant dark matter candidate. In this...
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ژورنال
عنوان ژورنال: Nuclear Physics B - Proceedings Supplements
سال: 2008
ISSN: 0920-5632
DOI: 10.1016/j.nuclphysbps.2008.09.075