منابع مشابه
Two-Photon Annihilation into Baryon-Antibaryon Pairs
We study the handbag contribution to two-photon annihilation into baryon-antibaryon pairs at large energy and momentum transfer. We derive factorization of the process amplitude into a hard γγ → qq subprocess and form factors describing the soft qq → BB transition, assuming that the process is dominated by configurations where the (anti)quark approximately carries the full momentum of the (anti...
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Mapping the expansion of the universe gives clues to the underlying physics causing the recently discovered acceleration of the expansion, and enables discrimination among cosmological models. We examine the utility of measuring the rate of expansion, H(z), at various epochs, both alone and in combination with distance measurements. Due to parameter degeneracies, it proves most useful as a comp...
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In the framework of the nonrelativistic diquark model of the heavy baryons and the perturbative approach of QCD we predict the value and energy dependence for the total cross section of the Λband Σ∗b-baryons pair production at the energy range of the KEKB and PEP-II ee-colliders.
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We discuss the possibility to observe the products of dark matter annihilation that was going on in the early Universe. Of all the particles that could be generated by this process we consider only photons, as they are both uncharged and easily detectable. The earlier the Universe was, the higher the dark matter concentration n and the annihilation rate (proportional to n) were. However, the em...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 1980
ISSN: 0035-8711,1365-2966
DOI: 10.1093/mnras/192.1.19p