W / Z bremsstrahlung as the dominant annihilation channel for dark matter

By N. Bell, J. Dent, T. Jacques, T. Weiler. 2010

138 citations recorded by the source corpus.

Dark matter annihilation to leptons, {chi}{chi}{yields}ll, is necessarily accompanied by electroweak radiative corrections, in which a W or Z boson is radiated from a final-state particle. Given that the W and Z gauge bosons decay dominantly via hadronic channels, it is thus impossible to produce final-state leptons without accompanying protons, antiprotons, and gamma rays. Significantly, while many dark matter models feature a helicity-suppressed annihilation rate to fermions, radiating a massive gauge boson from a final-state fermion removes this helicity suppression, such that the branching ratios Br(l{nu}W), Br(l{sup +}l{sup -}Z), and Br({nu}{nu}Z) dominate over Br(ll). W/Z bremsstrahlung thus allows indirect detection of many weakly interacting massive particle models that would otherwise be helicity suppressed, or v{sup 2} suppressed. Antiprotons and even antideuterons become consequential final-state particles. This is an important result for future dark matter searches. We discuss the implications of W/Z bremsstrahlung for 'leptonic' dark matter models which aim to fit recent cosmic ray positron and antiproton data.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/9aea77393d8b709883f4e61edec93c725e2a9df6

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Citations in the corpus

MadDM v.3.0: A comprehensive tool for dark matter studies (2018, background): “import model DMsimp_t_f3 define darkmatter xr generate indirect detection u u~ a output test_uuxa launch test_uuxa set sigmav_method madevent set indirect_flux_source pythia8 set vave_indirect 1e-3 set nevents 100000 set Mxr 100 set MYur1 scan:[101,105,110,120,200] set save_output all”
Astrophysical models for the origin of the positron (2011, background): “they implicitly need astrophysical sources anyway, whose role would be to tighten the constraints; b) for heavy DM, they neglect e ffects related to electroweak bremmsthralung [52, 53, 54, 55, 56], which have been shown to impact constraints (see for example [57, 58, 59, 60]); c) when engineering “l”
On the validity of the effective field theory for dark matter searches at the LHC part III: analysis for the t-channel (2013, background): “where X, Y are some combination of Dirac-matrices, and ΓB = {1, iγ5, γμ, γ5γ, σμν} and ΓB = {1,−iγ5, γμ,−γ5γμ, 12σμν} form a basis spanning 4×4 matrices over the complex number field [34].”