Unitarity and higher order corrections in neutralino dark matter annihilation into two photons
By J. Hisano, S. Matsumoto, M. Nojiri. 2002
140 citations recorded by the source corpus.
The neutralino pair annihilation into two photons in our galactic halo gives a robust dark matter signal, since it would give a quasimonotonic gamma ray. This process is radiatively induced, and the full one-loop calculation was done previously. However, for the heavy W-ino-like or Higgsino-like neutralino, the one-loop cross section violates unitarity; therefore, the higher-order corrections may be important. We construct a nonrelativistic theory for chargino and neutralino two-body states, and estimate all-order QED corrections and two-loop corrections by Z and/or W exchange. We find that the critical mass above which the two-loop contribution is larger than the one-loop one is about 8 TeV $[O(10)\mathrm{TeV}]$ in the limit where the neutralino is W-ino- [Higgsino-]like, respectively. Around and above the critical mass, the all-order Z and/or W exchange must be included to estimate the cross section. On the other hand, the QED corrections depend on the mass difference between the neutralino and chargino. In the W-ino-like limit where the neutralino is highly degenerate with the chargino in mass, we find that QED corrections enhance the pair annihilation cross section by 1.5--2.
Subfields: Nuclear and High Energy Physics
View Paper: https://www.semanticscholar.org/paper/6eea7b4d174399d74871c4d68a85554d3695d645
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In Nuclear and High Energy Physics
Citations in the corpus
- Dark Matter Candidates from Particle Physics and Methods of Detection (2010, background): “For massive φ, S is typically cut off at a value ∝ αXmX/mφ (106; 107; 108; 109).”
- Bound-state formation for thermal relic dark matter and unitarity (2014, background): “ility becomes of interest typically when DM is hypothesized to reside in a hidden sector [10]; however, even the weak interactions of the SM can manifest as long-range if DM is heavier than a few TeV [20,21]. For s-wave annihilation via a shortrange interaction, the annihilation cross-section times ”
- WIMP dark matter candidates and searches—current status and future prospects (2017, result): “As these points are subject to the Sommerfeld enhancement [564, 565], a non-perturbative effect that can give a significant boost to the annihilation cross section, they appear to be in tension with observations from the Galactic Center at the Cherenkov telescope H.”
- Hidden charged dark matter (2009, background): “First, at low velocities, its annihilation cross section is enhanced by the Sommerfeld effect [28]; in Feynman diagrammatic language, this enhancement arises from diagrams with additional U(1)EM gauge bosons exchanged in the t-channel that are higher order in gauge coupling, but kinematically enhanc”