Likelihood analysis of the minimal AMSB model

Abstract

Abstract We perform a likelihood analysis of the minimal anomaly-mediated supersymmetry-breaking (mAMSB) model using constraints from cosmology and accelerator experiments. We find that either a wino-like or a Higgsino-like neutralino LSP, $$\tilde{\chi }^0_{1}$$ χ ~ 1 0 , may provide the cold dark matter (DM), both with similar likelihoods. The upper limit on the DM density from Planck and other experiments enforces $$m_{\tilde{\chi }^0_{1}} \lesssim 3 \,\, \mathrm {TeV}$$ m χ ~ 1 0 ≲ 3 TeV after the inclusion of Sommerfeld enhancement in its annihilations. If most of the cold DM density is provided by the $$\tilde{\chi }^0_{1}$$ χ ~ 1 0 , the measured value of the Higgs mass favours a limited range of $$\tan \beta \sim 5$$ tan β ∼ 5 (and also for $$\tan \beta \sim 45$$ tan β ∼ 45 if $$\mu > 0$$ μ > 0 ) but the scalar mass $$m_0$$ m 0 is poorly constrained. In the wino-LSP case, $$m_{3/2}$$ m 3 / 2 is constrained to about $$900\,\, \mathrm {TeV}$$ 900 TeV and $$m_{\tilde{\chi }^0_{1}}$$ m χ ~ 1 0 to $$2.9\pm 0.1\,\, \mathrm {TeV}$$ 2.9 ± 0.1 TeV , whereas in the Higgsino-LSP case $$m_{3/2}$$ m 3 / 2 has just a lower limit $$\gtrsim 650\,\, \mathrm {TeV}$$ ≳ 650 TeV ( $$\gtrsim 480\,\, \mathrm {TeV}$$ ≳ 480 TeV ) and $$m_{\tilde{\chi }^0_{1}}$$ m χ ~ 1 0 is constrained to $$1.12 ~(1.13) \pm 0.02\,\, \mathrm {TeV}$$ 1.12 ( 1.13 ) ± 0.02 TeV in the $$\mu >0$$ μ > 0 ( $$\mu 0$$ μ > 0 .