Likelihood analysis of the minimal AMSB model

Bagnaschi, E.; Borsato, M.; Sakurai, K.; Buchmueller, O.; Cavanaugh, R.; Chobanova, V.; Citron, M.; Costa, J.C.; De Roeck, A.; Dolan, M.J.; Ellis, J.R.; Flächer, H.; Heinemeyer, S.; Isidori, G.; Lucio, M.; Luo, F.; Santos, D. Martínez; Olive, K.A.; Richards, A.; Weiglein, G.

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, χ~01χ~10 , may provide the cold dark matter (DM), both with similar likelihoods. The upper limit on the DM density from Planck and other experiments enforces mχ~01≲3TeVmχ~10≲3TeV after the inclusion of Sommerfeld enhancement in its annihilations. If most of the cold DM density is provided by the χ~01χ~10 , the measured value of the Higgs mass favours a limited range of tanβ∼5tan⁡β∼5 (and also for tanβ∼45tan⁡β∼45 if μ>0μ>0 ) but the scalar mass m0m0 is poorly constrained. In the wino-LSP case, m3/2m3/2 is constrained to about 900TeV900TeV and mχ~01mχ~10 to 2.9±0.1TeV2.9±0.1TeV , whereas in the Higgsino-LSP case m3/2m3/2 has just a lower limit ≳650TeV≳650TeV ( ≳480TeV≳480TeV ) and mχ~01mχ~10 is constrained to 1.12 (1.13)±0.02TeV1.12 (1.13)±0.02TeV in the μ>0μ>0 ( μ<0μ<0 ) scenario. In neither case can the anomalous magnetic moment of the muon, (g−2)μ(g−2)μ , be improved significantly relative to its Standard Model (SM) value, nor do flavour measurements constrain the model significantly, and there are poor prospects for discovering supersymmetric particles at the LHC, though there are some prospects for direct DM detection. On the other hand, if the χ~01χ~10 contributes only a fraction of the cold DM density, future LHC -based searches for gluinos, squarks and heavier chargino and neutralino states as well as disappearing track searches in the wino-like LSP region will be relevant, and interference effects enable BR(Bs,d→μ+μ−)BR(Bs,d→μ+μ−) to agree with the data better than in the SM in the case of wino-like DM with μ>0μ>0 .

Citation

Bagnaschi, E., Borsato, M., Sakurai, K., Buchmueller, O., Cavanaugh, R., Chobanova, V., …Weiglein, G. (2017). Likelihood analysis of the minimal AMSB model. The European Physical Journal C, 77(4), Article 268. https://doi.org/10.1140/epjc/s10052-017-4810-0

• Journal Article Type: Article
• Acceptance Date: Apr 5, 2017
• Online Publication Date: Apr 27, 2017
• Publication Date: Apr 27, 2017
• Deposit Date: Jul 13, 2017
• Publicly Available Date: Jul 13, 2017
• Journal: European Physical Journal C: Particles and Fields
• Print ISSN: 1434-6044
• Electronic ISSN: 1434-6052
• Publisher: SpringerOpen
• Peer Reviewed: Peer Reviewed
• Volume: 77
• Issue: 4
• Article Number: 268
• DOI: https://doi.org/10.1140/epjc/s10052-017-4810-0
• Public URL: https://durham-repository.worktribe.com/output/1355176