Closing in on Supersymmetric Electroweak Baryogenesis with Dark Matter Searches and the Large Hadron Collider

TL;DR

This paper analyzes how recent direct and indirect dark matter searches, along with LHC data, constrain MSSM electroweak baryogenesis scenarios driven by resonant neutralino/chargino interactions with heavy sfermions. By mapping viable BAU regions onto gaugino–higgsino mass planes under two typical hierarchies (M1<M2 and M2<M1), the authors compare predicted dark matter relic densities and detection signals to current Xenon100, IceCube, and Fermi constraints, as well as to LHC electroweakino production. They find that wino-like DM is essentially incompatible with EWB in the M2<M1 case, while bino-like DM remains viable only in limited regions, primarily at low m_A; most of the EWB-viable space will be probed by future DM searches. The LHC reach via trilepton channels is limited and will not fully test the DM-constrained EWB parameter space, implying that DM searches play a more decisive role in testing MSSM EWB.

Abstract

We study the impact of recent direct and indirect searches for particle dark matter on supersymmetric models with resonant neutralino- or chargino-driven electroweak baryogenesis (EWB) and heavy sfermions. We outline regions of successful EWB on the planes defined by gaugino and higgsino mass parameters, and calculate the portions of those planes excluded by dark matter search results, and the regions soon to be probed by current and future experiments. We conclude that dark matter searches robustly exclude a wino-like lightest supersymmetric particle in successful EWB regions. Bino-like dark matter is still a possibility, although one that will be probed with a modest improvement in the sensitivity of current direct and indirect detection experiments. We also calculate the total production cross section of chargino and neutralino pairs at the Large Hadron Collider, with a center of mass energy of 7 and 14 TeV.

Figures (8)

• Figure 1: Regions compatible with resonant chargino-neutralino electroweak baryogenesis, on the $(M_1,\mu)$ plane at $\tan\beta=40$, for maximal gaugino-higgsino CP-violating phase $\sin\phi_\mu=1$ and for $m_A=300$ GeV. The cyan region corresponds to the band in the wall velocity $v_w$ shown in the inset. The red shaded region is excluded by LEP searches for light neutralinos/charginos Amsler:2008zzb
• Figure 2: Left: Regions with a thermal relic neutralino abundance $0.095<\Omega_\chi h^2<0.13$ on the $(M_1,\mu)$ plane at $\tan\beta=40$, for maximal gaugino-higgsino CP-violating phase $\sin\phi_\mu=1$ and for $m_A=300$ GeV (dark green) and $m_A=1000$ GeV (light green). The black line indicates successful electroweak baryogenesis for $\sin\phi_\mu=1$ and $m_A=300$ GeV, as in Fig. \ref{['fig:tb40_ewb']}. Right: Regions of correct relic abundance, with a lightest stop set at a mass of 102 GeV, again for $m_A=300$ and 1000 GeV (darker and lighter green, respectively). The dashed blue line corresponds to the parameter space where the lightest neutralino has the same mass as the lightest stop. Bounds on the density of heavy relic charged or colored particles exclude the portion of the parameter space above and to the right of the dashed blue line, where the stop would be the lightest supersymmetric particle.
• Figure 3: Regions excluded by the Xenon100 direct detection results, on the $(M_1,\mu)$ plane at $\tan\beta=40$, for maximal gaugino-higgsino CP-violating phase $\sin\phi_\mu=1$ and for $m_A=1000$ GeV (solid blue line) and 300 GeV (green line). The dashed blue line corresponds to no CP violation, and $m_A=1000$ GeV. Finally, the turquoise dot-dashed line indicates the region corresponding to 10 times the Xenon100 current sensitivity. The black solid line outlines the region of parameter space where successful EWB can occur, for $m_A=300$ GeV, while the orange line corresponds to $m_A=1000$ GeV.
• Figure 4: The performance of indirect dark matter searches on the $(M_1,\mu)$ plane. In the left panel, we show the current and future reach of the IceCube neutrino telescope icecube, while on the right we indicate the regions of parameter space ruled out by Fermi observations of nearby dwarf spheroidal galaxies dsph
• Figure 5: As in Fig. \ref{['fig:tb40_1']}, right, but on the $(M_2,\mu)$ plane, and with an anomaly-mediated gaugino mass hierarchy (whereby $M_2\simeq M_1/3$).