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More on Electric Dipole Moment Constraints on Phases in the Constrained MSSM

Toby Falk, Keith A. Olive

Abstract

We reconsider constraints on $\cp$-violating phases in the Constrained Minimal Supersymmetric Standard Model. We include the recent calculations of Ibrahim and Nath on the chromoelectric and purely gluonic contributions to the quark electric dipole moment and combine cosmological limits on gaugino masses with experimental bounds on the neutron (and electron) electric dipole moments. The constraint on the phase of the Higgs mixing mass $μ$, $|\thm|$, is dependent on the value of the trilinear mass parameter, $A$, in the model and on $\tan β$. For values of $|A| < 300 \gev$ at the GUT scale, we find $|\thm|/π\la 0.05$, while for $|A| < 1500 \gev$, $|\thm|/π\la 0.3$. Thus, we find that in principle, large CP violating phases are compatible with the bounds on the electric dipole moments of the neutron and electron, as well as remaining compatible with the cosmological upper bound on the relic density of neutralinos. The other $\cp$-violating phase $\tha$ is essentially unconstrained.

More on Electric Dipole Moment Constraints on Phases in the Constrained MSSM

Abstract

We reconsider constraints on -violating phases in the Constrained Minimal Supersymmetric Standard Model. We include the recent calculations of Ibrahim and Nath on the chromoelectric and purely gluonic contributions to the quark electric dipole moment and combine cosmological limits on gaugino masses with experimental bounds on the neutron (and electron) electric dipole moments. The constraint on the phase of the Higgs mixing mass , , is dependent on the value of the trilinear mass parameter, , in the model and on . For values of at the GUT scale, we find , while for , . Thus, we find that in principle, large CP violating phases are compatible with the bounds on the electric dipole moments of the neutron and electron, as well as remaining compatible with the cosmological upper bound on the relic density of neutralinos. The other -violating phase is essentially unconstrained.

Paper Structure

This paper contains 9 equations, 4 figures.

Figures (4)

  • Figure 1: Contours of constant $\Omega_{\widetilde{\chi}}\, h^2=0.1$ and $0.3$, as a function of $m_0$ and $M$, for $A_0=0 {\rm \, Ge V}$ and $\tan\beta=2$. The dotted line represents the current LEP2 slepton exclusion contour, and the dot-dashed line corresponds to a chargino mass of $91{\rm \, Ge V}$. The shaded region at bottom right yields a stau as the LSP.
  • Figure 2: Contours of $m_{1\!/2}^{\rm min}$, the minimum $m_{1\!/2}$ required to bring the electron EDM below experimental bounds, for $\tan\beta=2, m_0=100{\rm \, Ge V}$, and a)$A_0=300{\rm \, Ge V}$, b)$A_0=1000{\rm \, Ge V}$, c)$A_0=1500{\rm \, Ge V}$ and d) as in c) but for the neutron edm. The central light zone labeled "I" has $m_{1\!/2}^{\rm min}<200{\rm \, Ge V}$, while the zones labeled "II", "III", and "IV" correspond to $200{\rm \, Ge V}<m_{1\!/2}^{\rm min}<300{\rm \, Ge V}$, $300{\rm \, Ge V}<m_{1\!/2}^{\rm min}<450{\rm \, Ge V}$, and $m_{1\!/2}^{\rm min}>450{\rm \, Ge V}$, respectively. Zone IV is therefore cosmologically excluded.
  • Figure 3: As in Fig. \ref{['fig:eedm']}a-\ref{['fig:eedm']}c, but requiring that both the electron and neutron EDM bounds be satisfied.
  • Figure 4: The maximum values of $\theta_\mu$ allowed by cosmology and a) the electron EDM and b) both the electron and neutron EDM's, as a function of $\tan\beta$, for several combinations of $m_0$ and $A_0$.