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Marrit Schutten

Publications and source records attributed to Marrit Schutten.

5 recordsLinked to original sources

The impact of CP-violating phases on DM observables in the cpMSSM

In this paper we examine the effect of adding CP-violating phases to the pMSSM on the Dark-Matter (DM) direct-detection cross sections, the velocity-weighted annihilation cross section, and the DM relic density. We show that $φ_{M_2}$ and $φ_μ$, the phases of the wino and higgsino mass parameters, are sufficiently constrained by electron electric-dipole-moment (EDM) measurements such that the allowed values of these phases are too small to influence these DM observables. Conversely, the phase of the bino-mass parameter $φ_{M_1}$ and the phases associated with the trilinear couplings, $φ_{A^t}$, $φ_{A^b}$, and $φ_{A^τ}$, are barely constrained by EDM experiments. We find that these cpMSSM phases can have an important impact on the mentioned DM observables. This especially concerns pMSSM points that lie on the boundary of exclusion, as observables can be affected by cpMSSM phases to the extent that they are either pushed into the observable region, or outside the excluded region.

hep-ph

Dark matter, fine-tuning and $(g-2)_μ$ in the pMSSM

In this paper we analyze spectra in the phenomenological supersymmetric Standard Model that simultaneously result in the right dark-matter relic density $Ω_{\rm DM} h^2$, offer an explanation for the $(g-2)_μ$ discrepancy $Δa_μ$ and are minimally fine-tuned. We discuss the LHC phenomenology resulting from these spectra and the sensitivity of dark-matter direct detection experiments to these spectra. We find that the latter type of experiments with sensitivity to the spin-dependent dark-matter-nucleon scattering cross section $σ_{\rm SD,p}$ will probe all of our found solutions.

hep-ph

Quantum-gravity phenomenology with primordial black holes

Quantum gravity may allow black holes to tunnel into white holes. If so, the lifetime of a black hole could be shorter than the one given by Hawking evaporation, solving the information paradox. More interestingly, this could open to a new window for quantum-gravity phenomenology, in connection with the existence of primordial black holes. We discuss in particular the power of the associated explosion and the possibility to observe an astrophysical signal in the radio and in the gamma wavelengths.

gr-qc

Bouncing black holes in quantum gravity and the Fermi gamma-ray excess

Non-perturbative quantum-gravity effects can change the fate of black holes and make them bounce in a time scale shorter than the Hawking evaporation time. In this article, we show that this hypothesis can account for the GeV excess observed from the galactic center by the Fermi satellite. By carefully taking into account the secondary component due to the decay of unstable hadrons, we show that the model is fully self-consistent. This phenomenon presents a specific redshift-dependance that could allow to distinguish it from other astrophysical phenomena possibly contributing to the GeV excess.

gr-qc

Asymptotic freedom in Horava-Lifshitz gravity

We use the Wetterich equation for foliated spacetimes to study the RG flow of projectable Horava-Lifshitz gravity coupled to n Lifshitz scalars. Using novel results for anisotropic heat kernels, the matter-induced beta functions for the gravitational couplings are computed explicitly. The RG flow exhibits an UV attractive anisotropic Gaussian fixed point where Newton's constant vanishes and the extra scalar mode decouples. This fixed point ensures that the theory is asymptotically free in the large-n expansion, indicating that projectable Horava-Lifshitz gravity is perturbatively renormalizable. Notably, the fundamental fixed point action does not obey detailed balance.

gr-qc