A Unified Theory of Matter Genesis: Asymmetric Freeze-In

Lawrence J. Hall, John March-Russell, Stephen West

Research output: Other contribution


We propose a unified theory of dark matter (DM) genesis and baryogenesis. Itexplains the observed link between the DM density and the baryon density, andis fully testable by a combination of collider experiments and precision tests.Our theory utilises the "thermal freeze-in" mechanism of DM production,generating particle anti-particle asymmetries in decays from visible to hiddensectors. Calculable, linked, asymmetries in baryon number and DM number areproduced by the feeble interaction mediating between the two sectors, while theout-of-equilibrium condition necessary for baryogenesis is provided by thedifferent temperatures of the visible and hidden sectors. An illustrative modelis presented where the visible sector is the MSSM, with the relevant CP violation arising from phases in the gaugino and Higgsino masses, and bothasymmetries are generated at temperatures of order 100 GeV. Experimentalsignals of this mechanism can be spectacular, including: long-lived metastablestates late decaying at the LHC; apparent baryon-number or lepton-numberviolating signatures associated with these highly displaced vertices; EDMsignals correlated with the observed decay lifetimes and within reach ofplanned experiments; and a prediction for the mass of the dark matter particlethat is sensitive to the spectrum of the visible sector and the nature of theelectroweak phase transition.
Original languageEnglish
Publication statusAccepted/In press - 1 Oct 2010


  • hep-ph
  • astro-ph.CO
  • hep-th

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