Baryogenesis and dark matter from B mesons

Abstract

We present a new mechanism of Baryogenesis and dark matter production in which both the dark matter relic abundance and the baryon asymmetry arise from neutral B meson oscillations and subsequent decays. This set-up is testable at hadron colliders and B-factories. In the early Universe, decays of a long lived particle produce B mesons and anti-mesons out of thermal equilibrium. These mesons/anti-mesons then undergo CP violating oscillations before quickly decaying into visible and dark sector particles. Dark matter will be charged under Baryon number so that the visible sector baryon asymmetry is produced without violating the total baryon number of the Universe. The produced baryon asymmetry will be directly related to the leptonic charge asymmetry in neutral B decays; an experimental observable. Dark matter is stabilized by an unbroken discrete symmetry, and proton decay is simply evaded by kinematics. We will illustrate this mechanism with a model that is unconstrained by di-nucleon decay, does not require a high reheat temperature, and would have unique experimental signals -a positive leptonic asymmetry in B meson decays, a new decay of B mesons into a baryon and missing energy, and a new decay of b-flavored baryons into mesons and missing energy. These three observables are testable at current and upcoming collider experiments, allowing for a distinct probe of this mechanism. 2 b b Out of equilibrium late time decay CP violating oscillations B-mesons decay into Dark Matter and hadrons B 0 d B 0 s B + B B 0 s B 0 d B ⇠ Dark Matter Baryon anti-Baryon T RH ⇠ 20 MeV A sÀd`B R(B ! ⇠ + Baryon + .

A supersymmetric theory of baryogenesis and sterile sneutrino dark matter from B mesons

“…A new mechanism for low-scale baryogenesis and DM production was introduced in [6] 1 . Contrary to the standard lore that baryogenesis is difficult to test experimentally, the mechanism of [6] predicts distinct signals at B factories and hadron colliders. In particular, a large positive enhancement of the charge/semileptonic-leptonic asymmetry in neutral B meson oscillation systems is required, as are new decay modes of charged and neutral B mesons into baryons and missing energy together with exotic decays of b-flavored baryons.…”

“…In the present work, we realize the mechanism of baryogenesis and DM production introduced in [6] in an R-SUSY setup where an exact U (1) R symmetry is identified with U (1) B baryon number 2 . In this baryogenesis scenario, neutral B mesons are produced at MeV temperatures in the early Universe, undergo CP-violating oscillations and subsequently decay to a Dirac gaugino (which is charged under the R-symmetry and therefore baryon number) through a four-fermion interaction obtained by integrating out heavy squarks.…”

“…However, previous work on R-SUSY models focused on scenarios with heavy Dirac gauginos (for instance [18] considers flavor constraints on a model where all the gauginos share the same mass scale of order 500 GeV − TeV). Realizing the mechanism of [6] motivates us to study the phenomenology of a complementary region of R-SUSY parameter space -one where multiple gaugino mass scales are present. This allows the bino to be light enough for baryogenesis purposes while the other gauge superpartners are heavier and avoid collider constraints.…”

“…This paper is organized as follows: in Sec. 2 we review the key ingredients and results of [6], i.e. the generic model and parameter space needed to achieve baryogenesis and DM from B mesons.…”

Oscillations of $$ {B}_s^0 $$ Mesons as a Probe of Decays with Unreconstructed Particles

“…involving neutrons, and for searches beyond the SM, such as decays with heavy neutrinos, axion-like particles and other dark matter candidates (e.g. [10][11][12]). The benchmark measurements that should be feasible already with the currently available LHCb dataset could employ Cabibbo-favoured open-charm decays such as B 0 s → D − s pn.…”