3,008 research outputs found
Baryogenesis and Dark Matter from Mesons
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 meson oscillations and subsequent decays. This set-up is testable
at hadron colliders and -factories. In the early Universe, decays of a long
lived particle produce 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
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 meson decays, a
new decay of mesons into a baryon and missing energy, and a new decay of
-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.Comment: 17 pages, 6 figures. v2: references added, corrected the antinucleon
abundance calculation (sec III.C.iii), and included comments on the viability
of a measurement of the decay of -flavored baryons into mesons and missing
energy at hadron colliders (sec IV.A.iii). v3: matches the published versio
Nonlinear field theories during homogeneous spatial dilation
The effect of a uniform dilation of space on stochastically driven nonlinear
field theories is examined. This theoretical question serves as a model problem
for examining the properties of nonlinear field theories embedded in expanding
Euclidean Friedmann-Lema\^{\i}tre-Robertson-Walker metrics in the context of
cosmology, as well as different systems in the disciplines of statistical
mechanics and condensed matter physics. Field theories are characterized by the
speed at which they propagate correlations within themselves. We show that for
linear field theories correlations stop propagating if and only if the speed at
which the space dilates is higher than the speed at which correlations
propagate. The situation is in general different for nonlinear field theories.
In this case correlations might stop propagating even if the velocity at which
space dilates is lower than the velocity at which correlations propagate. In
particular, these results imply that it is not possible to characterize the
dynamics of a nonlinear field theory during homogeneous spatial dilation {\it a
priori}. We illustrate our findings with the nonlinear Kardar-Parisi-Zhang
equation
- …