No Arabic abstract
Scalar singlet dark matter in anomaly-free composite Higgs models is accompanied by exotic particles to which the dark matter annihilates. The latter can therefore freeze out even in the absence of couplings to the Standard Model. In this regime, both current and future direct detection constraints can be avoided. Moreover, due to the different decay modes of the extra particles, the dark matter candidate can even escape indirect detection constraints. Assessing this issue requires dedicated simulations of the gamma ray spectrum, that we provide in the present article in the context of $SO(7)/SO(6)$. For the parameter space region that evades constraints from dark matter experiments, we develop new analyses to be performed at a future 100 TeV collider based on the search of the new particles produced in the decay of heavy vector-like quarks.
We explore new representations for lattice gauge theories with fermions, where the space-time lattice is divided into dynamically fluctuating regions, inside which different types of degrees of freedom are used in the path integral. The first kind of regions is a union of so-called bags, in which the dynamics is described by the free propagation of composite degrees of freedom of the original fermions. In the second region, called complementary domain, configurations of the remaining interacting degrees of freedom are used to describe the dynamics. We work out the bag representation for the gauge groups SU(2) and SU(3) and address the nature of the strong coupling effective degrees of freedom, which are fermions for SU(3) and bosons for SU(2). We discuss first steps towards a numerical simulation of the bag representations.
Composite dark matter is a natural setting for implementing inelastic dark matter - the O(100 keV) mass splitting arises from spin-spin interactions of constituent fermions. In models where the constituents are charged under an axial U(1) gauge symmetry that also couples to the Standard Model quarks, dark matter scatters inelastically off Standard Model nuclei and can explain the DAMA/LIBRA annual modulation signal. This article describes the early Universe cosmology of a minimal implementation of a composite inelastic dark matter model where the dark matter is a meson composed of a light and a heavy quark. The synthesis of the constituent quarks into dark mesons and baryons results in several qualitatively different configurations of the resulting dark matter hadrons depending on the relative mass scales in the system.
We consider the quantization of chiral solitons with baryon number $B>1$. Classical solitons are obtained within the framework of a variational approach. From the form of the soliton solution it can be seen that besides the group of symmetry describing transformations of the configuration as a whole there are additional symmetries corresponding to internal transformations. Taking into account the additional degrees of freedom leads to some sort of spin alignment for light nuclei and gives constraints on their spectra.
Peaking consistently in June for nearly eleven years, the annual modulation signal reported by DAMA/NaI and DAMA/LIBRA offers strong evidence for the identity of dark matter. DAMAs signal strongly suggest that dark matter inelastically scatters into an excited state split by O(100 keV). We propose that DAMA is observing hyperfine transitions of a composite dark matter particle. As an example, we consider a meson of a QCD-like sector, built out of constituent fermions whose spin-spin interactions break the degeneracy of the ground state. An axially coupled U(1) gauge boson that mixes kinetically with hypercharge induces inelastic hyperfine transitions of the meson dark matter that can explain the DAMA signal.
We consider Fraternal Twin Higgs models where the twin bottom quark, $b$, is much heavier than the twin confinement scale. In this limit aspects of quark bound states, like the mass and binding energy, can be accurately calculated. We show that in this regime, dark matter can be primarily made of twin baryons containing $b b b$ or, when twin hypercharge is gauged, twin atoms, composed of a baryon bound to a twin $tau$ lepton. We find that there are significant regions of parameter space which are allowed by current constraints but within the realm of detection in the near future. The case with twin atoms can alleviate the tension between dark matter properties inferred from dwarf galaxies and clusters.