相关论文: Acausality from a Dark Sector
The Lee-Wick theories require unusual Lee-Wick (LW) partners to the standard model (SM) particles. The excitations of the unusual fields may have indefinite norms in the Hilbert space. In the present talk the thermodynamic results of a toy…
We present some bottom-up motivations of axions and other weakly interacting sub-eV particles (WISPs) coupling to photons. Typically, these light particles are strongly constrained by their production or interaction in astrophysical and…
The Standard Model Higgs suffers from the hierarchy problem, typically implying new states within the reach of the LHC. If the Higgs is very heavy (~500 GeV) the states that cutoff the quadratic divergence may be beyond the reach of the…
The Lee-Wick (LW) formulation of higher-derivative theories can be extended from one in which the extra degrees of freedom are represented as a single heavy, negative-norm partner for each known particle (N=2), to one in which a second,…
We argue, based on typical properties of known solutions of string/$M$-theory, that the lightest supersymmetric particle of the visible sector will not be stable. In other words, dark matter is {\em not} a particle with Standard Model…
In a class of theories, dark matter is explained by postulating the existence of a `dark sector', which interacts gravitationally with ordinary matter. If this dark sector contains a U(1) symmetry, and a corresponding `dark' photon…
Dark matter is the name assigned to one of the most important contemporary challenges that fundamental physics research is facing. In recent years, the hypothesis that dark matter might be "light" is gaining interest. Following this idea,…
In a class of theories where the Higgs field emerges as a pseudo Nambu-Goldstone boson, it is often assumed that interactions to generate the top Yukawa coupling provide the Higgs potential as well. Such a scenario generically requires a…
A large set of models beyond the Standard Model of particle physics suggest that the top quark plays a special role in fundamental interactions. At the same time some of these models predict that a particle responsible for dark matter is…
Hidden sectors in connection with GeV-scale dark forces and dark matter are not only a common feature of physics beyond the Standard Model such as string theory and SUSY but are also phenomenologically of great interest regarding recent…
Theories of physics beyond the Standard Model that address the hierarchy problem generally involve top partners, new particles that cancel the quadratic divergences associated with the Yukawa coupling of the Higgs to the top quark. With…
Dark matter particles may interact with other dark matter particles via a new force mediated by a dark photon, $A^{\prime}$, which would be the dark-sector analog to the ordinary photon of electromagnetism. The dark photon can obtain a…
While the paradigm of a weakly interacting massive particle (WIMP) has guided our search strategies for dark matter in the past decades, their null-results have stimulated growing interest in alternative explanations pointing towards…
The assumption of a new symmetry provides a nice explanation of the existence of dark matter and an elegant way to avoid the electroweak constraints. This symmetry often requires the pair production of new particles at colliders and it…
Despite significant experimental sensitivity to point-like, weakly interacting particles at the electroweak mass scale, dark matter has not been found yet. This could hint at a more complex dark sector with multiple states or composite dark…
We assume that the mass of the heavy standard particles ($Z,W,t,...$) arises from a special coupling with dark matter and that this implies a corresponding peculiar connection of these particles to the dark sector. We give examples of…
We perform a detailed study of an effective field theory which includes the Standard Model particle content extended by a pair of Weyl fermionic SU(2)-doublets with opposite hypercharges. A discrete symmetry guarantees that a linear…
We present a systematic cosmological study of a universe in which the visible sector is coupled, albeit very weakly, to a hidden sector comprised of its own set of particles and interactions. Assuming that dark matter (DM) resides in the…
We examine the possibility that dark matter may be the manifestation of dark forces of a hidden sector, i.e. "Dark Force = Dark Matter." As an illustrative and minimal example we consider the hidden SU(2)_h x U(1)_h gauge group. The hidden…
In these proceedings we illustrate that light, very weakly interacting particles can arise naturally from physics which is fundamentally connected to very high energy scales. Searching for them therefore may give us interesting new insights…