Conveners
Dark Matter & colliders: I
- Alejandro Ibarra
- Kai Ronald Schmidt-Hoberg (Deutsches Elektronen-Synchrotron (DE))
- Geraldine Servant (Deutsches Elektronen-Synchrotron (DE))
- Laura Covi (Georg-August-Universitaet Goettingen (DE))
Dark Matter & colliders: II
- Alejandro Ibarra
- Geraldine Servant (Deutsches Elektronen-Synchrotron (DE))
- Kai Ronald Schmidt-Hoberg (Deutsches Elektronen-Synchrotron (DE))
- Felix Kahlhoefer (DESY)
Dark Matter & colliders: III
- Mathias Garny (CERN)
- Kai Ronald Schmidt-Hoberg (Deutsches Elektronen-Synchrotron (DE))
- Geraldine Servant (Deutsches Elektronen-Synchrotron (DE))
- Alejandro Ibarra
Dark Matter & colliders: IV
- Alejandro Ibarra
- Michael Duerr (DESY)
- Kai Ronald Schmidt-Hoberg (Deutsches Elektronen-Synchrotron (DE))
- Geraldine Servant (Deutsches Elektronen-Synchrotron (DE))
DM searches using missing ET at LHC (CMS)
Searches for light dark matter through dijets and long-lived particles at the LHC
It has been recently shown that if dark matter is produced at the LHC via spin-0 mediators, multijet+MET searches are more sensitive than the standard monojet ones. We have recast the latest multijet+MET analysis using 13 TeV data, to show the present and future prospects of exclusion power of this signal. We apply these constraints to several DM well motivated models, including the...
Expensive detector simulations are in general required to assess the implications of LHC data on extensions of the Standard Model of particle physics, as they allow to directly compare the predicted phenomenology for a given point in (an often high-dimensional) theory parameter space, with actual data. We show here that a suitable application of advanced machine learning methods that can...
After the monumental discovery of the Higgs boson, the LHC presently confronts the major challenge in searching for new physics. Any such observation necessitates the determination of mass and other quantum numbers like spin, polarization etc for the new resonance. Most of the BSM theories motivated from profound experimental indication of dark matter (DM), trying to accommodate them as some...
As above
SHIP is a new general purpose fixed target facility, whose Technical Proposal has been recently reviewed by the CERN SPS Committee and by the CERN Research Board. The two boards recommended that the experiment proceeds further to a Comprehensive Design phase in the context of the new CERN Working group "Physics Beyond Colliders", aiming at presenting a CERN strategy for the European Strategy...
Dark photons appear in many well-motivated dark matter scenarios, which
leads to a worldwide effort to search for them. In this talk, I will present
two novel search methods for dark photons at the LHCb experiment. One is an exclusive
search in charm meson decay, and the other is a fully data-driven
inclusive search based on di-muon resonances. These searches advance particle physics...
We analyze the present bounds of a scotogenic model, the Radiative Type III Seesaw (RSIII), in which an additional scalar doublet and at least two fermion triplets of $SU(2)_L$ are added to the Standard Model (SM). In the RSIII the new physics (NP) sector is odd under an exact global $Z_2$ symmetry. This symmetry guaranties that the lightest NP neutral particle is stable, providing a natural...
We present a classification of simplified models of coannihilating dark matter. Assuming tree-level and renormalizable interactions we construct all possible simplified models (containing dark matter, its coannihilation partner and a mediator) which respect gauge and Lorentz invariance. We go on to identify the possible LHC signatures associated with these models and identify new search...
I analyze the constraints on Dark Matter from direct and indirect detection and from the LHC in the case in which the interaction between the DM particle and the SM ones is spin-dependent. This can happen for example if the DM is a Majorana fermion and the interaction is mediated by a heavy Z’, or in the case in which the mediator is a pseudo-scalar (having in mind the possible 750 GeV...
The standard WIMP freeze-out analysis, based on Boltzmann equations,
contains unknown theoretical uncertainties, which may start to matter
now that many benchmark scenarios are strongly constrained by data.
In this talk a few issues which are not always included in
phenomenological analyses are elaborated upon. In particular the
potential importance of strongly interacting bound states (e.g....
A new Z' boson with couplings to quarks and dark matter offers an intriguing possibility for setting the dark matter relic abundance via thermal freeze-out. Hadron colliders are a promising tool for probing this set-up using searches for dijet resonances. Nevertheless, there are various ways to hide the new mediator: the Z' could couple so strongly to dark matter that it decays almost always...
We show that simplified models used to describe the interactions of dark matter with Standard Model particles do not in general respect gauge invariance and that perturbative unitarity may be violated in large regions of the parameter space. The modifications necessary to cure these inconsistencies may imply a much richer phenomenology and lead to stringent constraints on the model. We...
As results from Run II of the LHC continue to be released, it is important to evaluate the ways in which we study DM at colliders. EFTs can be a useful tool to constrain DM in a semi-model-independent way, but it is now clear that this approach has limitations.
EFTs are now supplemented by simplified models of dark matter, and it is important to approach these models in a logical and...
A reliable comparison of different dark matter searches requires models that satisfy certain consistency conditions like gauge invariance and perturbative unitarity. These conditions can easily be satisfied in U(1)' extensions of the Standard Model, where a fermionic dark matter candidate as well as a new Z' gauge boson obtain their mass from the spontaneous breaking of the U(1)' by a dark...
The nature of dark matter is perhaps the most intriguing and open issue in Physics, whose resolution is likely to bring us beyond the Standard Model. The experimental energy scale of TeV is most pivotal for the recent advances in the booming field of astroparticle. On the other side, recent astrophysical observations have revealed, in the distribution of matter in Galaxies, some extremely...
Observations with the Fermi Large Area Telescope indicate an excess in gamma rays originating from the center of our Galaxy. A possible explanation for this excess is the annihilation of Dark Matter (DM) particles. We have investigated the annihilation of neutralinos as DM candidates within the phenomenological Minimal Supersymmetric Standard Model (pMSSM) and found solutions that are not...
Effective theories are a great tool to present constraints on broad BSM assumptions in a rather model-independent fashion. However, effective theories have a limited range of validity which can, especially in collider searches, complicate an analysis. We argue that in order to achieve a consistent analysis more specific hypotheses about BSM physics are needed and can subsequently be tested....
Recent data from CMS and ATLAS experiments at CERN LHC suggest a diphoton excess of invariant mass around 750 GeV. Apparently the width of the resonance is around 45 GeV. To explain this anomaly we introduce a singlet scalar and a dark sector comprising of a vector-like lepton doublet and a singlet which are odd under a Z_2 symmetry. As a result the dark matter emerges as an admixture of the...
Standard Model and Dark sector can be related via a (pseudo)scalar mediator particle, 'messenger'. The scenario belongs to a wider class of 'simplified models' of DM. One can think the models expand the pure effective operator interactions including the degrees of freedom of a mediator particle. We will present some physical scenarios having a TeV scale messenger (for example, 750 GeV). We...
Momentum-dependent couplings between dark matter and the visible sector can appear in models where dark matter is a pseudo-Nambu-Goldstone boson, a scalar field associated with the spontaneous breaking of a global symmetry at a given energy scale. From a low-energy perspective, these couplings appear as non-renormalizable operators involving derivatives at the effective Lagrangian level. The...
The model T12A addresses two major questions of modern particle physics: by adding fermionic and bosonic singlets and doublets to the Standard Model particle content, this model allows to radiatively generate neutrino masses, while at the same time it includes viable candidates for the cold dark matter in our Universe.
We present the first extensive study of the parameter space of this model...
