TALKS
Rouzbeh Allahverdi - Nonthermal Dark Matter and Baryogenesis
We study a simple TeV scale model of baryon number violation which explains the observed proximity of the dark matter and baryon abundances. The model has constraints arising from both low and high energy processes, and in particular, predicts a sizable rate for the neutron antineutron (n−n¯) oscillation at low energy and the monojet signal at the LHC. We find an interesting complementarity among the constraints arising from the observed baryon asymmetry, ratio of dark matter and baryon abundances, n−n¯ oscillation lifetime and the LHC monojet signal. There are regions in the parameter space where the n−n¯oscillation lifetime is found to be more constraining than the LHC constraints, which illustrates the importance of the next generation n−n¯oscillation experiments.
Otávio Alonso - Probing Dark Matter properties using photometric surveys
Despite decades of its first proposal, Dark Matter is still one of the big mysteries in cosmology. Different probes can shed light into different aspects of it, but they agree in a good level that it can be modeled as a pressureless perfect fluid, although we have reason to call that into question. Here we discuss how can we learn about Dark Matter from weak lensing and galaxy clustering in the context of photometric surveys. In particular, we present a phenomenological framework that generalizes DM behavior and look for constraints using The Dark Energy Survey data.
Yang Bai - Primordial Extremal Black Holes as Dark Matter
We show that primordial (nearly) extremal black holes with a wide range of masses from the Planck scale to around 1000 tons could be cosmologically stable and explain dark matter, given a dark electromagnetism and a heavy dark electron. The merger events of binary systems provide an opportunity to directly observe Hawking radiation. Because the merger products are not extremal, they rapidly evaporate and produce transient high energy neutrino and gamma ray signals that can be observed at telescopes like IceCube and HAWC.
Ronaldo Batista - Describing Warm Dark Matter with the Reduced Relativistic Gas
The Reduced Relativistic Gas (RRG) is a simplified version of the ideal relativistic gas, which assumes that all particles have the same momentum magnitude. Although this is a very idealized situation, the resulting model preserves the phenomenology of Maxwell Boltzmann distribution and, in some situations, can be described as a perfect fluid, without introducing large errors in both cosmological background and first order perturbations. The perfect fluid description of RRG model was already used to study the warmness of dark matter, massive neutrinos and interaction of baryons and photons before recombination, showing very good agreement with previous works based on the full Einstein Boltzmann system of equations. In order to understand these results and construct a more general and formal framework for RRG, we develop a theoretical description of first order cosmological perturbations of RRG, based on a distribution function which encodes the simplifying assumption that all particles have the same momentum magnitude. The full set of Einstein Boltzmann equations for RRG distribution are derived and quantities beyond the perfect fluid approximation are studied. Using RRG to describe warm dark matter, we show that, for particles with m∼ keV, the perfect fluid approximation is valid on scales k<10h/Mpc, for most of the universe evolution. We also determine initial conditions for RRG in the early universe and study the evolution of potential in a toy model of universe composed only by RRG.
Antonio Delgado – Higgsino DM from natural susy
We consider a minimal natural supersymmetric model based on an extra dimension with supersymmetry breaking provided by the Scherk Schwarz mechanism. The lightest supersymmetric particle is a neutral, quasi Dirac Higgsino and, unlike in previous studies, we assume that all Standard Model fields are propagating in the bulk. The resulting setup is minimal, as neither extra matter, effective operators, nor extra U(1) groups are needed in order to be viable. Pasquale di-Bari - A unified model of neutrino masses, dark matter and leptogenesis testable at Neutrino Telescopes
Despite the lack of evidence of new physics at colliders, neutrino masses, dark matter and matter antimatter asymmetry of the universe require an extension of the Standard Model. After discussing some new concepts and tools in the description of seesaw neutrino models, such as motion in flavour lepton space and the introduction of the bridging matrix that nicely complements the orthogonal matrix, I discuss recent developments in the connections between neutrino data and scenarios of leptogenesis within some well motivated extensions of the Standard Model. Finally, I briefly review a simple unified picture of neutrino masses, leptogenesis and dark matter based on an extension of the seesaw Lagrangian where a non renormalizable effective operator coupling right handed neutrinos to the Higgs is introduced. This operator enhances the right handed neutrino mixing between a coupled heavy right handed neutrino and a decoupled one playing the role of dark matter. Interference between the two coupled RH neutrinos generate usual CP violation so that one can also achieve successful leptogenesis. Although the dark matter right handed neutrino escapes direct and collider searches, its decays produce a detectable contribution to the very high energy neutrino flux now discovered by IceCube, so that the model is predictive and can be tested at neutrino telescopes.
Marcos Cardoso -NMSSM and Dark Matter
We will present in one very nice SUSY B L model some nice candidate to Dark Matter. I can if it is necessary give talk (another poster) about Next to Minimal Supersymmetric Standard Model (NMSSM) and also the General Singlet Extensions of the MSSM (GSEMSSM) models. We can show we can get pseudoscalars and neutralinos can give nice results in some cosmological analyses as presented
Francesco D'Eramo - Displaced new physics at colliders and the pre-BBN universe
Sylvain Fichet – The warped dark sector
I present a dark sector scenario based on a 5d AdS space. Such a construction, also motivated as the AdS dual of a composite dark sector, naturally leads to models in which parts of the dark sector vanish at high 4d momentum or temperature.This sense of AdS "opacity" arises as a result of the dressing of propagators by bulk interactions. Exotic signatures are possible from laboratory to cosmological scales, including long range forces with non integer behaviour, non standard momentum losses, periodic signals at colliders, “soft bombs” events, as well as a dark phase transition and a typically small amount of dark radiation.
Vesselin Gueorguiev - The Scale Invariant Vacuum Theory as viable Cosmology Model
Recent studies in applying the Weyl's original gauge symmetry idea within the framework of the Weyl's Integrable Geometry to modern observational data in cosmology has resulted in the Scale Invariant Vacuum Theory (SIVT) idea. A sequence of papers by Prof. André Maeder has shown that SIVT is a viable contender to standard LamdaCDM model. It has been also shown that the growth of the density perturbations of the early universe can be modeled within SIVT without the need of dark matter. Furthermore, SIVT has been able to explain the asymptotic limit of the Radial Acceleration Relation (RAR) in Dwarf Spheroidals better than MOND and Dark Matter models. An overview of the SIVT results will be summarized and discussed subject to the time constraints of the workshop.
Nathan Herring - Particle Decay in the Expanding Spacetime of Post Inflationary Cosmology
The calculation of particle decay rates typically proceeds by an S matrix approach in Minkowski spacetime. While such an approach is often highly eff ective, it fails, in general, when performing calculations in dynamic spacetimes since the S matrix necessitates global energy conservation which is not present in an expanding universe, like ours. I will describe how the decay law of scalar particles decaying during the radiation dominated epoch of a standard cosmological model can be obtained by introducing an adiabatic approximation valid for degrees of freedom with typical wavelengths much smaller than the particle horizon at a given time. Furthermore, this decay law is calculated, treating the cosmological expansion consistently, through the non perturbative Wigner Weisskopf method adapted for cosmology. I will discuss both scalar to scalar and scalar to fermion (with Yukawa couplings) decays within this framework highlighting how the effects of cosmic expansion, such as cosmic redshift and the confluence of time dependent particle frequencies with a renormalizable theory, lead to salient differences from the usual Minkowski spacetime results. Finally I will discuss implications for very long lived particles (DM) and baryogenesis.
Jay Hubisz - Cosmology of Brane Worlds From Symmetry Principles
Alejandro Ibarra - Astrophysical Uncertainties on Local Dark Matter Searches
Dark matter substructure can contribute significantly to local dark matter searches and may provide a large uncertainty in the interpretation of those experiments. For direct detection experiments, sub halos give rise to an additional dark matter component on top of the smooth dark matter distribution of the host halo. In the case of dark matter capture in the Sun, sub halo encounters temporarily increase the number of captured particles. We assess the impact of sub halos on direct dark matter searches in a probabilistic way.
Markus Luty - Blowing in the Dark Matter Wind
Light bosonic dark matter can interact with ordinary matter, giving rise to steady state forces from the dark matter wind that are small but potentially observable. We compute these forces and give some estimates of experimental sensitivities to them.
Adam Martin - Custodial Dark Pions
A new, strongly coupled dark sector could be accessible to LHC searches now. These dark sectors consist of composites formed from constituents that are charged under the electroweak group and interact with the Higgs, but are neutral under Standard Model color. In these scenarios, the most promising target is the dark meson sector, consisting of dark vector mesons as well as dark pions. In this paper we study dark meson production and decay at the LHC in theories that preserve a global SU(2) dark flavor symmetry.
Téssio Rogério Nóbrega Borja de Melo - A two Higgs doublet model for dark matter and neutrino masses
Motivated by the interesting features of Two Higgs Doublet Models (2HDM) we present a 2HDM extension where the stability of dark matter, neutrino masses and the absence of flavor changing interactions are explained by promoting baryon and lepton number to gauge symmetries. Neutrino masses are addressed within the usual type I seesaw mechanism. A vector like fermion acts as dark matter and it interacts with Standard Model particles via the kinetic and mass mixings between the neutral gauge bosons. We compute the relevant observables such as the dark matter relic density and spin independent scattering cross section to outline the region of parameter space that obeys current and projected limits from collider and direct detection experiments via thermal and non thermal dark matter production.
Mariano Quiros - Electroweak Baryogenesis and Dark CP violation
We present a novel mechanism of electroweak baryogenesis where CP violation occurs in a dark sector, comprised of standard model gauge singlets, thereby evading the strong electric dipole moment constraints. In this framework, the background of time like component of a new gauge boson Z′µ, generated at electroweak temperatures, drives the electroweak sphaleron processes to create the required baryon asymmetry. We first discuss the crucial ingredients for this mechanism to work, and then show that all of them can be elegantly embedded in ultraviolet completions with spontaneously broken gauged lepton number. The models under consideration have a rich phenomenology and can be experimentally probed in leptophilic Z′ searches, dark matter searches, heavy Majorana neutrino searches, as well as through hunting for new Higgs portal scalars in multi lepton channels at colliders.
Diego Restrepo - Simplest Dirac scotogenic model The minimal Dirac scotogenic model is presented. The phenomenology related with dark matter experiments, collider phyisics, lepton flavor violation and cosmology is analysed in detail and the viable parameter space is obtained.
Tania Robens - Constraining the Inert Doublet Model at current and future colliders
The Inert Doublet Model is an intriguing new physics scenario that extends the SM scalar sector by a second electroweak doublet. A further discrete symmetry renders the lightest of the new particles stable, therefore providing a good dark matter candidate. I will discuss current constraints on this model as well as the discovery prospect at current and future colliders.
Riccardo Sturani - Gravitational wave astronomy
The recent observations of gravitational waves emitted by coalescences of binary compact objects like black holes and neutron stars marked the dawning of gravitational wave astronomy as a new science. Beyond the immediate and tremendous impact in Astrophysics, the consequences that the opening of this new observational window has on fundamental physics and cosmology will be highlighted. In particular the multi messenger observations can provide a way to unveil properties of the Universe on both short and large scales, with exciting prospects laying ahead of us with future gravitational detectors planned for the next 20 years.
Thiago Tomei - Dark Matter Searches in SPRACE
Ivone Zavala – Inflationary models
POSTERS
Tulio Caviquioli Cardoso - Search for Dark Matter Production at the CMS Experiment through the Mono-Photon Signature
After the discovery of the Higgs Boson, one of the main focus of the LHC experiments became the search for beyond standard model (BSM) physics. As the name suggests, BSM includes a wide range of physics scenarios, like extra dimensions, supersymmetry, dark matter, and many others. Dark Matter (DM), as cosmological observations suggests, is suposed to be a kind of matter that do not have electric charge and do not interact with strong force. At the Large Hadron Collider (LHC), and more specifically at the Compact Muon Solenoid Experiment (CMS), the search is performed using many theoretical frameworks, like DM production in SUSY decays, simplified models and DM production in the decay of a Higgs Boson, just to mention a few. Since this kind of matter do not have electric nor strong charge, the detector can not record their production but it is possible to infer its existence by analysing events with missing transverse energy (MET). Simplified models are a good way to a general search. It consists in production of DM through new mediators, which couples the DM with usual matter, and needs few free parameters (DM and mediator masses, spin and couplings). This work present a Monte Carlo simulation study of the production of events with a final state photon with large transverse momentum and large missing transverse energy at CMS. This is a sensitive probe of Dark Matter since this signature has the advantage of being identifiable with high efficiency.
Elaine Fortes - Extragalactic background generated by the annihilation / decay of dark matter
BINGO is a unique radio telescope designed to make the first detection of Baryon Acoustic Oscillations (BAO) at radio frequencies by measuring the distribution of neutral hydrogen gas at cosmological distances. Along with the cosmic microwave background, the scale of BAO is one the most powerful probes of cosmological parameters, including dark energy. The main BINGO partners are Brazil, United Kingdom, China and Switzerland. Assembly will take place in Brazil with most of the components supplied by Brazilian industry. An important motivation for the project is the training of Brazilian engineers, technicians and postdocs in the skills required so that in the future they can get involved in state of the art radio astronomy systems, specially the Square Kilometer Array. BINGO has two different pipelines and, one of them Hide\&Seek4BINGO, has been developing since and in this new pipeline, a specific module designed for non gaussian studies is under construction. We present the forecast for BINGO and the preliminary results of this non gaussian module.
Karin Silvia Franzoni Fornazier Guimarães - Forecasting for non-gaussian features in 21cm intensity mapping We propose a modification of the radio signals signals of dark matter, applying the mechanism of stochastic gravitational wave background as a function that integrates the distribution of dark matter in the universe according to the distance until redshift z ∼ 20. The difference between this and other works is that we will use a cosmological star formation model, which behaves as a dark matter tracer in big scales. So, we will deal with dark matter questions in the epoch of first stars formation and at the same time we will analyse the radio signals from a cosmological point of view.
Marcio de Sousa Mateus Junior - A investigation of the dark photon as mediator between dark matter and the standard model
Several studies have been proposed to investigate the nature of Dark Matter (DM), trying to uncover its origin. Distinct approaches have been employed aiming at understanding how DM interacts and what are the possible mechanisms for detecting it. Theories beyond the Standard Model of the Elementary Particles (SM) investigate the possible couplings of this DM with the conventional matter in order to obtain means to evidence its interaction in the laboratory. By employing effective models, or even more complete models, the experimental measurements obtained with the Large Hadron Collider (LHC) experiments have shown large regions of exclusion, indicating that DM has high mass constituents and mediators. Thus, this work aims to investigate the interaction between quarks and particles of DM by interaction through dark photons, which would be the mediators of the electromagnetic interaction of DM. Thus, we hope to establish new exclusion limits for the differential and total cross section for the processes involving the dark photon coupling with the standard matter, by analyzing three possible (fermionic, scalar and vector) candidates for relic dark matter. These results may shed some light in the experimental search for observation of such a mechanism of production in experiments of the LHC, like Compact Muon Solenoid (CMS) and explain observational evidences for the relic density of dark matter in the universe.
Eduardo Akio Sato - Self-energy correction to scalar triplet leptogenesis in the HTL scheme
We study how finite temperature corrections affect the dynamics of a leptogenesis model based on the type II seesaw mechanism. When finite temperature T is introduced in the formalism, there is two possible scales for the energy and momentum of particles, namely the “hard” momenta proportional to T and the “soft” momenta proportional to gT, where g is a coupling constant of the theory. As shown by Braaten & Pisarski, naive perturbation theories doesn’t give consistent results since N loop terms can give contributions as relevant as the tree level ones; This happen when all the external momenta of a diagram is soft and the internal loop momenta is hard. Using the Hard Thermal Loop (HTL) resummation, it’s possible to propose effective propagators and vertices for a given theory that are free of those anomalies. We investigate how to apply this procedure in the type II seesaw model.
Ana Maria de Sousa Slivar - Study of Mono-Z Production at the LHC as Evidence of Dark Matter
The existence of Dark Matter (DM) has been inferred from its cosmological signals, what allows its search in particle accelerators experiments. Exploring physics beyond the Standard Model is one of the main objectives of the CMS experiment at CERN LHC. Given that DM particles should not interact with the detectors, such particles can be searched for in the form of missing transverse energy (MET), the so called mono X searches. A simplified model is used to approach this kind of new physics, considering DM as a Dirac fermion and a new mediator between DM and SM particles as a neutral scalar boson. Due to the high mass of the mediator, if a Z boson recoils against it, the products of its decay will have large momentum and be collimated. The main backgrounds for a mono Z search are ZZ, WZ and WW production, with a dilepton signature and some missing energy. This study will show possible cuts for the signal improvement over expected backgrounds. This preliminary work uses standart tools, such as MadGraph and Pythia for the generation, and the CMSSW framework to perform CMS detector simulation and data reconstruction. The reconstructed data is then transformed into the more compact NanoAOD format and analysed with ROOT, using the standalone NanoAOD Tools package.
Ion Vasile Vancea - Simplified Models of Dark Matter with graviton mediators in de Sitter
In this presentation, we discuss the problems posed by the generalization of the simplified models with graviton mediators to de Sitter space.