The centers of galaxies provide promising targets to search for the nature of dark matter, but only if astrophysical emissions can be well understood. I will discuss studies of the Milky Way galactic center in pursuit of dark matter signals. I will cover a tantalizing signal, the Fermi Galactic Center Excess, and highlight the importance of astrophysical modeling to establish its validity and...
Observation of high energy cosmic neutrinos by ICECUBE has ushered in a new era in exploring both cosmos and new physics beyond the Standard Model (SM). In the standard picture, although mostly $\nu_\mu$ and $\nu_e$ are produced in the source, oscillation will produce $\nu_\tau$ {\it en route}. Certain beyond SM scenarios, like interaction with ultralight DM can alter this picture. Thus, the...
The leading explanation of the Fermi Galactic center gamma-ray excess is the extended emission from an unresolved population of millisecond pulsars (MSPs) in the Galactic bulge. Such a population would, along with the prompt gamma rays, also inject large quantities of electrons/positrons (e-e+) into the interstellar medium. These e-e+ could potentially inverse-Compton (IC) scatter ambient...
In the context of cosmic-ray physics, we introduce a novel strategy for the computation of the inverse-Compton scattering (ICS) and synchrotron-radiation (SR) signals in dwarf galaxies. In particular, we identify various regimes where, in analogy to prompt gamma rays, the diffuse ICS and SR signals from dark matter annihilation/decay can be expressed as the multiplication of a halo times a...
The inflationary production of dark matter (DM) can lead to several interesting scenarios in which DM may be homogeneously distributed or not. We are interested in studying clumpy DM and explore the characteristics of such clumps in a model independent way, orientating the analysis to the detectability of such inhomogeneities. To do so, we simulated a counting experiment and performed a...
Baryonic physics i.e. star formation and stellar feedback are debated topics in galaxy formation and are of paramount importance for dark matter phenomenology. Particularly, the dark matter (DM) distribution features that play the main role in dark matter detection efforts.
In this work, we aim to illustrate the reach of baryonic-physics-related uncertainties on the dark matter distribution...
Measurements of coherent elastic neutrino-nucleus scattering and neutrino-electron elastic scattering provide an useful tool to test neutrino properties at low thresholds. Stopped-pion neutrino sources as well as reactor and solar neutrinos can induce such signals. After a basic introduction to the subject, I will briefly mention various measurements and physics cases that could be studied at...
Dark matter remains one of the most important open problems in particle physics and cosmology. Weakly interacting massive particles (WIMPs) appear as an appealing solution, providing the right relic density with a cross-section at the electroweak scale, however, no WIMP signals were observed until now. Secluded models are good alternatives to the standard ones. In this case, instead of a...
I will discuss some models where the masses of the light active neutrinos are radiatively generated. Mechanisms for generating the SM charged fermion mass hierarchy will also be presented. Some phenomenological aspects, such as Dark matter, charged lepton flavor violation, electron and muon anomalous magnetic moments will be discussed as well.
Dark Matter and neutrinos are one of the most puzzling components of the Universe. Generation of Neutrino masses can be obtained via radiative processes where Dark Matter particles are involved. Such models are known as Scotogenic DM models. The Dark Matter candidate in these models are stable thanks to the same symmetry that protect the radiative process. We present a realization of the...
If neutrinos get their masses at the loop level, a dark sector might be involved in the mass generation mechanism as suggested by the scotogenic model. In this talk, I will review constraints and viable parameter space region for fermion dark matter candidates connected to the neutrino mass.
In multi-component scalar dark matter scenarios, a single $Z_N$ ($N\geq 4$) symmetry may account for the stability of different dark matter particles. Here we study the case where $N$ is even ($N=2n$) and two species, a complex scalar and a real scalar, contribute to the observed dark matter density.
We show that, thanks to the new interactions allowed by the $Z_{2n}$ symmetry, current...
We will present ATLAS and CMS searches for dark matter particles, mediators, as well as dark sector extensions. We will cover analyses using several different final states, topologies, and kinematic variables utilizing partial but also full Run-II data-sets collected at the LHC. We will finish with an overview and an outlook towards Run III and beyond.
There are many possibilities to link dark matter and neutrino masses, Scotogenic models being among the most popular options. In this talk I will discuss a variant of the Scotogenic model that includes charged fermions and a doublet with hypercharge $3/2$. In constrast with the standard Scotogenic model, only the scalar dark matter candidate is viable in this version. After presenting the...
We propose an appealing alternative scenario of leptogenesis assisted by dark
sector which leads to the baryon asymmetry of the Universe satisfying all theoretical and
experimental constraints. The dark sector carries a non minimal set up of singlet doublet
fermionic dark matter extended with copies of a real singlet scalar field. A small Majorana
mass term for the singlet dark fermion, in...
In this talk, I will discuss the freeze-in production of Feebly Interacting Massive Particle (FIMP) dark matter candidates through a neutrino portal, in the case where an early matter-dominated era took place for some period between inflation and Big Bang Nucleosynthesis. In this model, we consider a hidden sector comprised of a fermion and a complex scalar, with the lightest one regarded as a...
In this talk I will discuss a simple model of maximal axion misalignment. Maximally-misaligned axions with masses larger than 10^{-22} eV constitute an attractive DM candidate with interesting phenomenology. On the other hand, maximally-misaligned axions with masses m=O(1-100)H_0 generically behave as dark energy with a decay constant that can take values well below the Planck scale, avoiding...
We study the possible Vector Boson Fusion signatures that arise from Simplified models for DM production at the LHC. We develop a strategy for looking for these signals and compare it with monojet type of searches. We show how different DM searches in simplified models are complimentary and needed to establish a full picture of DM production at the LHC.
In JHEP 11 (2020) 159, we have investigated the possible existence of graviballs, a system of bound gravitons, and show that two gravitons can be bound together by their gravitational interaction. This conclusion is consistent with older classical studies on gravitational geons. Our calculations rely on the formalism and techniques of quantum field theory, specifically on low-energy quantum...
We analyze interactions between dark matter and standard model particles with spin one mediators in an effective field theory framework. In this paper, we are considering dark particles masses in the range from a few MeV to the mass of the Z boson. We use bounds from different experiments: Z invisible decay width, relic density, direct detection experiments, and indirect detection limits from...
We study natural supersymmetric scenarios with light right-handed neutrino superfields, and consider the possibility of having a sneutrino as a dark matter candidate. We consider thermal and nonthermal production, taking into account freeze-out, freeze-in, and super-WIMP mechanisms. For the nonthermal case, we find that the R-sneutrino can reproduce the observed relic density by adjusting...
We study the impact of thermalization and number-changing processes in the
dark sector on the yield of gravitationally produced dark matter (DM). We take
into account the DM production through the $s$-channel exchange of a massless
graviton both from the scattering of inflatons during the reheating era, and
from the Standard Model bath via the UV freeze-in mechanism. By considering the
DM...
The scalar-tensor theory introduced by Horndeski has a sound and firm basis since it avoids the Ostrograski’s instability. The generalized SU(2) Proca Theory, which is a vector-tensor theory where the vector content enjoys a SU(2) global symmetry, has been built following Horndeski’s spirit. Such a theory exhibits interesting properties that make it a candidate to describe the primordial...
We propose a model with spin 3/2 fermions and vector doublets. We compute neutrino masses via radiative seesaw mechanism. We investigate the consequences of the model in the dark matter relic abundance. Furthermore, we implement the Casas-Ibarra parametrization to constraint the parameter space considering theoretical constraints. We also analyze the parameter space for direct detection of...
In this work we study the one-loop realizations of the d = 5 operator $\bar L \tilde H N_R S$ that leads to Dirac neutrino masses, where $S$ is a singlet scalar field that hosts the QCD axion, $N_R$ represents three right-handed neutrinos, $L$ is the lepton doublet and $H$ is the SM Higgs boson. As usual, the axion arises from the breaking of the Peccei-Quinn symmetry, which in our setup we...
DEAP-3600 is a WIMP dark matter direct-detection experiment located deep underground at SNOLAB near Sudbury in Canada, which uses liquid argon as target material. This experiment has set the most stringent limits in argon. A recent study was developed using a Non-Relativistic Effective Field Theory (NREFT) to consider other dark matter-nucleon interactions. The research includes some specific...
The standard freeze-in paradigm has a hidden UV sensitivity in that the initial DM population is assumed to be exactly zero. We explore how a pre-existing population of DM, either alone or as part of a thermalized dark sector, affects the dynamics of freeze-in. The UV sensitivity of this more general scenario, which we dub “glaciation”, is manifested in the dependence of the late-time relic...
Many scenarios of physics beyond the Standard Model predict new particles with masses well below the electroweak scale. Low-energy, high luminosity colliders such as BABAR are ideally suited to discover these particles. We present several recent searches for low-mass dark sector particles at BABAR, including leptophilic scalars, self-interacting dark matter, and axion like particles produced...
The Belle II experiment at the asymmetric $e^+e^-$ collider, SuperKEKB, is a substantial upgrade of the Belle/KEKB experiment. Belle II aims to record 50 ab$^{-1}$ of data over the course of the project. During the first physics runs in 2018-2020, around 100 fb$^{-1}$ of data were collected. These early data include specifically-designed low-multiplicity triggers which allow a variety of...
If dark matter particles interact too feebly with ordinary matter, they have never been able to thermalize in the early universe. Such Feebly Interacting Massive Particles (FIMPs) would be therefore produced via the freeze-in mechanism. Testing FIMPs is a challenging task, given the smallness of their couplings. In this talk, after giving a brief overview on the phenomenology of FIMPs, I will...
In this talk, I will discuss the effects of self-interactions on the production of sterile-neutrino dark matter. For the case of self-interacting active neutrinos, the new interaction plays an important role in the resonant production of dark matter. We have analyzed such a scenario in the case of vector and scalar mediators. The case of self-interactions in the sterile sector provides an...
We present a multicomponent subGeV dark matter model where the new dark sector particles interact with each other and the Standard Model through a dark photon. The new massive gauge boson arises from a broken U(1) dark symmetry. We will show how the relic abundance depends on the dark sector parameter space and the very important dark matter conversion channel. Moreover, we will show that...
Dark matter complementarity is commonly thought of in terms of direct, indirect and collider searches. Indeed most dark matter models can be probed that way. However, if dark matter is very light or too heavy, or possesses velocity suppressed interactions, these techniques become not as effective. We will show that using neutron stars to realize a fourfold dark matter complementarity study ...
Three-level Dirac seesaw mechanisms with fermion dark matter candidates
