The comparable abundances of dark matter and baryons imply that the dark sector should be related to the QCD sector. In this talk, I will present a solution based on the unification of the dark and visible gauge groups. The unification guarantees common interactions and the unified gauge coupling at a high scale, which can explain the similar number densities and masses among the two sectors...
The origin of matter in the universe from a decaying inflaton field in the process of reheating is a basic feature of all realistic inflationary models.
In this work we study the evolution of Dark Matter as a freeze-out process during reheating assuming this occurs at a minimum of a scalar potential that is expanded as a quartic power of the inflaton field. We consider the simplest scenario...
In this work, we compare two SUSY extensions of the Standard Model, the MSSM and the NMSSM. Through numerical simulations, as well as utilizing MicrOMEGA's we perform a parameter space scan for each model, aiming to obtain a heavy first neutralino $M_{\chi_{1}^{0}} \in [1, 10]$ TeV to be the LSP as well as the values for its Photon Flux and Relic Density. Our research aims to provide possible...
We study the thermal freeze-out of two-component dark matter (DM). The freeze-out in a multicomponent dark sector can be more complex and richer than the canonical single-component WIMP DM. This is owing to the relevance of processes of conversions, co-annihilations, co-scatterings, decays and self-scatterings in addition to those of annihilations and elastic scatterings, which can affect the...
Dark matter particles in the sub-GeV range are exciting candidates as they evade the strongest constraints from direct direction using nuclear recoils. On the other hand, they are strongly constrained by the relic abundance, indirect detection with X-rays, observations of the Bullet cluster as well as searches at beam-bump and electron-positron colliders. In this talk I will show the results...
We study the coscattering mechanism in a simple Higgs portal which adds two real singlet scalars to the Standard Model. In this scenario, the lighter scalar is stabilized by a single $\mathcal{Z}_2$ symmetry and acts as the dark matter relic, whose freeze-out is driven by conversion processes. The heavier scalar becomes an unstable state which participates actively in the coscattering. We find...
The presence of a non-baryonic Dark Matter (DM) component in the Universe is inferred from the observation of its gravitational interaction. If Dark Matter interacts weakly with the Standard Model (SM) it could be produced at the LHC. The ATLAS Collaboration has developed a broad search program for DM candidates in final states with large missing transverse momentum produced in association...
Determination of the nature of dark matter is one of the most fundamental problems of particle physics and cosmology. This talk presents recent searches for dark matter particles from the CMS experiment at the Large Hadron Collider. The results are based on proton-proton collisions recorded at sqrt(s) = 13 TeV with the CMS detector.
Dark Matter models that employ a vector portal to a dark sector are usually treated as an effective theory that incorporates kinetic mixing of the photon with a new U(1) gauge boson, with the Z boson integrated out. However, a more complete theory must employ the full SU(2)LรU(1)รU(1)' gauge group, in which kinetic mixing of the Z boson with the new U(1)' gauge boson is taken into account. The...
We explore the Large Hadron Collider (LHC) constraints on dark matter models (DM) based on a new $\mathrm{U(1)}^{\prime}$ symmetry. Within this framework, DM production is mediated by a spin-1 or a scalar resonance. We focus on ATLAS and CMS experimental searches for spin-1 resonances with decays to jets, $b$-jets, top quarks, or DM, and the resonant production of a scalar that decays into a...
We reappraise the viability of asymmetric dark matter (ADM) realized as a Dirac fermion coupling dominantly to the Standard Model fermions. Treating the interactions of such a DM particle with quarks/leptons in an effective-interactions framework, we derive updated constraints using mono-jet searches from the Large Hadron Collider (LHC) and mono-photon searches at the Large Electron-Positron...
Conventional methods for elucidating the behavior of Dark Matter (DM), such as effective field theory (EFT) and simplified models, have inherent limitations, including their limited applicability in LHC searches for DM and lack of generality, respectively. In this study, we propose a hybrid formulation aimed at reconciling these shortcomings by addressing both generality and applicability at...
The particles composing the dark matter are thought to be distributed in haloes around the galaxies and then, they can be detected on Earth-based very sensitive instruments if they couple to normal matter other than gravitationally. However, the many unknowns and uncertainties in the properties of the particles and their distribution in the galaxy affect these direct searches of the dark...
DAMA/LIBRA observation of an annual modulation in the low energy detection rate compatible with that expected for dark matter has accumulated evidence for more than twenty years. It is the only hint about a positive identification of the dark matter, but it is in strong tension with the negative results of other experiments. However, this comparison depends on the models assumed for the dark...
As nuclear recoil direct detection experiments carve out more and more dark matter parameter space in the WIMP mass range, the need for searches probing lower masses has become evident. Since lower dark matter masses lead to smaller momentum transfers, we can look to the low momentum limit of nuclear recoils: phonon excitations in crystals. Single phonon experiments promise to eventually probe...
Direct-detection experiments seek signals generated by dark matter particles interacting with the microscopic constituents of detector materials.
In our work, we combine a non-relativistic effective theory for DM-electron interactions with the linear response theory to describe the scattering of sub-GeV DM particles in Si, Ge, Xe and Ar detectors.
Within this formalism, the detector...
In this work we present a modular procedure for estimating the dark matter (DM) parameters from DM direct detection experiments. We use machine learning techniques to perform a Bayesian analysis to determine the discovery potential and to estimate the model parameters without the need of assuming a likelihood functional form. Since each dataset can be trained individually, one of the main...
Motivated by the recent release of new results from five different pulsar timing array (PTA) experiments claiming to have found compelling evidence for primordial gravitational waves (GW) at nano-Hz frequencies, we consider the prospects of generating such a signal from inflationary blue-tilted tensor power spectrum in a specific dark matter (DM) scenario dubbed as Miracle-less WIMP. While...
An ultra slow roll phase during inflation could potentially produce large numbers of primordial black holes which are dark matter candidates. This scenario is considered with transitions from and to slow roll inflation. $\delta N$ analysis shows this model can only possess at most $f_{\text{NL}} = \mathcal{O}{(1)}$ non-Gaussianity. To compute the primordial black hole abundance, we keep the...
Metastable cosmic strings are gathering attention as potential progenitors of stochastic gravitatioanl wave background. They result from a two-step symmetry breaking $G\to H\to 1$ with $\pi_1(H)\ne 0$ and $\pi_1(G)=0$, and decay via internal monopole-antimonopole pair creation.
Conventionally, the breaking rate has been estimated by an infinitely thin string approximation, which requires a...
Under the assumption that the recent pulsar timing array evidence for a stochastic gravitational wave (GW) background at nanohertz frequencies is generated by metastable cosmic strings, we analyze the potential of present and future GW observatories for probing the change of particle degrees of freedom caused, e.g., by a supersymmetric (SUSY) extension of the Standard Model (SM). We find that...
Several Pulsar Timing Array collaborations have recently found evidence for the presence of a Gravitational Wave Background (GWB) at nHz frequencies. This background could either be sourced by the overlapping GW emission of a population of supermassive black hole binaries or by cosmological sources generating GW in the early Universe. In this talk, I will discuss the prospects of...
Peccei-Quinn (PQ) mechanism is a prominent solution to the strong CP problem. In this mechanism, spontaneous breaking of an anomalous global symmetry (PQ symmetry) generates a pseudo-Nambu-Goldstone boson called axion, which is also a dark matter candidate. From observational reasons, the energy scale of the symmetry breaking is constrained to be greater than about 10^9 GeV, or even more to...
We study the dynamics of axions at first-order phase transitions in non-Abelian gauge theories. When the duration of the phase transition is short compared to the timescale of the axion oscillations, the axion dynamics is similar to the trapped misalignment mechanism. On the other hand, if this is not the case, the axions are initially expelled from the inside of the bubbles, generating axion...
We present a new mechanism to generate a coherently oscillating dark vector field from axion-SU(2) gauge field dynamics during inflation. The SU(2) gauge field acquires a nonzero background sourced by an axion during inflation, and it acquires a mass through spontaneous symmetry breaking after inflation. We find that the coherent oscillation of the dark vector field can account for dark matter...
After several decades of intense experimental effort to find them, SUSY Neutralinos remain elusive and much of the attention has shifted to alternative Dark Matter (DM) candidates in the past few years. There still remain, nevertheless, large unexplored parameter regions inaccessible by direct (collider) detection experiments.
Indirect detection using current and next-generation air...
The nature of dark matter (DM) and its interaction with the Standard Model (SM) is one of the biggest open questions in physics nowadays. The vast majority of theoretically-motivated Ultralight-DM (ULDM) models predict that ULDM couples dominantly to the SM strong/nuclear sector. This coupling leads to oscillations of nuclear parameters that are detectable by comparing clocks with different...
Constraints on dark sector particles decaying into neutrinos typically focus on their impact on the effective number of relativistic species, $N_{eff}$, in the early Universe. However, for heavy relics with longer lifetimes, constraints mainly arise from the photo-disintegration of primordial abundances. The high-energy neutrinos injected by the decay can interact with both the thermal...
The fast orbital decay observed in some of the black hole Low-Mass X-ray binaries (BH-LMXBs) (of a few solar masses) in our Galaxy can be explained by the dynamical friction between Dark Matter (DM) and the companion stars orbiting around the BHs. In these cases the values of the index of the DM spike surrounding the BHs can be pinned down with an accuracy of a few percent, way better than...
