### Conveners

#### Dark Matter and Particle Astrophysics

- Tyler Corbett (ARC CoEPP Melbourne)

#### Dark Matter and Particle Astrophysics

- Anupam Mazumdar (Lancaster University)

#### Dark Matter and Particle Astrophysics

- Genevieve Belanger (Laboratoire d'Annecy-le-Vieux de Physique Théorique)

#### Dark Matter and Particle Astrophysics

- Anupam Mazumdar (Lancaster University)

#### Dark Matter and Particle Astrophysics

- Giorgio Busoni ()

#### Dark Matter and Particle Astrophysics

- Genevieve Belanger (Laboratoire d'Annecy-le-Vieux de Physique Théorique)

Recently a number of alternative dark matter models have been introduced as a means of explaining the physics of small-scale structure formation. These include, warm dark matter and dark matter with late kinetic decoupling both of which differ substantially from the canonical cold dark matter formalism. One interesting way of constraining the phenomenology in these models is to look at the...

We describe an eight-coupled-Boltzmann equation calculation of the mixed axion-higgsino dark matter scenario which is expected from natural SUSY. Typically the relic density is axion dominated unless late decaying axinos or saxions feed the WIMP abundance. While thermal leptogenesis is barely viable, non-thermal and Affleck-Dine leptogenesis remain robust scenarios to generate the...

We investigate the production of keV sterile neutrino dark matter via the decay of a frozen-in complex scalar with a feeble Higgs portal coupling. Sterile neutrinos at the keV range is an attractive class of model because it can naturally explain Standard Model neutrino masses and can be cosmologically warm dark matter. This is the first time a complex scalar has been considered in this...

I discuss the cosmological impact of dark matter bound state formation in the early universe in the context of complete simplified models of dark matter interactions. In particular, I show that the effects of relativity on the nature and behavior of these bound states are important to correctly describe the physics in cases of interest. I continue on to discuss the implications of these...

To gain for a more precise prediction of the supersymmetric dark matter relic density, we have calculated next-to-leading order SUSY-QCD corrections to neutralino (co)annihilation processes including Coulomb enhancement effects. We demonstrate that these corrections can have significant impact and are thus of general interest for parameter studies. For particle physics observables at...

I will discuss ultraviolet completion of the Standard Model Higgs inflation. I will argue why the Standard Model Higgs cannot be the inflaton once quantum corrections are taken into account.I will argue in this respect MSSM ( minimal supersymmetric Standard Model ) is still a plausible candidate to explain dark matter, baryogenesis and large scale structures.

We consider the indirect detection signals for a self-consistent hidden U (1) sector, containing a fermionic dark matter candidate, dark gauge boson and a Dark Higgs. The presence of an additional scalar, the Dark Higgs, provides a mass generation mechanism for the dark sector particles and is required to avoid unitarity violation at high energies. We find that the inclusion of the additional...

We consider Majorana dark matter annihilation to fermion - anti-fermion pair and a photon in the effective field theory paradigm, by introducing dimension 6 and dimension 8 operators in the Lagrangian. For a given value of the cut-off scale, the latter dominates the annihilation process for heavier dark matter masses. We find a cancellation in the dark matter annihilation to a fermion -...

Since the WIMP paradigm has dominated for decades, dark matter (DM) in the sub-GeV mass range is only now receiving significant attention. I will discuss indirect detection of such models in light of the recently proposed ComPair experiment, which will increase sensitivity to 1–100 MeV gamma rays by two orders of magnitude. Using a scalar-mediated model as an example, I illustrate how to...

We have studied a specific case that the dark matter particles annihilate into right-handed neutrinos. We calculate the predicted gamma-ray excess from the galactic center and compare our results with the data from the Fermi-LAT. An approximately 10-60 GeV right-handed neutrino with heavier dark matter particle can perfectly explain the observed spectrum. The annihilation cross section ⟨σv⟩...

Searches in CMS for dark matter in final states with invisible particles recoiling against hadronic final states are presented. Various topologies and kinematic variables are explored, as well as jet substructure as a means of tagging heavy bosons. The focus of the talk ...

Searches in CMS for dark matter in final states with invisible particles recoiling against leptons and photons are presented. Various topologies are explored, covering several specific dark-matter production modes. The talk focuses on the recent results obtained using data collected ...

Searches in CMS for dark matter in final states with invisible particles recoiling against top or bottom quarks are presented. Various topologies are explored, covering several specific dark-matter production modes. The focus of the talk is the recent results obtained using ...

Effective Field Theories have shown to suffer from some validity problems when applied to DM search at collider. EFT operators are generated by integrating out heavy mediators of some UV theory, and therefore are valid up to some energy scale below the mass of the integrated out particles.

To overcome such problems, different proposals have been made. An appealing possibility is certainly to...

After successful 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...

Astronomical and cosmological observations strongly suggest the presence of dark matter. The direct search for evidence of Weakly Interacting Massive Particle (WIMP) dark matter continues to be one of the forefront activities in experimental particle physics. In this talk I will give an overview of the evidences of dark matter and present in particular XENON1T experiment which has achieved...

DEAP-3600 is a single phase liquid argon (LAr) dark matter experiment, located 2 km underground at SNOLAB, in Sudbury, Ontario. The detector has 1 tonne fiducial mass of LAr. The target sensitivity to spin-independent scattering of 100 GeV WIMPs is 1$\times$10$^{-46}$ cm$^2$. The DEAP-3600 background target is <1 background events in the WIMP region of interest in 3 tonne-years exposure. ...

I will outline the unique direct detection phenomenology which arises if dark matter is self-interacting. The crucial point is that, in the Earth frame, the halo wind interaction with Earth-captured dark matter generically results in a spatially dependent near-Earth dark matter environment. This implies distinctive signatures in the direct detection signal, including latitudinal dependence,...

The Korea Invisible Mass Search (KIMS) searches for WIMP dark matter signals using an array of ultra-pure NaI(Tl) crystals. The target goal of the KIMS-NaI experiment is to confirm or reject the DAMA/LIBRA claim of an annual modulation signature in similar NaI(Tl) crystals. We have studied the properties of more then ten prototype NaI(Tl) crystals, each with different internal radioisotope...

I will examine the projected ability to reconstruct the mass, scattering, and annihilation cross section of dark matter in the new generation of large underground detectors in combination with diffuse gamma radiation from expected 15 years of data from Fermi-LAT observation of 46 local spiral dwarf galaxies and projected CTA sensitivity to a signal from the Galactic Center. I will consider...

The superpartner of the right-handed neutrino provides an alternative

to the neutralino WIMP dark matter in supersymmetry.

We consider the case where this feebly interacting particle is

produced via the decay of the long-lived next-to-lightest charged sfermion.

After taking into account constraints such as dark matter relic

density or big-bang nucleosynthesis, we discuss the discovery...

We combine and extend the analyses of effective scalar, vector, Majorana and Dirac fermion Higgs portal models of Dark Matter (DM), in which DM couples to the Standard Model (SM) Higgs boson via an operator of the form $\mathcal{O}_{\textrm{DM}}\, H^\dagger H$. For the fermion models, we take an admixture of scalar $\overline{\psi} \psi$ and pseudoscalar $\overline{\psi} i\gamma_5 \psi$...

We study the simplest singlet Majoron model for the dark radiation and dark matter and it 1-loop RGE running.

We found that a smaller effective number of neutrinos $\triangle N_{eff}\sim 0.05$ is preferred.

Moreover, a heavy scalar dark matter, $\rho$, of mass $1.5-4$ TeV is required by the stability of the scalar potential

and an operational type-I see-saw mechanism for neutrino masses....

We consider a scalar top-philic Dark Matter (DM) $S$ coupling, apart from the Higgs portal, exclusively to the right-handed top quark $t_R$ and a colored vector-like top partner $T$ with a Yukawa coupling $y_{ST}$ which we call the topVL portal. When the Higgs portal is closed and $y_{ST}$ is perturbative $ (<1)$, $TS\to (W^+b, gt)$, $SS\to t\bar{t}$ and $T\bar{T}\to (q\bar{q},gg)$ provide the...

We propose a general method to analytically solve transport equations as well as the bubble wall profile during a cosmic phase transition. For the bubble wall profile we approximately solve the general one dimensional problem and derive a perturbative series of corrections to this ansatz and prove convergence. We then present general analytic solutions for coupled transport equations that...

We review our recent work on gravitationally bound condensates formed by Hermitian bosons interacting with a potential energy $\Lambda^4[1-\cos(A/f)]$. We have used an expansion method to simplify the equations of motion. The expansion parameters are the binding energy of the condensed bosons, and the ratio between the scale of the Bose field $f$ and the Planck mass. Applying our analysis to...

We investigate the propagation of gravitational waves through the cosmic neutrino background, assuming it carries a non-zero lepton asymmetry. In this background, the graviton dispersion relation is found to exhibit birefringent behaviour leading to an enhancement/suppression of the gravitational wave amplitudes depending on the polarisation, where the magnitude of this effect is related to...

It has been shown that gravitational waves propagate through ideal fluids without experiencing any dispersion or dissipation. However, if the medium has a non-zero shear viscosity, gravitational waves will be dissipated at a rate proportional to $G \eta$?. We test Dark Matter and Dark Energy models with non-zero shear viscosity by calculating the dissipation of GW150914 which propagates over a...

Axions and axion-like particles are among the best-motivated candidates for dark matter. In particular, the QCD axion is capable of not only providing a dark matter candidate, but it also gives a natural explanation for the strong CP problem. Consequently, the detection of dark matter axions is of great interest as it would solve two of the most significant problems of modern physics. To this...

Axion-like particles (ALPs) can induce localised O(10%) oscillatory modulations in the spectra of photon sources passing through astrophysical magnetic fields. Ultra-deep Chandra observations of the Perseus cluster contain over 5×10^5 counts from the central NGC1275 AGN and represent a dataset of extraordinary quality for ALP searches. We use these to search for X-ray spectral irregularities...

We propose a new cosmological scenario for the production of the baryon asymmetry of the Universe which exploits a multistep phase transition in which SU(3) color symmetry is fist broken and then restored. Baryon production occurs during the initial transition mainly due to spontaneous breaking of B-L near the phase boundary. The same B-L violation leads to washout far away from the wall. ...