Alviss

The amount of energy released by a nuclear recoil ionizing the atoms of the active volume of detection appears "quenched" compared to an electron of the same kinetic energy. This different behavior in ionization between electrons and nuclei is described by the Ionization Quenching Factor (IQF) and it plays a crucial role in direct dark matter searches. For low kinetic energies (below $50~\mathrm{k...

The New Experiments With Spheres-Gas (NEWS-G) collaboration intends to achieve $\mathrm{sub-GeV/c^{2}}$ Weakly Interacting Massive Particles (WIMPs) detection using Spherical Proportional Counters (SPCs). SPCs are gaseous detectors relying on ionization with a single ionization electron energy threshold. The latest generation of SPC for direct dark matter searches has been installed at SNOLAB in C...

Coherent elastic neutrino-nucleus scattering (CE$\nu$NS) is a process in which neutrinos scatter on a nucleus which acts as a single particle. Though the total cross section is large by neutrino standards, CE$\nu$NS has long proven difficult to detect, since the deposited energy into the nucleus is $\sim$ keV. In 2017, the COHERENT collaboration announced the detection of CE$\nu$NS using a stopped...

Directional detection of non-baryonic Dark Matter is a promising search strategy for discriminating WIMP events from background. However, this strategy requires both a precise measurement of the energy down to a few keV and 3D reconstruction of tracks down to a few mm. To achieve this goal, the MIMAC project has been developed. It is based on a gaseous micro-TPC matrix, filled with CF4 and CHF3. T...

Many low-threshold experiments observe sharply rising event rates of yet unknown origins below a few hundred eV, and larger than expected from known backgrounds. Due to the significant impact of this excess on the dark matter or neutrino sensitivity of these experiments, a collective effort has been started to share the knowledge about the individual observations. For this, the EXCESS Workshop was...

The MIMAC project is a multi-chamber detector for Dark Matter search, aiming at measuring both track and ionization with a matrix of micromegas micro-TPC filled with He3 and CF4. Recent experimental results on the first measurements of the Helium quenching factor at low energy (1 keV recoil) are presented, together with the first simulation of the track reconstruction. Recontruction of track of al...

Recent N-Body simulations are in favor of the presence of a co-rotating Dark Disk that might contribute significantly (10%-50%) to the local Dark Matter density. Such substructure could have dramatic effect on directional detection. Indeed, in the case of a null lag velocity, one expects an isotropic WIMP velocity distribution arising from the Dark Disk contribution, which might weaken the strong ...

We have studied preheating of field perturbations in a 3-dimensional lattice including the effect of scalar metric perturbations, in two generic models of inflation: chaotic inflation with a quartic potential, and standard hybrid inflation. We have prepared the initial state for the classical evolution of the system with vanishing vector and tensor metric perturbations, consistent with the constra...

There is considerable experimental effort dedicated to the directional detection of particle dark matter. Gaseous mu-TPC detectors present the privileged features of being able to reconstruct the track and the energy of the recoil nucleus following the interaction. A precise measurement of the recoil energy is a key point for the directional search strategy. Quenching has to be taken into account,...