arXiv subjects

D. Alonso-González

Publications and source records attributed to D. Alonso-González.

4 recordsLinked to original sources

arXiv2026

Calibration and Performance of Germanium High Voltage Detectors for SuperCDMS SNOLAB

As SuperCDMS SNOLAB is getting ready to search for low mass dark matter particles, using cryogenic Ge and Si detectors, a set of six of the new SuperCDMS High Voltage (HV) detectors (four Ge and two Si) were tested in the Cryogenic Underground TEst facility (CUTE) at SNOLAB. This provided the first opportunity to gain experience with this new detector type and assess their performance thoroughly under low background conditions. Here we describe the SuperCDMS HV detector concept and discuss some of the newly developed analysis methods and approaches. Focusing on the Ge detectors, we investigate the detector performance under voltage bias (up to 90 V), exercise the low energy (keV to sub-keV range) calibration based on the electron capture peaks generated by the decay of $^{71}$Ge, assess the detector resolution, and demonstrate the unexpected (and encouraging) ability of these detectors to also measure high energy interactions in the hundreds of keV range with good resolution (better than 3% at 356 keV).

physics.ins-det↗

arXiv2026

GeV-scale thermal dark matter from dark photons: tightly constrained, yet allowed

GeV-scale thermal dark matter (DM) is highly constrained by the null results of both direct and indirect detection experiments, especially in the context of simplified models. In this work, we study the interplay of collider, direct and indirect detection constraints on an extension of the dark Abelian Higgs model that includes a Dirac fermionic DM candidate, $χ$. We take into account in a consistent fashion the dilution of the indirect and direct detection signals when the relic abundance of $χ$ is smaller than the total observed DM density (assuming that it is a subdominant component in those cases). As a consequence, we show that indirect detection constraints cannot probe regions with large kinetic mixing, and direct detection experiments provide the leading constraints in most of the parameter space. Collider searches for the (invisibly decaying) vector mediator provide complementary bounds in areas with large kinetic mixing. We find that the only way to avoid both indirect and direct detection limits is in narrow windows of parameter space close to $m_χ\lesssim m_{Z_D}/2$, when $χ$ is produced resonantly in the early universe, and it can constitute all of the DM. For this to happen, a small dark sector coupling is required: $α_D~\lesssim10^{-3}$ for DM masses below $6$ GeV, or $α_D~\lesssim10^{-5}$ for DM masses larger than $10$ GeV. The remaining areas of the parameter space can be probed in a complementary way by future direct detection experiments (which will narrow down the allowed area around the resonant region) and collider searches (which will set limits for smaller values of the kinetic mixing).

hep-ph↗

arXiv2026

Search for low-mass electron-recoil dark matter using a single-charge sensitive SuperCDMS-HVeV Detector

We present constraints on low-mass dark matter electron scattering and absorption interactions using a SuperCDMS high-voltage eV-resolution (HVeV) detector. Data were taken underground in the NEXUS facility located at Fermilab with an overburden of 225 meters of water equivalent. The experiment benefits from the minimizing of luminescence from the printed circuit boards in the detector holder used in all previous HVeV studies. A blind analysis of $6.1\,\mathrm{g\cdot days}$ of exposure produces exclusion limits for dark matter-electron scattering cross sections for masses as low as $1\,\mathrm{MeV}/c^2$, as well as on the photon-dark photon mixing parameter and the coupling constant between axionlike particles and electrons for particles with masses $>1.2\,\mathrm{eV}/c^2$ probed via absorption processes.

hep-ex↗

arXiv2024

Light Dark Matter Constraints from SuperCDMS HVeV Detectors Operated Underground with an Anticoincidence Event Selection

This article presents constraints on dark-matter-electron interactions obtained from the first underground data-taking campaign with multiple SuperCDMS HVeV detectors operated in the same housing. An exposure of 7.63 g-days is used to set upper limits on the dark-matter-electron scattering cross section for dark matter masses between 0.5 and 1000 MeV/$c^2$, as well as upper limits on dark photon kinetic mixing and axion-like particle axioelectric coupling for masses between 1.2 and 23.3 eV/$c^2$. Compared to an earlier HVeV search, sensitivity was improved as a result of an increased overburden of 225 meters of water equivalent, an anticoincidence event selection, and better pile-up rejection. In the case of dark-matter-electron scattering via a heavy mediator, an improvement by up to a factor of 25 in cross-section sensitivity was achieved.

hep-ex↗