Publications

Order by: publication date number of citations

• Searching for wave-like dark matter with QSHS

  Ian Bailey, Bhaswati Chakraborty, Gemma Chapman, Edward J. Daw, John Gallop, Gianluca Gregori, Edward Hardy, Ling Hao, Edward Laird, Peter Leek, John March-Russell, Phil Meeson, Seaárbhan Ó Peatáin, Yuri Pashkin, Mitchell G. Perry, Michele Piscitelli, Edward Romans, Subir Sarkar, Paul J. Smith, Ningqiang Song, Mahesh Soni, Boon K. Tan, Stephen West, Stafford Withington

  SciPost Phys. Proc. 12, 040 (2023) · published 4 July 2023 | Toggle abstract · pdf

  In 2021 the Quantum Sensors for the Hidden Sector (QSHS) collaboration was founded in the UK and received funding to develop and demonstrate quantum devices with the potential to detect hidden sector particles in the $\mu$eV to 100 $\mu$eV mass window. The collaboration has been developing a range of devices. It is building a high-field, low-temperature facility at the University of Sheffield to characterise and test the devices in a haloscope geometry. This paper introduces the collaboration's motivation, aims, and progress.

• ISAI: Investigating Solar Axion by Iron-57

  Tomonori Ikeda, Toshihiro Fujii, Takeshi Go Tsuru, Yuki Amano, Kazuho Kayama, Masamune Matsuda, Hiromu Iwasaki, Mizuki Uenomachi, Kentaro Miuchi, Yoshiyuki Onuki, Yoshizumi Inoue, Akimichi Taketa

  SciPost Phys. Proc. 12, 041 (2023) · published 4 July 2023 | Toggle abstract · pdf

  The existence of the axion is a unique solution for the strong CP problem, and the axion is one of the most promising candidates of the dark matter. Investigating Solar Axion by Iron-57 (ISAI) is being prepared as a complemented table-top experiment to confirm the solar axion scenario. Probing an X-ray emission from the nuclear transitions associated with the axion-nucleon coupling is a leading approach. ISAI searches for the monochromatic 14.4 keV X-ray from the first excited state of $^{57}$Fe using a state-of-the-art pixelized silicon detector, dubbed XRPIX, under an extremely low-background environment. We highlight scientific objectives, experimental design and the latest status of ISAI.

• Improved Galactic diffuse emission model strengthens the case for a Millisecond Pulsar explanation of the Fermi GeV excess

  Oscar Macias, Martin Pohl, Chris Gordon, Phaedra Coleman

  SciPost Phys. Proc. 12, 049 (2023) · published 4 July 2023 | Toggle abstract · pdf

  After more than a decade since its discovery, the Galactic center gamma-ray excess - discovered with the Fermi Large Area Telescope - remains puzzling. While the spectrum of the signal can be explained by either dark matter or an unresolved population of millisecond pulsars, the spatial morphology of this excess seems to hold the key to separate the two theories. In this contribution, we present the results of a recent study in which we use bleeding edge models for interstellar gas, inverse Compton emission, and stellar mass models to reanalyze the Galactic center excess. We find that the spatial morphology of the excess is highly correlated with stellar matter in the Galactic bulge, providing strong support for the millisecond pulsar hypothesis.

• Ruling out QCD phase transition as a PBH origin of LIGO/Virgo events

  Joaquim Iguaz Juan

  SciPost Phys. Proc. 12, 052 (2023) · published 5 July 2023 | Toggle abstract · pdf

  The best-motivated scenario for a sizable primordial black hole (PBH) contribution to the LIGO/Virgo binary black hole mergers invokes the QCD phase transition, which naturally enhances the probability to form PBH with masses of stellar scale. We reconsider the expected mass function assuming a CMB-like primordial spectrum and associated not only to the QCD phase transition proper, but also the $e^{+}e^{-}$ annihilation process, and analyze the constraints on this scenario from a number of observations. We find that the scenario is not viable, unless an ad hoc mass evolution for the PBH mass function and a cutoff in power-spectrum very close to the QCD scale are introduced by hand.

• Exploring coherent elastic neutrino-nucleus scattering of reactor neutrinos with the NUCLEUS experiment

  C. Goupy, H. Abele, G. Angloher, A. Bento, L. Canonica, F. Cappella, L. Cardani, N. Casali, R. Cerulli, I. Colantoni, A. Cruciani, G. del Castello, M. del Gallo Roccagiovine, A. Doblhammer, S. Dorer, A. Erhart, M. Friendl, A. Garai, V. M. Ghete, D. Hauff, F. Jeanneau, E. Jericha, M. Kaznacheeva, A. Kinast, H. Kluck, A. Langenkämper, T. Lasserre, D. Lhuillier, M. Mancuso, B. Mauri, A. Mazzolari, E. Mazzucato, H. Neyrial, C. Nones, L. Oberauer, T. Ortmann, L. Pattavina, L. Peters, F. Petricca, W. Potzel, F. Pröbst, F. Pucci, F. Riendl, R. Rogly, M. Romagnoni, J. Rothe, N. Schermer, J. Schieck, S. Schönert, C. Schwertner, L. Scola, G. Soum Sidikov, L. Stodolsky, R. Strauss, M. Tamisari, C. Tomei, M. Vignati, M. Vivier, V. Wagner, A. Wex (The NUCLEUS collaboration)

  SciPost Phys. Proc. 12, 053 (2023) · published 5 July 2023 | Toggle abstract · pdf

  The NUCLEUS experiment aims to perform a high-precision measurement of Coherent Elastic Neutrino-Nucleus Scattering (CEvNS) at the EdF Chooz B nuclear power plant in France. CEvNS is a unique process to study neutrino properties and to search for physics beyond the Standard Model. The study of CEvNS is also important for light Dark-Matter searches. It could be a possible irreducible background for high-sensitivity Dark-Matter experiments. NUCLEUS is an experiment under construction based on ultra-low threshold ($\sim$20 eV$_{nr}$) cryogenic calorimeters, operated at tens-of-mK temperatures.

• Mergers as a probe of particle dark matter

  Anupam Ray

  SciPost Phys. Proc. 12, 056 (2023) · published 5 July 2023 | Toggle abstract · pdf

  Black holes below Chandrasekhar mass limit (1.4 $M_{\odot}$) can not be produced via any standard stellar evolution. Recently, gravitational wave experiments have also discovered unusually low mass black holes whose origin is yet to be known. We propose a simple yet novel formation mechanism of such low mass black holes. Non-annihilating particle dark matter, owing to their interaction with stellar nuclei, can gradually accumulate inside compact stars, and eventually swallows them to low mass black holes, ordinarily impermissible by the Chandrasekhar limit. We point out several avenues to test this proposal, concentrating on the cosmic evolution of the binary merger rates.

• Improved treatment of dark matter capture in compact stars

  Sandra Robles

  SciPost Phys. Proc. 12, 057 (2023) · published 5 July 2023 | Toggle abstract · pdf

  Compact stellar objects are promising cosmic laboratories to test the nature of dark matter (DM). DM captured by the strong gravitational field of these stellar remnants transfers kinetic energy to the star during the collision. This can have various effects such as anomalous heating of old compact stars. The proper calculation of the DM capture rate is key to derive bounds on DM interactions in any scenario involving DM accretion in a star. We improve former calculations, which rely on approximations, for both white dwarfs (WDs) and neutron stars (NSs). We account for the stellar structure, gravitational focusing, relativistic kinematics, Pauli blocking, realistic form factors, and strong interactions (NSs). Considering DM capture by scattering off either ions or degenerate electrons in WDs, we show that old WDs in DM-rich environments could probe the elusive sub-GeV mass regime for both DM-nucleon and DM-electron scattering. In NSs, DM can be captured via collisions with strongly interacting baryons or relativistic leptons. We project the NS sensitivity to DM-nucleon and DM-lepton scattering cross sections which greatly exceeds that of direct detection experiments, especially for low mass DM.

• Self-interacting dark matter on small and large scales

  Camila A. Correa

  SciPost Phys. Proc. 12, 059 (2023) · published 5 July 2023 | Toggle abstract · pdf

  In the self-interacting dark matter paradigm (hereafter SIDM), dark matter (DM) is assumed to have non-gravitational interactions with itself. SIDM has been constrained by observations of galaxy clusters. More recently, measurements of large DM densities at the center of the Milky Way's galaxy satellites are indicating that DM-DM interactions can potentially induce gravothermal core collapse. In this proceeding an overview of the combined measurements of cluster-size galaxies and kinematics of local satellite galaxies is used to argue that DM interactions should depend on the relative velocity of the DM particles.

• Self-similar solutions for fuzzy dark matter

  Raquel Galazo-Garcia, Philippe Brax, Patrick Valageas

  SciPost Phys. Proc. 12, 060 (2023) · published 5 July 2023 | Toggle abstract · pdf

  Self-similar solutions for fuzzy dark matter are very different from their counterparts in the standard cold dark matter model. In contrast to the familiar hierarchical collapse of the current model for structure formation, they correspond to an inverse hierarchical blow-up. This fact highlights the gravitational cooling process, which in the absence of dissipation, allows the system to eject excess energy through the intermittent expulsion of clumps of matter. These surprising behaviours are due to the wave properties of the Schrödinger equation and to the quantum pressure. These features are printed in the Eulerian density-velocity representation of the nonrelativistic scalar field, or in the Lagrangian representation in the mass-shell trajectories.

• ELOISE - Reliable background simulation at sub-keV energies

  Holger Kluck

  SciPost Phys. Proc. 12, 064 (2023) · published 5 July 2023 | Toggle abstract · pdf

  CaWO$_4$ and Al$_2$O$_3$ are well-established target materials used by experiments searching for rare events like the elastic scattering off of a hypothetical Dark Matter particle. In recent years, experiments have reached detection thresholds for nuclear recoils at the 10 eV-scale. At this energy scale, a reliable Monte Carlo simulation of the expected background is crucial. However, none of the publicly available general-purpose simulation packages are validated at this energy scale and for these targets. The recently started ELOISE project aims to provide reliable simulations of electromagnetic particle interactions for this use case by obtaining experimental reference data, validating the simulation code against them, and, if needed, calibrating the code to the reference data.