Publications

Order by: publication date number of citations

• Light thermal relics enabled by a second Higgs

  Johannes Herms, Sudip Jana, Vishnu P. K., Shaikh Saad

  SciPost Phys. Proc. 12, 046 (2023) · published 4 July 2023 | Toggle abstract · pdf

  Sub-GeV thermal relic dark matter typically requires the existence of a light mediator particle. We introduce the light two-Higgs-doublet portal, illustrated by a minimal UV-complete model for sub-GeV dark matter with kinematically forbidden annihilations into leptons. All new physics states in this scenario lie at or below the electroweak scale, affecting Higgs physics, the muon anomalous magnetic moment and potentially neutrino masses. Observation of radiative dark matter annihilation by future MeV gamma-ray telescopes would be key to unambiguously identify the scenario.

• The SU(2)$_{D}$ lepton portals for muon g - 2, W boson mass and dark matter

  Seong-Sik Kim, Hyun Min Lee, Adriana Guerrero Menkara, Kimiko Yamashita

  SciPost Phys. Proc. 12, 045 (2023) · published 4 July 2023 | Toggle abstract · pdf

  We propose a novel model which extends the Standard Model (SM) by introducing a $SU(2)_D$ gauge symmetry. In this model, a dark $SU(2)_D$ Higgs doublet and a Higgs bi-doublet can contribute to the muon g-2 anomaly and the $W$ boson mass, remaining in tune with the recent experimental results. At the same time, the isospin charged gauge boson of $SU(2)_D$ becomes a plausible candidate for Dark Matter(DM). We find that the resulting parameter space can fit the muon g-2, the W boson mass and the DM constraints simultaneously.

• Global fits of Dirac dark matter effective field theories

  Ankit Beniwal (On behalf of the GAMBIT Collaboration)

  SciPost Phys. Proc. 12, 044 (2023) · published 4 July 2023 | Toggle abstract · pdf

  In this proceeding, we present results from a global fit of Dirac fermion dark matter (DM) effective field theory (EFT) based on arXiv:2106.02056 using the GAMBIT framework. Here we show results only for the dimension-6 operators that describe the interactions between a gauge-singlet Dirac fermion and Standard Model quarks. Our global fit combines the latest constraints from Planck, direct and indirect DM detection, and the LHC. For DM mass below 100 GeV, it is impossible to simultaneously satisfy all constraints while maintaining the EFT validity at high energies. For higher masses, however, large regions of parameter space remain viable where the EFT is valid and saturates the observed DM abundance.

• Photon-ALP oscillations at CTA energies

  M. Kachelriess, J. Tjemsland

  SciPost Phys. Proc. 12, 043 (2023) · published 4 July 2023 | Toggle abstract · pdf

  Axions and axion-like-particles (ALPs) are well motivated beyond the standard model particles that can explain a variety of unsolved problems in physics, such as the strong CP problem and the nature of dark matter. These particles are characterised by their two-photon coupling, which leads to so-called photon-ALP oscillation as photons propagate through an external magnetic field. Such oscillations lead to characteristic signatures in the energy spectrum of high-energy photons from astrophysical sources, allowing us to probe the existence of ALPs and possibly dark matter. We review the signatures from ALPs in photon spectra and discuss a new method that can be used to directly search for the energy dependence of the oscillations. The focus is on photons at TeV-energies relevant for the upcoming Cherenkov Telescope Array (CTA).

• Can we really detect relic neutrinos?

  Yevheniia Cheipesh, Ivan Ridkokasha, Vadim Cheianov, Alexey Boyarsky

  SciPost Phys. Proc. 12, 042 (2023) · published 4 July 2023 | Toggle abstract · pdf

  Detecting relic neutrinos is a longstanding goal in fundamental physics. Experimentally, this goal is extremely challenging as the required energy resolution is defined by the tiny neutrino masses ($\sim$ 10 meV). The current consensus is that sufficient statistics together with a clean spectrum could only be achieved if beta decayers are attached to a solid state substrate. However, this inevitably imposes irreducible intrinsic limitations on the energy resolution coming from Heisenberg's uncertainty principle. This limitation appears to be critical for the currently accepted decayer - Tritium. Here, we analyze the state of the art approaches to mitigate this limitation and conclude that the most promising solution is to change Tritium for a heavier emitter. We find that the two suitable candidates are $^{171}$Tm, $^{63}$Ni.

  2 citations

• 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.

• 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.

• Approaching the first any light particle search II science run

  Aaron D. Spector for the ALPS Collaboration

  SciPost Phys. Proc. 12, 039 (2023) · published 4 July 2023 | Toggle abstract · pdf

  The Any Light Particle Search II (ALPS II) is a light-shining-through-a-wall (LSW) experiment based at DESY in Hamburg, Germany, that will search for axions and axion-like particles down to the coupling of the axion to two photons of $g_{a\gamma\gamma}$ >2$\times10^{-11}$ GeV$^{-1}$ for masses below 0.1 meV. ALPS II will use two strings of superconducting dipole magnets that are over one hundred meters in length, as well as optical cavities before and after the wall to boost the effective signal rate of the regenerated photons by more than 12 orders of magnitude when compared to previous generations of LSW experiments. Data taking with a simplified optical system is expected to begin in early 2023.

• Axion-like particle as cold dark matter via the misalignment mechanism with PQ symmetry unbroken during inflation

  Pawel Kozow, Marek Olechowski

  SciPost Phys. Proc. 12, 038 (2023) · published 4 July 2023 | Toggle abstract · pdf

  The QCD axion and axion-like particles (ALPs) are well motivated candidates for Cold Dark Matter (CDM). Such models may be divided into two classes depending on whether the associated Peccei-Quinn (PQ) symmetry is broken or not during inflation. The latter case is usually considered to be quite simple with relic density depending only on the corresponding decay constant and with no constraints from the known bounds on isocurvature perturbations. We will show that the situation is much more complicated. We will discuss conditions which should be fulfilled by ALP models with U(1) unbroken during inflation to be phenomenologically interesting.

• Probing ALPs at the LUXE experiment

  Federico Meloni on behalf of the LUXE collaboration

  SciPost Phys. Proc. 12, 037 (2023) · published 4 July 2023 | Toggle abstract · pdf

  The proposed LUXE experiment (LASER Und XFEL Experiment) at DESY, Hamburg, aims to probe QED in its non-perturbative regime. In order to do this, LUXE will study the interactions between 16.5 GeV electrons from the European XFEL and high-intensity laser pulses. This experiment also provides a unique opportunity to probe physics beyond the Standard Model: exploiting the large photon flux generated at LUXE, it is possible to design a dedicated detector to probe axion-like-particles up to a mass of 350 MeV and with photon coupling of $3 \cdot 10^{-6}$ GeV$^{-1}$. This reach is comparable to the projected sensitivity of experiments like FASER2 at the HL-LHC and NA62 operating in dump mode.