The publications of the group (since May 2020) are ordered by the date they appeared in arXiv.org.
2025
2024
David Alonso-González, David Cerdeño, Marina Cermeño, and Andres D. Perez
2412.19890 [hep-ph]
In this work, we show that, if axion-like particles (ALPs) from core-collapse supernovae (SNe) couple to protons, they would produce very characteristic signatures in neutrino water Cherenkov detectors through their scattering off free protons via a p → p γ interactions. Specifically, sub-MeV ALPs would generate photons with energies ∼ 30 MeV, which could be observed by Super-Kamiokande and Hyper-Kamiokande as a delayed signal after a future detection of SN neutrinos. We apply this to a hypothetical neighbouring SN (at a maximum distance of 100 kpc) and demonstrate that the region in the parameter space with ALP masses between 10−4 MeV and 1 MeV and ALP-proton couplings in the range 3 × 10−6 − 4 × 10−5 could be probed. We argue that this new signature, combined with the one expected at ∼ 7 MeV from oxygen de-excitation, would allow us to disentangle ALP-neutron and ALP-proton couplings.
Abdallah et al [with Elías López-Asamar]
2412.14960 [hep-ex]
This summary of the second Terrestrial Very-Long-Baseline Atom Interferometry (TVLBAI) Workshop provides a comprehensive overview of our meeting held in London in April 2024, building on the initial discussions during the inaugural workshop held at CERN in March 2023. Like the summary of the first workshop, this document records a critical milestone for the international atom interferometry community. It documents our concerted efforts to evaluate progress, address emerging challenges, and refine strategic directions for future large-scale atom interferometry projects. Our commitment to collaboration is manifested by the integration of diverse expertise and the coordination of international resources, all aimed at advancing the frontiers of atom interferometry physics and technology, as set out in a Memorandum of Understanding signed by over 50 institutions.
David Alonso-González, David Cerdeño, Marina Cermeño, and Andres D. Perez
2412.09595 [hep-ph]
In this article, we claim that axion-like particles (ALPs) with MeV masses can be produced with semi-relativistic velocities in core-collapse supernovae (SNe), generating a diffuse galactic flux. We show that these ALPs can be detected in neutrino water Cherenkov detectors via ap→pγ interactions. Using Super-Kamiokande data, we derive new constraints on the ALP parameter space, excluding a region spanning more than one order of magnitude in the ALP-proton coupling above cooling bounds for ALP masses in the range of 1−80 MeV and ALP-proton couplings between 6×10−6−2×10−4. We show that the future Hyper-Kamiokande will be able to probe couplings as small as 2×10−6, fully closing the allowed region above SN 1987A cooling bounds.
Karen Macías Cárdenas, Gopolang Mohlabeng, Aaron C. Vincent
2411.03470 [hep-ph]
We investigate a dark matter model that couples to the standard model through a one-loop interaction with neutrinos, where the mediator particles also generate neutrino masses. We perform a global fit that incorporates dark matter relic abundance, primordial nucleosynthesis, neutrino mass, collider and indirect detection constraints. Thanks to the loop suppression, large couplings are allowed, and we find that the model parameters are constrained on all sides. Dark matter masses from 10 MeV to a few TeV are allowed, but sub-GeV masses are preferred for the model to also account for the heaviest neutrino mass. Though our results are valid for a single neutrino mass eigenstate at a time, the model and methods are generalizable to the full 3-flavor case.
Ernesto Arganda, Marcela Carena, Martín de los Rios, Andres D. Perez, Duncan Rocha, Rosa M. Sandá Seoane, Carlos E. M. Wagner
2410.13799 [hep-ph]
The search for weakly interacting matter particles (WIMPs) is one of the main objectives of the High Luminosity Large Hadron Collider (HL-LHC). In this work we use Machine-Learning (ML) techniques to explore WIMP radiative decays into a Dark Matter (DM) candidate in a supersymmetric framework. The minimal supersymmetric WIMP sector includes the lightest neutralino that can provide the observed DM relic density through its co-annihilation with the second lightest neutralino and lightest chargino. Moreover, the direct DM detection cross section rates fulfill current experimental bounds and provide discovery targets for the same region of model parameters in which the radiative decay of the second lightest neutralino into a photon and the lightest neutralino is enhanced. This strongly motivates the search for radiatively decaying neutralinos which, however, suffers from strong backgrounds. We investigate the LHC reach in the search for these radiatively decaying particles by means of cut-based and ML methods and estimate its discovery potential in this well-motivated, new physics scenario.
David Cerdeño, Andres Daniel Perez, Martín de los Ríos
2407.21008 [hep-ph]
We carry out a Bayesian analysis of dark matter (DM) direct detection data to determine particle model parameters using the Truncated Marginal Neural Ratio Estimation (TMNRE) machine learning technique. TMNRE avoids an explicit calculation of the likelihood, which instead is estimated from simulated data, unlike in traditional Markov Chain Monte Carlo (MCMC) algorithms. This considerably speeds up, by several orders of magnitude, the computation of the posterior distributions, which allows to perform the Bayesian analysis of an otherwise computationally prohibitive number of benchmark points. In this article we demonstrate that, in the TMNRE framework, it is possible to include, combine, and remove different datasets in a modular fashion, which is fast and simple as there is no need to re-train the machine learning algorithm or to define a combined likelihood. In order to assess the performance of this method, we consider the case of WIMP DM with spin-dependent and independent interactions with protons and neutrons in a xenon experiment. After validating our results with MCMC, we employ the TMNRE procedure to determine the regions where the DM parameters can be reconstructed. Finally, we present CADDENA, a Python package that implements the modular Bayesian analysis of direct detection experiments described in this work.
Daniel E. López-Fogliani, Andres D. Perez, Roberto Ruiz de Austri
2406.10372 [hep-ph]
The detection of Dark Matter (DM) remains a significant challenge in particle physics. This study exploits advanced machine learning models to improve detection capabilities of liquid xenon time projection chamber experiments, utilizing state-of-the-art transformers alongside traditional methods like Multilayer Perceptrons and Convolutional Neural Networks. We evaluate various data representations and find that simplified feature representations, particularly corrected S1 and S2 signals, retain critical information for classification. Our results show that while transformers offer promising performance, simpler models like XGBoost can achieve comparable results with optimal data representations. We also derive exclusion limits in the cross-section versus DM mass parameter space, showing minimal differences between XGBoost and the best performing deep learning models. The comparative analysis of different machine learning approaches provides a valuable reference for future experiments by guiding the choice of models and data representations to maximize detection capabilities.
Patrick Foldenauer and Jaime Hoefken Zink
JHEP 07 (2024) 096
2405.00094 [hep-ph]
DOI: 10.1007/JHEP07(2024)096
In recent years, the gauge group U(1)Lμ−Lτ has received a lot of attention since it can, in principle, account for the observed excess in the anomalous muon magnetic moment (g−2)μ, as well as the Hubble tension. Due to unavoidable, loop-induced kinetic mixing with the SM photon and Z, the U(1)Lμ−Lτ gauge boson A′ can contribute to stellar cooling via decays into neutrinos. In this work, we perform for the first time an \textit{ab initio} computation of the neutrino emissivities of white dwarf stars due to plasmon decay in a model of gauged U(1)Lμ−Lτ. Our central finding is that an observation of the early-stage white dwarf neutrino luminosity at the 30% level could exclude (or partially exclude) the remaining allowed parameter space for explaining (g−2)μ. In this work, we present the relevant white dwarf sensitivities over the entire A′ mass range. In particular, we have performed a rigorous computation of the luminosities in the resonant regime, where the A′ mass is comparable to the white dwarf plasma frequencies.
2023
Ernesto Arganda, Daniel A. Díaz, Andres D. Perez, Rosa Sandá Seoane, Alejandro Szynkman
Phys.Rev.D 109 (2024) 5, 055032
2309.05407 [hep-ph]
DOI: 10.1103/PhysRevD.109.055032
We study the impact of machine-learning algorithms on LHC searches for leptoquarks in final states with hadronically decaying tau leptons, multiple b-jets, and large missing transverse momentum. Pair production of scalar leptoquarks with decays only into third-generation leptons and quarks is assumed. Thanks to the use of supervised learning tools with unbinned methods to handle the high-dimensional final states, we consider simple selection cuts which would possibly translate into an improvement in the exclusion limits at the 95% confidence level for leptoquark masses with different values of their branching fraction into charged leptons. In particular, for intermediate branching fractions, we expect that the exclusion limits for leptoquark masses extend to ∼1.3 TeV. As a novelty in the implemented unbinned analysis, we include a simplified estimation of some systematic uncertainties with the aim of studying their possible impact on the stability of the results. Finally, we also present the projected sensitivity within this framework at 14 TeV for 300 fb-1 and 3000 fb-1 that extends the upper limits to ∼1.6 TeV and ∼1.8 TeV, respectively.
LUX-ZEPLIN Collaboration [with Elías López-Asamar]
Phys.Rev.D 108 (2023) 7, 072006
2307.15753 [hep-ex]
DOI: 10.1103/PhysRevD.108.072006
The LUX-ZEPLIN (LZ) experiment is a dark matter detector centered on a dual-phase xenon time projection chamber. We report searches for new physics appearing through few-keV-scale electron recoils, using the experiment’s first exposure of 60 live days and a fiducial mass of 5.5t. The data are found to be consistent with a background-only hypothesis, and limits are set on models for new physics including solar axion electron coupling, solar neutrino magnetic moment and millicharge, and electron couplings to galactic axion-like particles and hidden photons. Similar limits are set on weakly interacting massive particle (WIMP) dark matter producing signals through ionized atomic states from the Migdal effect.
David Alonso-González, Dorian W. P. Amaral, Adriana Bariego-Quintana, David Cerdeño, Martín de los Rios
JHEP 12 (2023) 096
2307.05176 [hep-ph]
DOI: 10.1007/JHEP12(2023)096
We explore the complementarity of direct detection (DD) and spallation source (SS) experiments for the study of sterile neutrino physics. We focus on the sterile baryonic neutrino model: an extension of the Standard Model that introduces a massive sterile neutrino with couplings to the quark sector via a new gauge boson. In this scenario, the inelastic scattering of an active neutrino with the target material in both DD and SS experiments gives rise to a characteristic nuclear recoil energy spectrum that can allow for the reconstruction of the neutrino mass in the event of a positive detection. We first derive new bounds on this model based on the data from the COHERENT collaboration on CsI and LAr targets, which we find do not yet probe new areas of the parameter space. We then assess how well future SS experiments will be able to measure the sterile neutrino mass and mixings, showing that masses in the range 15-50 MeV can be reconstructed. We show that there is a degeneracy in the measurement of the sterile neutrino mixing that substantially affects the reconstruction of parameters for masses of the order of 40 MeV. Thanks to their lower energy threshold and sensitivity to the solar tau neutrino flux, DD experiments allow us to partially lift the degeneracy in the sterile neutrino mixings and considerably improve its mass reconstruction down to 9 MeV. Our results demonstrate the excellent complementarity between DD and SS experiments in measuring the sterile neutrino mass and highlight the power of DD experiments in searching for new physics in the neutrino sector.
C. Antel et al. [with Patrick Foldenauer]
Eur.Phys.J.C 83 (2023) 12, 1122
2305.01715 [hep-ph]
DOI: 10.1140/epjc/s10052-023-12168-5
SuperCDMS Collaboration [with David Alonso González, David Cerdeño, Elías López Asamar, and Martín de los Ríos]
Physical Review Letters 131.9 (2023): 091801
2303.02196 [physics.ins-det]
DOI: 10.1103/PhysRevLett.131.091801
We measured the nuclear–recoil ionization yield in silicon with a cryogenic phonon-sensitive gram-scale detector. Neutrons from a mono-energetic beam scatter off of the silicon nuclei at angles corresponding to energy depositions from 4 keV down to 100 eV, the lowest energy probed so far. The results show no sign of an ionization production threshold above 100 eV. These results call for further investigation of the ionization yield theory and a comprehensive determination of the detector response function at energies below the keV scale.
Dorian W.P Amaral, David Cerdeño, Andrew Cheek and Patrick Foldenauer
JHEP 07 (2023) 071
2302.12846 [hep-ph]
DOI: 10.1007/JHEP07(2023)071
In this article, we study the potential of direct detection experiments to explore the parameter space of general non-standard neutrino interactions (NSI) via solar neutrino scattering. Due to their sensitivity to neutrino-electron and neutrino-nucleus scattering, direct detection provides a complementary view of the NSI landscape to that of spallation sources and neutrino oscillation experiments. In particular, the large admixture of tau neutrinos in the solar flux makes direct detection experiments well-suited to probe the full flavour space of NSI. To study this, we develop a re-parametrisation of the NSI framework that explicitly includes a variable electron contribution and allows for a clear visualisation of the complementarity of the different experimental sources. Using this new parametrisation, we explore how previous bounds from spallation source and neutrino oscillation experiments are impacted. For the first time, we compute limits on NSI from the first results of the XENONnT and LUX-ZEPLIN experiments, and we obtain projections for future xenon-based experiments. These computations have been performed with our newly developed software package, SNuDD. Our results demonstrate the importance of using a more general NSI parametrisation and indicate that next generation direct detection experiments will become powerful probes of neutrino NSI.
SuperCDMS Collaboration [with David Alonso González, David Cerdeño, Elías López Asamar and Martín de los Ríos]
Phys.Rev.D 107 (2023) 11, 2023
2302.09115 [hep-ex]
DOI: 10.1103/PhysRevD.107.112013
We present a new analysis of previously published of SuperCDMS data using a profile likelihood framework to search for sub-GeV dark matter (DM) particles through two inelastic scattering channels: bremsstrahlung radiation and the Migdal effect. By considering these possible inelastic scattering channels, experimental sensitivity can be extended to DM masses that are undetectable through the DM-nucleon elastic scattering channel, given the energy threshold of current experiments. We exclude DM masses down to 220 MeV/c2 at 2.7×10−30 cm2 via the bremsstrahlung channel. The Migdal channel search provides overall considerably more stringent limits and excludes DM masses down to 30 MeV/c2 at 5.0×10−30 cm2.
David Cerdeño, Marina Cermeño, Yasaman Farzan
Phys.Rev.D 107 (2023) 12, 123012
2301.00661 [hep-ph]
DOI: 10.1103/PhysRevD.107.123012
In this article, we study the on-shell production of low-mass vector mediators from neutrino-antineutrino coalescence in the core of protoneutron stars. Taking into account the radial dependence of the density, energy, and temperature inside the protoneutron star, we compute the neutrino-antineutrino interaction rate in the star interior in the well-motivated U(1)Lmu-Ltau model. First, we determine the values of the coupling above which neutrino-antineutrino interactions dominate over the Standard Model neutrino-nucleon scattering. We argue that, although in this regime a redistribution of the neutrino energies might take place, making low-energy neutrinos more trapped, this only affects a small part of the neutrino population and it cannot be constrained with the SN 1987A data. Thus, contrary to previous claims, the region of the parameter space where the U(1)Lmu-Ltau model explains the discrepancy in the muon anomalous magnetic moment is not ruled out. We then focus on small gauge couplings, where the decay length of the new gauge boson is larger than the neutrino-nucleon mean free path, but still smaller than the size of protoneutron star. We show that in this regime, the on-shell production of a long-lived Z’ and its subsequent decay into neutrinos can significantly reduce the duration of the neutrino burst, probing values of the coupling below O(10^-7) for mediator masses between 10 and 100 MeV. This disfavors new areas of the parameter space of the U(1)Lmu-Ltau model.
2022
Ernesto Arganda, Andres D. Perez, Martin de los Rios, Rosa Sandá Seoane
Eur.Phys.J.C 83 (2023) 12, 1158
2211.04806 [hep-ph]
DOI: 10.1140/epjc/s10052-023-12314-z
Machine-learned likelihoods (MLL) combines machine-learning classification techniques with likelihood-based inference tests to estimate the experimental sensitivity of high-dimensional data sets. We extend the MLL method by including kernel density estimators (KDE) to avoid binning the classifier output to extract the resulting one-dimensional signal and background probability density functions. We first test our method on toy models generated with multivariate Gaussian distributions, where the true probability distribution functions are known. Later, we apply the method to two cases of interest at the LHC: a search for exotic Higgs bosons, and a Z′Z′ boson decaying into lepton pairs. In contrast to physical-based quantities, the typical fluctuations of the ML outputs give non-smooth probability distributions for pure-signal and pure-background samples. The non-smoothness is propagated into the density estimation due to the good performance and flexibility of the KDE method. We study its impact on the final significance computation, and we compare the results using the average of several independent ML output realizations, which allows us to obtain smoother distributions. We conclude that the significance estimation turns out to be not sensible to this issue.
Juan Antonio Aguilar Saavedra, José Cano, David Cerdeño, José Miguel No
Phys.Rev.D 106 (2022) 11, 115023
2206.01214 [hep-ph]
DOI: 10.1103/PhysRevD.106.115023
We study exotic Higgs decays h→ZX, with X an invisible beyond the Standard Model (SM) particle, resulting in a semi-dark final state. Such exotic Higgs decays may occur in theories of axion-like-particles (ALPs), dark photons or pseudoscalar mediators between the SM and dark matter. The SM process h→Zνν¯ represents an irreducible «neutrino floor» background to these new physics searches, providing also a target experimental sensitivity for them. We analyze h→Z+invisible searches at the LHC and a future ILC, showing that these exotic Higgs decays can yield sensitivity to unexplored regions of parameter space for ALPs and dark matter models.
Juan Antonio Aguilar Saavedra, José Cano, David Cerdeño, José Miguel No
Phys.Rev.D 106 (2022) 11, 115023
2206.01214 [hep-ph]
DOI: 10.1103/PhysRevD.106.115023
We study exotic Higgs decays h→ZX, with X an invisible beyond the Standard Model (SM) particle, resulting in a semi-dark final state. Such exotic Higgs decays may occur in theories of axion-like-particles (ALPs), dark photons or pseudoscalar mediators between the SM and dark matter. The SM process h→Zνν¯ represents an irreducible «neutrino floor» background to these new physics searches, providing also a target experimental sensitivity for them. We analyze h→Z+invisible searches at the LHC and a future ILC, showing that these exotic Higgs decays can yield sensitivity to unexplored regions of parameter space for ALPs and dark matter models.
SuperCDMS Collaboration [with David Cerdeño and Elías López-Asamar]
Phys.Rev.D 105 (2022) 11, 112006
2204.08038 [hep-ex]
DOI: 10.1103/PhysRevD.105.112006
Recent experiments searching for sub-GeV/c2 dark matter have observed event excesses close to their respective energy thresholds. Although specific to the individual technologies, the measured excess event rates have been consistently reported at or below event energies of a few-hundred eV, or with charges of a few electron-hole pairs. In the present work, we operated a 1-gram silicon SuperCDMS-HVeV detector at three voltages across the crystal (0 V, 60 V and 100 V). The 0 V data show an excess of events in the tens of eV region. Despite this event excess, we demonstrate the ability to set a competitive exclusion limit on the spin-independent dark matter–nucleon elastic scattering cross section for dark matter masses of (100) MeV/c2, enabled by operation of the detector at 0 V potential and achievement of a very low (10) eV threshold for nuclear recoils. Comparing the data acquired at 0 V, 60 V and 100 V potentials across the crystal, we investigated possible sources of the unexpected events observed at low energy. The data indicate that the dominant contribution to the excess is consistent with a hypothesized luminescence from the printed circuit boards used in the detector holder.
SuperCSMS Collaboration [with David Cerdeño and Elías López-Asamar]
Contribution to Snowmass 2021
2203.08463 [physics.ins-det]
The SuperCDMS Collaboration is currently building SuperCDMS SNOLAB, a dark matter search focused on nucleon-coupled dark matter in the 1-5 GeV/c2 mass range. Looking to the future, the Collaboration has developed a set of experience-based upgrade scenarios, as well as novel directions, to extend the search for dark matter using the SuperCDMS technology in the SNOLAB facility. The experienced-based scenarios are forecasted to probe many square decades of unexplored dark matter parameter space below 5 GeV/c2, covering over 6 decades in mass: 1-100 eV/c2 for dark photons and axion-like particles, 1-100 MeV/c2 for dark-photon-coupled light dark matter, and 0.05-5 GeV/c2 for nucleon-coupled dark matter. They will reach the neutrino fog in the 0.5-5 GeV/c2 mass range and test a variety of benchmark models and sharp targets. The novel directions involve greater departures from current SuperCDMS technology but promise even greater reach in the long run, and their development must begin now for them to be available in a timely fashion.
The experienced-based upgrade scenarios rely mainly on dramatic improvements in detector performance based on demonstrated scaling laws and reasonable extrapolations of current performance. Importantly, these improvements in detector performance obviate significant reductions in background levels beyond current expectations for the SuperCDMS SNOLAB experiment. Given that the dominant limiting backgrounds for SuperCDMS SNOLAB are cosmogenically created radioisotopes in the detectors, likely amenable only to isotopic purification and an underground detector life-cycle from before crystal growth to detector testing, the potential cost and time savings are enormous and the necessary improvements much easier to prototype.
SuperCDMS Collaboration [with David Cerdeño and Elías López-Asamar]
Phys.Rev.D 105 (2022) 12, 122002
2202.07043 [physics.ins-det]
DOI: 10.1103/PhysRevD.105.122002
Two photo-neutron sources, 88Y9Be and 124Sb9Be, have been used to investigate the ionization yield of nuclear recoils in the CDMSlite germanium detectors by the SuperCDMS collaboration. This work evaluates the yield for nuclear recoil energies between 1 keV and 7 keV at a temperature of ∼ 50 mK. We use a Geant4 simulation to model the neutron spectrum assuming a charge yield model that is a generalization of the standard Lindhard model and consists of two energy dependent parameters. We perform a likelihood analysis using the simulated neutron spectrum, modeled background, and experimental data to obtain the best fit values of the yield model. The ionization yield between recoil energies of 1 keV and 7 keV is shown to be significantly lower than predicted by the standard Lindhard model for germanium. There is a general lack of agreement among different experiments using a variety of techniques studying the low-energy range of the nuclear recoil yield, which is most critical for interpretation of direct dark matter searches. This suggests complexity in the physical process that many direct detection experiments use to model their primary signal detection mechanism and highlights the need for further studies to clarify underlying systematic effects that have not been well understood up to this point.
2021
R. Alves Batista et al. [with David Cerdeño]
2110.10074 [astro.ph.HE]
Astroparticle physics is undergoing a profound transformation, due to a series of extraordinary new results, such as the discovery of high-energy cosmic neutrinos with IceCube, the direct detection of gravitational waves with LIGO and Virgo, and many others. This white paper is the result of a collaborative effort that involved hundreds of theoretical astroparticle physicists and cosmologists, under the coordination of the European Consortium for Astroparticle Theory (EuCAPT). Addressed to the whole astroparticle physics community, it explores upcoming theoretical opportunities and challenges for our field of research, with particular emphasis on the possible synergies among different subfields, and the prospects for solving the most fundamental open questions with multi-messenger observations.
David Cerdeño, Marina Cermeño, M. Ángeles Pérez-García, Elliott Reid
Phys.Rev.D 104 (2021) 6, 063013
2106.11660 [hep-ph]
DOI: 10.1103/PhysRevD.104.06301
In this article, we reevaluate supernovae (SN) constraints on the diffusion time of neutrinos for a family of extensions of the Standard Model that incorporate new light scalar and vector mediators. We compute the neutrino mean free path, taking into account medium effects in the neutrino-nucleon scattering cross-section, and a radial dependence of the density, energy, and temperature inside the proto-neutron star to determine the coupling strengths compatible with SN1987A constraints on the time duration signal of diffusing neutrinos. We show that medium effects can induce an order of magnitude enhancement in the neutrino mean free path with respect to the vacuum calculation. The increase is more significant when new physics terms dominate over the Standard Model contribution (that is, for small mediator mass and large couplings). Finally, we interpret these results as bounds on the parameter space of a vector U(1)B−L model and scalar lepton number conserving and lepton number violating scenarios, improving on previous results in the literature where medium effects were ignored. We show that SN constraints on the neutrino diffusion time lie within regions of the parameter space that are already ruled out by other experimental constraints. We also comment on potential limits due to changes in the SN equation of state or right-handed neutrino free-streaming, but argue that detailed numerical simulations are needed to improve the reliability of these limits.
Dorian W.P. Amaral, David Cerdeño, Andrew Cheek, Patrick Foldenauer
Eur.Phys.J.C 81 (2021) 861
2104.03297 [hep-ph]
DOI: 10.1140/epjc/s10052-021-09670-z
The recent measurement of the muon anomalous magnetic moment by the Fermilab E989 experiment, when combined with the previous result at BNL, has confirmed the tension with the SM prediction at 4.2σ CL, strengthening the motivation for new physics in the leptonic sector. Among the different particle physics models that could account for such an excess, a gauged U(1)Lμ−Lτ stands out for its simplicity. In this article, we explore how the combination of data from different future probes can help identify the nature of the new physics behind the muon anomalous magnetic moment. In particular, we contrast U(1)Lμ−Lτ with an effective U(1)Lμ-type model. We first show that muon fixed target experiments (such as NA64μ) will be able to measure the coupling of the hidden photon to the muon sector in the region compatible with (g−2)μ, and will have some sensitivity to the hidden photon’s mass. We then study how experiments looking for coherent elastic neutrino-nucleus scattering (CEνNS) at spallation sources will provide crucial additional information on the kinetic mixing of the hidden photon. When combined with NA64μ results, the exclusion limits (or reconstructed regions) of future CEνNS detectors will also allow for a better measurement of the mediator mass. Finally, the observation of nuclear recoils from solar neutrinos in dark matter direct detection experiments will provide unique information about the coupling of the hidden photon to the tau sector. The signal expected for U(1)Lμ−Lτ is larger than for U(1)Lμ with the same kinetic mixing, and future multi-ton liquid xenon proposals (such as DARWIN) have the potential to confirm the former over the latter.
SuperCDMS Collaboration [with David Cerdeño]
Phys.Rev.Lett. 127 (2021) 8, 081802
2011.09183 [hep-ex]
DOI: 10.1103/PhysRevLett.127.081802
The Cryogenic Dark Matter Search low ionization threshold experiment (CDMSlite) achieved efficient detection of very small recoil energies in its germanium target, resulting in sensitivity to Lightly Ionizing Particles (LIPs) in a previously unexplored region of charge, mass, and velocity parameter space. We report first direct-detection limits calculated using the optimum interval method on the vertical intensity of cosmogenically-produced LIPs with an electric charge smaller than e/(3×105), as well as the strongest limits for charge ≤e/160, with a minimum vertical intensity of 1.36×10−7\,cm−2s−1sr−1 at charge e/160. These results apply over a wide range of LIP masses (5\,MeV/c2 to 100\,TeV/c2) and cover a wide range of βγ values (0.1 — 106), thus excluding non-relativistic LIPs with βγ as small as 0.1 for the first time.
SuperCDMS Collaboration [with David Cerdeño]
Phys.Rev.Lett. 127 (2021) 061801
2007.14289 [hep-ex]
DOI: 10.1103/PhysRevLett.127.061801
We present limits on spin-independent dark matter-nucleon interactions using a 10.6 g Si athermal phonon detector with a baseline energy resolution of σE=3.86±0.04 (stat.)+0.19−0.00 (syst.) eV. This exclusion analysis sets the most stringent dark matter-nucleon scattering cross-section limits achieved by a cryogenic detector for dark matter particle masses from 93 to 140 MeV/c2, with a raw exposure of 9.9 g⋅d acquired at an above-ground facility. This work illustrates the scientific potential of detectors with athermal phonon sensors with eV-scale energy resolution for future dark matter searches.
2020
Dorian WP Amaral, David Cerdeño, Andrew Cheek, Patrick Foldenauer
JHEP 12 (2020) 155
2006.11225 [hep-ph]
DOI: 10.1007/JHEP12(2020)155
Models of gauged U(1)Lμ−Lτ can provide a solution to the long-standing discrepancy between the theoretical prediction for the muon anomalous magnetic moment and its measured value. The extra contribution is due to a new light vector mediator, which also helps to alleviate an existing tension in the determination of the Hubble parameter. In this article, we explore ways to probe this solution via the scattering of solar neutrinos with electrons and nuclei in a range of experiments and considering high and low solar metallicity scenarios. In particular, we reevaluate Borexino constraints on neutrino-electron scattering, finding them to be more stringent than previously reported, and already excluding a part of the (g − 2)μ explanation with mediator masses smaller than 2 × 10^−2 GeV. We then show that future direct dark matter detectors will be able to probe most of the remaining solution. Due to its large exposure, LUX-ZEPLIN will explore regions with mediator masses up to 5 × 10^−2 GeV and DARWIN will be able to extend the search beyond 10^−1 GeV, thereby covering most of the area compatible with (g − 2)μ. For completeness, we have also computed the constraints derived from the recent XENON1T electron recoil search and from the CENNS-10 LAr detector, showing that none of them excludes new areas of the parameter space. Should the excess in the muon anomalous magnetic moment be confirmed, our work suggests that direct detection experiments could provide crucial information with which to test the U(1)Lμ−Lτ solution, complementary to efforts in neutrino experiments and accelerators.
Celine Bœhm, David Cerdeño, Malcolm Fairbairn, Pedro A. N. Machado, Aaron C. Vincent
Phys.Rev.D 102 (2020) 115013
2006.11250 [hep-ph]
DOI: 10.1103/PhysRevD.102.115013
We examine the recently-reported low-energy electron recoil spectrum observed at the XENON1T underground dark matter direct detection experiment, in the context of new interactions with solar neutrinos. In particular we show that scalar and vector mediators with masses ≲50 keV coupled to leptons could already leave a visible signature in the XENON1T experiment, similar to the observed peak below 7 keV. This signals that dark matter detectors are already competing with neutrino scattering experiments such as GEMMA, CHARM-II and Borexino. If these results from XENON1T are interpreted as a new signal of such physics, the parameters which fit the excess face challenges from astrophysics which seem very difficult to overcome. If they are rather viewed as a constraint on new couplings, they herald the start of an era of novel precise probes of physics beyond the standard model with dark matter detectors.
SuperCDMS Collaboration [with David Cerdeño]
Phys.Rev.D 102 (2020) 9, 091101
2005.14067 [hep-ex]
DOI: 10.1103/PhysRevD.102.091101
This article presents an analysis and the resulting limits on light dark matter inelastically scattering off of electrons, and on dark photon and axion-like particle absorption, using a second-generation SuperCDMS high-voltage eV-resolution detector. The 0.93 gram Si detector achieved a 3 eV phonon energy resolution; for a detector bias of 100 V, this corresponds to a charge resolution of 3% of a single electron-hole pair. The energy spectrum is reported from a blind analysis with 1.2 gram-days of exposure acquired in an above-ground laboratory. With charge carrier trapping and impact ionization effects incorporated into the dark matter signal models, the dark matter-electron cross section σ¯e is constrained for dark matter masses from 0.5–104MeV/c2; in the mass range from 1.2–50 eV/c2 the dark photon kinetic mixing parameter ε and the axioelectric coupling constant gae are constrained. The minimum 90% confidence-level upper limits within the above mentioned mass ranges are σ¯e=8.7×10−34 cm2, ε=3.3×10−14, and gae=1.0×10−9.
SuperCDMS Collaboration [with David Cerdeño]
Phys.Rev.D 101 (2020) 5, 052008, Phys.Rev.D 103 (2021) 3, 039901 (erratum)
1911.11905 [hep-ex]
DOI: 10.1103/PhysRevD.101.052008, 10.1103/PhysRevD.103.039901
We present an analysis of electron recoils in cryogenic germanium detectors operated during the SuperCDMS Soudan experiment. The data are used to set new constraints on the axioelectric coupling of axion-like particles and the kinetic mixing parameter of dark photons, assuming the respective species constitutes all of the galactic dark matter. This study covers the mass range from 40 eV/c2 to 500 eV/c2 for both candidates, excluding previously untested parameter space for masses below ~1 keV/c2. For the kinetic mixing of dark photons, values below 10−15 are reached for particle masses around 100 eV/c2; for the axioelectric coupling of axion-like particles, values below 10−12 are reached for particles with masses in the range of a few-hundred eV/c2.
Nassim Bozorgnia, Azadeh Fattahi, Carlos S. Frenk, Andrew Cheek, David Cerdeño
JCAP 07 (2020) 036
1910.07536 [astro-ph.GA]
DOI: 10.1088/1475-7516/2020/07/036
We study the properties of the dark matter component of the radially anisotropic stellar population recently identified in the Gaia data, using magneto-hydrodynamical simulations of Milky Way-like halos from the Auriga project. We identify 10 simulated galaxies that approximately match the rotation curve and stellar mass of the Milky Way. Four of these have an anisotropic stellar population reminiscent of the Gaia structure. We find an anti-correlation between the dark matter mass fraction of this population in the Solar neighbourhood and its orbital anisotropy. We estimate the local dark matter density and velocity distribution for halos with and without the anisotropic stellar population, and use them to simulate the signals expected in future xenon and germanium direct detection experiments. We find that a generalized Maxwellian distribution fits the dark matter halo integrals of the Milky Way-like halos containing the radially anisotropic stellar population. For dark matter particle masses below approximately 10 GeV, direct detection exclusion limits for the simulated halos with the anisotropic stellar population show a mild shift towards smaller masses compared to the commonly adopted Standard Halo Model.