Javier F. Acevedo
Research Associate-Theoretical, SLAC National Accelerator Laboratory
Bio
I am a theoretical physicist specializing in novel dark matter search strategies, with an emphasis on using celestial bodies as natural probes. My research also delves into the exploration of novel dark matter signatures in terrestrial detectors, with a strong focus on the complementarity between astrophysical observations and direct detection experiments.
Current Role at Stanford
Postdoctoral Research Associate at SLAC
Education & Certifications
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PhD, Queen's University, Physics (2022)
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Undergrad, Universidad Nacional de Mar del Plata, Physics (2017)
Work Experience
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Research Associate, SLAC National Accelerator Laboratory (October 1, 2022 - Present)
Elementary Particle Theory Group, Fundamental Physics Directorate.
Location
Menlo Park CA
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Research Associate, Queen's University (May 1, 2022 - September 30, 2022)
Dept. of Physics, Eng. Physics and Astronomy & McDonald Institute for Astroparticle Physics
Location
Kingston, ON, Canada
All Publications
- Milky Way White Dwarfs as Sub-GeV to Multi-TeV Dark Matter Detectors arXiv. 2023 29
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Evaporation Barrier for Dark Matter in Celestial Bodies
arXiv e-print.
2023
20
Abstract
The minimum testable dark matter (DM) mass for almost all DM signatures in celestial bodies is determined by the rate at which DM evaporates. DM evaporation has previously been calculated assuming a competition between the gravitational potential of the object, and thermal kicks from the celestial-body matter. We point out a new effect, where mediators with a range larger than the interparticle spacing induce a force proportional to the density gradient of celestial objects, forming an evaporation barrier for the DM. This effect can be so significant that evaporation does not occur even for sub-MeV DM, in stark contrast to previous calculations. This opens up a wide range of new light DM searches, many orders of magnitude in DM mass below the sensitivity of direct detection.
arXiv e-print: 2303.01516 -
Warming nuclear pasta with dark matter: kinetic and annihilation heating of neutron star crusts
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
2020
View details for DOI 10.1088/1475-7516/2020/03/038
View details for Web of Science ID 000528029100039
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Loosely Bound Composite Dark Matter
Arxiv.
2024
12
Abstract
We investigate loosely bound composite states made of dark matter, where the binding energy for constituent particles is less than the constituent mass. We focus on models of nuclear and molecular dark matter, where constituents are separated by length scales larger than the inverse constituent mass, just like nuclei and atoms in the Standard Model. The cosmology, structure, and interactions at underground experiments are described. We find that loosely bound composites can have a very large cross section for scattering with nuclei that scales with nucleon number like ∼A^4. For some couplings, these composites produce extremely soft (≪ keV) individual atomic recoils while depositing a large amount of total recoil energy (≫ keV) in a single passage through a detector, implying an interesting new class of signatures for low threshold direct detection.
arXiv:2408.03983 -
Dark Kinetic Heating of Exoplanets and Brown Dwarfs
Arxiv.
2024
24
Abstract
Dark kinetic heating of neutron stars has been previously studied as a promising dark matter detection avenue. Kinetic heating occurs when dark matter is sped up to relativistic speeds in the gravitational well of high-escape velocity objects, and deposits kinetic energy after becoming captured by the object, thereby increasing its temperature. We show that dark kinetic heating can be significant even in objects with low-escape velocities, such as exoplanets and brown dwarfs, increasing the discovery potential of such searches. This can occur if there is a long-range dark force, creating a "dark escape velocity", leading to heating rates substantially larger than those expected from neutron stars. We consequently set constraints on dark sector parameters using Wide-field Infrared Survey Explorer and JWST data on Super-Jupiter WISE 0855-0714, and map out future sensitivity to the dark matter scattering cross section below 10−40 cm2. We compare dark kinetic heating rates of other lower escape velocity objects such as the Earth, Sun, and white dwarfs, finding complementary kinetic heating signals are possible depending on particle physics parameters.
arXiv:2405.02393 -
Dark Matter Raining on DUNE and Other Large Volume Detectors
Arxiv.
2024
28
Abstract
Direct detection is a powerful means of searching for particle physics evidence of dark matter (DM) heavier than about a GeV with O(kiloton)O(kiloton) volume, low-threshold detectors. In many scenarios, some fraction of the DM may be boosted to large velocities enhancing and generally modifying possible detection signatures. We investigate the scenario where 100% of the DM is boosted at the Earth due to new attractive long-range forces. This leads to two main improvements in detection capabilities: 1) the large boost allows for detectable signatures of DM well below a GeV at large-volume neutrino detectors, such as DUNE, Super-K, Hyper-K, and JUNO, as possible DM detectors, and 2) the flux at the Earth's surface is enhanced by a focusing effect. In addition, the model leads to a significant anisotropy in the signal with the DM flowing dominantly vertically at the Earth's surface instead of the typical approximately isotropic DM signal. We develop the theory behind this model and also calculate realistic constraints using a detailed GENIE simulation of the signal inside detectors.
arXiv:2407.01670 -
Old rocks, new limits: excavated ancient mica searches for dark matter
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
2023
View details for DOI 10.1088/1475-7516/2023/11/085
View details for Web of Science ID 001121623400008
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ino and Gamma-Ray Signatures of Inelastic Dark Matter Annihilating outside Neutron StarsNeutr
arXiv
2023: 19
View details for DOI 10.48550/arXiv.2404.10039
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Mineral Detection of Neutrinos and Dark Matter. A whitepaper
arXiv
2023: 113
View details for DOI 10.48550/arXiv.2301.07118
- Dark Matter-Induced Baryonic Feedback in Galaxies arXiv. 2023 17
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Accelerating composite dark matter discovery with nuclear recoils and the Migdal effect
PHYSICAL REVIEW D
2022; 105 (2)
View details for DOI 10.1103/PhysRevD.105.023012
View details for Web of Science ID 000743871300006
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Diffuse x-ray and gamma-ray limits on boson stars that interact with nuclei
Journal of Cosmology and Astroparticle Physics
2022
View details for DOI 10.1088/1475-7516/2022/12/031
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Nuclear fusion inside dark matter
PHYSICAL REVIEW D
2021; 103 (12)
View details for DOI 10.1103/PhysRevD.103.123022
View details for Web of Science ID 000664530200004
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Dark matter, destroyer of worlds: neutrino, thermal, and existential signatures from black holes in the Sun and Earth
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
2021
View details for DOI 10.1088/1475-7516/2021/04/026
View details for Web of Science ID 000644501000001
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Supernovae sparked by dark matter in white dwarfs
PHYSICAL REVIEW D
2019; 100 (4)
View details for DOI 10.1103/PhysRevD.100.043020
View details for Web of Science ID 000482088100001
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Front propagation dynamics: Qualitative differences revealed by very high intensity fluctuations
PHYSICAL REVIEW E
2018; 98 (5)
View details for DOI 10.1103/PhysRevE.98.052213
View details for Web of Science ID 000450141800003
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Limiting the stroke of a Schmitt trigger with multiplicative noise
PHYSICAL REVIEW E
2017; 95 (5): 052143
Abstract
We have devised an experiment whereby a bistable system is confined away from its deterministic attractors by means of multiplicative noise. Together with previous numerical results, our experimental results validate the hypothesis that the higher the slope of the noise's multiplicative factor, the more it shifts the stationary states.
View details for DOI 10.1103/PhysRevE.95.052143
View details for Web of Science ID 000402019600005
View details for PubMedID 28618519