144 citations · 1.2k across the 47 of their papers we have counts for
53 papers
Testing the inelastic dark matter interpretation of the LZ event with heavy-element experiments
Peter W. Graham, Juan P. Luengas, Harikrishnan Ramani +1
We consider the inelastic dark matter interpretation of the recent 248 keV event observed by LZ and identify different experiments that could test it. Details of the underlying mod…
Constraints on Complex Electroweak WIMPs from Solar Capture
Juan P. Luengas, Maxim Pospelov, Harikrishnan Ramani
One of the most convincing realizations of particle dark matter is provided by models based on electroweak multiplets. The lightest neutral state of such a multiplet can be a stabl…
Mineral Detection of Neutrinos and Dark Matter 2026 Proceedings
Alexey Elykov, Patrick Stengel, Natsue Abe +81
The fourth "Mineral Detection of Neutrinos and Dark Matter" (MDvDM'26) meeting was held April 14-17, 2026 in Karlsruhe, Germany, hosted by the Institute for Astroparticle Physics (…
Strong Constraints on Higgsino Dark Matter from Solar Capture
Maxim Pospelov, Harikrishnan Ramani
Higgsino dark matter remains one of the most convincing dark matter candidates. It can exist in a ``quasi-Dirac" regime, when the splitting between two Majorana components is on th…
Probing large mass-splitting inelastic Dark Matter with RES-NOVA
D. Alloni, G. Benato, P. Carniti +46
Probing inelastic dark matter at large mass splittings requires heavy target nuclei, an extended recoil-energy range, and the high-velocity tail of the dark-matter distribution. We…
Heavy-element paleodetectors for Higgsino dark matter
Peter W. Graham, Harikrishnan Ramani, Samuel S. Y. Wong
Paleodetectors have been proposed as a new approach to direct detection of weakly interacting massive particles (WIMPs), through the search for damage tracks in ancient minerals in…
Melting LHC detectors: a novel search for stopped long-lived particles
Julia L. Gonski, Peter W. Graham, Surjeet Rajendran +2
Particles at the TeV scale with lifetimes of a year or longer could have been abundantly produced at the LHC yet escaped detection because of backgrounds, and could still be trappe…
Cosmological Limits on Strong Dark Forces
Peter W. Graham, Harikrishnan Ramani, Olivier Simon +1
We showcase cosmology's ability to constrain long-range forces between dark matter particles. Specifically, we consider a fermionic dark matter interacting via a Yukawa-coupled lig…
Electric Accumulation of Millicharged Particles
Asher Berlin, Zachary Bogorad, Peter W. Graham +1
A terrestrial population of millicharged particles that interact significantly with normal matter can arise if they make up a dark matter subcomponent or if they are light enough t…
Cavendish Tests of Millicharged Particles
Asher Berlin, Zachary Bogorad, Peter W. Graham +1
A terrestrial population of room-temperature millicharged particles can arise if they make up a dark matter subcomponent or if they are light enough to be produced in cosmic ray ai…
Search for dark matter Particles via Invisible Decays in Sc Nuclear Cascades with a CsI(Tl) Detector
Sharada Sahoo, Jing-han Chen, Mahdi Mirzakhani +3
Dark matter remains one of the most compelling open problems in modern physics, motivating experimental searches for new light, weakly coupled particles beyond the Standard Model.…
Robust bounds on MACHOs from the faintest galaxies
Peter W. Graham, Harikrishnan Ramani, Maximilian Ruhdorfer
We use the dynamical heating of stars in ultrafaint dwarf (UFD) galaxies to set limits on Massive Compact Halo Objects (MACHOs). In our analysis we study the robustness of the boun…
Direct Deflection of Millicharged Radiation
Asher Berlin, Surjeet Rajendran, Harikrishnan Ramani +1
Millicharged particles are generic in theories of dark sectors. A cosmic or local abundance of them may be produced by the early universe, stellar environments, or the decay or ann…
Constraints on Long-Ranged Interactions Between Dark Matter and the Standard Model
Zachary Bogorad, Peter Graham, Harikrishnan Ramani
Dark matter's existence is known thanks to its gravitational interaction with Standard Model particles, but it remains unknown whether this is the only force present between them.…
Highly Excited Electron Cyclotron for QCD Axion and Dark-Photon Detection
Xing Fan, Gerald Gabrielse, Peter W. Graham +3
We propose using highly excited cyclotron states of a trapped electron to detect meV axion and dark photon dark matter, marking a significant improvement over our previous proposal…
Enhancing Direct Detection of Higgsino Dark Matter
Peter W. Graham, Harikrishnan Ramani, Samuel S. Y. Wong
While much supersymmetric weakly interacting massive particle (WIMP) parameter space has been ruled out, one remaining important candidate is Higgsino dark matter. The Higgsino can…
Constraints on Dark Matter from Dynamical Heating of Stars in Ultrafaint Dwarfs. Part 2: Substructure and the Primordial Power Spectrum
Peter W. Graham, Harikrishnan Ramani
There is a large and growing interest in observations of small-scale structure in dark matter. We propose a new way to probe dark matter structures in the $\sim 10 - 10^8 \, M_\odo…
Constraints on Dark Matter from Dynamical Heating of Stars in Ultrafaint Dwarfs. Part 1: MACHOs and Primordial Black Holes
Peter W. Graham, Harikrishnan Ramani
We place limits on dark matter made up of compact objects significantly heavier than a solar mass, such as MACHOs or primordial black holes (PBHs). In galaxies, the gas of such obj…
Coherent Self-Interactions of Dark Matter in the Bullet Cluster
Zachary Bogorad, Peter W. Graham, Harikrishnan Ramani
Many models of dark matter include self-interactions beyond gravity. A variety of astrophysical observations have previously been used to place limits on the strength of such self-…
Dark Matter Constraints from Isomeric Hf
D. S. M. Alves, S. R. Elliott, R. Massarczyk +2
We describe a first measurement of the radiation from a Hf sample to search for dark matter. The flux from this sample, possessed by Los Alamos National Laboratory…
Constraints on the decay of Ta
I. J. Arnquist, F. T. Avignone, A. S. Barabash +56
Ta is a rare nuclear isomer whose decay has never been observed. Its remarkably long lifetime surpasses the half-lives of all other known and electron capture decays d…
Dark Matter Annihilation inside Large Volume Neutrino Detectors
David McKeen, David E. Morrissey, Maxim Pospelov +2
New particles in theories beyond the standard model can manifest as stable relics that interact strongly with visible matter and make up a small fraction of the total dark matter a…
The Terrestrial Density of Strongly-Coupled Relics
Asher Berlin, Hongwan Liu, Maxim Pospelov +1
The simplest cosmologies motivate the consideration of dark matter subcomponents that interact significantly with normal matter. Moreover, such strongly-coupled relics may have eva…
Dark Matter Direct Detection with Quantum Dots
Carlos Blanco, Rouven Essig, Marivi Fernandez-Serra +2
We propose using Quantum Dots as novel targets to probe sub-GeV dark matter-electron interactions. Quantum dots are nanocrystals of semiconducting material, which are commercially…