A5076918141- Dark Matter and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Cosmology and Gravitation Theories
- Particle Detector Development and Performance
- Atomic and Subatomic Physics Research
- Neutrino Physics Research
- Galaxies: Formation, Evolution, Phenomena
- Computational Physics and Python Applications
- Radiation Therapy and Dosimetry
- Black Holes and Theoretical Physics
- Astrophysics and Cosmic Phenomena
- Particle Accelerators and Free-Electron Lasers
- Muon and positron interactions and applications
- Quantum Chromodynamics and Particle Interactions
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Relativity and Gravitational Theory
- Superconducting and THz Device Technology
- Advanced Thermodynamics and Statistical Mechanics
- Quantum Electrodynamics and Casimir Effect
- Quantum, superfluid, helium dynamics
- Scientific Research and Discoveries
- Age of Information Optimization
- Photocathodes and Microchannel Plates
- Pulsars and Gravitational Waves Research
Netherlands Institute for Radio Astronomy
2022-2025
Fermi National Accelerator Laboratory
2016-2025
University of Chicago
2020-2024
Kavli Institute for Particle Astrophysics and Cosmology
2021-2023
Institut National des Sciences Appliquées de Lyon
2022
Centre National de la Recherche Scientifique
2022
Institut National de Physique Nucléaire et de Physique des Particules
2022
Perimeter Institute
2013-2016
Johns Hopkins University
2010-2012
This paper describes the physics case for a new fixed target facility at CERN SPS. The SHiP (Search Hidden Particles) experiment is intended to hunt in largely unexplored domain of very weakly interacting particles with masses below Fermi scale, inaccessible LHC experiments, and study tau neutrino physics. same proton beam setup can be used later look decays tau-leptons lepton flavour number non-conservation, $\tau\to 3\mu$ search weakly-interacting sub-GeV dark matter candidates. We discuss...
We systematically study light (< few GeV) Dark Matter (DM) models that thermalize with visible matter through the Higgs portal and identify remaining gaps in viable parameter space. Such require a comparably scalar mediator mixes to avoid DM overproduction can be classified according whether this decays (in)visibly. In representative benchmark model Dirac fermion DM, we find that, even conservative assumptions about DM-mediator coupling mass ratio, regime which is heavier than fully ruled...
Abstract With the establishment and maturation of experimental programs searching for new physics with sizeable couplings at LHC, there is an increasing interest in broader particle astrophysics community exploring light feebly-interacting particles as a paradigm complementary to New Physics sector TeV scale beyond. FIPs 2020 has been first workshop fully dedicated was held virtually from 31 August 4 September 2020. The gathered together experts collider, beam dump, fixed target experiments,...
The EDGES Collaboration has recently reported the detection of a stronger-than-expected absorption feature in global 21-cm spectrum, centered at frequency corresponding to redshift z≃17. This observation been interpreted as evidence that gas was cooled during this era result scattering with dark matter. In Letter, we explore possibility, applying constraints from cosmic microwave background, light element abundances, Supernova 1987A, and variety laboratory experiments. After taking these...
In this paper, we explore in detail the cosmological implications of an abelian $L_\mu-L_\tau$ gauge extension Standard Model featuring a light and weakly coupled $Z'$. Such scenario is motivated by longstanding $\sim \, 4 \sigma$ discrepancy between measured predicted values muon's anomalous magnetic moment, $(g-2)_\mu$, as well tension late early time determinations Hubble constant. If sufficiently light, $Z'$ population will decay to neutrinos, increasing overall energy density radiation...
The proposed LDMX experiment would provide roughly a meter-long region of instrumented tracking and calorimetry that acts as beam stop for multi-GeV electrons in which each electron is tagged its evolution measured. This offer an unprecedented opportunity to access both collider-invisible ultrashort-lifetime decays new particles produced (or muon) nuclear fixed-target collisions. In this paper, we show the missing momentum channel displaced decay signals such could world-leading sensitivity...
Large, nonstandard neutrino self-interactions have been shown to resolve the $\ensuremath{\sim}4\ensuremath{\sigma}$ tension in Hubble constant measurements and a milder amplitude of matter fluctuations. We demonstrate that interactions necessary size imply existence force carrier with large coupling ($>{10}^{\ensuremath{-}4}$) mass keV--100 MeV range. This mediator is subject stringent cosmological laboratory bounds, we find nearly all realizations such particle are excluded by existing...
A bstract If even a relatively small number of black holes were created in the early universe, they will constitute an increasingly large fraction total energy density as space expands. It is thus well-motivated to consider scenarios which universe included era primordial dominated density. Within this context, we Hawking radiation mechanism produce both dark and matter. hole era, find that at level Δ N eff ∼ 0 . 03 − 2 for each light decoupled species spin 0, 1/2, or 1. This range well...
Abstract There is controversy surrounding the origin and evolution of our universe's largest supermassive black holes (SMBHs). In this study, we consider possibility that some these formed from direct collapse primordial density perturbations. Since mass a hole limited by size cosmological horizon at time collapse, SMBHs must form rather late, are naively in conflict with constraints CMB spectral distortions. These limits can be avoided, however, if distribution curvature perturbations...
We propose that dark matter is dominantly comprised of atomic bound states. build a simple model and map the parameter space results in early universe formation hydrogen-like atoms. find has interesting implications for cosmology as well direct detection: Weak-scale atoms can accommodate hyperfine splittings order 100 keV, consistent with inelastic interpretation DAMA data while naturally evading detection bounds. Moreover, protohalo be suppressed below Mproto ∼ 103–106M⊙ weak scale due to...
Dark sectors, consisting of new, light, weakly-coupled particles that do not interact with the known strong, weak, or electromagnetic forces, are a particularly compelling possibility for new physics. Nature may contain numerous dark each their own beautiful structure, distinct particles, and forces. This review summarizes physics motivation sectors exciting opportunities experimental exploration. It is summary Intensity Frontier subgroup "New, Light, Weakly-coupled Particles" Community...
We analyze the present status of sub-GeV thermal dark matter annihilating through Standard Model mixing and identify a small set future experiments that can decisively test these scenarios.
In a broad class of consistent models, MeV to few-GeV dark matter interacts with ordinary through weakly coupled GeV-scale mediators. We show that suitable meter-scale (or smaller) detector situated downstream an electron beam-dump can sensitively probe interacting via sub-GeV mediators, while B-factory searches cover the 1-5 GeV range. Combined, such experiments explore well-motivated and otherwise inaccessible region parameter space sensitivity several orders magnitude beyond existing...
It has recently been shown that if the dark matter is in thermal equilibrium with a sector highly decoupled from Standard Model, it can freeze out an acceptable relic abundance, even as heavy $\ensuremath{\sim}1--100\text{ }\text{ }\mathrm{PeV}$. In such scenarios, both and visible sectors are populated after inflation, but independent temperatures. The lightest particle will be generically long-lived come to dominate energy density of Universe. Upon decaying, these particles significantly...
In this letter, we consider a class of scenarios in which the dark matter is part heavy hidden sector that thermally decoupled from Standard Model early universe. The freezes-out by annihilating to lighter, metastable state, whose subsequent abundance can naturally come dominate energy density When state decays, it reheats visible and dilutes all relic abundances, thereby allowing be orders magnitude heavier than weak scale. For concreteness, simple realization with Dirac fermion candidate...
We present a simple UV completion of Atomic Dark Matter (aDM) in which heavy right-handed neutrinos decay to induce both dark and lepton number densities. This model addresses several outstanding cosmological problems: the matter/anti-matter asymmetry, matter abundance, light degrees freedom early universe, smoothing small-scale structure. Additionally, this realization aDM may reconcile CoGeNT excess with recently published null results predicts signal CRESST Oxygen band. also find that,...
Dark Matter particles with inelastic interactions are ubiquitous in extensions of the Standard Model, yet remain challenging to fully probe existing strategies. We propose a series powerful searches at hadron and lepton colliders that sensitive dark matter dynamics. In representative models featuring either massive photon or magnetic dipole interaction, we find LHC BABAR could offer strong sensitivity thermal relic parameter space for masses between $\ensuremath{\sim}100\text{ }\text{...
In a popular class of models, dark matter comprises an asymmetric population composite particles with short range interactions arising from confined nonabelian gauge group. We show that coupling this sector to well-motivated light mediator particle yields efficient darkleosynthesis, dark-sector version big-bang nucleosynthesis (BBN), in generic regions parameter space. Dark self-interaction bounds typically require the confinement scale be above \Lambda_{QCD}, which generically large...
It has recently been shown that dark-matter annihilation to bottom quarks provides a good fit the Galactic Center gamma-ray excess identified in Fermi-LAT data. In favored mass range $m\ensuremath{\sim}30--40\text{ }\text{ }\mathrm{GeV}$, achieving best-fit rate $\ensuremath{\sigma}v\ensuremath{\sim}5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}26}\text{ }{\mathrm{cm}}^{3}\text{ }{\mathrm{s}}^{\ensuremath{-}1}$ with perturbative couplings requires sub-TeV mediator particle interacts...
The longstanding muon $g\ensuremath{-}2$ anomaly may indicate the existence of new particles that couple to muons, which could either be light $(\ensuremath{\lesssim}\mathrm{GeV})$ and weakly coupled, or heavy $(\ensuremath{\gg}100\text{ }\text{ }\mathrm{GeV})$ with large couplings. If states are responsible, upcoming intensity frontier experiments will discover further evidence physics. However, if many candidates beyond reach existing colliders. We show that,...
We introduce a novel program of fixed-target searches for thermal-origin dark matter (DM), which couples inelastically to the Standard Model. Since DM only interacts by transitioning heavier state, freeze-out proceeds via coannihilation and unstable state is depleted at later times. For sufficiently large mass splittings, direct detection kinematically forbidden indirect impossible, so this scenario can be tested with accelerators. Here we propose new proton- electron-beam experiments probe...
There are currently several existing and proposed experiments designed to probe sub-GeV dark matter (DM) using electron ionization in various materials. The projected signal rates for these assume that this yield arises only from DM scattering directly off targets, ignoring secondary contributions nuclear targets. We investigate the validity of assumption show if couples with comparable strength both protons electrons, as would be case a photon mediator, atomic via Migdal effect scales...