A5090109748- Dark Matter and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Particle Detector Development and Performance
- Cosmology and Gravitation Theories
- Atomic and Subatomic Physics Research
- Black Holes and Theoretical Physics
- Computational Physics and Python Applications
- Quantum Chromodynamics and Particle Interactions
- Radiation Detection and Scintillator Technologies
- Photocathodes and Microchannel Plates
- Neutrino Physics Research
- Quantum Electrodynamics and Casimir Effect
- Radiation Therapy and Dosimetry
- Cold Atom Physics and Bose-Einstein Condensates
- Scientific Computing and Data Management
- Quantum Information and Cryptography
- Noncommutative and Quantum Gravity Theories
- Astrophysics and Cosmic Phenomena
- Quantum Mechanics and Applications
- Advanced Thermodynamics and Statistical Mechanics
- Physics of Superconductivity and Magnetism
- Astronomy and Astrophysical Research
- High-Energy Particle Collisions Research
- Stellar, planetary, and galactic studies
- Relativity and Gravitational Theory
SLAC National Accelerator Laboratory
2018-2025
Menlo School
2011-2024
Perimeter Institute
2011-2023
Stanford University
2009-2023
Thomas Jefferson National Accelerator Facility
2005-2022
Institute for Advanced Study
2012
Harvard University
2005
Fixed-target experiments are ideally suited for discovering new MeV--GeV mass $U(1)$ gauge bosons through their kinetic mixing with the photon. In this paper, we identify production and decay properties of light that dictate fixed-target search strategies. We summarize existing limits suggest five experimental approaches anticipate can cover most natural parameter space, using currently operating GeV-energy beams well-established detection methods. Such particularly timely in recent...
This document proposes a collection of simplified models relevant to the design new-physics searches at LHC and characterization their results. Both ATLAS CMS have already presented some results in terms models, we encourage them continue expand this effort, which supplements both signature-based benchmark model interpretations. A is defined by an effective Lagrangian describing interactions small number new particles. Simplified can equally well be described masses cross-sections. These...
Low-energy supersymmetry (SUSY) and several other theories that address the hierarchy problem predict pair-production at LHC of particles with standard model quantum numbers decay to jets, missing energy, possibly leptons. If an excess such events is seen in data, a theoretical framework which describe it will be essential constraining structure new physics. We propose basis four deliberately simplified models, each specified by only 2--3 masses 4--5 branching ratios, for use first...
We present a search at the Jefferson Laboratory for new forces mediated by sub-GeV vector bosons with weak coupling ${\ensuremath{\alpha}}^{\ensuremath{'}}$ to electrons. Such particle ${A}^{\ensuremath{'}}$ can be produced in electron-nucleus fixed-target scattering and then decay an ${e}^{+}{e}^{\ensuremath{-}}$ pair, producing narrow resonance QED trident spectrum. Using APEX test run data, we searched mass range 175--250 MeV, found no evidence...
We analyze the unique capability of existing SeaQuest experiment at Fermilab to discover well-motivated dark sector physics by measuring displaced electron, photon, and hadron decay signals behind a compact shield. A planned installation refurbished electromagnetic calorimeter could provide powerful new sensitivity GeV-scale vectors, Higgs bosons, scalars, axions, inelastic strongly interacting matter models. This is both comparable complementary NA62, SHiP, FASER. SeaQuest's ability collect...
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...
A dark sector---a new non-Abelian gauge group Higgsed or confined near the GeV scale---can be spectacularly probed in low-energy ${e}^{+}{e}^{\ensuremath{-}}$ collisions. low-mass sector can explain annual modulation signal reported by DAMA/LIBRA and PAMELA, ATIC, INTEGRAL observations generating small mass splittings interactions for weak-scale matter. Some of these may first signs a that collider searches definitively confirm. Production decay $\mathcal{O}(\mathrm{GeV})$-mass states is...
Experiments designed to measure neutrino oscillations also provide major opportunities for discovering very weakly-coupled states. In order produce neutrinos, experiments such as Liquid Scintillator Neutrino Detector collide thousands of Coulombs protons into fixed targets, while MINOS and MiniBooNE focus then dump beams muons. The detectors beyond these beam dumps are therefore an excellent arena in which look long-lived pseudoscalars or vector bosons that kinetically mix with the photon....
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...
We describe an experiment to search for a new vector boson A' with weak coupling alpha' > 6 x 10^{-8} alpha electrons (alpha=e^2/4pi) in the mass range 65 MeV < m_A' 550 MeV. New bosons such small couplings arise naturally from kinetic mixing of "dark photon" photon -- one very few ways which forces can couple Standard Model and have received considerable attention as explanation various dark matter related anomalies. are produced by radiation off electron beam, could appear narrow...
A natural possibility for dark matter is that it composed of the stable pions a QCD-like hidden sector. Existing literature largely assumes pion self-interactions alone control early universe cosmology. We point out processes involving vector mesons typically dominate physics freeze-out and significantly widen viable mass range these models. The also give rise to striking signals at accelerators. For example, in most cosmologically favored parameter space, are naturally long-lived produce...
A bstract We propose an approach to search for axion dark matter with a specially designed superconducting radio frequency cavity, targeting axions masses m ≲ 10 − 6 eV. Our exploits axion-induced transitions between nearly degenerate resonant modes of ∼ GHz. scan over mass is achieved by varying the splitting two modes. Compared traditional approaches, this allows parametrically enhanced signal power lighter than The projected sensitivity covers unexplored parameter space QCD 8 eV and...
Indirect detection experiments typically measure the flux of annihilating dark matter (DM) particles propagating freely through galactic halos. We consider a new scenario where celestial bodies ``focus'' DM annihilation events, increasing efficiency halo annihilation. In this setup, is first captured by bodies, such as neutron stars or brown dwarfs, and then annihilates within them. If to sufficiently long-lived particles, they can escape subsequently decay into detectable radiation. This...
Dark matter charged under a new gauge sector, as motivated by recent data, suggests rich GeV-scale "dark sector" weakly coupled to the Standard Model kinetic mixing. The bosons can decay leptons, but this mode is suppressed if decays into lighter dark sector particles are kinematically allowed. These in turn typically have macroscopic lifetimes that constrained two classes of experiments, which we discuss. Lifetimes 10 cm < c tau 10^8 existing terrestrial beam-dump experiments. If, addition,...
We describe an approach to detect dark matter and other invisible particles with mass below a GeV, exploiting missing energy-momentum measurements kinematic features of fixed-target production. In the case invisibly decaying MeV-GeV-scale photon, this can improve on present constraints by 2-6 orders magnitude over entire range, reaching sensitivity as low $\epsilon^2\sim 10^{-14}$. Moreover, explore essentially all viable parameter space for thermal or asymmetric annihilating through vector portal.
The search for particle-like dark matter with meV-to-GeV masses has developed rapidly in the past few years. We summarize science case these searches, recent progress, and exciting upcoming opportunities. Funding Research Development a portfolio of small projects will allow community to capitalize on substantial advances theory experiment probe vast regions unexplored dark-matter parameter space coming decade.
We propose the first covariant local action describing propagation of a single free continuous-spin degree freedom. The theory is simply formulated as gauge in ``vector superspace,'' but can also be terms tower symmetric tensor fields. When spin invariant $\ensuremath{\rho}$ vanishes, helicity correspondence manifest---familiar actions are recovered and couplings to conserved currents easily introduced. For nonzero $\ensuremath{\rho}$, must present, which only lowest rank exactly conserved....
It has recently been demonstrated that a program of parasitic electron-beam fixed-target experiments would have powerful discovery potential for dark matter and other new weakly coupled particles in the MeV-GeV mass range. The first stage this can be realized at Jefferson Laboratory using an existing plastic-scintillator detector downstream Hall D electron beam dump. This paper studies physics such experiment highlights its unique sensitivity to inelastic ``exciting'' leptophilic scenarios....