A5032972743- 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
- German Economic Analysis & Policies
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Quantum Electrodynamics and Casimir Effect
- Noncommutative and Quantum Gravity Theories
- Quantum Chromodynamics and Particle Interactions
- Computational Physics and Python Applications
- European Monetary and Fiscal Policies
- European Socioeconomic and Political Studies
- Radiation Therapy and Dosimetry
- Relativity and Gravitational Theory
- Cold Atom Physics and Bose-Einstein Condensates
- Gamma-ray bursts and supernovae
- High-Energy Particle Collisions Research
- Corporate Taxation and Avoidance
- Superconducting Materials and Applications
- Radiation Detection and Scintillator Technologies
- Photocathodes and Microchannel Plates
- Age of Information Optimization
SLAC National Accelerator Laboratory
2010-2025
Menlo School
2009-2024
Johannes Kepler University of Linz
2019
Perimeter Institute
2011-2018
Stanford University
2010-2018
Institute for Advanced Study
2012
Harvard University
2005-2006
Thomas Jefferson National Accelerator Facility
2005
Massachusetts Institute of Technology
2003
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...
Abstract The Physics Beyond Colliders initiative is an exploratory study aimed at exploiting the full scientific potential of CERN’s accelerator complex and infrastructures through projects complementary to LHC other possible future colliders. These will target fundamental physics questions in modern particle physics. This document presents status proposals presented framework Standard Model working group, explore their reach impact that CERN could have next 10–20 years on international landscape.
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,...
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...
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...
Peaking consistently in June for nearly eleven years, the annual modulation signal reported by DAMA/NaI and DAMA/LIBRA offers strong evidence identity of dark matter. DAMA's strongly suggest that matter inelastically scatters into an excited state split O(100 keV). We propose DAMA is observing hyperfine transitions a composite particle. As example, we consider meson QCD-like sector, built out constituent fermions whose spin-spin interactions break degeneracy ground state. An axially coupled...
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...
At the dawn of a new decade, particle physics faces challenge explaining mystery dark matter, origin matter over antimatter in Universe, apparent fine-tuning electroweak scale, and many other aspects fundamental physics. Perhaps most striking frontier to emerge search for answers involves New Physics at mass scales comparable that familiar matter—below GeV scale but with very feeble interaction strength. theoretical ideas address questions predict such feebly interacting particles (FIPs)...
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...
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.
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....