A5009912646- Dark Matter and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Cosmology and Gravitation Theories
- Atomic and Subatomic Physics Research
- Particle Detector Development and Performance
- Distributed and Parallel Computing Systems
- Neutrino Physics Research
- Advanced Thermodynamics and Statistical Mechanics
- Scientific Computing and Data Management
- Astronomy and Astrophysical Research
- Computational Physics and Python Applications
- Galaxies: Formation, Evolution, Phenomena
- Historical Astronomy and Related Studies
- Quantum Chromodynamics and Particle Interactions
- Fuzzy Logic and Control Systems
- CCD and CMOS Imaging Sensors
- Age of Information Optimization
- History and Developments in Astronomy
- Geophysics and Gravity Measurements
- Quantum, superfluid, helium dynamics
- High-Energy Particle Collisions Research
- Scientific Research and Discoveries
- Stock Market Forecasting Methods
Weber State University
2021-2022
McGill University
2016-2020
University of Cincinnati
2019-2020
Cornell University
2017
European Organization for Nuclear Research
2017
University of California, Santa Cruz
2012-2014
Stockholm University
2013-2014
One of the simplest viable models for dark matter is an additional neutral scalar, stabilised by a Z2 symmetry. Using GAMBIT package and combining results from four independent samplers, we present Bayesian frequentist global fits this model. We vary singlet mass coupling along with 13 nuisance parameters, including nuclear uncertainties relevant direct detection, local density, selected quark masses couplings. include relic density measured Planck, searches LUX, PandaX, SuperCDMS XENON100,...
We introduce DarkBit, an advanced software code for computing dark matter constraints on various extensions to the Standard Model of particle physics, comprising both new native and interfaces external packages. This release includes a dedicated signal yield calculator gamma-ray observations, which significantly extends current tools by implementing cascade-decay Monte Carlo, as well likelihood future experiments (gamLike). provides general solution studying complex physics models that...
We present global analyses of effective Higgs portal dark matter models in the frequentist and Bayesian statistical frameworks. Complementing earlier studies scalar portal, we use GAMBIT to determine preferred mass coupling ranges for with vector, Majorana Dirac fermion matter. also assess relative plausibility all four using model comparison. Our analysis includes up-to-date likelihood functions relic density, invisible decays, direct indirect searches weakly-interacting including latest...
We describe the open-source global fitting package GAMBIT: Global And Modular Beyond-the-Standard-Model Inference Tool. GAMBIT combines extensive calculations of observables and likelihoods in particle astroparticle physics with a hierarchical model database, advanced tools for automatically building analyses essentially any model, flexible powerful system interfacing to external codes, suite different statistical methods parameter scanning algorithms, host other utilities designed make...
We present the most comprehensive global fits to date of three supersymmetric models motivated by grand unification: Constrained Minimal Supersymmetric Standard Model (CMSSM), and its Non-Universal Higgs Mass generalisations NUHM1 NUHM2. include likelihoods from a number direct indirect dark matter searches, large collection electroweak precision flavour observables, searches for supersymmetry at LEP Runs I II LHC, constraints observables. Our analysis improves on existing results not only...
Searches for supersymmetric electroweakinos have entered a crucial phase, as the integrated luminosity of Large Hadron Collider is now high enough to compensate their weak production cross-sections. Working in framework where neutralinos and charginos are only light sparticles Minimal Supersymmetric Standard Model, we use gambit perform detailed likelihood analysis electroweakino sector. We focus on impacts recent ATLAS CMS searches with 36 fb$^{-1}$ 13 TeV proton-proton collision data. also...
We study the seven-dimensional Minimal Supersymmetric Standard Model (MSSM7) with new GAMBIT software framework, all parameters defined at weak scale. Our analysis significantly extends previous weak-scale, phenomenological MSSM fits, by adding more and newer experimental analyses, improving accuracy detail of theoretical predictions, including dominant uncertainties from Model, Galactic dark matter halo quark content nucleon, employing novel highly-efficient statistical sampling methods to...
Scalar singlet dark matter is one of the simplest and most predictive realisations WIMP (weakly-interacting massive particle) idea. Although model constrained from all directions by latest experimental data, it still has viable regions parameter space. Another compelling aspect scalar singlets their ability to stabilise electroweak vacuum. Indeed, models are not low-energy effective theories, but can be valid way Planck scale. Using GAMBIT framework, we present first global fit include both...
We report on the status of efforts to improve reinterpretation searches and measurements at LHC in terms models for new physics, context Reinterpretation Forum. detail current experimental offerings direct particles, measurements, technical implementations Open Data, provide a set recommendations further improving presentation results order better enable future. also brief description existing software frameworks recent global analyses physics that make use data.
We assess the status of a wide class WIMP dark matter (DM) models in light latest experimental results using global fitting framework $\textsf{GAMBIT}$. perform analysis effective field theory (EFT) operators describing interactions between gauge-singlet Dirac fermion and Standard Model quarks, gluons photon. In this bottom-up approach, we simultaneously vary coefficients 14 such up to dimension 7, along with DM mass, scale new physics several nuisance parameters. Our likelihood functions...
There are presently several discrepancies in $b\ensuremath{\rightarrow}s{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$ decays of $B$ mesons suggesting new physics coupling to $b$ quarks and leptons. We show that a ${Z}^{\ensuremath{'}}$, with couplings muons can explain the $B$-decay anomalies, also couple dark matter way is consistent its relic abundance, direct detection limits, hints indirect detection. The latter include possible excess events antiproton spectra recently...
Hints of lepton flavor violation have been observed by LHCb in the rate decay B→Kμ+μ− relative to that B→Ke+e−. This can be explained new scalars and fermions which couple standard model particles contribute these processes at loop level. We explore a simple this kind, one is dark matter candidate, while other heavy vector-like quark scalar an inert Higgs doublet. constraints on from observables, direct detection, LHC run II searches, find that, currently viable, scenario will directly...
The size of the smallest dark matter collapsed structures, or protohalos, is set by temperature at which particles fall out kinetic equilibrium. process decoupling involves elastic scattering off Standard Model in early universe, and relevant cross section thus closely related to for nuclei (direct detection) but also, via crossing symmetries, pair production colliders annihilation. In this study, we employ an effective field theoretic approach calculate constraints on temperature, from a...
A bstract CP-violating contributions to Higgs-fermion couplings are absent in the standard model of particle physics (SM), but motivated by models electroweak baryogenesis. Here, we employ framework SM effective theory (SMEFT) parameterise deviations from Yukawa couplings. We present leading relevant operators fermionic electric dipole moments (EDMs). obtain constraints on SMEFT Wilson coefficients combination LHC data and experimental bounds electron, neutron, mercury EDMs. perform, for...
New decay channels for the neutron into dark matter plus other particles have been suggested explaining a long-standing discrepancy between lifetime measured from trapped neutrons versus those decaying in flight. Many such scenarios are already ruled out by their effects on stars, and photon has experimentally excluded. Here we explore Dirac fermion $\chi$ $A'$, which can be consistent with all constraints if is subdominant component of matter. Neutron star evaded mass to coupling ratio...
Dark matter (DM) annihilations have been widely studied as a possible explanation of excess gamma rays from the galactic center seen by Fermi/LAT. However most such models are in conflict with constraints dwarf spheroidals. Motivated this tension, we show that p-wave annihilating dark can easily accommodate both sets observations due to lower DM velocity dispersion galaxies. Explaining relic abundance is then challenging. We outline scenario which usual thermal obtained through s-wave...
It was recently suggested that dark matter consists of ~GeV particles carry baryon number and mix with the neutron. We demonstrate this could allow for resonant matter-neutron oscillations in early universe, at finite temperature, leading to low-scale baryogenesis starting from a primordial asymmetry. In scenario, asymmetry transfer happens around 30 MeV, just before big bang nucleosynthesis. illustrate idea using model U(1)' gauge interaction, which has been as way addressing neutron...
Dark matter kinetic decoupling involves elastic scattering of dark off leptons and quarks in the early universe, same process relevant for direct detection capture rate celestial bodies; resulting size smallest collapsed structures should thus correlate with quantities connected rates flux high-energy neutrinos from annihilation Sun or Earth. In this paper we address general question context two widely studied paradigmatic weakly-interacting particle models: lightest neutralino minimal...
The existence of supermassive black holes at high redshifts ($z\sim7$) is difficult to accommodate in standard astrophysical scenarios. It has been shown that dark matter models with a subdominant self-interacting component are able produce early seeds for through the gravothermal catastrophe. Previous studies used fluid equation approach, requiring some limiting assumptions. Here we reconsider problem using $N$-body gravitational simulations starting from formation initial halo. We consider...
In Ref. (GAMBIT Collaboration: Athron et. al., Eur. Phys. J. C. arXiv:1705.07908 , 2017) we introduced the global-fitting framework GAMBIT. this addendum, describe a new minor version increment of package. GAMBIT 1.1 includes full support for Mathematica backends, which in some detail here. As an example, backend SUSYHD (Vega and Villadoro, JHEP 07:159, 2015), calculates mass Higgs boson MSSM from effective field theory. We also updated likelihoods PrecisionBit DarkBit, decay data included DecayBit.
The recent discovery of a Higgs boson with mass about 125 GeV, along its striking similarity to the prediction from standard model, informs and constrains many models new physics. exhausts one out three input parameters minimal, five-dimensional version universal extra dimension models, other two being Kaluza-Klein (KK) scale cutoff theory. presence KK fermions large coupling implies short-lived electroweak vacuum, unless is at most few times higher than scale, providing an additional tight...
In supersymmetric theories without R-parity, the gravitino can play role of a decaying Dark Matter candidate problem late NLSP decays affecting Big Bang Nucleosynthesis. this work, we elaborate on recently discussed limits R- parity violating couplings from to antideuterons and discuss implications for two classes flavor symmetries: horizontal symmetries, Minimal Flavor Violation. most parameter space antideuteron constraints R-parity are stronger than low-energy baryon-number-violating...
The wide range of probes physics beyond the standard model leads to need for tools that combine experimental results make most robust possible statements about validity theories and preferred regions their parameter space. Here we introduce a new code such analyses: GAMBIT, Global Modular BSM Inference Tool. GAMBIT is flexible extensible framework global fits essentially any theory. currently incorporates direct indirect searches dark matter, limits on production particles from LHC LEP,...