A5029179986- Particle physics theoretical and experimental studies
- Dark Matter and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Neutrino Physics Research
- Computational Physics and Python Applications
- Quantum Chromodynamics and Particle Interactions
- Black Holes and Theoretical Physics
- Atomic and Subatomic Physics Research
- Astrophysics and Cosmic Phenomena
- Cold Atom Physics and Bose-Einstein Condensates
- Astronomy and Astrophysical Research
- History and Developments in Astronomy
- Quantum and Classical Electrodynamics
- Galaxies: Formation, Evolution, Phenomena
- Pulsars and Gravitational Waves Research
University of Oxford
2022-2025
Royal Holloway University of London
2025
California Institute of Technology
2023-2024
Johns Hopkins University
2023
Instituto de Física Corpuscular
2016-2021
Universitat de València
2016-2021
Perimeter Institute
2020
Parc Científic de la Universitat de València
2016-2019
A bstract We show that the couplings of axions to gauge bosons are highly restricted in Grand Unified Theories where standard model is embedded a simple 4D group. The topological nature these allows them be matched from UV IR, and ratio anomaly with photons gluons for any axion fixed by unification. This implies there single axion, QCD an anomalous coupling photons. Other light axion-like particles can couple mixing through portal lie right line mass-coupling plane. Axions which break...
A bstract We propose to use atoms and molecules as quantum sensors of axion-mediated monopole-dipole forces. show that electron spin precession experiments using atomic molecular beams are well-suited for axion searches thanks the presence co-magnetometer states single-shot temporal resolution. Experimental strategies detect gradients from localised sources earth presented, taking ACME III a prototype example. Other possibilities including beams, laser-cooled discussed.
An ultralight axion with <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mi>C</a:mi><a:mi>P</a:mi></a:mrow></a:math> violating interactions a dark sector and <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mrow><c:mi>C</c:mi><c:mi>P</c:mi></c:mrow></c:math> preserving the visible can act as novel portal between matter Standard Model. In such theories, sources an field extending over entire galaxy, gradient of which be searched for...
A bstract We study the coupling of axions to gauge bosons in heterotic string theory. The axion-gauge boson couplings low energy 4d theory are derived by matching mixed anomalies between higher-form global symmetries and zero-form symmetry 10d When standard model group is embedded a single simple — as case for almost all models studied literature ratio axion-photon axion mass bounded above QCD line. This bound relevant large number searches which have sensitivity parameter space this...
Axions and other very weakly interacting slim (with $m <$ 1 GeV) particles (WISPs) are a common feature of several extensions the Standard Model Particle Physics. The search WISPs was already recommended in last update European strategy on particle physics (ESPP). After that, case for has gained additional momentum. Indeed, may provide new paradigm to explain nature dark matter puzzling astrophysical observations. This document briefly summarizes current searches perspectives this research...
Here we propose a realistic $\mathrm{SU}(3{)}_{\mathrm{c}}\ensuremath{\bigotimes}\mathrm{SU}(3{)}_{\mathrm{L}}\ensuremath{\bigotimes}\mathrm{U}(1{)}_{\mathrm{X}}$ electroweak gauge model with enlarged Higgs sector. The scheme allows for the natural implementation of type II seesaw mechanism Dirac neutrinos, while charged lepton and quark masses are reproduced in way thanks to presence new scalars. energy scale characterizing neutrino mass generation could be accessible current LHC experiments.
We propose a simple theory for the idea that cosmological dark matter (DM) may be present today mainly in form of stable neutral hadronic thermal relics. In our model, neutrino masses arise radiatively from exchange colored DM constituents, giving common origin both and mass. The exact conservation $B\ensuremath{-}L$ symmetry ensures stability Dirac nature neutrinos. can falsified by nuclear recoil direct detection experiments, leading also to possible signals at next generation hadron collider.
Motivated by the idea of comprehensive unification, we study a gauged $SO(3)$ flavor extension extended Standard Model, including right-handed neutrinos and Peccei-Quinn symmetry with simple charge assignments. The model accommodates observed fermion masses mixings yields characteristic, successful relation among them. is an essential ingredient.
We consider different types of storage rings as precision probes axion-mediated monopole-dipole forces. show that current and planned experiments aiming to measure magnetic electric dipole moments protons, muons electrons very precisely may explore new parts the parameter space beyond existing laboratory bounds and, in some cases, astrophysical constraints. Remarkably, a light axion coupled explain FNAL/BNL $(g-2)_\mu$ anomaly an environmental effect -- coherent field generated by earth...
We analyze the strong $CP$ problem and implications for axion physics in context of ${U}_{1}$ vector leptoquark models, recently put forward as an elegant solution to hints lepton flavor universality violation $B$-meson decays. It is shown that minimal gauge models containing a boson, Peccei-Quinn requires introduction two axions. Characteristic predictions associated axions can be deduced from model parameter space hinted by $B$-physics, allowing new sector account dark matter Universe....
The post-inflationary breaking of Peccei-Quinn (PQ) symmetry can lead to the cosmic domain wall catastrophe. In this paper we show how avoid walls by implementing instanton interference effect with a new interaction which itself breaks PQ and confines at an energy scale smaller than ${\mathrm{\ensuremath{\Lambda}}}_{\mathrm{QCD}}$. We give general description mechanism consider its cosmological implications constraints within minimal model. Contrary other mechanisms, do not require inverse...
We propose a simple scenario in which dark matter (DM) emerges as stable neutral hadronic thermal relic, its stability following from an exact U(1)D symmetry. Neutrinos pick up radiatively induced Majorana masses the exchange of colored DM constituents. There is common origin for both and neutrino mass, with lower bound neutrinoless double beta decay. Direct searches at nuclear recoil experiments will test proposal, may also lead to other phenomenological signals future hadron collider...
Comprehensive – that is, gauge and family unification using spinors has many attractive features, but it been challenged to explain chirality. Here, by combining an orbifold construction with more traditional ideas, we address difficulty. Our candidate model features three chiral families leads acceptable result for quantitative of couplings. A potential target accelerator astronomical searches emerges.
We propose a realistic theory based on the $\mathrm{SU(3)_c \otimes SU(3)_L SU(3)_R U(1)_{X}}$ gauge group which requires number of families to match colors. In simplest realization neutrino masses arise from canonical seesaw mechanism and their smallness correlates with observed V-A nature weak force. Depending symmetry breaking path Standard Model one recovers either left-right symmetric or U(1)}$ as "next" step towards new physics.
We show that for a relatively light majoron (≪ 100 eV) non-thermal production from topological defects is an efficient mechanism. Taking the type I seesaw as benchmark scheme, we estimate primordial abundance and determine required parameter choices where it can account observed cosmological dark matter. The latter consistent with scale of unification. Possible direct detection majorons future experiments such PTOLEMY formation boson stars matter are also discussed.
The QCD axion is one of the best motivated dark matter candidates. misalignment mechanism well known to produce an abundance consistent with for decay constant order $10^{12}$ GeV. For a smaller constant, axion, Peccei-Quinn symmetry broken during inflation, makes up only fraction unless field starts oscillating very close top its potential, in scenario called "large-misalignment". In this scenario, small partially comprised dense structures. We present simple dynamical model realising...
A bstract In addition to spectacular signatures such as black hole superradiance and the rotation of CMB polarization, plenitude axions appearing in string axiverse may have potentially dangerous implications. An example is cosmological overproduction relic moduli by misalignment mechanism, more pronounced regions where signals mentioned above be observable, that for large axion decay constant. this work, we study minimal requirements soften problem show fundamental requirement a long period...
We consider the possibility of gauge coupling unification within simplest realizations $\mathrm{SU}(3{)}_{\mathrm{c}}\ifmmode\times\else\texttimes\fi{}\mathrm{SU}(3{)}_{\mathrm{L}}\ifmmode\times\else\texttimes\fi{}\mathrm{SU}(3{)}_{\mathrm{R}}\ifmmode\times\else\texttimes\fi{}\mathrm{U}(1{)}_{\mathrm{X}}$ theory. present a first exploration renormalization group equations governing ``bottom-up'' evolution couplings in generic model with free normalization for generators. Interestingly, we...
We show that if global lepton number symmetry is spontaneously broken in a postinflation epoch, then it can lead to the formation of cosmological domain walls. This happens well-known "Majoron paradigm" for neutrino mass generation. propose some realistic examples allow spontaneous breaking be safe from such
We suggest a new left-right symmetric model implementing low-scale seesaw mechanism in which quantum consistency requires three families of fermions. The symmetry breaking route to the Standard Model determines profile "next" expected physics, characterized either by simplest gauge or 3-3-1 scenario. resulting Z ′ bosons can be probed at LHC and provide production portal for right-handed neutrinos. On other hand, its flavor changing interactions would affect K, D B neutral meson systems.
A bstract We show that a new chiral, confining interaction can be used to break PecceiQuinn symmetry dynamically and solve the domain wall problem, simultaneously. The resulting theory is an invisible QCD axion model without walls. No dangerous heavy relics appear.
We show that a very simple solution to the strong CP problem naturally leads Dirac neutrinos. Small effective neutrino masses emerge from type I seesaw mechanism. Neutrino mass limits probe axion parameters in regions currently inaccessible conventional searches.
We propose a new interpretation of Peccei-Quinn symmetry within the Standard Model, identifying it with axial $B + L$ i.e. $U(1)_{PQ} \equiv U(1)_{\gamma_5(B+L)}$. This retains all attractive features solution to strong CP problem but in addition also leads several other and interesting consequences. Owing identification U(1)_{\gamma_5(B+L)}$ axion behaves like Majoron inducing small seesaw masses for neutrinos after spontaneous breaking. Another novel feature this is phenomenon (and chiral)...
A bstract The Scotogenic model is an economical setup that induces Majorana neutrino masses at the 1-loop level and includes a dark matter candidate. We discuss generalization of original with arbitrary numbers generations singlet fermion inert doublet scalar fields. First, full form light mass matrix presented, some comments on its derivation special attention to particular cases. behavior theory high energies explored by solving Renormalization Group Equations.
We consider different types of storage rings as precision probes axion-mediated monopole-dipole forces. show that current and planned experiments aiming to measure magnetic electric dipole moments protons, muons electrons very precisely may explore new parts the parameter space beyond existing laboratory bounds and, in some cases, astrophysical constraints. Remarkably, a light axion coupled explain FNAL/BNL $(g-2)_\mu$ anomaly an environmental effect -- coherent field generated by earth...