A5017710017- Particle physics theoretical and experimental studies
- Neutrino Physics Research
- Quantum Chromodynamics and Particle Interactions
- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Cosmology and Gravitation Theories
- High-Energy Particle Collisions Research
- Black Holes and Theoretical Physics
- Advanced Data Storage Technologies
- Parallel Computing and Optimization Techniques
- CCD and CMOS Imaging Sensors
- Astronomy and Astrophysical Research
- Geomagnetism and Paleomagnetism Studies
- Radiation Effects in Electronics
- Amino Acid Enzymes and Metabolism
- Gas Dynamics and Kinetic Theory
- Nuclear physics research studies
- Advanced Algebra and Logic
- Particle Detector Development and Performance
- Neural Networks and Applications
- Hemoglobin structure and function
- GNSS positioning and interference
- Stochastic processes and financial applications
- Fluid Dynamics and Turbulent Flows
- Computational Fluid Dynamics and Aerodynamics
University of Cambridge
2021-2024
Los Alamos National Laboratory
2024
Niels Brock
2020-2021
University of Copenhagen
2020-2021
Deutsches Elektronen-Synchrotron DESY
2018-2020
Folkwang University of the Arts
2016-2018
University of Siegen
2016-2018
University of Bern
2018
University of Oxford
2014-2017
University of California, Los Angeles
2016
The recent observation by the IceCube experiment of cosmic neutrinos at energies up to a few PeV heralds beginning neutrino astronomy. At such high energies, 'conventional' flux is suppressed and 'prompt' component from charm meson decays expected become dominant background astrophysical neutrinos. Charm production however theoretically uncertain, both since scale uncertainties NLO calculation are large, also because it directly sensitive poorly-known gluon PDF small-x. In this work we...
The recent observation of very high energy cosmic neutrinos by IceCube heralds the beginning neutrino astronomy. At these energies, dominant background to astrophysical signal is flux `prompt' neutrinos, arising from decay charmed mesons produced ray collisions in atmosphere. In this work we provide predictions for prompt atmospheric framework perturbative QCD, using state-of-the-art Monte Carlo event generators. Our calculation includes constraints set charm production measurements LHCb...
We present compact integral representations for the calculation of two-loop anomalous dimensions a generic class soft functions that are defined in terms two light-like Wilson lines. Our results relevant resummation Sudakov logarithms e+ e- event-shape variables and inclusive hadron-collider observables at next-to-next-to-leading logarithmic accuracy within Soft-Collinear Effective Theory (SCET). formalism applies to both SCET-1 SCET-2 we clarify relation between respective dimension...
A bstract We show that a universal texture zero in the (1,1) position of all fermionic mass matrices, including heavy right-handed Majorana neutrinos driving type-I see-saw mechanism, can lead to viable spectrum mass, mixing and CP violation for both quarks leptons, (but not limited to) three important postdictions: Cabibbo angle, charged lepton masses, leptonic ‘reactor’ angle. model this with non-Abelian discrete family symmetry easily be embedded grand unified framework, discuss details...
We study the implications of single leptoquark extensions Standard Model (SM) under assumption that their enhanced Yukawa sectors are invariant global Abelian flavour symmetries already present in SM mass terms. Such symmetries, assumed to be ‘residual’ subgroups an ultra-violet theory, have previously been considered order predict fermionic mixing angles. Here we focus instead on effect novel structures sourced by representations address $${R}_{K^{(\star )}}$$ anomalies semileptonic rare...
We employ a bottom-up and model-independent technique to search for non-Abelian discrete flavour symmetries capable of predicting viable CKM PMNS matrices alongside special patterns leptoquark couplings. In particular, we analyze derived when an ultra-violet theory is assumed break global Abelian in Standard Model fermion masses new Yukawa-like terms sourced by the representation. The phenomenology different classes these `simplified models' can be explored without reference explicit...
A bstract We write down a geometric realization of the Standard Model Effective Field Theory (SMEFT) extended by n f flavours light sterile neutrinos, so-called geo ν SMEFT. As with geoSMEFT introduced Helset, Martin and Trott, we show that refactorization SMEFT’s operator product expansion is possible, such two- three-point composite forms are dressed field-space connections composed towers Higgs dressings symmetry generators, valid at all-orders in $$ {\overline{v}}_T/\Lambda <mml:math...
We present a novel procedure for identifying discrete, leptonic flavour symmetries, given class of unitary mixing matrices. By creating explicit 3D representations generators residual symmetries in both the charged lepton and neutrino sector, we reconstruct large(r) non-abelian groups using GAP language computational finite algebra. use experimental data to construct only those that yield acceptable (or preferable) patterns. Such an approach is advantageous because it 1) can reproduce known...
We present predictions for the $e^{+}e^{-}$ event shape angularities at NNLL$^{\prime}$ resummed and $\mathcal{O}(\alpha_s^{2})$ matched accuracy compare them to LEP data center-of-mass energies $Q=91.2$ GeV $Q=197$ GeV. perform resummation within framework of Soft-Collinear Effective Theory, make use recent results two-loop angularity soft function. determine remaining $\mathcal{O}(\alpha_s^2)$ ingredients from a fit EVENT2 generator, implement function with renormalon-free gap parameter...
We study the role of renormalon cancellation schemes and perturbative scale choices in extractions strong coupling constant <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msub><a:mi>α</a:mi><a:mi>s</a:mi></a:msub><a:mo stretchy="false">(</a:mo><a:msub><a:mi>m</a:mi><a:mi>Z</a:mi></a:msub><a:mo stretchy="false">)</a:mo></a:math> leading nonperturbative shift parameter <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:msub><e:mi...
A bstract We present a systematic algorithm for the perturbative computation of soft functions that are defined in terms two light-like Wilson lines. Our method is based on universal parametrisation phase-space integrals, which we use to isolate singularities Laplace space. The observable-dependent integrations can then be performed numerically, and they implemented new, publicly available package SoftSERVE derive all our numerical results. applies both SCET-1 SCET-2 functions, current...
We perform a bottom-up search for discrete non-Abelian symmetries capable of quantizing the Cabibbo angle that parameterizes CKM mixing. Given particular Abelian symmetry structure in up and down sectors, we construct representations associated residual generators which explicitly depend on degrees freedom present our effective mixing matrix. then discretize those utilize Groups, Algorithms, Programming (GAP) package to close finite groups. This short study is performed context recent...
A bstract We extend our algorithm for automating the calculation of two-loop dijet soft functions to observables that do not obey non-Abelian exponentiation theorem, i.e. those require an independent uncorrelated-emission contribution. As singularity structure uncorrelated double emissions differs substantially from one correlated emissions, we introduce a novel phase-space parametrisation isolates corresponding divergences. The resulting integrals are implemented in SoftSERVE 1.0, which...
We report a set of exact formulae for computing Dirac masses, mixings, and CP-violation parameter(s) from 3$\times$3 Yukawa matrices $Y$ valid when $Y Y^\dagger \rightarrow U^\dagger \,Y \, U$ under global $U(3)_{Q_L}$ flavour symmetry transformations $U$. The results apply to the Standard Model Effective Field Theory (SMEFT) its `geometric' realization (geoSMEFT). thereby complete, in sector, catalogue geoSMEFT parameters derived at all orders $\sqrt{2 \langle H^\dagger H \rangle} /...
We present a systematic framework for the calculation of dijet soft functions, which are defined as matrix element two light-like Wilson lines that is weighted by generic measurement function. Based on universal parametrisation phase-space integrals, we isolate singular terms in Laplace space and evaluate observable-dependent integrations numerically. discuss implementation our algorithm into public program SecDec, results various SCET-1 functions to two-loop order. In particular, obtain new...
This document collects the proceedings of "Parton Radiation and Fragmentation from LHC to FCC-ee" workshop (http://indico.cern.ch/e/ee\_jets16) held at CERN in Nov. 2016. The writeup reviews latest theoretical experimental developments on parton radiation parton-hadron fragmentation studies --including analyses LEP, B-factories, data-- with a focus future perspectives reacheable $e^+e^-$ measurements Future Circular Collider (FCC-ee), multi-ab$^{-1}$ integrated luminosities yielding...
A bstract We consider the higher-order resummation of Sudakov double logarithms in presence multiple coupled gauge in. The associated evolution equations depend on β functions two (or more) coupling constants α a and b , as well anomalous dimensions that have joint perturbative series . discuss possible strategies for solving system arises. As an example, we obtain complete three-loop (NNLL) QCD⊗QED factor. Our results also readily apply to electroweak QCD logarithms. part our analysis...
We demonstrate how residual flavour symmetries, infrared signatures of symmetry breaking in complete models flavour, can naturally forbid (or limit a specific way) flavour-changing neutral currents (FCNC) multi-Higgs-doublet (MHDM) without using mass hierarchies. first review this model-independent mechanism control the fermionic mixing patterns Standard Model, and then implement symmetries Yukawa sector MHDM, which allows us to intimately connect predictivity given model with its ability...
We extend our framework for the automated calculation of dijet soft functions to observables that do not obey non-Abelian exponentiation theorem, like jet-veto or grooming are sensitive clustering effects jet algorithm. Although matrix element uncorrelated double emissions has a simpler structure than one correlated emissions, we argue its singularity poses more stringent constraints on required phase-space parametrisation. Our algorithm applies both SCET-1 and SCET-2 it is implemented in...
The recent observation by the IceCube experiment of cosmic neutrinos at energies up to a few PeV heralds beginning neutrino astronomy. At such high energies, conventional flux is suppressed and prompt component from charm meson decays expected become dominant background astrophysical neutrinos. Charm production however theoretically uncertain, both since mass boundary applicability perturbative QCD, also because calculations are sensitive poorly-known gluon PDF small-x. In this work we...
We show that the discrete anomaly constraints governing popular non-Abelian symmetries of use in (e.g.) flavoured, supersymmetric, and dark matter model building typically subdivide into two classes differentiated by simple restrictions they impose on number fields transforming under certain irreducible representations relevant groups. These lead us both to generic conclusions for common Beyond-the-Standard-Model constructions (including rather powerful statements Grand Unified theories) as...
We revisit the phenomenological predictions of Universal Texture Zero (UTZ) model flavour originally presented in arXiv:1710.01741, and update them light both improved experimental constraints numerical analysis techniques. In particular, we have developed an in-house Markov Chain Monte Carlo (MCMC) algorithm to exhaustively explore UTZ's viable parameter space, considering leading- next-to-leading contributions model's effective operator product expansion. also extract -- for first time...
We consider the phenomenological signatures of Simplified Models Flavourful Leptoquarks, whose Beyond-the-Standard Model (SM) couplings to fermion generations occur via textures that are well motivated from a broad class ultraviolet flavour models (which we briefly review). place particular emphasis on study vector leptoquark $\Delta_\mu$ with assignments $\left({\bf{3}}, {\bf{1}}, 2/3 \right)$ under SM's gauge symmetry, $SU(3)_C \times SU(2)_L U(1)_Y$, which has tantalising possibility...
We discuss the possible origin of Majorana mass scale(s) required for "Neutrino Option" where electroweak scale is generated simultaneously with light neutrino masses in a type-I seesaw model, by common dimension four interactions. establish no-go constraints on perturbative generation due to global symmetries Lagrangian.