A5032205509- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Black Holes and Theoretical Physics
- Computational Physics and Python Applications
- Dark Matter and Cosmic Phenomena
- Atomic and Subatomic Physics Research
- Superconducting Materials and Applications
- Nuclear physics research studies
- Advanced NMR Techniques and Applications
- Neutrino Physics Research
- Physics of Superconductivity and Magnetism
- Geophysics and Gravity Measurements
- Cosmology and Gravitation Theories
- Economic Theory and Policy
- Quantum chaos and dynamical systems
- International Science and Diplomacy
- Scientific Research and Discoveries
- Numerical Methods and Algorithms
- Particle accelerators and beam dynamics
- Quantum, superfluid, helium dynamics
- Quantum and Classical Electrodynamics
- Statistical and numerical algorithms
- Mathematical functions and polynomials
- Medical Imaging Techniques and Applications
Universidade de São Paulo
2016-2025
Universidade Federal de São Carlos
2015-2024
Universitat Autònoma de Barcelona
2008-2022
Institute for High Energy Physics
2008-2022
University of Vienna
2022
York University
2012-2020
High Energy Accelerator Research Organization
2019-2020
University of Liverpool
2019-2020
San Francisco State University
2012-2020
University of Mississippi
2019-2020
We apply an analysis method previously developed for the extraction of strong coupling from OPAL data to recently revised ALEPH nonstrange hadronic $\ensuremath{\tau}$ decays. Our yields values ${\ensuremath{\alpha}}_{s}({m}_{\ensuremath{\tau}}^{2})=0.296\ifmmode\pm\else\textpm\fi{}0.010$ using fixed-order perturbation theory, and ${\ensuremath{\alpha}}_{s}({m}_{\ensuremath{\tau}}^{2})=0.310\ifmmode\pm\else\textpm\fi{}0.014$ contour-improved theory. Averaging these with our obtained data, we...
Abstract Theoretical predictions for particle production cross sections and decays at colliders rely heavily on perturbative Quantum Chromodynamics (QCD) calculations, expressed as an expansion in powers of the strong coupling constant α S . The current <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi class="MJX-tex-calligraphic" mathvariant="script">O</mml:mi> <mml:mo stretchy="false">(</mml:mo> <mml:mn>1</mml:mn> <mml:mo>%</mml:mo>...
Employing our previous framework to treat non-perturbative effects self-consistently, including duality violations, we update the determination of strong coupling, \alpha_s, using a modified version 1998 OPAL data, updated reflect current values exclusive mode hadronic \tau decay branching fractions. Our best n_f=3 from data are \alpha_s(m^2_\tau)=0.325+-0.018 and \alpha_s(m^2_\tau)=0.347+-0.025 in fixed-order contour-improved perturbation theory, respectively. To account for effects,...
We present a new framework for the extraction of strong coupling from hadronic τdecays through finite-energy sum rules. Our focus is on small, but still significant non-perturbative effects that, in principle, affect both central value and systematic error. employ quantitative model order to accommodate violations quark-hadron duality, enforce consistent treatment higher-dimensional contributions Operator Product Expansion our Using 1998 OPAL data non-strange isovector vector axial-vector...
The quantum chromodynamics (QCD) coupling α_{s} is not a physical observable of the theory, since it depends on conventions related to renormalization procedure. We introduce definition QCD coupling, denoted by α[over ^]_{s}, whose running explicitly scheme invariant. dependence new ^]_{s} parametrized single parameter C, transformations scale Λ. It demonstrated that appropriate choices C can lead substantial improvements in perturbative prediction observables. As phenomenological...
A bstract Perturbative QCD corrections to hadronic τ decays and e + − annihilation into hadrons below charm are obtained from the Adler function, which at present is known in chiral limit five-loop accuracy. Extractions of strong coupling, α s , these processes suffer an ambiguity related treatment unknown higher orders perturbative series. In this work, we exploit method Padé approximants its convergence theorems extract information about higher-order function a systematic way. First,...
We combine ALEPH and OPAL results for the spectral distributions measured in $\tau\to\pi^-\pi^0\nu_\tau$, $\tau\to 2\pi^-\pi^+\pi^0\nu_\tau$ $\tau\to\pi^-3\pi^0\nu_\tau$ decays with (i) recent BaBar analogous K^- K^0\nu_\tau$ distribution (ii) estimates of contributions from other hadronic $\tau$-decay modes obtained using CVC electroproduction data, to obtain a new more precise non-strange, inclusive vector, isovector function. The $K^- K^0$ CVC/electroproduction provide us alternate,...
We propose a simple and easy-to-implement scheme for renormalon-free gluon condensate (GC) matrix element, which is analogous to implementations of short-distance heavy-quark mass renormalization schemes existing in the literature already long time. Because based on perturbative subtraction at level with freely adaptable infrared factorization scale, it can be implemented little effort any observable where GC relevant. The depends renormalon norm has supplemented independently. apply...
We develop a number of sum rules comparing spectral integrals involving judiciously chosen weights to over the corresponding Euclidean two-point function. The applications we have in mind are hadronic vacuum polarization that determines most important correction $a_\mu^{\rm HVP}$ muon anomalous magnetic moment. First, point out how may be emphasize narrow regions $\sqrt{s}$, providing tool investigate emerging discrepancies between data-driven and lattice determinations HVP}$. Alternatively,...
A number of discrepancies have emerged between lattice computations and data-driven dispersive evaluations the RBC/UKQCD intermediate-window-hadronic contribution to muon anomalous magnetic moment. It is therefore interesting obtain estimates for light-quark-connected strange-plus-disconnected components this window quantity, allowing a more detailed comparison approaches. The aim paper provide these estimates, extending analysis several other quantities, including two windows designed focus...
In the context of anomalous magnetic moment muon, hadronic contribution plays a crucial role, especially given its large to final error. Currently, lattice QCD simulations are in disagreement with dispersive calculations based on \(e^+e^-\) cross sections. The new MUonE experiment intends shed light this situation extracting running electromagnetic coupling space-like region, \(\Delta\alpha_{\mathrm{had}}(t)\), from elastic \(e\mu\) scattering. Still, due limited kinematic range that can be...
A key issue affecting the attempt to reduce uncertainty on Standard Model prediction for muon anomalous magnetic moment is current discrepancy between lattice-QCD and data-driven results hadronic vacuum polarization. Progress this benefits from precise determinations of isospin-limit light-quark-connected (lqc) strange-plus-light-quark-disconnected (<a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mi...
In previous work we have combined the $\pi^-\pi^0$, $2\pi^-\pi^+\pi^0$ and $\pi^-3\pi^0$ spectral data obtained from hadronic $\tau$ decays measured by ALEPH OPAL experiments, together with electroproduction for several of subleading modes BaBar $K\bar{K}$ mode to construct an inclusive non-strange vector function entirely based on experimental data, no Monte-Carlo generated input. this paper, include, first time, Belle $\tau\to\pi^-\pi^0\nu_\tau$ high-statistics decay a new that combines...
We study in detail the impact of anomalous Higgs couplings angular asymmetries crossing-symmetric processes H --> Zl+l- and e+e- HZ. Beyond Standard Model physics is parametrized terms SU(3)xSU(2)_LxU(1)_Y dimension-six effective Lagrangian. In light present bounds on d = 6 interactions we how can reveal non-standard CP-even CP-odd couplings. provide approximate expressions to all observables interest making transparent their dominant dependence show that some may BSM effects are hidden...
We investigate the origin of quark-hadron duality-violating terms in expansion QCD two-point vector correlation function at large energies complex ${q}^{2}$ plane. Starting from dispersive representation for associated polarization, analytic continuation operator product Euclidean to Minkowski region is performed by means a generalized Borel-Laplace transform, borrowing techniques hyperasymptotics. establish connection between singularities Borel plane and contributions. with assumption that...
A bstract We employ Padé approximants in the study of analytic structure four-dimensional SU(2) Landau-gauge gluon and ghost propagators infrared regime. The approximants, which are model independent, serve as fitting functions for lattice data. carefully propagate uncertainties due to procedure, taking into account all possible correlations. For gluon-propagator data, we confirm presence a pair complex poles at $$ {p}_{\textrm{pole}}^2 <mml:math...
We present the first data-driven result for ${a}_{\ensuremath{\mu}}^{\mathrm{win},\mathrm{lqc}}$, isospin-limit light-quark connected component of intermediate-window Hadronic-vacuum-polarization contribution to muon anomalous magnetic moment. Our result, $(198.8\ifmmode\pm\else\textpm\fi{}1.1)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}$, is in significant tension with eight recent mutually compatible high-precision lattice-QCD determinations, and provides enhanced evidence a...
We introduce parametrizations of hadronic three-body $B$ and $D$ weak decay amplitudes that can be readily implemented in experimental analyses are a sound alternative to the simplistic widely used sum Breit-Wigner type amplitudes, also known as isobar model. These particularly useful interpretation CP asymmetries Dalitz plots. They derived from previous calculations based on quasi-two-body factorization approach which two-body final state interactions fully taken into account terms unitary...
Several different analysis methods have been developed to determine the strong coupling via finite-energy sum-rule analyses of hadronic $\ensuremath{\tau}$ decay data. While most agree on existence well-known ambiguity in choice a resummation scheme due slow convergence QCD perturbation theory at mass, there is an ongoing controversy over how deal properly with nonperturbative effects. These are small, but not negligible, and include quark-hadron ``duality violations'' (i.e., resonance...
In a previous article, we have shown that the discrepancy between fixed-order (FOPT) and contour-improved (CIPT) perturbative expansions for $\tau$ hadronic spectral function moments, which had affected precision of $\alpha_s$ determinations many years, may be reconciled by employing renormalon-free (RF) scheme gluon condensate (GC) matrix element. addition, convergence moments with sizeable GC correction can improved. The RF depends on an IR factorization scale $R$ normalization $N_g$...
Theory predictions for g-2, the muon's anomalous magnetic moment, can be made with dispersive methods or lattice calculations, but some current estimates show tension between two. This becomes especially important in view of apparent discrepancy experimental value. The authors this Suggestion how a subset contributions to hadronic vacuum polarization, leading source theory uncertainty, related physical observables. results help isolate disagreement differing calculations.