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We present a new approach to determining the strong coupling $\alpha_s(Q)$, over the entire range of validity of perturbative QCD, for scales above $\Lambda_{\mathrm{QCD}}$ and up to the Planck scale $\sim1.22\cdot10^{19}$\,GeV, with the…

High Energy Physics - Phenomenology · Physics 2025-09-16 Leonardo Di Giustino , Stanley J. Brodsky , Philip G. Ratcliffe , Sheng-Quan Wang , Xing-Gang Wu

We present the first determination of the strong coupling constant from a fit of next-to-next-to-leading order QCD predictions to event-shape variables, measured in $e^+e^-$ annihilations at LEP. The data have been collected by the ALEPH…

High Energy Physics - Phenomenology · Physics 2008-12-30 G. Dissertori , A. Gehrmann-De Ridder , T. Gehrmann , E. W. N. Glover , G. Heinrich , H. Stenzel

In this work, we investigate the nature of the strong coupling constant and related physics. Through the analysis of accumulated experimental data from around the world, we employ the ability of machine learning to unravel its physical…

High Energy Physics - Phenomenology · Physics 2024-03-06 Xiao-Yun Wang , Chen Dong , Xiang Liu

The vector meson strong decays rho-->pi pi, phi-->KK, and K^star-->pi K are studied within a covariant approach based on the ladder-rainbow truncation of the QCD Dyson--Schwinger equation for the quark propagator and the Bethe--Salpeter…

Nuclear Theory · Physics 2009-11-07 D. Jarecke , P. Maris , P. C. Tandy

Hadronic $\tau$ decays are studied as probe of new physics. We determine the dependence of several inclusive and exclusive $\tau$ observables on the Wilson coefficients of the low-energy effective theory describing charged-current…

High Energy Physics - Phenomenology · Physics 2022-07-06 Vincenzo Cirigliano , David Díaz-Calderón , Adam Falkowski , Martín González-Alonso , Antonio Rodríguez-Sánchez

Hadronic event shape distributions from e+e- annihilation measured by the OPAL experiment at centre-of-mass energies between 91 GeV and 209 GeV are used to determine the strong coupling {\alpha}S. The results are based on QCD predictions…

High Energy Physics - Experiment · Physics 2015-05-20 The OPAL Collaboration

We present the first determination of the value of the strong coupling via a simultaneous global fit of the proton parton distribution functions (PDFs) at approximate N$^{3}$LO (aN$^{3}$LO) order in QCD. This makes use of the MSHT global…

High Energy Physics - Phenomenology · Physics 2024-04-05 T. Cridge , L. A. Harland-Lang , R. S. Thorne

A challenge - and opportunity - is offered to the Hubbard Model community of solutions extant for the strong coupling region. A rigorous and quantitatively demanding test - a Computer Lab - is presented based on certain exact results for…

Strongly Correlated Electrons · Physics 2018-12-11 Donald M. Esterling

Using HISQ $N_f=2+1+1$ MILC ensembles with five different values of the lattice spacing, including four ensembles with physical quark masses, we have performed the most precise computation to date of the $K\to\pi\ell\nu$ vector form factor…

We study the medium modifications of the spectral functions as well as production cross-sections of the strange vector mesons ($\phi$, $K^*$ and $\bar {K^*}$) in isospin asymmetric strange hadronic matter. These are obtained from the…

Nuclear Theory · Physics 2021-04-14 Amruta Mishra , S. P. Misra

Precision atomic spectroscopy provides a solid model independent bound on the existence of new dark forces among the atomic constituents. We focus on the keV-GeV region investigating the sensitivity to such dark sectors of the recent…

High Energy Physics - Phenomenology · Physics 2022-05-18 Claudia Frugiuele , Clara Peset

This is a sequel to our recent work [1] in which we calculated the lepton number violating (LNV) $K^\pm$ decays due to contact dimension-9 (dim-9) quark-lepton effective interactions that are induced at a high energy scale. In this work we…

High Energy Physics - Phenomenology · Physics 2020-01-22 Yi Liao , Xiao-Dong Ma , Hao-Lin Wang

The spectral function $\rho_{V-A}(s)$ is determined from ALEPH and OPAL data on hadronic tau decays using a neural network parametrization trained to retain the full experimental information on errors, their correlations and chiral sum…

High Energy Physics - Phenomenology · Physics 2010-02-03 Joan Rojo , Jose I. Latorre

We study (inverse) photoemission from systems with strong coupling of doped carriers to phonons. Using an adiabatic approximation, we develop a method for calculating spectra. This method is particularly simple for systems where the…

Strongly Correlated Electrons · Physics 2007-05-23 O. Rösch , O. Gunnarsson

A combination of finite energy sum rule techniques and Chiral Perturbation Theory (ChPT) is used in order to exploit recent ALEPH data on the non-strange tau vector (V) and axial-vector (A) spectral functions with respect to an experimental…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Davier , L. Girlanda , A. Hoecker , J. Stern

Recent analyses of flavor-breaking hadronic-$\tau$-decay-based sum rules produce values of $\vert V_{us}\vert$ $\sim 3\sigma$ low compared to 3-family unitarity expectations. An unresolved systematic issue is the significant variation in…

High Energy Physics - Phenomenology · Physics 2015-06-18 P. A. Boyle , L. Del Debbio , N. Garron , R. J. Hudspith , E. Kerrane , K. Maltman , J. M. Zanotti

A previously proposed non-canonical coupled-perturbed Kohn-Sham density functional theory (KS-DFT)/Hartree-Fock (HF) treatment for spin-orbit coupling is here generalized to infinite periodic systems. The scalar-relativistic periodic…

We derive in detail a novel solution of the spin fermion model which is valid in the quasi-static limit pi T<<omega_sf, found in the intermediate (pseudoscaling) regime of the magnetic phase diagram of cuprate superconductors, and use it to…

Condensed Matter · Physics 2009-10-31 Joerg Schmalian , David Pines , Branko Stojkovic

We study and constrain the parameter space of the vector color-octet model from observed data at Tevatron by studying top quark pair production and associated observables afbt and spin-correlation. In particular we study invariant mass and…

High Energy Physics - Phenomenology · Physics 2013-07-09 Sukanta Dutta , Ashok Goyal , Mukesh Kumar

We study the $\tau^- \to \nu_{\tau} \pi^{-}\pi^{0}\ell^{+}\ell^{-}$ ($\ell=e,\,\mu$) decays, which are $O(\alpha^2)$-suppressed with respect to the dominant di-pion tau decay channel. Both the inner-bremsstrahlung and the structure- (and…

High Energy Physics - Phenomenology · Physics 2021-02-03 J. L. Gutiérrez Santiago , G. López Castro , P. Roig