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Related papers: Results for $\alpha_s$ from the decoupling strateg…

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We present a lattice determination of the $\Lambda$ parameter in three-flavor QCD and the strong coupling at the Z pole mass. Computing the nonperturbative running of the coupling in the range from $0.2\,$GeV to $70\,$GeV, and using…

High Energy Physics - Lattice · Physics 2017-09-13 M. Bruno , M. Dalla Brida , P. Fritzsch , T. Korzec , A. Ramos , S. Schaefer , H. Simma , S. Sint , R. Sommer

The evolution of the strong coupling constant $\alpha_s$ from $M_Z$ to the GUT scale is presented, involving three-loop running and two-loop decoupling. Accordingly, the two-loop transition from the $\bar{\rm MS}$ to the $\bar{\rm DR}$…

High Energy Physics - Phenomenology · Physics 2007-10-12 Luminita Mihaila

We examine gauge coupling unification and prediction for $\alpha_s (M_Z)$ in minimal flipped SU(5) with gauge-mediated supersymmetry breaking. We include threshold corrections at weak scale, messenger scale and unification scale, and…

High Energy Physics - Phenomenology · Physics 2009-10-31 K. T. Mahanthappa , Sechul Oh

We compute the renormalized running coupling of SU(3) gauge theory coupled to N_f = 8 flavors of massless fundamental Dirac fermions. The recently proposed finite volume gradient flow scheme is used. The calculations are performed at…

High Energy Physics - Lattice · Physics 2015-06-11 Zoltan Fodor , Kieran Holland , Julius Kuti , Santanu Mondal , Daniel Nogradi , Chik Him Wong

We describe the first lattice determination of the strong coupling constant with 3 flavors of dynamical quarks. The method follows previous analyses in using a perturbative expansion for the plaquette and Upsilon spectroscopy to set the…

High Energy Physics - Lattice · Physics 2015-06-25 C. Davies , A. Gray , M. Alford , E. Follana , J. Hein , P. Lepage , Q. Mason , M. Nobes , J. Shigemit su , H. Trottier , M. Wingate

We apply Ginzburg-Landau theory to determine BCS pairing in a strongly-coupled uniform superfluid of three-flavor massless quarks in flavor equilibrium. We elucidate the phase diagram near the critical temperature in the space of the…

High Energy Physics - Phenomenology · Physics 2014-11-17 Kei Iida , Gordon Baym

We present a new determination of the strong coupling constant $\alpha_s$ from a global QCD analysis CT25 of parton distribution functions (PDFs) that incorporates high-precision experimental measurements from the Run-2 of the Large Hadron…

High Energy Physics - Phenomenology · Physics 2026-03-18 Alim Ablat , Sayipjamal Dulat , Marco Guzzi , Joey Huston , Kirtimaan Mohan , Pavel Nadolsky , Dan Stump , C. -P. Yuan

We describe the coupling of the strong force. Denoted as $\alpha_s$, it sets the strength of that force, just as $G$ or $\alpha$ specify the strength of the gravity and electromagnetism. Its value depends on the scale at which phenomena are…

High Energy Physics - Phenomenology · Physics 2025-10-22 A. Deur

The fermion flavor $N_f$ dependence of non-perturbative solutions in the strong coupling phase of the gauge theory is reexamined based on the interrelation between the inversion method and the Schwinger-Dyson equation approach. Especially…

High Energy Physics - Theory · Physics 2009-10-28 Kei-Ichi Kondo , Takuya Iizuka , Eiji Tanaka , Toru Ebihara

One interesting feature of 3d $\mathcal{N}=2$ theories is that gauge-invariant operators can decouple by strong-coupling effects, leading to emergent flavor symmetries in the IR. The details of such decoupling, however, depends very…

High Energy Physics - Theory · Physics 2016-06-29 Jeongseog Lee , Masahito Yamazaki

In order to study the running coupling in four-flavour QCD, we review the set-up of the Schr\"odinger functional (SF) with staggered quarks. Staggered quarks require lattices which, in the usual counting, have even spatial lattice extent…

High Energy Physics - Lattice · Physics 2009-04-14 P. Perez-Rubio , S. Sint

The finite energy sum rule extraction of the strong coupling {\alpha}_s from hadronic {\tau} decay data provides one of its most precise experimental determinations. As precision improves, small non-perturbative effects become increasingly…

High Energy Physics - Lattice · Physics 2011-11-23 Diogo Boito , Oscar Catà , Maarten Golterman , Matthias Jamin , Kim Maltman , James Osborne , Santiago Peris

We perform the step-scaling investigation of the running coupling constant, using the gradient-flow scheme, in SU(3) gauge theory with twelve massless fermions in the fundamental representation. The Wilson plaquette gauge action and…

High Energy Physics - Lattice · Physics 2015-12-18 C. -J. David Lin , Kenji Ogawa , Alberto Ramos

A physically defined QCD coupling parameter naturally incorporates massive quark flavor thresholds in a gauge invariant, renormalization scale independent and analytical way. In this paper we summarize recent results for the finite-mass…

High Energy Physics - Phenomenology · Physics 2009-10-31 Michael Melles

We summarize the results recently reported in Ref.[1] [A. Deuzeman, M.P. Lombardo, T. Nunes da Silva and E. Pallante,"The bulk transition of QCD with twelve flavors and the role of improvement"] for the SU(3) gauge theory with Nf=12…

High Energy Physics - Lattice · Physics 2012-11-16 Tiago Nunes da Silva , Elisabetta Pallante

We calculate the renormalized step scaling function for twelve fundamental flavors nonperturbatively by determining the gradient flow coupling on gauge field configurations generated with dynamical stout-smeared M\"obius domain wall…

High Energy Physics - Lattice · Physics 2018-10-15 Anna Hasenfratz , Claudio Rebbi , Oliver Witzel

We present two determinations of the strong coupling \(\alpha_s\). The first one is from the static energy at three-loop accuracy, and may be considered an update of earlier determinations by some of us. The new analysis includes new…

Nonperturbative determinations of the renormalization group $\beta$ function are essential to connect lattice results to perturbative predictions of strongly coupled gauge theories and to determine the $\Lambda$ parameter or the strong…

High Energy Physics - Lattice · Physics 2023-07-13 Anna Hasenfratz , Curtis Taylor Peterson , Jake van Sickle , Oliver Witzel

We present a determination of the strong coupling constant $\alpha_s(m_Z)$ using inclusive top-quark pair production cross section measurements performed at the LHC and at the Tevatron. Following a procedure first applied by the CMS…

High Energy Physics - Phenomenology · Physics 2017-12-06 Thomas Klijnsma , Siegfried Bethke , Günther Dissertori , Gavin P. Salam

We present a comparison of the strong couplings of light ($u$,~$d$,~and~$s$), $c$, and $b$ quarks determined from multijet rates in flavor-tagged samples of hadronic $Z^0$ decays recorded with the SLC Large Detector at the SLAC Linear…

High Energy Physics - Experiment · Physics 2009-09-25 K. Abe