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Related papers: The strong coupling constant at large distances

200 papers

A summary is given of the current status of measurements of the strong coupling constant $\alpha_s$ performed at LEP. These include measurements from inclusive observables as well as from event shape variables. Recent results based on power…

High Energy Physics - Experiment · Physics 2007-05-23 G. Dissertori

Complex nature of finite density QCD with heavy quarks in the strong coupling region is studied. For this purpose, we consider the effective potential as a function of Polyakov line, and study thermodynamic singularities and associated…

High Energy Physics - Lattice · Physics 2015-11-17 Shinji Ejiri , Hiroshi Yoneyama

The status of determinations of the QCD coupling constant, alphas, at HERA is reviewed. Since jet final states provide the most relevant input to the HERA determinations of alphas, the relevant methods used in and results from jet physics…

High Energy Physics - Experiment · Physics 2011-12-06 Thomas Schoerner-Sadenius

We consider an interacting quantum dot strongly coupled to two superconducting leads in a Josephson junction geometry. By defining symmetry-adapted superpositions of states from the leads, we formulate an effective Hamiltonian for the…

Mesoscale and Nanoscale Physics · Physics 2024-01-17 Luka Pavešič , Ramón Aguado , Rok Žitko

The strict coupling constant expansion for the free energy of hot QCD plasma shows bad convergence at all reasonable temperatures, and does not agree well with its 4d lattice determination. This has recently lead to various refined…

High Energy Physics - Phenomenology · Physics 2009-10-31 K. Kajantie , M. Laine , K. Rummukainen , Y. Schroder

The QCD-coupling is a necessary input in the computation of many observables, and the parametric error on input parameters can be a dominant source of uncertainty. The coupling can be extracted by comparing high order perturbative…

High Energy Physics - Lattice · Physics 2022-03-16 Leonardo Chimirri , Rainer Sommer

Multi-hadronic events produced in e+e- collisions provide an excellent laboratory to study QCD, the theory of strong interactions, and in particular to determine the strong coupling parameter alpha_s and demonstrate its predicted behavior…

High Energy Physics - Experiment · Physics 2017-08-23 T. Wengler

A novel method to extract the QCD coupling alpha_s from the energy evolution of the moments of the parton-to-hadron fragmentation functions at low fractional hadron momentum z, is presented. The evolution of the moments (multiplicity, peak,…

High Energy Physics - Phenomenology · Physics 2014-08-14 David d'Enterria , and Redamy Perez-Ramos

If QCD is renormalized by minimal subtraction (MS), at higher orders, the strong coupling constant alpha_s and the quark masses m_q exhibit discontinuities at the flavour thresholds, which are controlled by so-called decoupling constants,…

High Energy Physics - Phenomenology · Physics 2007-05-23 B. A. Kniehl

We report on recently published experimental results on spin sum rules, and particularly on the generalized spin polarizabilities $\gamma_0(Q^2)$ (for both the proton and neutron) and $\delta_\mathrm{LT}(Q^2)$ (for the neutron). The data…

Nuclear Experiment · Physics 2022-02-23 Alexandre Deur

We compute the QCD running coupling on the lattice as defined from the 3-gluon vertex. We present the results of an exploratory study at $\beta=6.0$ on a $16^4$ lattice, which show that for momenta larger than 2 \Gev, the coupling runs…

High Energy Physics - Lattice · Physics 2007-05-23 D. Henty , C. Parrinello , C. Pittori

The cold and dense regime of the QCD phase diagram is to this day inaccessible to first principle lattice calculations owing to the sign problem. Here we present progress of an ongoing effort to probe this particularly difficult regime…

High Energy Physics - Lattice · Physics 2015-11-04 Jonas Glesaaen , Mathias Neuman , Owe Philipsen

We compute the low energy mass spectrum of lattice QCD in the large $N_C$ limit. Expanding around a gauge-invariant ground state, which spontaneously breaks the discrete chiral symmetry, we derive an improved strong-coupling expansion and…

High Energy Physics - Lattice · Physics 2009-11-10 G. Grignani , D. Marmottini , P. Sodano

We present a significantly improved determination of the Bjorken Sum for 0.6$\leq Q^{2}\leq$4.8 GeV$^{2}$ using precise new $g_{1}^{p}$ and $g_{1}^{d}$ data taken with the CLAS detector at Jefferson Lab. A higher-twist analysis of the…

Nuclear Experiment · Physics 2014-07-22 A. Deur , Y. Prok , V. Burkert , D. Crabb , F. -X. Girod , K. A. Griffioen , N. Guler , S. E. Kuhn , N. Kvaltine

We discuss the strong couplings $g_{PPV}$ and $g_{VVP}$ for vector ($V$) and pseudoscalar ($P$) mesons, at least one of which is a charmonium state $J/\psi$ or $\eta_c$. The strong couplings are obtained as residues at the poles of suitable…

High Energy Physics - Phenomenology · Physics 2016-01-12 Wolfgang Lucha , Dmitri Melikhov , Hagop Sazdjian , Silvano Simula

We extend our recent analytic study of the strong coupling $\alpha_{\rm eff}$ in the nonperturbative and near-perturbative regimes~\cite{deTeramond:2024ikl} by imposing rigorous renormalization-group results from asymptotically free gauge…

High Energy Physics - Phenomenology · Physics 2025-05-27 Guy F. de Teramond , Arpon Paul , Hans Gunter Dosch , Stanley J. Brodsky , Alexandre Deur , Tianbo Liu , Raza Sabbir Sufian

The experimental data obtained for the polarized Bjorken sum rule \Gamma^{(p-n)}_1(Q^2) for small values of Q2 are approximated by the predictions obtained in the framework of analytic QCD up to the 5th order perturbation theory, whose…

High Energy Physics - Phenomenology · Physics 2023-09-26 I. R. Gabdrakhmanov , N. A Gramotkov , A. V. Kotikov , D. A. Volkova , I. A. Zemlyakov

We propose a modified procedure for extracting the numerical value for the strong coupling constant $\alpha_s$ from the $\tau$ lepton hadronic decay rate into non-strange particles in the vector channel. We employ the concept of the…

High Energy Physics - Phenomenology · Physics 2012-11-06 B. A. Magradze

We propose a set of lattice measurements which could test whether the deconfined, quark-gluon plasma, phase of QCD shows strong coupling aspects at temperatures a few times the critical temperature for deconfinement, in the region where the…

High Energy Physics - Phenomenology · Physics 2009-11-05 E. Iancu , A. H. Mueller

This talk offers a brief review of the determination of coupling constants in the framework of dimensionally reduced effective field theories for thermal QCD, specializing on its gluonic sector. Interestingly, higher-order operators that go…

High Energy Physics - Phenomenology · Physics 2018-08-20 York Schroder