Search results for "coupling constant"
showing 2 items of 262 documents
The strong coupling constant: State of the art and the decade ahead
2022
This document provides a comprehensive summary of the state-of-the-art, challenges, and prospects in the experimental and theoretical study of the strong coupling $\alpha_s$. The current status of the seven methods presently used to determine $\alpha_s$ based on: (i) lattice QCD, (ii) hadronic $\tau$ decays, (iii) deep-inelastic scattering and parton distribution functions fits, (iv) electroweak boson decays, hadronic final-states in (v) e+e-, (vi) e-p, and (vii) p-p collisions, and (viii) quarkonia decays and masses, are reviewed. Novel $\alpha_s$ determinations are discussed, as well as the averaging method used to obtain the PDG world-average value at the reference Z boson mass scale, $\…
Role of the N-*(1535) in the J/psi -> pp and J/psi -> p(+)Lambda reactions
2009
We study the J/psi -> p eta p and J/psi -> pK(+)Lambda reactions with a unitary chiral approach. We find that the unitary chiral approach, which generates the N-*(1535) dynamically, can describe the data reasonably well, particularly the ratio of the integrated cross sections. This study provides further support for the unitary chiral description of the N-*(1535). We also discuss some subtle differences between the coupling constants determined from the unitary chiral approach and those determined from phenomenological studies