Radial Regge trajectories and leptonic widths of the isovector mesons

2016/03/15 by А. М. Бадалян, A. M. Badalian, B. L. G. Bakker
Physics and Astronomy · #Atomic physics #Excited state #High-Energy Particle Collisions Research #Isovector #Meson #Nucleon #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #hep-ex #hep-ph

paper · pdf · doi:10.1103/physrevd.93.074034

published as Phys. Rev. D 93, 074034 (2016) · 12 pages

arxiv created 2016/03/15 · openalex publication_date 2016/04/26 · arxiv updated 2016/05/04 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

It is shown that two physical phenomena are important for high excitations: (i) the screening of the universal gluon-exchange potential and (ii) the flattening of the confining potential owing to creation of quark loops, and both effects are determined quantitatively. Taking the first effect into account, we predict the masses of the ground states with l=0, 1, 2 in agreement with experiment. The flattening effect ensures the observed linear behavior of the radial Regge trajectories M²(n)=m₀²+n_r\ensuremathμ² GeV², where the slope \ensuremathμ² is very sensitive to the parameter \ensuremathγ, which determines the weakening of the string tension \ensuremathσ(r) at large distances. For the \ensuremathρ trajectory the linear behavior starts with n_r=1 and the values \ensuremathμ²=1.40(2) GeV² for \ensuremathγ=0.40 and \ensuremathμ²=1.34(1) GeV² for \ensuremathγ=0.45 are obtained. For the excited states the leptonic widths \mathrm\ensuremathΓ_ee(\ensuremathρ(775))=7.0(3) keV, \mathrm\ensuremathΓ_ee(\ensuremathρ(1450))=1.7(1) keV, \mathrm\ensuremathΓ_ee(\ensuremathρ(1900))=1.0(1) keV, \mathrm\ensuremathΓ_ee(\ensuremathρ(2150))=0.7(1) keV, and \mathrm\ensuremathΓ_ee(1³D₁)=0.26(5) keV are calculated, if these states are considered as purely qq states. The width \mathrm\ensuremathΓ_ee(\ensuremathρ(1700)) increases if \ensuremathρ(1700) is mixed with the 2³S₁ state, giving for a mixing angle \ensuremathθ=21\ifmmode^∘\else\textdegree\fi almost equal widths: \mathrm\ensuremathΓ_ee(\ensuremathρ(1700))=0.75(6) keV and \mathrm\ensuremathΓ_ee(1450)=1.0(1) keV.

Citations

• Universality of Regge and vibrational trajectories in a semiclassical model
• High-statistics measurement of the pion form factor in the ρ-meson energy range with the CMD-2 detector
• New nonperturbative approach to the Debye mass in hot QCD
• Light meson radial Regge trajectories
• Big-Bang Nucleosynthesis