Low energy theorems and photo- and electroproduction near threshold by current algebra

1972 ◽  
pp. 118-147 ◽  
Author(s):  
G. Furlan ◽  
N. Paver ◽  
C. Verzegnassi
Keyword(s):  
Current Algebra ◽  
Low Energy ◽  
Near Threshold

scholarly journals Resonant excitation of molecules by low-energy electrons

2008 ◽  
Vol 6 (1) ◽  
pp. 41-55 ◽  
Author(s):  
Goran Poparic
Keyword(s):  
Cross Sections ◽  
Valence State ◽  
Vibrational Excitation ◽  
Rydberg States ◽  
Low Energy ◽  
Resonant Excitation ◽  
Excitation Spectra ◽  
Energy Excitation ◽  
The Cross ◽  
Near Threshold

Low-energy electron impact vibrational and electronic excitation cross sections of the CO, N2 and CO2 molecules are measured by use of a high resolution crossed-beams double trochoidal electron spectrometer. The spectrometer is designed to work in standard and time-of-flight regimes. The energy dependences of the resonant vibrational excitation of the first several vibrational levels of the N2, CO, and CO2 molecules, have been measured. Characteristic substructures in energy excitation spectra in the cases of N2 and CO have been obtained and discussed for some vibrational channels for the first time. The ratio of forward-to-backward scattered electrons from the 2? resonance in CO is found to be equal to 1, and thus the angular distribution of scattered electrons to be symmetric relative to 90?. This conclusion supports the fact that the contribution of the p? partial wave is dominant in the energy region of the 2? resonance in CO. The energy dependences of the near threshold resonant excitation of the valence and Rydberg states of the N2 and CO molecules have been measured. The cross sections of the near threshold resonant excitation of the C 3?u valence state, and the E 3?+ g and a'' 1?+ g Rydberg states of the N2 molecule have been measured. In the case of the CO molecule, the cross sections of the near threshold resonant excitation of the a 3? valence state, and the b 3?+ and B 1?+ Rydberg states have been measured. Resonant structures in excitation functions of all measured electronic states are observed and their locations are compared with resonances obtained in different decay channels.

scholarly journals QCD TESTS OF: G(1.6)=GLUEBALL

1989 ◽  
Vol 04 (11) ◽  
pp. 2751-2763 ◽  
Author(s):  
S. NARISON ◽  
G. VENEZIANO
Keyword(s):  
Current Algebra ◽  
Sum Rules ◽  
Low Energy ◽  
Qcd Sum Rules

QCD sum rules, low-energy theorems and current algebra for the pseudoscalar nonet are used to support the hypothesis that the recently observed G(1.6 GeV) meson is a (relatively pure) gluonium state.

MEASUREMENT OF THE ω MESON POLARIZATION IN THE pd → 3He ω REACTION AT 1360 AND 1450 MeV

2009 ◽  
Vol 18 (02) ◽  
pp. 253-260
Author(s):  
◽  
K. SCHÖNNING ◽  
H. CALÉN ◽  
K. FRANSSON ◽  
B. HÖISTAD ◽  
...  
Keyword(s):  
Meson Production ◽  
Low Energy ◽  
Vector Mesons ◽  
Tensor Polarization ◽  
Decay Products ◽  
Near Threshold

The tensor polarization of ω mesons produced in the pd → 3 He ω reaction has been measured at two energies near threshold. The 3 He nuclei were detected in coincidence with the π0π+π- or π0γ decay products of the ω. The ω mesons are found to be unpolarised, which is in complete contrast to the case of ϕ-meson production from the corresponding reaction pd → 3 He ϕ. This brings into question the applicability of the Okubo-Zweig-Iizuka rule when comparing the production of vector mesons in low energy hadronic reactions.

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