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Radiative decay width measurements of neutral kaon excitations using the primakoff effect.
A Alavi-Harati1, T Alexopoulos, M Arenton
1University of Wisconsin, Madison 53706, USA.
Physical Review Letters
|August 23, 2002
Summary
Researchers measured radiative widths of axial vector mesons K1(1270) and K1(1400) using K(L) interactions. Results are lower than quark-model predictions, offering new insights into particle physics.
Area of Science:
- High Energy Physics
- Particle Physics
- Nuclear Physics
Background:
- Axial vector mesons play a crucial role in understanding strong interactions.
- Previous theoretical models, like the quark model, predicted specific radiative widths for these mesons.
Purpose of the Study:
- To experimentally determine the radiative widths of the axial vector mesons K1(1270) and K1(1400).
- To compare these measurements with existing quark-model predictions.
- To establish upper limits for the radiative widths of K(*)(1410) and K(*)(2)(1430).
Main Methods:
- Utilized K(L) beams in the 100-200 GeV energy range.
- Produced candidate events of the axial vector pair K1(1270)-K1(1400) in the nuclear Coulomb field of a lead (Pb) target.
- Analyzed 147 candidate events to determine radiative widths.
Main Results:
- Measured Gamma(K1(1400)-->K0+gamma) = 280.8 ± 23.2(stat) ± 40.4(syst) keV.
- Measured Gamma(K1(1270)-->K0+gamma) = 73.2 ± 6.1(stat) ± 28.3(syst) keV.
- These experimental values are lower than quark-model predictions.
Conclusions:
- The measured radiative widths of K1(1270) and K1(1400) provide crucial experimental data that challenges current quark-model predictions.
- Upper limits for K(*)(1410) and K(*)(2)(1430) radiative widths were established, with K(*)(2)(1430) being vanishingly small, consistent with SU(3) invariance.
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