Observation of a New Narrow Axial-Vector Meson<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>a</mml:mi><mml:mn>1</mml:mn></mml:msub><mml:mo stretchy="false">(</mml:mo><mml:mn>1420</mml:mn><mml:mo stretchy="false">)</mml:mo></mml:math>
Physical review letters