Study of the electromagnetic Dalitz decays <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>ψ</mml:mi><mml:mo mathvariant="bold" stretchy="false">(</mml:mo><mml:mi mathvariant="normal">ϒ</mml:mi><mml:mo mathvariant="bold" stretchy="false">)</mml:mo><mml:mo stretchy="false">→</mml:mo><mml:msub><mml:mi>η</mml:mi><mml:mi>c</mml:mi></mml:msub><mml:mo mathvariant="bold" stretchy="false">(</mml:mo><mml:msub><mml:mi>η</mml:mi><mml:mi>b</mml:mi></mml:msub><mml:mo …
Physical review. D/Physical review. D.