<span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi mathvariant="normal">He</mi></mrow><mprescripts></mprescripts><mrow></mrow><mrow><mn>4</mn></mrow><mrow></mrow><mrow></mrow></mmultiscripts></mrow><mo>(</mo><mi>γ</mi><mo>,</mo><mi>p</mi><mrow><msup><mrow><mi>π</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow><mo>)</mo></math></span> Cross Section Around <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Δ</mi><mn></mn><mo>(</mo><mn>1236</mn><mo>)</mo><mn></mn></math></span>

P. E. Argan; G. Audit; N. De Botton; J.-M. Laget; J. Martin; C. Schuhl; G. Tamas

doi:10.1103/PhysRevLett.29.1191

${}^{4}{He} (γ, p π^{-})$ Cross Section Around $Δ (1236)$

P. E. Argan, G. Audit, N. De Botton, J.-M. Laget, J. Martin, C. Schuhl, and G. Tamas

Phys. Rev. Lett. 29, 1191 – Published 23 October 1972

Abstract

The cross section of the reaction ${}^{4}{He} + γ \to p + π^{-} + (ppn)$ has been measured in the region of the first resonance for various values of the recoil momentum. An anomaly is observed for high values of this momentum and a tentative explanation is suggested.