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Parity conserving gamma asymmetry in n-p radiative capture

Attila Csoto·B. F. Gibson·G. L. Payne
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Abstract

The importance of n-p radiative capture, utilizing polarized cold neutrons, as a means of measuring the weak pion coupling constant is reviewed. Parity conserving processes of the form k_gamma*[s_n,k_n] can contribute to the s_n*k_gamma photon asymmetry in any such experiment, if the apparatus is not perfectly symmetric. For an incident laboratory neutron energy of 0.003 eV a value of A^{PC}_{gamma}=0.67*10^{-8} is obtained for two different potential models (Argonne AV14 and Nijmegen Reid93). Serving as an extreme test case, the Reid soft core potential yields 0.61*10^{-8}, close to the result of the contemporary forces. Implications for extracting the weak pion coupling constant and for monitoring the beam polarization are discussed.

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Attila Csoto, B. F. Gibson, G. L. Payne. 1997-04-28. Parity conserving gamma asymmetry in n-p radiative capture. https://doi.org/10.1103/physrevc.56.631

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