P‐Even Effects in a Direct γ Transition Following Neutron Capture in 113Cd Around Ep=7 eV Resonance

About the resonance approximation in neutron induced reactions

“…It is obvious that the contribution of the 'negative' resonances is of the same order of magnitude. Therefore, they can essentially change the ayb value and eliminate all discrepancies in [8][9][10]. It should be noted that a similar picture will be found for other correlations 9 Therefore, it is impossible to obtain x and y (or spin dependent parts of the neutron [8][9][10] due to the complicated multi resonance nature of the (n, 7) correlations and due to the absence any information about 'negative' neutron resonances.…”

“…It is known that the two resonance approximation is good enough to estimate the P-odd and P-even correlations in neutron induced reactions 9 In the framework of this approximation the parameters x and y were calculated [8][9][10] using values of arz and afb obtained in the vicinity of p-wave resonances in the 117Sn and ~13Cd nuclei. The surprising result was that it is impossible to describe the aj'b value by means of the x and y magnitudes obtained from the experimental data for a,~ and the obvious condition x z + y2 = 1.…”

Acquired polarization ink�I PNC experiments

“…The resonance parameters were taken from the literature [13,14] and are listed in Table 1. The "mixing angle" parameter (see Appendix) has been measured only for one resonance in each of two nuclei: n3Cd and ~17Sn [15,16,17]. For the remaining nuclei the mixing parameters were chosen to set the "b" and "c" coefficients in the cross section equal in the limit of very large thickness t. We assume a parity nonconserving matrix element V PNc= 1 meV; this appears to be a typical value [3-5, 18, 19].…”

“…Mughabghab [14] lists the potential scattering cross section for natural cadmium as %or = 5.6 barns. The cross [15,17] and 117Sn [15,16]. For "lCd and 139La the mixing angles were chosen arbitrarily such that the "b" and "e" coefficients in the cross section are equal b Neutron widths for subthreshold s-wave resonances are referred to 1 eV E. [~vl section for isotopic 113Cd is treated simply as that due to the known resonances plus a 5.6 barn constant background.…”

“…The nuclide 113Cd has I= I/2. The resonance parameters are known, including the entrance channel mixing parameter for the p-wave resonance [15,17]. However, experimental neutron cross sections are not available for isotopic recd.…”