Showing papers by "Werner Tornow published in 1976"

Equality of analyzing power and polarization in the reaction /sup 3/H(p,n)/sup 3/He

Abstract: The quantities A/sub y/ and P/sub y/ were remeasured for E/sub p/<4 MeV in the reaction /sup 3/H(p,n)/sup 3/He. Although our A/sub y/ data confirm previous data, our P/sub y/ values are appreciably larger than earlier results and in fact agree well with those for A/sub y/. Elimination of the previously reported A/sub y/-P/sub y/ difference has important consequences. Charge-symmetry-breaking effects must be small or nonexistent in this reaction; and the previously required f-wave admixture to the lowest J/sup pi/=2/sup -/ state of /sup 4/He is no longer necessary. (AIP)

Measurements of Vector Polarization Transfer Coefficients for \((\vec d,\vec n)\) Reactions on 14N, 160, and 28Si

Abstract: In a \((\vec d,\vec n)\) reaction, the polarization transfer coefficient K y y′ measures the fraction of vector polarization of the incident deuteron transferred to the outgoing neutron. For the D\((\vec d,\vec n)\) 3He reaction at θ = 0°, it is known that this parameter remains at nearly 90% of a simple stripping model value of 2/3 over the energy range extending from 4 to 15 MeV1,2). In order to investigate the systematics of the same polarization transfer coefficient for heavier nuclei, we have made similar measurements for targets of 12C, 14N, 160, and 28Si. In this paper we report our results for the reactions \(^{16}0{(\vec d,{\vec n_0} + {\vec n_1})^{17}}F,{^{28}}Si{(\vec d,{\vec n_o})^{29}}p,an{d^{14}}N{(\vec d,\vec n)^{15}}0\) (leading to states around 5 MeV in excitation of 150.) In each of these reactions, it is believed that the dominant contribution to the measured neutron groups is lp = 0.

Neutron Polarization and Analyzing Power in the 15N(p, n0)15O Reaction

Abstract: Although the (p, n) reaction between mirror nuclei has long been used to explore the effective neutron-proton interactionl,2), special attention has recently been given to differences between the polarization P and analyzing power A3,4). Following Conzett4), we consider a measurement of P in the reaction \( B\left( {p,\vec n} \right)B' \), for which invariance under time reversal I gives $$ B\left( {p,\vec n} \right)B' = B'\left( {\vec n,p} \right)B\left( {P = {A_I}} \right). $$

Comparison of Py and Ay for 9Be(p,n)9B at 8.1 and 9.1 MeV

Abstract: Differences between Py and Ay for mirror reactions may be capable of yielding information about isospin violation terms in nuclear interactions [see ref.1)]. Thus far such studies have been reported only for T(p,n)3He and 7Li(p,n)7Be. In the first case, large differences were observed; in the second, considerable similarities were reported, particularly at 3 MeV, the highest energy for which Ay was measured. In order to extend the comparison of these two observables to heavier targets, the 9Be(p,n)9B and 15N(p,n)15O) reactions have been investigated at our laboratory. This report gives the preliminary results of the 9Be(p,n)9B experiment, which obtained Ay data in 10° steps from 20° to 100° at 8.1 and 9.1 MeV and Py data at 8.1 MeV for the same angles.

Neutron-Proton Polarization Measurements at 14.2 MeV

Abstract: The magnitude of the polarization observed in neutron-proton scattering for En < 20 MeV is known to be less than a few percent and has been difficult to measure accurately. The usual experimental arrangement used to obtain n-p polarization data involves organic scintillators as scatterers; consequently, the systematic accuracy depends on the amount of multiple scattering from carbon and hydrogen in the scatterer. Although n-12C scattering yields large polarization in the relevant energy region1), the background polarization has been either assumed to be zero or, in one instance at 23.1 MeV2), demonstrated to be small by measurements with two scatteres of different size.