The imaginary components of T=1 nucleon-nucleon phase-shifts and their effect on spin-dependent inelastic cross sections

1979 ◽  
Vol 5 (4) ◽  
pp. 503-510 ◽  
Author(s):  
A M Green ◽  
M E Sainio

The nucleon-antinucleon ( N-N ) problem is formulated in the new Tamm-Dancoff (NTD) approximation in the lowest order, and the integral equation for N-N̅ scattering derived, taking account of both the exchange and annihilation interactions. It is found convenient to represent the N-N̅ wave-function as a 4 x 4 matrix, rather than the usual 16 x 1 matrix for the nucleon-nucleon wave-function, and a complete correspondence is established between these two representations. The divergences associated with the annihilation interaction and their renormalization are discussed in detail in the following paper (Mitra & Saxena 1960; referred to as II). The integral equation with the exchange interaction alone, is then separated into eigenstates of T, J, L and S in the usual manner and the various phase shifts obtained. The results of II for the contribution of the annihilation term are then used to calculate the complete phase shifts from which the various cross-sections (scattering and charge exchange) are derived. The results indicate that while the exchange term alone gives too small values for the total cross-sections versus energy, inclusion of the annihilation interaction without renormalization effects makes the cross-sections nearly three times larger than those observed. On the other hand, inclusion of the finite effects of renormalization (which manifest themselves essentially as a suppression of the virtual meson propagator) brings down these cross-sections to the order of magnitude of the observed ones.


2008 ◽  
Vol 23 (20) ◽  
pp. 3057-3072 ◽  
Author(s):  
F. HUANG ◽  
W. L. WANG ◽  
Z. Y. ZHANG

The chiral SU(3) quark model and the extended chiral SU(3) quark model have proven to be quite successful in reproducing the binding energy of the deuteron, the nucleon–nucleon (NN) scattering phase shifts and the hyperon–nucleon (YN) cross-sections. In the chiral SU(3) quark model, the quark–quark interaction contains one-gluon exchange (OGE), confinement potential and boson exchanges stemming from scalar and pseudoscalar nonets. In the extended chiral SU(3) quark model, the OGE is nearly replaced by vector meson exchange. It was shown in our previous work that these two models give quite similar descriptions for the S, P, D, F wave KN phase shifts, which means that in the KN system the contribution of OGE can be replaced by that of vector meson exchange. In this paper, we use the same models, the same parameters and the same methods to study the [Formula: see text] system with the purpose to test the effects of OGE and vector meson exchange. The cross-sections for K-p scattering into K-p, K0n, π+Σ-, π-Σ+, π0Σ0 and π0Λ channels are dynamically calculated by solving the resonating group method equation. While some channels are well described in one or the other model, a good agreement between the theoretical cross-sections and the experimental data for all channels is not successfully obtained. The present work indicates that both OGE and vector meson exchange are necessary to be included in the quark–quark interactions if one tries to simultaneously describe the KN phase shifts and [Formula: see text] cross-sections using one set of parameters in a constituent quark model.


1961 ◽  
Vol 124 (4) ◽  
pp. 1269-1273 ◽  
Author(s):  
Daniel M. Greenberger ◽  
B. Margolis
Keyword(s):  

1987 ◽  
Vol 48 (11) ◽  
pp. 1901-1924 ◽  
Author(s):  
J. Bystricky ◽  
P. La France ◽  
F. Lehar ◽  
F. Perrot ◽  
T. Siemiarczuk ◽  
...  

1982 ◽  
Vol 26 (1) ◽  
pp. 301-303 ◽  
Author(s):  
R. M. DeVries ◽  
N. J. DiGiacomo ◽  
J. S. Kapustinsky ◽  
J. C. Peng ◽  
W. E. Sondheim ◽  
...  

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