TY - JOUR
T1 - Up-down quark mass difference
T2 - Couplings of pions to nucleons or isobars and low-energy nucleon-nucleon scattering
AU - Cao, Zong Jian
AU - Hwang, W. Y.P.
N1 - Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.
PY - 1984
Y1 - 1984
N2 - We investigate effects of the up-down quark mass difference on the couplings of pions to nucleons or isobars. The calculated NN and N couplings are used to derive the long-range one-pion-exchange potential and the intermediate-range attraction for the three different cases: p-p, n-p, and n-n. The resultant potentials are then used to determine numerically the low-energy scattering parameters, including both the scattering length a and the effective range r. Our results indicate that a reasonable up-down quark mass difference such as 10 MeV yields a value for |app|-|ann| of about + 0.6 fm, which is sizable from the experimental point of view. Our results also suggest that the large observed value for |anp|-|ann| can be understood primarily as a manifestation of the pion mass difference. [NUCLEAR REACTIONS Application of quark models to nuclear physics; effects of the up-down quark mass difference on couplings of pions to nucleons or isobars; charge dependence and charge symmetry breaking in low energy nucleon-nucleon scattering.]
AB - We investigate effects of the up-down quark mass difference on the couplings of pions to nucleons or isobars. The calculated NN and N couplings are used to derive the long-range one-pion-exchange potential and the intermediate-range attraction for the three different cases: p-p, n-p, and n-n. The resultant potentials are then used to determine numerically the low-energy scattering parameters, including both the scattering length a and the effective range r. Our results indicate that a reasonable up-down quark mass difference such as 10 MeV yields a value for |app|-|ann| of about + 0.6 fm, which is sizable from the experimental point of view. Our results also suggest that the large observed value for |anp|-|ann| can be understood primarily as a manifestation of the pion mass difference. [NUCLEAR REACTIONS Application of quark models to nuclear physics; effects of the up-down quark mass difference on couplings of pions to nucleons or isobars; charge dependence and charge symmetry breaking in low energy nucleon-nucleon scattering.]
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U2 - 10.1103/PhysRevC.29.1
DO - 10.1103/PhysRevC.29.1
M3 - Article
AN - SCOPUS:4244012094
VL - 29
SP - 1
EP - 12
JO - Physical Review C - Nuclear Physics
JF - Physical Review C - Nuclear Physics
SN - 0556-2813
IS - 1
ER -