Relation Between the Pion-Nucleon and theρ-Meson Coupling Constants from Pion Scattering Lengths

1966 ◽  
Vol 17 (10) ◽  
pp. 552-553 ◽  
Author(s):  
J. J. Sakurai
Keyword(s):  
Coupling Constants ◽  
Pion Scattering ◽  
Meson Coupling ◽  
Pion Nucleon ◽  
Scattering Lengths

Quark mass differences and isospin violation in the pion-nucleon coupling constants

1989 ◽  
Vol 39 (5) ◽  
pp. 2054-2056 ◽  
Author(s):  
Véronique Bernard ◽  
Ulf-G. Meissner
Keyword(s):  
Quark Mass ◽  
Coupling Constants ◽  
Isospin Violation ◽  
Pion Nucleon

scholarly journals Relative entropy in scattering and the S-matrix bootstrap

2020 ◽  
Vol 9 (5) ◽  
Author(s):  
Anjishnu Bose ◽  
Parthiv Haldar ◽  
Aninda Sinha ◽  
Pritish Sinha ◽  
Shaswat Tiwari
Keyword(s):  
Relative Entropy ◽  
Cross Sections ◽  
High Energy ◽  
Quantum Field Theories ◽  
Superstring Theory ◽  
Information Theoretic ◽  
Pion Scattering ◽  
S Matrix ◽  
Information Theoretic Measures ◽  
Scattering Lengths

We consider entanglement measures in 2-2 scattering in quantum field theories, focusing on relative entropy which distinguishes two different density matrices. Relative entropy is investigated in several cases which include \phi^4ϕ4 theory, chiral perturbation theory (\chi PTχPT) describing pion scattering and dilaton scattering in type II superstring theory. We derive a high energy bound on the relative entropy using known bounds on the elastic differential cross-sections in massive QFTs. In \chi PTχPT, relative entropy close to threshold has simple expressions in terms of ratios of scattering lengths. Definite sign properties are found for the relative entropy which are over and above the usual positivity of relative entropy in certain cases. We then turn to the recent numerical investigations of the S-matrix bootstrap in the context of pion scattering. By imposing these sign constraints and the \rhoρ resonance, we find restrictions on the allowed S-matrices. By performing hypothesis testing using relative entropy, we isolate two sets of S-matrices living on the boundary which give scattering lengths comparable to experiments but one of which is far from the 1-loop \chi PTχPT Adler zeros. We perform a preliminary analysis to constrain the allowed space further, using ideas involving positivity inside the extended Mandelstam region, and other quantum information theoretic measures based on entanglement in isospin.

Universality of Rho-Meson coupling and sum rules for pion scattering on hadrons

1969 ◽  
Vol 1 (9) ◽  
pp. 436-440 ◽  
Author(s):  
H. Banerjee ◽  
B. Dutta-Roy ◽  
S. Mallik
Keyword(s):  
Sum Rules ◽  
Pion Scattering ◽  
Rho Meson ◽  
Meson Coupling
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