scholarly journals Can current algebra determine the low-energy π-π scattering amplitude?

1968 ◽  
Vol 53 (2) ◽  
pp. 552-556 ◽  
Author(s):  
J. Iliopoulos
1968 ◽  
Vol 54 (2) ◽  
pp. 536-536 ◽  
Author(s):  
J. Iliopoulos

1971 ◽  
Vol 29 (2) ◽  
pp. 405-412 ◽  
Author(s):  
G.M. Radutsky ◽  
A.N. Tabachenco

Duality gives a satisfying connexion between two different areas of strong interaction physics, Regge poles at high energy and resonances at low energy. This interlocking gives powerful bootstrap conditions, and together with the assumption that certain channels do not contain resonances it gives strong restrictions on the hadron spectrum. Since there is some confusion about the term duality, we shall explain what is meant by the various forms of duality (f. e. s. r. (finite energy sum rules) duality, local duality), and what is meant by ‘building up’, and we shall show in what way antidual models (such as the generalized interference model) come into conflict with basic empirical facts. Duality expresses the relation between two descriptions of the hadronic scattering amplitude. At low energy (l. e.) the description by direct-channel resonances is simple and useful (see figure 1). At low energy the data show prominent peaks as a function of energy, and one may try the approximation of resonance saturation, i. e. of neglecting the non-resonating background. The second description is the exchange of Regge poles, and it is useful at high energies (h.e.), where typical features are forward peaks, energy dependence s α , and structure at fixed t (see figure 2). The two descriptions are very different; resonance formation corresponds to poles in the s channel, Regge exchange to poles in the t channel. Duality says that there are direct relations between these two descriptions, that they are equivalent in a certain sense. In complete contrast, the interference models postulate that one must add the two descriptions. (If lowest order perturbation theory was relevant to strong interactions, one would be led to adding the diagrams.)


1977 ◽  
Vol 55 (24) ◽  
pp. 2158-2165 ◽  
Author(s):  
K. Nakano ◽  
Chi-Shiang Wu

The importance of the nucleon Fermi motion in π–nucleus elastic scattering is investigated in the framework of the multiple scattering theory. Conventional factorization approximations on the π–nucleus scattering amplitude are compared with calculations that take into account the nucleon Fermi motion by using π–12C as an example. The importance of a careful treatment of the Fermi motion in low energy scattering will be stressed.


1976 ◽  
pp. 325-330 ◽  
Author(s):  
Michael Scadron
Keyword(s):  

1972 ◽  
Vol 50 (17) ◽  
pp. 2033-2036
Author(s):  
R. K. Logan

We consider a generalized interference model in which the Pomeron and the other Regge poles are built in the sense of a FESR bootstrap from both the resonance and background part of the low energy scattering amplitude. We develop a test of strong exchange degeneracy on the background part of the low energy scattering amplitude through the use of FESR. We show that the restrictions through FESR imposed by exchange degeneracy are weaker than those of duality. Finally, we are able to relate the amount of duality breaking in [Formula: see text] in the absence of exotic mesons to the ratio of NN or πN, P′, and ρ Regge residues.


2013 ◽  
Vol 28 (12) ◽  
pp. 1350039 ◽  
Author(s):  
E. MATSINOS ◽  
G. RASCHE

We analyze the charge-exchange (CX) measurements π-p→π0n below pion laboratory kinetic energy of 100 MeV. After the removal of five degrees of freedom from the initial database, we combine it with the truncated π+p database [E. Matsinos and G. Rasche, J. Mod. Phys.3, 1369 (2012)] and fit the ETH model [P. F. A. Goudsmit, H. J. Leisi, E. Matsinos, B. L. Birbrair and A. B. Gridnev, Nucl. Phys. A575, 673 (1994)] to the resulting data. The set of the parameter values of the ETH model, as well as the predictions derived on their basis for the hadronic phase shifts and for the low-energy πN constants, are significantly different from the results obtained in the analysis of the truncated π±p elastic-scattering databases. The main difference in the hadronic phase shifts occurs in [Formula: see text]. We discuss the implications of these findings in terms of the violation of the isospin invariance in the hadronic part of the πN interaction. The effect observed amounts to the level of 7–8% in the CX scattering amplitude below 70 MeV. The results and conclusions of this study agree well with those obtained in the mid 1990s, when the isospin invariance was first tested by using πN experimental data, and disagree with the predictions obtained within the framework of the heavy-baryon Chiral-Perturbation Theory.


2007 ◽  
Vol 16 (10) ◽  
pp. 3108-3114 ◽  
Author(s):  
I. M. DREMIN

Beside comparatively low energy Cherenkov gluons observed at RHIC, there could be high energy gluons at LHC, related to the high energy region of positive real part of the forward scattering amplitude. In both cases they give rise to particles emitted along some cone. The characteristics of the cones produced by these two types of gluons are different. Therefore different experiments are needed to detect them. The cosmic ray event which initiated this idea is described in detail.


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