Experimental Estimate for the Left-Hand-Cut Contributions in Nucleon-Nucleon Scattering

Furuich, Susumu; Suemitsu, Hiroshi; Watari, Watarô; Yonezawa, Minoru

doi:10.1143/ptp.40.523

Cited by 7 publications

(4 citation statements)

References 4 publications

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“…With input of results of phase-shift analyses into Rehj and Imhj in (7), the left-hand-cut integral terms hj B (s) have been evaluated at 25, 50, 95, 142, and 210 MeV. 10 They are called "Kantor amplitudes." 11 We compare our OBE amplitudes with the Kantor amplitudes, taking into account the deuteron-pole contribution.…”

Section: Rekas)-reh J (S M )mentioning

confidence: 99%

One-Boson-Exchange Model ofN−NScattering for the 0- to 3-GeV Energy Range

Ueda¹

1971

Phys. Rev. Lett.

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With the use of a dispersion relation and a high-energy cutoff, the model involving 7r, p, co, 7] v , f, and a (0 + , 7 = 0, 416 MeV) is studied for nucleon-nucleon interactions below 3 GeV. All nucleon-nucleon elastic-scattering data and those for p-p collisions at 0.67, 0.97, and 1.4 GeV are in qualitative agreement with the calculations.While the one-boson-exchange model (OBEM) 1 was found to be successful in describing nucleonnucleon interactions at an internucleon distance larger than 0.5ii^' 1 , there was difficulty in explaining the S-wave phase shifts which essentially represent the interaction at the smaller distance. In our recent works, however, we have introduced a nucleon-meson form factor into the OBEM, taking into account the IT, p, co, rj v [0 + , 7 = 0, m(7? y ) = 1070 MeV], and a [0 + , 7 = 0, m(a) = 416 MeV], and showed that the S-wave phase shifts can be reproduced as well as other phase shifts associated with higher partial waves. 2 ' 3 As is well known, the X S 0 phase shift becomes negative at energies higher than about 250 MeV, representing the repulsive interaction at a close internucleon distance. In our works 2 * 3 this has been explained in terms of the vectormeson-exchange (especially co-exchange) contribution.However there is criticism against it. There are some other mesons with higher spin and heavier mass whose exchange gives forces with the opposite sign to that for the vector meson. The/ embodies just such a property. 4 Consequently there is a possibility that the repulsive interaction arising from the vector-meson exchange might be canceled by the /.In this Letter we consider an OBEM including the / in addition to the 77, p, co, r) v , and a. These are all established mesons except for the a. The a is used as a fitting device taking care of the L = 7 = 0 two-pion-state part of the two-pion-exchange contribution. 5 We calculate phase shifts of the 1 S 0 , 3 P 0>lt2 , and 1 D 2 states for the 0-to 3-GeV energy range, employing a partial-wave dispersion relation which includes absorption effects. 6 For the calculation of the 3 P 2 phase shift a coupling effect between the 3 P 2 and 3 F 2 states is neglected. This approximation gives an error of a few percent in the phase shift, which is estimated by the damping relation. 1 Thus let us consider an uncoupled scattering of nucleons with mass m, energy E, and momentum/? in the center-of-mass system. Define a scattering amplitude for a state specified by J with the phase shift 6j(s) and an absorption coefficient rjj(s):where s -4E 2 . Pj(s) is a kinematical factor chosen, for reasonable threshold behavior, as pj(s) = m{p/E) n , where n = 1 for the 1 S 0 and 3 P 0 , 1|2 states and n = 3 for the 1 D 2 state. With the N/D method applied to the Aj(s), the following integral equation for the ReN is derived 6 : 1 + vAs)where s E~A m 2 , and(3)Here Bj(s) is a left-hand-cut integral term and the second term comes from the absorption effects. {Sj corresponds to the inelastic threshold.) With Bj(s) and rjj(s) given, Eq.(2) can be solved by a num...

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Section: Rekas)-reh J (S M )mentioning

confidence: 99%

One-Boson-Exchange Model ofN−NScattering for the 0- to 3-GeV Energy Range

Ueda¹

1971

Phys. Rev. Lett.

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“…g pNN is determined in accordance with g P""" to satisfy the universal p coupling to the isospin current and g sn is determined by taking the 3 . …”

Section: § I Introductionmentioning

confidence: 99%

“…On the other hand, we put (24) instead of the value 11.0 in reference 6) in order to obtain better agreement.The particle exchange contributions Aj,~S) (s, t, u) and Bj,~s) (s, t, u) are written as linear combinations of the N, Ll, p and e-contributions BN, (A, B)"~> (A, B)P and As as follows:where A);zi? )(s, t, u) = _!A.t(u, t, s) +2AP(s, t, u) +As(s, t, u),(25)3 A~k 2 ) (s, t, u) = _!__A.t (u, t, s) -AP (s, t, u) +As (s, t, u),…”

mentioning

confidence: 99%

Particle Exchange, Regge Pole Exchange and the Generalized Potential in πNScattering

Kinoshita

1970

Prog. Theor. Phys.

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I 1287The generalized potentials for the nN system are formulated as functions of the (s, t, u) variables, in a form free from kinematical singularities, and their values in the resonance region are obtained from experimental phase shifts. The contributions from the N, .J, p and c(700) exchange as elementary particles reproduce qualitatively the generalized potentials near the threshold and in the forward direction, but they differ from the generalized potentials in the region of large momentum transfer and/ or higher energy. The generalized potential can be well reproduced by multiplying the Regge-like damping factors to all the particle exchange terms and omitting the t-dependence of the residues of the .

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“…(hereafter we refer to this paper as I), in terms of the partial wave dispersion relation, we have analyzed the experimental values for the left-hand-cut contributions 2 ) for the T= 1 nucleon-nucleon states by considering the one-, two-and three-pion-exchange effects.…”

Section: § 1 Introductionmentioning

confidence: 99%

One-Boson-Exchange Modes and Two- and Three-Pion Exchange in Nucleon-Nucleon Scattering. II

et al. 1969

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461A detailed comparison is made between the theoretical two-pian-exchange amplitudes and the experimental values for the left-hand-cut contribution in nucleon-nucleon scatte:ring for both the T= 1 and T=O nucleon-nucleon states in order to confirm the conclusions of the previous analysis where only the T=l states are analyzed. The conclusion obtained in the previous analysis was that the uncorrelated two-pian-exchange amplitudes can explain the T= 1 nucleon-nucleon scattering together with the effects of the one-pion, one~p-meson and one-C!)-meson exchanges and without effects of scalar mesons, if the squared momentum. of the exchanged pions is cut off at tmax"-'9,u2. It is shown in this paper that this conclusion is also valid for the T=O nucleon-nucleon states. Some positive evidence is found for the fact that the two-pian-continuum contributions are favourable over the discrete (scalar boson) poletype contributions. Implication of the small cutoff momentum, tmax'"'-'9,u2, is discussed. § 1. IntroductionIn a previous paper!) (hereafter we refer to this paper as I), in terms of the partial wave dispersion relation, we have analyzed the experimental values for the left-hand-cut contributions 2 ) for the T= 1 nucleon-nucleon states by considering the one-, two-and three-pion-exchange effects.There we have used the experimental vaules for the left-hand-cut contributions estimated according to Kantor's prescriptionS) and the theoretical two-pion exchange amplitudes 4 ) calculated from the CGLN amplitudes. 5 )The three-pion exchange effects have been treated phenomenologically.6) The purpose of this paper is to present a more detailed analysis ,of the problem focusing mainly on the' two-pion-exchange contributions, taking both the T = 0 and T = 1 nucleonnucleon states.In addition to this we also examine the one-boson-exchange modeF) by the dispersion relation In connection with the K-matrix method how the unfavourable features of the K-matrix method such as the p-meson coupling constants, the S-wave problem, etc. will be improved by the dispersion theoretic approach. *) This report is a part of the results of the research project "Strong interaction ~t around

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Experimental Estimate for the Left-Hand-Cut Contributions in Nucleon-Nucleon Scattering

Cited by 7 publications

References 4 publications

One-Boson-Exchange Model ofN−NScattering for the 0- to 3-GeV Energy Range

One-Boson-Exchange Model ofN−NScattering for the 0- to 3-GeV Energy Range

Particle Exchange, Regge Pole Exchange and the Generalized Potential in πNScattering

One-Boson-Exchange Modes and Two- and Three-Pion Exchange in Nucleon-Nucleon Scattering. II

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