pp→ppπ0 reaction near threshold: A chiral power counting approach

Thomas D. Cohen, James L. Friar, Gerald A. Miller, Ubirajara Van Kolck

Research output: Contribution to journalArticle

147 Citations (Scopus)

Abstract

We use power-counting arguments as an organizing principle to apply chiral perturbation theory, including an explicit Δ, to the pp → pp π0 reaction near threshold. There are two lowest-order leading mechanisms expected to contribute to the amplitude with similar magnitudes: an impulse term, and a Δ-excitation mechanism. We examine formally subleading but potentially large mechanisms, including pion-rescattering and short-ranged contributions. We show that the pion-rescattering contribution is enhanced by off-shell effects and has a sign opposite to that of a recent estimate based on a PCAC pion interpolating field. Our result is that the impulse term interferes destructively with the pion-rescattering and Δ-excitation terms. In addition, we have modeled the short-ranged interaction using σ and ω exchange mechanisms. A recoil correction to the impulse approximation is small. The total amplitude obtained including all of these processes is found to yield cross sections substantially smaller than the measured ones.

Original languageEnglish (US)
Pages (from-to)2661-2673
Number of pages13
JournalPhysical Review C - Nuclear Physics
Volume53
Issue number6
DOIs
StatePublished - Jun 1996
Externally publishedYes

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counting
pions
impulses
thresholds
organizing
excitation
perturbation theory
cross sections
estimates
approximation
interactions

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Nuclear and High Energy Physics

Cite this

pp→ppπ0 reaction near threshold : A chiral power counting approach. / Cohen, Thomas D.; Friar, James L.; Miller, Gerald A.; Van Kolck, Ubirajara.

In: Physical Review C - Nuclear Physics, Vol. 53, No. 6, 06.1996, p. 2661-2673.

Research output: Contribution to journalArticle

Cohen, Thomas D. ; Friar, James L. ; Miller, Gerald A. ; Van Kolck, Ubirajara. / pp→ppπ0 reaction near threshold : A chiral power counting approach. In: Physical Review C - Nuclear Physics. 1996 ; Vol. 53, No. 6. pp. 2661-2673.
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