A ug 2 00 8 Role of the N ∗ ( 1440 ) resonance in the pp → pnπ + reaction
نویسندگان
چکیده
New measurement by CELSIUS-WASA Collaboration on the pp → pnπ+ reaction reveals clear evidence for the presence of the Roper resonance N∗(1440) which has been ignored in previous theoretical calculations. In this article, based on an effective Lagrangian approach and available knowledge on the Roper resonance, we investigate the role of the Roper resonance for the pp → pnπ+ reaction. It is found that the contribution from the Roper resonance N∗(1440) becomes significant for kinetic energy above 1.1 GeV, consistent with the new experimental observation. The t-channel σ-meson exchange is dominant for the production of the Roper resonance. PACS: 13.75.Cs.; 14.20.Gk.; 13.30.Eg.
منابع مشابه
Role of the N ∗ ( 1440 ) resonance in the pp → pnπ + reaction
New measurement by CELSIUS-WASA Collaboration on the pp → pnπ+ reaction reveals clear evidence for the presence of the Roper resonance N∗(1440) which has been ignored in previous theoretical calculations. In this article, based on an effective Lagrangian approach and available knowledge on the Roper resonance, we investigate the role of the Roper resonance for the pp → pnπ+ reaction. It is foun...
متن کاملpnπ REACTION AT MEDIUM ENERGIES
The pp → pnπ reaction is a channel with the largest total cross section for pp collision in COSY/CSR energy region. In this work, we investigate individual contributions from various N and ∆ resonances with mass up to about 2 GeV for the pp → pnπ reaction. We extend a resonance model, which can reproduce the observed total cross section quite well, to give theoretical predictions of various dif...
متن کاملar X iv : n uc l - ex / 0 10 50 02 v 2 1 3 Se p 20 01 Spin - triplet final - state dominance in the pp → pnπ + reaction at 492 MeV
The near-forward cross section for the pp → pnπ + reaction has been measured at 492 MeV by using the large acceptance ANKE magnetic spectrometer placed at an internal target position of the storage ring COSY-Jülich. Protons and pions emitted near zero degrees were detected in coincidence, and those with θ π ≤ 2 • and θ p ≤ 2.5 • were subjected to detailed analysis. Under these conditions, the e...
متن کاملar X iv : n uc l - th / 0 30 30 27 v 2 1 1 M ay 2 00 3 Nuclear response functions for the N − N ∗ ( 1440 ) transition
Parity-conserving and -violating response functions are computed for the inclusive electroexcitation of the N∗(1440) (Roper) resonance in nuclear matter modeled as a relativistic Fermi gas. Using various empirical parameterizations and theoretical models of the N −N∗(1440) transition form factors, the sensitivity of the response functions to details of the structure of the Roper resonance is in...
متن کاملar X iv : h ep - p h / 06 02 21 0 v 2 6 A ug 2 00 6 Resonance production by neutrinos : The second resonance region
The article contains new results for spin-3/2 and -1/2 resonances. It specializes to the second resonance region, which includes the P11(1440), D13(1520) and S11(1535) resonances. New data on electroproduction enable us to determine the vector form factors accurately. Estimates for the axial couplings are obtained from decay rates of the resonances with the help of the partially conserved axial...
متن کامل