Abstract
The charge symmetry breaking amplitudes for the recently observed dd → απ0 reaction are investigated. Chiral perturbation theory is used to classify and identify the leading-order terms. Specific forms of the related one- and two-body tree-level diagrams are derived. As a first step toward a full calculation, a few tree-level two-body diagrams are evaluated at each considered order, using a simplified set of d and α wave functions and a plane-wave approximation for the initial dd state. The leading-order pion-exchange term is shown to be suppressed in this model because of poor overlap of the initial and final states. The higher-order one-body and short-range (heavy-meson-exchange) amplitudes provide better matching between the initial and final states and therefore contribute significantly and coherently to the cross section. The consequences this might have for a full calculation, with realistic wave functions and a more complete set of amplitudes, are discussed.
Original language | English |
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Article number | 044606 |
Pages (from-to) | 044606-1-044606-16 |
Journal | Physical Review C - Nuclear Physics |
Volume | 69 |
Issue number | 4 |
DOIs | |
State | Published - Apr 2004 |
Externally published | Yes |
Bibliographical note
Funding Information:We are grateful to Andrew Bacher, Edward Stephenson, and Allena Opper for encouragement, many useful discussions, and providing results from the IUCF and TRIUMF experiments prior to publication. We thank Ulf-G. Meißner for useful discussions. We are grateful to the National Institute for Nuclear Theory at the University of Washington for its hospitality and for arranging CSB workshops where part of this work was completed. U.v.K. is grateful to the Nuclear Theory Group at the University of Washington for its hospitality, and to RIKEN, Brookhaven National Laboratory and the U.S. Department of Energy [Grant No. DE-AC02-98CH10886] for providing the facilities essential for the completion of this work. G.A.M. acknowledges the ECT* (Trento), the INT (UW, Seattle), and the CSSM (Adelaide) for providing hospitality during the completion of this work. This work was supported in part by the Magnus Ehrnrooth Foundation (J.A.N.), Grant No. POCTI∕FNU∕37280∕2001 (A.C.F), the NSF Grant No. NSF-PHY-00-70368 (A.G.), the DOE Grant Nos. DE-FG02-87ER40365 (C.J.H.), DE-FG02-93ER40756 and DE-FG02-02ER41218 (A.G.), DE-FC02-01ER41187 and DE-FG03-00ER41132 (A.N.), DE-FG-02-97ER41014 (G.A.M.), and DE-FG03-01ER41196 (U.v.K.) and the Alfred P. Sloan Foundation (U.v.K).
Funding
We are grateful to Andrew Bacher, Edward Stephenson, and Allena Opper for encouragement, many useful discussions, and providing results from the IUCF and TRIUMF experiments prior to publication. We thank Ulf-G. Meißner for useful discussions. We are grateful to the National Institute for Nuclear Theory at the University of Washington for its hospitality and for arranging CSB workshops where part of this work was completed. U.v.K. is grateful to the Nuclear Theory Group at the University of Washington for its hospitality, and to RIKEN, Brookhaven National Laboratory and the U.S. Department of Energy [Grant No. DE-AC02-98CH10886] for providing the facilities essential for the completion of this work. G.A.M. acknowledges the ECT* (Trento), the INT (UW, Seattle), and the CSSM (Adelaide) for providing hospitality during the completion of this work. This work was supported in part by the Magnus Ehrnrooth Foundation (J.A.N.), Grant No. POCTI∕FNU∕37280∕2001 (A.C.F), the NSF Grant No. NSF-PHY-00-70368 (A.G.), the DOE Grant Nos. DE-FG02-87ER40365 (C.J.H.), DE-FG02-93ER40756 and DE-FG02-02ER41218 (A.G.), DE-FC02-01ER41187 and DE-FG03-00ER41132 (A.N.), DE-FG-02-97ER41014 (G.A.M.), and DE-FG03-01ER41196 (U.v.K.) and the Alfred P. Sloan Foundation (U.v.K).
Funders | Funder number |
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U.S. Department of Energy | DE-FG02-93ER40756, DE-FG02-02ER41218, DE-FC02-01ER41187, DE-AC02-98CH10886, DE-FG03-01ER41196, DE-FG-02-97ER41014, DE-FG03-00ER41132, DE-FG02-87ER40365 |
Alfred P. Sloan Foundation | |
Magnus Ehrnroothin Säätiö | NSF-PHY-00-70368 |
RIKEN |