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Author Jido, D.; Oset, E.; Sekihara, T.
Title The K(-)d -> pi Sigma n reaction revisited Type Journal Article
Year 2013 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 49 Issue 8 Pages 95 - 11pp
Keywords
Abstract The appearance of some papers dealing with the K(-)d -> pi Sigma n reaction, with some discrepancies in the results and a proposal to measure the reaction at forward n angles at J-PARC justifies to retake the theoretical study of this reaction. We do this in the present paper showing results using the Watson approach and the truncated Faddeev approach. We argue that the Watson approach is more suitable to study the reaction because it takes into account the potential energy of the nucleons forming the deuteron, which is neglected in the truncated Faddeev approach. The paper shows the strength and limitations of both approaches and we perform calculations using four different approximations. Comparison of the results shows that the truncated Faddeev approach produces a strong asymmetry between the energy of the two nucleons of the deuteron, while in the Watson approach this energy is equally shared. From the experimental point of view the results are very valuable since they show that the different approximations share the feature that the peak of the pi Sigma mass distribution is drastically shifted in the presence of the Lambda(1405). Additionally, we also show that in the angle-integrated cross section the threshold cusp effects are basically washed away and all approximations show a clear shape of the Lambda(1405). In this sense, measurements of all these magnitudes in different K- energies are bound to bring new information that sheds new light on the properties and nature of the Lambda(1405) resonance.
Address [Jido, Daisuke] Kyoto Univ, Yukawa Inst Theoret Phys, Kyoto 6068502, Japan, Email: jido@tmu.ac.jp
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (down) 1434-6001 ISBN Medium
Area Expedition Conference
Notes WOS:000323900500001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1569
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Author Sekihara, T.; Yamagata-Sekihara, J.; Jido, D.; Kanada-En'yo, Y.
Title Branching ratios of mesonic and nonmesonic antikaon absorptions in the nuclear medium Type Journal Article
Year 2012 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 86 Issue 6 Pages 065205 - 17pp
Keywords
Abstract The branching ratios of K- absorption in nuclear matter are theoretically investigated in order to understand the mechanism of K- absorption into nuclei. For this purpose mesonic and nonmesonic absorption potentials are evaluated as functions of nuclear density, the kaon momentum, and energy from one- and two-body K- self-energy, respectively. By using a chiral unitary approach for the s-wave (K) over bar N amplitude we find that both the mesonic and nonmesonic absorption potentials are dominated by the Lambda(1405) contributions. The fraction of the mesonic and nonmesonic absorptions are evaluated to be respectively about 70% and 30% at the saturation density almost independently of the kaon momentum. We also observe different behavior of the branching ratios to pi(+)Sigma(-) and pi(-)Sigma(+) channels in mesonic absorption due to the interference between Lambda(1405) and the I = 1 nonresonant background, which is consistent with experimental results. The nonmesonic absorption ratios [Lambda p]/[Sigma(0)p] and [Lambda n]/[Sigma(0)n] are about unity while [Sigma(+)n]/[Sigma(0)p] and [Sigma(-) p]/[Sigma(0)n] are about 2 due to the Lambda(1405) dominance in absorption. Taking into account the kaon momenta and energies, the absorption potentials become weaker due to the downward shift of the initial K- N two-body energy, but this does not drastirally change the nonmesonic fraction. The Sigma(1385) contribution in the p-wave (K) over bar N amplitude is examined and found to be very small compared to the Lambda(1405) contribution in slow K- absorption.
Address [Sekihara, Takayasu] Tokyo Inst Technol, Dept Phys, Tokyo 1528551, Japan
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (down) 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000312293900002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1270
Permanent link to this record