Records |
Author |
Sekihara, T.; Oset, E.; Ramos, A. |
Title |
On the structure observed in the in-flight He-3(K-, Lambda p)n reaction at J-PARC |
Type |
Journal Article |
Year |
2016 |
Publication |
Progress of Theoretical and Experimental Physics |
Abbreviated Journal |
Prog. Theor. Exp. Phys. |
Volume |
2016 |
Issue |
12 |
Pages |
123D03 - 27pp |
Keywords |
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Abstract |
A theoretical investigation is done to clarify the origin of the peak structure observed near the K-pp threshold in the in-flight He-3(K-, Lambda p)n reaction of the J-PARC E15 experiment, which could be a signal of the lightest kaonic nuclei, i.e., the (K) over bar NN (I = 1/2) state. For the investigation, we evaluate the Lambda p invariant mass spectrum assuming two possible scenarios to interpret the experimental peak. One assumes that the Lambda (1405) resonance is generated after the emission of an energetic neutron from the absorption of the initial K-, not forming a bound state with the remaining proton. This uncorrelated Lambda (1405)p system subsequently decays into the final Lambda p. The other scenario implies that, after the emission of the energetic neutron, a (K) over bar NN bound state is formed, decaying eventually into a Lambda p pair. Our results show that the experimental signal observed in the in-flight He-3(K-, Lambda p)n reaction at J-PARC is qualitatively well reproduced by the assumption that a (K) over bar NN bound state is generated in the reaction, definitely discarding the interpretation in terms of an uncorrelated Lambda (1405)p s tate. |
Address |
[Sekihara, Takayasu] Japan Atom Energy Agcy, Adv Sci Res Ctr, Tokai, Ibaraki 3191195, Japan, Email: sekihara@post.j-parc.jp |
Corporate Author |
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Thesis |
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Publisher |
Oxford Univ Press Inc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2050-3911 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000393905400018 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2954 |
Permanent link to this record |
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Author |
Navarra, F.S.; Nielsen, M.; Oset, E.; Sekihara, T. |
Title |
Testing the molecular nature of D-s0*(2317) and D-0*(2400) in semileptonic B-s and B decays |
Type |
Journal Article |
Year |
2015 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
92 |
Issue |
1 |
Pages |
014031 - 14pp |
Keywords |
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Abstract |
We study the semileptonic B-s and B decays into the D-s0*(2317) and D-0*(2400) resonances, respectively. With the help of a chiral unitarity model in coupled channels we compute the ratio of the decay widths of both processes. Using current values of the width for the (B) over bar (0) -> D-0*(2400)(+)(v) over bar (l)l(-) we make predictions for the rate of the (B) over bar (0)(s) -> D-s0*(2317)(+)(v) over bar (l)l(-) decay and for the DK invariant mass distribution in the (B) over bar (0)(s) -> DK (v) over bar (l)l(-) decay. |
Address |
[Navarra, Fernando S.; Nielsen, Marina] Univ Sao Paulo, Inst Fis, BR-05389970 Sao Paulo, SP, Brazil, Email: navarra@if.usp.br; |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1550-7998 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000358604700008 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2339 |
Permanent link to this record |
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Author |
Sekihara, T.; Oset, E. |
Title |
Investigating the nature of light scalar mesons with semileptonic decays of D mesons |
Type |
Journal Article |
Year |
2015 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
92 |
Issue |
5 |
Pages |
054038 - 17pp |
Keywords |
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Abstract |
We study the semileptonic decays of D-s(+), D+, and D-0 mesons into the light scalar mesons [f(0)(500), K-0(*)(800), f(0)(980), and a(0)(980)] and the light vector mesons [rho(770), omega(782), K-*(892), and phi(1020)]. With the help of a chiral unitarity approach in coupled channels, we compute the branching fractions for scalar meson processes of the semileptonic D decays in a simple way. Using current known values of the branching fractions, we make predictions for the branching fractions of the semileptonic decay modes with other scalar and vector mesons. Furthermore, we calculate the pi(+)pi(-), pi eta, pi K, and K+K- invariant mass distributions in the semileptonic decays of D mesons, which will help us clarify the nature of the light scalar mesons. |
Address |
[Sekihara, Takayasu] Osaka Univ, Res Ctr Nucl Phys, Ibaraki, Osaka 5670047, Japan, Email: sekihara@rcnp.osaka-u.ac.jp; |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1550-7998 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000362089100001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2401 |
Permanent link to this record |
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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 |
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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 |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0556-2813 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000312293900002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1270 |
Permanent link to this record |
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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 |
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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 |
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Thesis |
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Publisher |
Springer |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1434-6001 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000323900500001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1569 |
Permanent link to this record |