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Author  |
Roca, L.; Mai, M.; Oset, E.; Meissner, U.G. |
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Title |
Predictions for the Lambda(b) -> J/psi Lambda (1405) decay |
Type |
Journal Article |
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Year |
2015 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
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Volume |
75 |
Issue |
5 |
Pages |
218 - 9pp |
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Abstract |
We calculate the shape of the pi Sigma and (K) over bar N invariant mass distributions in the Lambda(b) -> J/psi pi Sigma and Lambda(b) -> J/psi (K) over bar N decays that are dominated by the Lambda (1405) resonance. The weak interaction part is the same for both processes and the hadronization into the different meson-baryon channels in the final state is given by symmetry arguments. The most important feature is the implementation of the meson-baryon final-state interaction using two chiral unitary models from different theoretical groups. Both approaches give a good description of antikaon-nucleon scattering data, the complex energy shift in kaonic hydrogen and the line shapes of pi Sigma K in photoproduction, based on the two-pole scenario for the Lambda (1405). We find that this reaction reflects more the higher mass pole and we make predictions of the line shapes and relative strength of the meson-baryon distributions in the final state. |
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Address |
[Roca, L.] Univ Murcia, Dept Fis, Murcia 30100, Spain, Email: luisroca@um.es; |
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Springer |
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English |
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Edition |
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ISSN |
1434-6044 |
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Conference |
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Notes |
WOS:000355678900006 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
2271 |
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Author |
Roca, L.; Nieves, J.; Oset, E. |
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Title |
LHCb pentaquark as a (D)over-bar*Sigma(c) – (D)over-bar*Sigma(c)* molecular state |
Type |
Journal Article |
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Year |
2015 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
92 |
Issue |
9 |
Pages |
094003 - 6pp |
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Keywords |
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Abstract |
We perform a theoretical analysis of the Lambda(b) -> J/psi K(-)p reaction from where a recent LHCb experiment extracts a Lambda(1405) contribution in the K(-)p spectrum close to threshold and two baryon states of hidden charm in the J/psi p spectrum. We recall that baryon states of this type have been theoretically predicted matching the mass, width and J(P) of the experiment; concretely some states built up from the J/psi N, (D) over bar*Lambda(c), (D) over bar*Sigma(c), (D) over bar Sigma(c)* and (D) over bar*Sigma(c)* coupled channels. We assume that the observed narrow state around 4450 MeV has this nature and we are able to describe simultaneously the shapes and relative strength of the the K(-)p mass distribution close to threshold and the peak of the J/psi p distribution, with values of the J/psi p coupling to the resonance in line with the theoretical ones. The nontrivial matching of many properties gives support to a J(P) = 3/2(-) assignment to this state and to its nature as a molecular state mostly made of (D) over bar*Sigma(c) and (D) over bar*Sigma(c)*. |
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Address |
[Roca, L.] Univ Murcia, Dept Fis, E-30100 Murcia, Spain |
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Corporate Author |
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Publisher |
Amer Physical Soc |
Place of Publication |
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English |
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ISSN |
1550-7998 |
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Conference |
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Notes |
WOS:000364019700004 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
2448 |
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Author |
Roca, L.; Oset, E. |
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Title |
Scalar resonances in the D+ -> K-K+K+ decay |
Type |
Journal Article |
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Year |
2021 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
103 |
Issue |
3 |
Pages |
034020 - 9pp |
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Abstract |
We study theoretically the resonant structure of the double Cabibbo suppressed D+ -> K-K+K+ decay. We start from an elementary production diagram, considered subleading in previous approaches, which cannot produce a final K-K+ pair at the tree level but which we show to be able to provide the strength of the decay through final meson-meson state interaction. The different meson-meson elementary productions are related through SU(3), and the final rescattering is implemented from a suitable implementation of unitary extensions of chiral perturbation theory, which generate dynamically the scalar resonances1 f(0)(980) and a(0)(980). We obtain a good agreement with recent experimental data from the LHCb Collaboration with a minimal freedom in the fit and show the dominance of the a(0)(980) contribution close to the threshold of the K-K+ spectrum. |
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Address |
[Roca, L.] Univ Murcia, Dept Fis, E-30071 Murcia, Spain, Email: luisroca@um.es; |
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Publisher |
Amer Physical Soc |
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Language |
English |
Summary Language |
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Original 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 |
2470-0010 |
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Conference |
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Notes |
WOS:000621332000004 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
4742 |
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Author |
Roca, L.; Oset, E. |
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Title |
Role of a triangle singularity in the pi Delta decay of N(1700)(3/2(-)) |
Type |
Journal Article |
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Year |
2017 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
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Volume |
95 |
Issue |
6 |
Pages |
065211 - 8pp |
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Keywords |
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Abstract |
We show the important role played by the pi Delta(1232) channel in the build up of the N(1700)(3/2(-)) resonance due to the nontrivial enhancement produced by a singularity of a triangular loop. The N(1700) is one of the dynamically generated resonances produced by the coupled-channel vector-baryon interaction. The pi Delta channel was neglected in previous works but we show that it has to be incorporated into the coupled-channel formalism due to an enhancement produced by a singularity in the triangular loop with., nucleon, and p as internal loop lines and pi and Delta as external ones. The enhancement is of nonresonant origin but it contributes to the dynamical generation of the N(1700) resonance due to the nonlinear dynamics involved in the coupled-channel mechanisms. We obtain an important increase of the total width of the N(1700) resonance when the pi Delta channel is included and provide predictions for the partial widths of the N(1700) decays into VB and pi Delta. |
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Address |
[Roca, L.] Univ Murcia, Dept Fis, E-30100 Murcia, Spain |
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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 |
2469-9985 |
ISBN |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000404022100005 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
3177 |
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Author |
Roca, L.; Oset, E. |
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Title |
On the hidden charm pentaquarks in Lambda(b) -> J/psi K- p decay |
Type |
Journal Article |
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Year |
2016 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
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Volume |
76 |
Issue |
11 |
Pages |
591 - 12pp |
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Keywords |
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Abstract |
In a previous work we presented a theoretical analysis of the Lambda(b) -> J/psi K- p reaction based on which a recent experiment by the LHCb collaboration at CERN claimed the existence of two hidden charm pentaquarks, P-c(4380)(+) and P-c(4450)(+). In that work we focused only on the Lambda(1405) and P-c(4450)(+) signals and discussed the possible explanation of this pentaquark state within the picture of a dynamical meson-baryon molecule made up mostly from (D) over bar*Sigma(c) and (D) over bar*Sigma(c)* components. In the present work we improve upon the previous one by considering the total K- p and J/psi p data including all the relevant resonances contributing to the spectra, and discuss the possible nature of both P-c(4380)(+) and P-c(4450)(+). We also discuss several important topics, like the effect of the contact term in the reaction, the viability of reproducing the data without the P-c(4380)(+) and the possible quantum number assignment to these pentaquarks. |
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Address |
[Roca, L.] Univ Murcia, Dept Fis, E-30100 Murcia, Spain, Email: luisroca@um.es |
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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 |
1434-6044 |
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:000399930700001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
3065 |
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Author |
Roca, L.; Oset, E. |
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Title |
Lambda(1405) poles obtained from pi(0)Sigma(0) photoproduction data |
Type |
Journal Article |
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Year |
2013 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
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Volume |
87 |
Issue |
5 |
Pages |
055201 - 8pp |
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Keywords |
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Abstract |
We present a strategy to extract the position of the two Lambda(1405) poles from experimental photoproduction data measured recently at different energies in the gamma p -> K+pi(0)Sigma(0) reaction at Jefferson Laboratory. By means of a chiral dynamics motivated potential with free parameters, we solve the Bethe-Salpeter equation in the coupled channels (K) over barN and pi Sigma in isospin I = 0 and parametrize the amplitude for the photonuclear reaction in terms of a linear combination of the pi Sigma -> pi Sigma and (K) over barN -> pi Sigma scattering amplitudes in I = 0, with a different linear combination for each energy. Good fits to the data are obtained with some sets of parameters, by means of which one can also predict the cross section for the K- p -> pi(0)Sigma(0) reaction. These later results help us decide among the possible solutions. The result is that the different solutions lead to two poles similar to those found in the chiral unitary approach. With the best result we find the two Lambda(1405) poles at 1385 – 68i MeV and 1419 – 22i MeV. |
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Address |
Univ Murcia, Dept Fis, E-30100 Murcia, Spain |
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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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Area |
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Expedition |
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Conference |
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Notes |
WOS:000318527400004 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
1442 |
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Author |
Roca, L.; Oset, E. |
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Title |
Isospin 0 and 1 resonances from pi Sigma photoproduction data |
Type |
Journal Article |
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Year |
2013 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
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Volume |
88 |
Issue |
5 |
Pages |
055206 - 7pp |
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Keywords |
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Abstract |
Recently we presented a successful strategy to extract the position of the two Lambda ( 1405) poles from experimental photoproduction data on the gamma p -> K+pi(0)Sigma(0) reaction at Jefferson Lab. Following a similar strategy, we extend the previous method to incorporate also the isospin 1 component which allows us to consider in addition the experimental data on gamma p -> K+pi(+/-)Sigma(-/+). The idea is based on considering a production mechanism as model independent as possible and implementing the final state interaction of the final meson-baryon pair based on small modifications of the unitary chiral perturbation theory amplitudes. Good fits to the data are obtained with this procedure, by means of which we can also predict the cross sections for the K- p -> (K) over barN, pi Sigma, and pi Lambda reactions for the different charge channels. Besides the two poles found for the Lambda(1405) resonance, we discuss the possible existence of an isospin 1 resonance in the vicinity of the (K) over barN threshold. |
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Address |
[Roca, L.] Univ Murcia, Dept Fis, E-30100 Murcia, Spain |
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Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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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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Area |
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Expedition |
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Conference |
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Notes |
WOS:000327315800008 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
1655 |
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Author |
Roca, L.; Oset, E. |
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Title |
Scattering of unstable particles in a finite volume: The case of pi rho scattering and the a(1)(1260) resonance |
Type |
Journal Article |
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Year |
2012 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
85 |
Issue |
5 |
Pages |
054507 - 13pp |
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Keywords |
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Abstract |
We present a way to evaluate the scattering of unstable particles quantized in a finite volume with the aim of extracting physical observables for infinite volume from lattice data. We illustrate the method with the pi rho scattering which generates dynamically the axial-vector a(1)(1260) resonance. Energy levels in a finite box are evaluated both considering the rho as a stable and unstable resonance and we find significant differences between both cases. We discuss how to solve the problem to get the physical scattering amplitudes in the infinite volume, and hence phase shifts, from possible lattice results on energy levels quantized inside a finite box. |
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Address |
[Roca, L.] Univ Murcia, Dept Fis, E-30071 Murcia, Spain |
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Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Language |
English |
Summary Language |
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Series Editor |
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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:000301706700004 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
941 |
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Author |
Roca, L.; Oset, E. |
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Title |
Description of the f(2)(1270), rho(3)(1690), f(4)(2050), rho(5)(2350), f(6)(2510) resonances as multi-rho(770) states |
Type |
Journal Article |
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Year |
2010 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
82 |
Issue |
5 |
Pages |
054013 - 11pp |
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Keywords |
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Abstract |
In a previous work regarding the interaction of two rho(770) resonances, the f(2)(1270) (J(PC) = 2(++)) resonance was obtained dynamically as a two-rho molecule with a very strong binding energy, 135 MeV per rho particle. In the present work we use the rho rho interaction in spin 2 and isospin 0 channel to show that the resonances rho(3)(1690) (3(--)), f(4)(2050) (4(++)), rho(5)(2350) (5(--)), and f(6)(2510) (6(++)) are basically molecules of increasing number of rho(770) particles. We use the fixed center approximation of the Faddeev equations to write the multibody interaction in terms of the two-body scattering amplitudes. We find the masses of the states very close to the experimental values and we get an increasing value of the binding energy per rho as the number of rho mesons is increased. |
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Address |
[Roca, L.] Univ Murcia, Dept Fis, E-30071 Murcia, Spain |
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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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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 |
ISI:000281791100002 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ elepoucu @ |
Serial |
381 |
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Author |
Roca, L.; Oset, E. |
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Title |
Asymmetry observables in e(+)e(-) -> pi(+) pi(-) gamma in the phi region within a chiral unitary approach |
Type |
Journal Article |
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Year |
2010 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
81 |
Issue |
1 |
Pages |
014010 - 8pp |
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Keywords |
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Abstract |
We make a theoretical study of the charge and forward-backward pion asymmetries in the e(+)e(-) -> pi(+) pi(-) gamma process on and off the phi resonance energy. These observables are rather sensitive to the inner details of the theoretical models to describe the reaction. In addition to the standard implementation of the initial state radiation and the bremsstrahlung contribution to the final state radiation, we use the techniques of the chiral unitary approach to evaluate the contribution from the mechanisms of phi decay into pi(+) pi(-) gamma. This contribution involves the implementation of final state interaction from direct chiral loops, the exchange of vector and axial-vector resonances and the final state interaction through the consideration of the meson-meson unitarized amplitudes, which were found important in a previous work describing the phi -> pi pi gamma. We find a good reproduction of the experimental data from KLOE for the forward-backward asymmetry, both at the phi peak and away from it. We also make predictions for the angular distributions of the charge asymmetry and show that this observable is very sensitive to the chiral loops involved in phi radiative decay. |
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Address |
[Roca, L.] Univ Murcia, Dept Fis, E-30071 Murcia, Spain |
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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 |
ISI:000274002800021 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ elepoucu @ |
Serial |
503 |
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| Permanent link to this record |
