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Author |
Debastiani, V.R.; Sakai, S.; Oset, E. |
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Title |
Considerations on the Schmid theorem for triangle singularities |
Type |
Journal Article |
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Year |
2019 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
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Volume  |
79 |
Issue |
1 |
Pages |
69 - 13pp |
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Keywords |
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Abstract |
We investigate the Schmid theorem, which states that if one has a tree level mechanism with a particle decaying to two particles and one of them decaying posteriorly to two other particles, the possible triangle singularity developed by the mechanism of elastic rescattering of two of the three decay particles does not change the cross section provided by the tree level. We investigate the process in terms of the width of the unstable particle produced in the first decay and determine the limits of validity and violation of the theorem. One of the conclusions is that the theorem holds in the strict limit of zero width of that resonance, in which case the strength of the triangle diagram becomes negligible compared to the tree level. Another conclusion, on the practical side, is that for realistic values of the width, the triangle singularity can provide a strength comparable or even bigger than the tree level, which indicates that invoking the Schmid theorem to neglect the triangle diagram stemming from elastic rescattering of the tree level should not be done. Even then, we observe that the realistic case keeps some memory of the Schmid theorem, which is visible in a peculiar interference pattern with the tree level. |
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Address |
[Debastiani, V. R.; Sakai, S.; Oset, E.] Ctr Mixto Univ Valencia, CSIC, Inst Invest Paterna, Dept Fis Teor, Aptdo 22085, Valencia 46071, Spain, Email: vinicius.rodrigues@ific.uv.es; |
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Springer |
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English |
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ISSN |
1434-6044 |
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Notes |
WOS:000456999600008 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3904 |
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Author |
Yu, Q.X.; Pavao, R.; Debastiani, V.R.; Oset, E. |
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Title |
Description of the Xic and Xib states as molecular states |
Type |
Journal Article |
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Year |
2019 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
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Volume |
79 |
Issue |
2 |
Pages |
167 - 14pp |
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Keywords |
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Abstract |
In this work we study several c and b states dynamically generated from the meson-baryon interaction in coupled channels, using an extension of the local hidden gauge approach in the Bethe-Salpeter equation. These molecular states appear as poles of the scattering amplitudes, and several of them can be identified with the experimentally observed c states, including the c(2790), c(2930), c(2970), c(3055) and c(3080). Also, for the recently reported b(6227) state, we find two poles with masses and widths remarkably close to the experimental data, for both the JP=1/2- and JP=3/2- sectors. |
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Address |
[Yu, Q. X.] Beijing Normal Univ, Coll Nucl Sci & Technol, Beijing 100875, Peoples R China, Email: qixinyu@ific.uv.es; |
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Publisher |
Springer |
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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 |
1434-6044 |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000459831800008 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3929 |
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Author |
Debastiani, V.R.; Navarra, F.S. |
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Title |
A non-relativistic model for the [cc][(c)over-bar(c)over-bar] tetraquark |
Type |
Journal Article |
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Year |
2019 |
Publication |
Chinese Physics C |
Abbreviated Journal |
Chin. Phys. C |
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Volume |
43 |
Issue |
1 |
Pages |
013105 - 20pp |
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Keywords |
tetraquark; charmonium; diquark-antidiquark; nonrelativistic; spin |
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Abstract |
We use a non-relativistic model to study the spectroscopy of a tetraquark composed of [cc][(c) over bar(c) over bar] in a diquark-antidiquark configuration. By numerically solving the Schrodinger equation with a Cornell-inspired potential, we separate the four-body problem into three two-body problems. Spin-dependent terms (spin-spin, spin-orbit and tensor) are used to describe the splitting structure of the c (c) over bar spectrum and are also extended to the interaction between diquarks. Recent experimental data on charmonium states are used to fix the parameters of the model and a satisfactory description of the spectrum is obtained. We find that the spin-dependent interaction is sizable in the diquark-antidiquark system, despite the heavy diquark mass, and also that the diquark has a finite size if treated in the same way as the c (c) over bar systems. We find that the lowest S-wave T-4c tetraquarks might be below their thresholds of spontaneous dissociation into low-lying charmonium pairs, while orbital and radial excitations would be mostly above the corresponding charmonium pair thresholds. Finally, we repeat the calculations without the confining part of the potential and obtain bound diquarks and bound tetraquarks. This might be relevant to the study of exotic charmonium in the quark-gluon plasma. The T4c states could be investigated in the forthcoming experiments at the LHC and Belle II. |
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Address |
[Debastiani, V. R.] Univ Valencia, CSIC, Inst Invest Paterna, Dept Fis Teor, Aptdo 22085, Valencia 46071, Spain, Email: vinicius.rodrigues@ific.uv.es; |
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Corporate Author |
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Thesis |
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Publisher |
Iop Publishing Ltd |
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 |
1674-1137 |
ISBN |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000454936600005 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3865 |
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Author |
Dias, J.M.; Debastiani, V.R.; Xie, J.J.; Oset, E. |
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Title |
The radiative decay D-0 -> (K)over-bar*(0)gamma with vector meson dominance |
Type |
Journal Article |
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Year |
2018 |
Publication |
Chinese Physics C |
Abbreviated Journal |
Chin. Phys. C |
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Volume |
42 |
Issue |
4 |
Pages |
043106 - 7pp |
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Keywords |
radiative decay; vector meson dominance; local hidden gauge symmetry |
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Abstract |
Motivated by the experimental measurements of D-0 radiative decay modes, we have proposed a model to study the D-0 -> (K) over bar*(0)gamma decay, by establishing a link with D-0 -> (K) over bar*(0) V (V = rho(0), omega) decays through the vector meson dominance hypothesis. In order to do this properly, we have used the Lagrangians from the local hidden gauge symmetry approach to account for V gamma conversion. As a result, we have found the branching ratio B[D-0 -> (K) over bar*(0)gamma]=(1.55-3.44)x10(-4), which is in fair agreement with the experimental values reported by the Belle and BaBar collaborations. |
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Address |
[Dias, J. M.; Debastiani, V. R.; Xie, Ju-Jun; Oset, E.] Chinese Acad Sci, Inst Modern Phys, Lanzhou 730000, Gansu, Peoples R China, Email: jdias@if.usp.br; |
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Corporate Author |
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Thesis |
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Publisher |
Iop Publishing Ltd |
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 |
1674-1137 |
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:000430884300010 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
3572 |
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| Permanent link to this record |
