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Author |
Xie, J.J.; Nieves, J. |
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Title |
Role of the N * (2080) resonance in the (gamma)over-right-arrowp -> K+ Lambda(1520) reaction |
Type |
Journal Article |
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Year |
2010 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
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Volume |
82 |
Issue |
4 |
Pages |
045205 - 8pp |
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Keywords |
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Abstract |
We investigate the Lambda (1520) photoproduction in the (gamma) over right arrowp -> K+ Lambda(1520) reaction within the effective Lagrangian method near threshold. In addition to the “background” contributions from the contact, t-channel K-exchange, and s-channel nucleon pole terms, which were already considered in previous studies, the contribution from the nucleon resonance N*(2080) (spin-parity J(P) = 3/2(-)) is also considered. We show that the inclusion of the nucleon resonance N*(2080) leads to a fairly good description of the new LEPS differential cross-section data, and that these measurements can be used to determine some of the properties of this latter resonance. However, serious discrepancies appear when the predictions of the model are compared to the photon-beam asymmetry, which was also measured by the LEPS Collaboration. |
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Address |
[Xie, Ju-Jun; Nieves, J.] Univ Valencia, IFIC, Ctr Mixto, Inst Invest Paterna,CSIC, E-46071 Valencia, Spain, Email: xiejujun@ific.uv.es |
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Publisher |
Amer Physical Soc |
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English |
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Edition |
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ISSN |
0556-2813 |
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Notes |
ISI:000283120200004 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial |
353 |
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Permanent link to this record |
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Author |
Gamermann, D.; Nieves, J.; Oset, E.; Ruiz Arriola, E. |
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Title |
Couplings in coupled channels versus wave functions: Application to the X(3872) resonance |
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 |
014029 - 14pp |
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Keywords |
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Abstract |
We perform an analytical study of the scattering matrix and bound states in problems with many physical coupled channels. We establish the relationship of the couplings of the states to the different channels, obtained from the residues of the scattering matrix at the poles, with the wave functions for the different channels. The couplings basically reflect the value of the wave functions around the origin in coordinate space. In the concrete case of the X(3872) resonance, understood as a bound state of D-0(D) over bar*(0) and D+D*(-) (and c.c. From now on, when we refer to D-0(D) over bar*(0), D+D*(-), or D (D) over bar* we are actually referring to the combination of these states with their complex conjugate in order to form a state with positive C-parity), with the D-0(D) over bar*(0) loosely bound, we find that the couplings to the two channels are essentially equal leading to a state of good isospin I = 0 character. This is in spite of having a probability for finding the D-0(D) over bar*(0) state much larger than for D+D*(-) since the loosely bound channel extends further in space. The analytical results, obtained with exact solutions of the Schrodinger equation for the wave functions, can be useful in general to interpret results found numerically in the study of problems with unitary coupled channels methods. |
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Address |
[Gamermann, D.; Nieves, J.; Oset, E.] Univ Valencia, Ctr Mixto, Inst Fis Corpuscular IFIC, CSIC,Inst Invest Paterna, Valencia 46071, Spain, Email: daniel.gamermann@ific.uv.es |
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Publisher |
Amer Physical Soc |
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English |
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Abbreviated Series Title |
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ISSN |
1550-7998 |
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Conference |
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Notes |
ISI:000284268800001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ elepoucu @ |
Serial |
329 |
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Permanent link to this record |
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Author |
Garcia-Recio, C.; Nieves, J.; Tolos, L. |
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Title |
D mesic nuclei |
Type |
Journal Article |
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Year |
2010 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
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Volume |
690 |
Issue |
4 |
Pages |
369-375 |
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Keywords |
Charm; Mesic nuclei; Heavy quark symmetry |
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Abstract |
The energies and widths of several D-0 meson bound states for different nuclei are obtained using a D-meson selfenergy in the nuclear medium, which is evaluated in a selfconsistent manner using techniques of unitarized coupled-channel theory. The kernel of the meson-baryon interaction is based on a model that treats heavy pseudoscalar and heavy vector mesons on equal footing, as required by heavy quark symmetry. We find D-0 bound states in all studied nuclei, from C-12 up to Pb-208. The inclusion of vector mesons is the keystone for obtaining an attractive D-nucleus interaction that leads to the existence of D-0-nucleus bound states, as compared to previous studies based on SU(4) flavor symmetry. In some cases, the half widths are smaller than the separation of the levels, what makes possible their experimental observation by means of a nuclear reaction. This can be of particular interest for the future PANDA@FAIR physics program. We also find a D+ bound state in C-12, but it is too broad and will have a significant overlap with the energies of the continuum. |
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Address |
[Garcia-Recio, C.] Univ Granada, Dept Fis Atom Mol & Nucl, E-18071 Granada, Spain, Email: g_recio@ugr.es |
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Publisher |
Elsevier Science Bv |
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English |
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Original Title |
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Series Volume |
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Edition |
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ISSN |
0370-2693 |
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Conference |
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Notes |
ISI:000279835300007 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial |
407 |
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Permanent link to this record |
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Author |
Albertus, C.; Hernandez, E.; Nieves, J. |
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Title |
Hyperfine mixing in electromagnetic decay of doubly heavy bc baryons |
Type |
Journal Article |
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Year |
2010 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
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Volume |
690 |
Issue |
3 |
Pages |
265-271 |
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Keywords |
Hyperfine mixing; Double heavy bc baryons |
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Abstract |
We investigate the role of hyperfine mixing in the electromagnetic decay of ground state doubly heavy bc baryons. As in the case of a previous calculation on b -> c semileptonic decays of doubly heavy baryons, we find large corrections to the electromagnetic decay widths due to this mixing. Contrary to the weak case just mentioned, we find here that one cannot use electromagnetic width relations obtained in the infinite heavy quark mass limit to experimentally extract information on the admixtures in a model independent way. |
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Address |
[Albertus, C.; Hernandez, E.] Univ Salamanca, Dept Fis Fundamental, E-37008 Salamanca, Spain, Email: gajatee@usal.es |
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Publisher |
Elsevier Science Bv |
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English |
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Series Issue |
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ISSN |
0370-2693 |
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Expedition |
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Conference |
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Notes |
ISI:000279388800012 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ elepoucu @ |
Serial |
416 |
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Permanent link to this record |
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Author |
Gamermann, D.; Garcia-Recio, C.; Nieves, J.; Salcedo, L.L.; Tolos, L. |
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Title |
Exotic dynamically generated baryons with negative charm quantum number |
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 |
9 |
Pages |
094016 - 11pp |
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Keywords |
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Abstract |
Following a model based on the SU(8) symmetry that treats heavy pseudoscalars and heavy vector mesons on an equal footing, as required by heavy quark symmetry, we study the interaction of baryons and mesons in coupled channels within an unitary approach that generates dynamically poles in the scattering T-matrix. We concentrate in the exotic channels with negative charm quantum number for which there is the experimental claim of one state. |
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Address |
[Gamermann, D.; Nieves, J.] Univ Valencia, CSIC, Inst Fis Corpuscular IFIC, Inst Invest Paterna, Valencia 46071, Spain, Email: daniel.gamermann@ific.uv.es |
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Publisher |
Amer Physical Soc |
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English |
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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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Area |
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Expedition |
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Conference |
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Notes |
ISI:000278145100034 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial |
438 |
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Permanent link to this record |
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Author |
Hernandez, E.; Nieves, J.; Valverde, M.; Vicente Vacas, M.J. |
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Title |
N-Delta(1232) axial form factors from weak pion production |
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 |
8 |
Pages |
085046 - 5pp |
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Keywords |
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Abstract |
The N Delta axial form factors are determined from neutrino induced pion production ANL and BNL data by using a theoretical model that accounts both for background mechanisms and deuteron effects. We find violations of the off-diagonal Goldberger-Treiman relation at the level of 2 sigma which might have an impact in background calculations for T2K and MiniBooNE low energy neutrino oscillation precision experiments. |
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Address |
[Hernandez, E.] Univ Salamanca, Dept Fis Fundamental, E-37008 Salamanca, Spain |
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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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ISSN |
1550-7998 |
ISBN |
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Conference |
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Notes |
ISI:000277205000163 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial |
462 |
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Permanent link to this record |
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Author |
Albertus, C.; Hernandez, E.; Nieves, J. |
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Title |
Hyperfine mixing in b -> c semileptonic decay of doubly heavy baryons |
Type |
Journal Article |
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Year |
2010 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
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Volume |
683 |
Issue |
1 |
Pages |
21-25 |
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Keywords |
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Abstract |
We qualitatively corroborate the results of [W. Roberts, M. Pervin, Int. J. Mod. Phys. A 24 (2009) 2401] according to which hyperfine mixing greatly affects the decay widths of b -> c semileptonic decays involving doubly heavy bc baryons. However, our predictions for the decay widths of the unmixed states differ from those reported in the work of Roberts and Pervin by a factor of 2, and this discrepancy translates to the mixed case. We further show that the predictions of heavy quark spin symmetry, might be used in the future to experimentally extract information on the admixtures in the actual physical bc baryons, in a model independent manner. |
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Address |
[Hernandez, E.] Univ Salamanca, Dept Fis Fundamental, E-37008 Salamanca, Spain, Email: gajatee@usal.es |
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Corporate Author |
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Publisher |
Elsevier Science Bv |
Place of Publication |
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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 Issue |
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ISSN |
0370-2693 |
ISBN |
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Expedition |
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Conference |
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Notes |
ISI:000274129600005 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ elepoucu @ |
Serial |
501 |
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Permanent link to this record |
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Author |
Hernandez, E.; Nieves, J. |
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Title |
Study of the strong Sigma(b) -> Lambda(b)pi and Sigma*(b) -> Lambda(b)pi in a nonrelativistic quark model |
Type |
Journal Article |
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Year |
2011 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
84 |
Issue |
5 |
Pages |
057902 - 5pp |
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Keywords |
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Abstract |
We present results for the strong widths corresponding to the Sigma(b) -> Lambda(b)pi and Sigma*(b) -> Lambda(b)pi decays. We apply our model from Phys. Rev. D 72, 094022 (2005), where we previously studied the corresponding transitions in the charmed sector. Our nonrelativistic constituent quark model uses wave functions that take advantage of the constraints imposed by heavy quark symmetry. The partial conservation of axial current hypothesis allows us to determine the strong vertices from an analysis of the axial current matrix elements. |
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Address |
[Hernandez, E] Univ Salamanca, Dept Fis Fundamental, E-37008 Salamanca, 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 |
WOS:000295327700002 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ elepoucu @ |
Serial |
776 |
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Permanent link to this record |
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Author |
Nieves, J.; Valderrama, M.P. |
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Title |
Deriving the existence of B(B)over-bar* bound states from the X(3872) and heavy quark symmetry |
Type |
Journal Article |
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Year |
2011 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
84 |
Issue |
5 |
Pages |
056015 - 21pp |
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Keywords |
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Abstract |
We discuss the possibility and the description of bound states between B and (B) over bar* mesons. We argue that the existence of such a bound state can be deduced from (i) the weakly bound X(3872) state, (ii) certain assumptions about the short-range dynamics of the D (D) over bar* system and (iii) heavy quark symmetry. From these assumptions the binding energy of the possible B (B) over bar* bound states is determined, first in a theory containing only contact interactions which serves as a straightforward illustration of the method, and then the effects of including the one-pion exchange potential are discussed. In this latter case three isoscalar states are predicted: a positive and negative C-parity (3)S(1) – (3)D(1) state with a binding energy of 20 MeV and 6 MeV below threshold, respectively, and a positive C-parity (3)P(0) shallow state located almost at the B (B) over bar* threshold. However, large uncertainties are generated as a consequence of the 1/m(Q) corrections from heavy quark symmetry. Finally, the newly discovered isovector Z(b)(10610) state can be easily accommodated within the present framework by a minor modification of the short-range dynamics. |
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Address |
[Nieves, J] Univ Valencia, Dept Fis Teor, Inst Invest Paterna, Ctr Mixto,CSIC, E-46071 Valencia, Spain, Email: m.pavon.valderrama@ific.uv.es |
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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 |
WOS:000295267700006 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ elepoucu @ |
Serial |
778 |
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Permanent link to this record |
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Author |
Nieves, J.; Pich, A.; Ruiz Arriola, E. |
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Title |
Large-N(C) properties of the rho and f(0)(600) mesons from unitary resonance chiral dynamics |
Type |
Journal Article |
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Year |
2011 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
84 |
Issue |
9 |
Pages |
096002 - 20pp |
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Keywords |
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Abstract |
We construct pi pi amplitudes that fulfill exact elastic unitarity, account for one-loop chiral perturbation theory contributions and include all 1/N(C) leading terms, with the only limitation of considering just the lowest-lying nonet of exchanged resonances. Within such a scheme, the N(C) dependence of sigma and rho masses and widths is discussed. Robust conclusions are drawn in the case of the rho resonance, confirming that it is a stable meson in the limit of a large number of QCD colors, N(C). Less definitive conclusions are reached in the scalar-isoscalar sector. With the present quality of data, we cannot firmly conclude whether or not the N(C) = 3 f(0)(600) resonance completely disappears at large N(C) or if it has a subdominant component in its structure, which would become dominant for a number of quark colors sufficiently large. |
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Address |
[Nieves, J] Ctr Mixto Univ Valencia, Inst Fis Corpuscular, CSIC, IFIC, Valencia 46071, Spain |
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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:000296890300012 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial |
799 |
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Permanent link to this record |