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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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Amer Physical Soc |
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English |
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ISSN |
1550-7998 |
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Notes |
WOS:000296890300012 |
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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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Author |
Albertus, C.; Hernandez, E.; Nieves, J. |
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Title |
Exclusive c -> s, d semileptonic decays of ground-state spin-1/2 doubly charmed baryons |
Type |
Journal Article |
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Year |
2011 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
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Volume |
704 |
Issue |
5 |
Pages |
499-509 |
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Keywords |
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Abstract |
We evaluate exclusive semileptonic decays of ground-state spin-1/2 doubly heavy charmed baryons driven by a c -> s, d transition at the quark level. Our results for the form factors are consistent with heavy quark spin symmetry constraints which are valid in the limit of an infinitely massive charm quark and near zero recoil. Only a few exclusive semileptonic decay channels have been theoretically analyzed before. For those cases we find that our results are in a reasonable agreement with previous calculations. |
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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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Edition |
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ISSN |
0370-2693 |
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Conference |
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Notes |
WOS:000296549200017 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ elepoucu @ |
Serial |
828 |
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Author |
Gamermann, D.; Garcia-Recio, C.; Nieves, J.; Salcedo, L.L. |
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Title |
Odd-parity light baryon resonances |
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 |
056017 - 30pp |
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Keywords |
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Abstract |
We use a consistent SU(6) extension of the meson-baryon chiral Lagrangian within a coupled channel unitary approach in order to calculate the T matrix for meson-baryon scattering in the s wave. The building blocks of the scheme are the pi and N octets, the rho nonet and the UDELTA; decuplet. We identify poles in this unitary T matrix and interpret them as resonances. We study here the nonexotic sectors with strangeness S = 0, -1, -2, -3 and spin J = 1/2, 3/2 and 5/2. Many of the poles generated can be asociated with known N, UDELTA;, sigma, Lambda, Xi and Omega resonances with negative parity. We show that most of the low-lying three and four star odd-parity baryon resonances with spin 1/2 and 3/2 can be related to multiplets of the spin-flavor symmetry group SU(6). This study allows us to predict the spin-parity of the Xi (1620), Xi (1690), Xi (1950), Xi (2250), Omega (2250) and Omega (2380) resonances, which have not been determined experimentally yet. |
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Address |
[Gamermann, D.] Univ Catolica Valencia San Vicente Martir, Catedra Energesis Tecnol Interdisciplinar, E-46003 Valencia, Spain, Email: daga1@upvnet.upv.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 |
WOS:000294404700008 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
843 |
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Author |
Hernandez, E.; Nieves, J.; Valverde, M. |
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Title |
Coherent pion production off nuclei at T2K and MiniBooNE energies revisited |
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 |
7 |
Pages |
077303 - 4pp |
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Keywords |
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Abstract |
As a result of a new improved fit to old bubble chamber data of the dominant axial C-5(A) nucleon-to-delta form factor, and due to the relevance of this form factor for neutrino induced coherent pion production, we reevaluate our model predictions in [Phys. Rev. D 79, 013002 ( 2009)] for different observables of the latter reaction. Central values for the total cross sections increase by 20%-30%, while differential cross sections do not change their shape appreciably. Furthermore, we also compute the uncertainties on total, differential, and flux-averaged cross sections induced by the errors in the determination of C-5(A). Our new results turn out to be compatible within about 1 sigma with the former ones. Finally, we stress the existing tension between the recent experimental determination of the sigma(CCcoh pi(+))/sigma(NCcoh pi(0)) ratio by the SciBooNE Collaboration and the theoretical predictions. |
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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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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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Area |
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Expedition |
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Conference |
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Notes |
ISI:000282945200003 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ elepoucu @ |
Serial |
361 |
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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 |
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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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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Conference |
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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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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 |
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 |
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: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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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 |
Place of Publication |
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Language |
English |
Summary Language |
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Abbreviated Series Title |
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Series Volume |
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Edition |
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ISSN |
0370-2693 |
ISBN |
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Expedition |
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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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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 |
Summary Language |
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Edition |
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ISSN |
0370-2693 |
ISBN |
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Area |
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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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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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Series Issue |
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Edition |
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ISSN |
1550-7998 |
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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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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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Corporate Author |
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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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Abbreviated Series Title |
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Series Volume |
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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: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 |
