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Author Albertus, C.; Hernandez, E.; Nieves, J. url  doi
openurl 
  Title Hyperfine mixing in b -> c semileptonic decay of doubly heavy baryons Type Journal Article
  Year 2010 Publication Physics Letters B Abbreviated Journal Phys. Lett. B  
  Volume 683 Issue 1 Pages 21-25  
  Keywords  
  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.  
  Address [Hernandez, E.] Univ Salamanca, Dept Fis Fundamental, E-37008 Salamanca, Spain, Email: gajatee@usal.es  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0370-2693 ISBN (up) Medium  
  Area Expedition Conference  
  Notes ISI:000274129600005 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ elepoucu @ Serial 501  
Permanent link to this record
 

 
Author Pavao, R.; Gubler, P.; Fernandez-Soler, P.; Nieves, J.; Oka, M.; Takahashi, T.T. url  doi
openurl 
  Title The negative-parity spin-1/2 A baryon spectrum from lattice QCD and effective theory Type Journal Article
  Year 2021 Publication Physics Letters B Abbreviated Journal Phys. Lett. B  
  Volume 820 Issue Pages 136473 - 8pp  
  Keywords  
  Abstract The spectrum of the negative-parity spin-1/2 Lambda baryons is studied using lattice QCD and hadronic effective theory in a unitarized coupled-channel framework. A direct comparison between the two approaches is possible by considering the hadronic effective theory in a finite volume and with hadron masses and mesonic decay constants that correspond to the situation studied on the lattice. Comparing the energy level spectrum and SU(3) flavor decompositions of the individual states, it is found that the lowest two states extracted from lattice QCD can be associated with one of the two Lambda(1405)-poles and the Lambda(1670) resonance. The quark mass dependences of these two lattice QCD levels are in good agreement with their effective theory counterparts. However, as current lattice QCD studies still rely on three-quark operators to generate the physical states, clear signals corresponding to the meson-baryon scattering states, that appear in the finite volume effective theory calculation, are not yet seen.  
  Address [Pavao, Rafael; Fernandez-Soler, Pedro; Nieves, Juan] Univ Valencia, CSIC, Inst Invest Paterna, Inst Fis Corpuscular IFIC,Ctr Mixto, Apartado 22085, E-46071 Valencia, Spain, Email: gubler@post.j-parc.jp  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0370-2693 ISBN (up) Medium  
  Area Expedition Conference  
  Notes WOS:000713101800041 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5022  
Permanent link to this record
 

 
Author Hernandez, E.; Nieves, J. url  doi
openurl 
  Title Study of the strong Sigma(b) -> Lambda(b)pi and Sigma*(b) -> Lambda(b)pi in a nonrelativistic quark model Type Journal Article
  Year 2011 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 84 Issue 5 Pages 057902 - 5pp  
  Keywords  
  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.  
  Address [Hernandez, E] Univ Salamanca, Dept Fis Fundamental, E-37008 Salamanca, Spain  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1550-7998 ISBN (up) Medium  
  Area Expedition Conference  
  Notes WOS:000295327700002 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ elepoucu @ Serial 776  
Permanent link to this record
 

 
Author Nieves, J.; Valderrama, M.P. url  doi
openurl 
  Title Deriving the existence of B(B)over-bar* bound states from the X(3872) and heavy quark symmetry Type Journal Article
  Year 2011 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 84 Issue 5 Pages 056015 - 21pp  
  Keywords  
  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.  
  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  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1550-7998 ISBN (up) Medium  
  Area Expedition Conference  
  Notes WOS:000295267700006 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ elepoucu @ Serial 778  
Permanent link to this record
 

 
Author Nieves, J.; Pich, A.; Ruiz Arriola, E. url  doi
openurl 
  Title Large-N(C) properties of the rho and f(0)(600) mesons from unitary resonance chiral dynamics Type Journal Article
  Year 2011 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 84 Issue 9 Pages 096002 - 20pp  
  Keywords  
  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.  
  Address [Nieves, J] Ctr Mixto Univ Valencia, Inst Fis Corpuscular, CSIC, IFIC, Valencia 46071, Spain  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1550-7998 ISBN (up) Medium  
  Area Expedition Conference  
  Notes WOS:000296890300012 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 799  
Permanent link to this record
 

 
Author Albertus, C.; Hernandez, E.; Nieves, J. url  doi
openurl 
  Title Exclusive c -> s, d semileptonic decays of ground-state spin-1/2 doubly charmed baryons Type Journal Article
  Year 2011 Publication Physics Letters B Abbreviated Journal Phys. Lett. B  
  Volume 704 Issue 5 Pages 499-509  
  Keywords  
  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.  
  Address [Albertus, C.; Hernandez, E.] Univ Salamanca, Dept Fis Fundamental, E-37008 Salamanca, Spain, Email: gajatee@usal.es  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0370-2693 ISBN (up) Medium  
  Area Expedition Conference  
  Notes WOS:000296549200017 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ elepoucu @ Serial 828  
Permanent link to this record
 

 
Author Gamermann, D.; Garcia-Recio, C.; Nieves, J.; Salcedo, L.L. url  doi
openurl 
  Title Odd-parity light baryon resonances Type Journal Article
  Year 2011 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 84 Issue 5 Pages 056017 - 30pp  
  Keywords  
  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.  
  Address [Gamermann, D.] Univ Catolica Valencia San Vicente Martir, Catedra Energesis Tecnol Interdisciplinar, E-46003 Valencia, Spain, Email: daga1@upvnet.upv.es  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1550-7998 ISBN (up) Medium  
  Area Expedition Conference  
  Notes WOS:000294404700008 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 843  
Permanent link to this record
 

 
Author Flynn, J.M.; Hernandez, E.; Nieves, J. url  doi
openurl 
  Title Triply heavy baryons and heavy quark spin symmetry Type Journal Article
  Year 2012 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 85 Issue 1 Pages 014012 - 10pp  
  Keywords  
  Abstract We study the semileptonic b -> c decays of the lowest-lying triply heavy baryons made from b and c quarks in the limit m(b), m(c) >> Lambda(QCD) and close to the zero-recoil point. The separate heavy-quark spin symmetries strongly constrain the matrix elements, leading to single form factors for ccb -> ccc, bbc -> ccb, and bbb -> bbc baryon decays. We also study the effects on these systems of using a Y-shaped confinement potential, as suggested by lattice QCD results for the interaction between three static quarks.  
  Address [Flynn, J. M.] Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1550-7998 ISBN (up) Medium  
  Area Expedition Conference  
  Notes WOS:000298989300007 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 874  
Permanent link to this record
 

 
Author Pavon Valderrama, M.; Xie, J.J.; Nieves, J. url  doi
openurl 
  Title Are there three Xi (1950) states? Type Journal Article
  Year 2012 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 85 Issue 1 Pages 017502 - 5pp  
  Keywords  
  Abstract Different experiments on hadron spectroscopy have long suspected the existence of several cascade states in the 1900-2000 MeV region. They are usually labeled under the common name of Xi (1950). As we argue here, there are also theoretical reasons supporting the idea of several Xi (1950) resonances. In particular, we propose the existence of three Xi (1950) states: one of these states would be part of a spinparity 1/2(-) decuplet and the other two probably would belong to the 5/2(+) and 5/2(-) octets. We also identify which decay channels are more appropriate for the detection of each of the previous states.  
  Address [Pavon Valderrama, M.; Xie, Ju-Jun; Nieves, J.] Univ Valencia, Ctr Mixto CSIC, Inst Fis Corpuscular IFIC, Inst Invest Paterna, E-46071 Valencia, Spain, Email: m.pavon.valderrama@ific.uv.es  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1550-7998 ISBN (up) Medium  
  Area Expedition Conference  
  Notes WOS:000298989300008 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 875  
Permanent link to this record
 

 
Author Nieves, J.; Ruiz Simo, I.; Vicente Vacas, M.J. url  doi
openurl 
  Title The nucleon axial mass and the MiniBooNE quasielastic neutrino-nucleus scattering problem Type Journal Article
  Year 2012 Publication Physics Letters B Abbreviated Journal Phys. Lett. B  
  Volume 707 Issue 1 Pages 72-75  
  Keywords  
  Abstract The charged-current double differential neutrino cross section, measured by the MiniBooNE Collaboration, has been analyzed using a microscopical model that accounts for, among other nuclear effects, long range nuclear (RPA) correlations and multinucleon scattering. We find that MiniBooNE data are fully compatible with the world average of the nucleon axial mass in contrast with several previous analyses which have suggested an anomalously large value. We also discuss the reliability of the algorithm used to estimate the neutrino energy.  
  Address [Nieves, J.] Univ Valencia, Ctr Mixto, CSIC, Inst Invest Paterna,Inst Fis Corpuscular IFIC, E-46071 Valencia, Spain, Email: jmnieves@ific.uv.es  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0370-2693 ISBN (up) Medium  
  Area Expedition Conference  
  Notes WOS:000299757000010 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 903  
Permanent link to this record
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