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Author Nieves, J.; Pavao, R.; Sakai, S. url  doi
openurl 
  Title Lambda(b) decays into Lambda cl(nu)over-barl and Lambda c*pi(-) [ Lambda(c)* = Lambda(c)( 2595) and Lambda(c)(2625)] and heavy quark spin symmetry Type Journal Article
  Year 2019 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C  
  Volume 79 Issue 5 Pages 417 - 20pp  
  Keywords  
  Abstract (up) We study the implications for bc=c(2595) and c(2625)] decays that can be deduced from heavy quark spin symmetry (HQSS). Identifying the odd parity c(2595) and c(2625) resonances as HQSS partners, with total angular momentum-parity jqP=1- for the light degrees of freedom, we find that the ratios (bc(2595)-)/(bc(2625)-) and (bc(2595)) agree, within errors, with the experimental values given in the Review of Particle Physics. We discuss how future, and more precise, measurements of the above branching fractions could be used to shed light into the inner HQSS structure of the narrow c(2595) odd-parity resonance. Namely, we show that such studies would constrain the existence of a sizable jqP</mml:msubsup>=0- component in its wave-function, and/or of a two-pole pattern, in analogy to the case of the similar (1405) resonance in the strange sector, as suggested by most of the approaches that describe the c(2595) as a hadron molecule. We also investigate the lepton flavor universality ratios R[c]=B( may be affected by a new source of potentially large systematic errors if there are two) poles.  
  Address [Nieves, J.; Pavao, R.] Ctr Mixto CSIC UV, Inst Fis Corpuscular, Inst Invest Paterna, Aptdo 22085, Valencia 46071, Spain, Email: shsakai@itp.ac.cn  
  Corporate Author Thesis  
  Publisher Springer Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1434-6044 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000468374700002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4021  
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 (up) 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 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 Nieves, J.; Pavao, R. url  doi
openurl 
  Title Nature of the lowest-lying odd parity charmed baryon Lambda(c)(2595) and Lambda(c)(2625) resonances Type Journal Article
  Year 2020 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 101 Issue 1 Pages 014018 - 17pp  
  Keywords  
  Abstract (up) We study the structure of the Lambda(c) (2595) and Lambda(c) (2625) resonances in the framework of an effective field theory consistent with heavy quark spin and chiral symmetries, which incorporates the interplay between Sigma(()(c)*() )pi – ND(*()) baryon-meson degrees of freedom (d.o.f.) and bare P-wave c (u) over bard quark-model states. We show that these two resonances are not heavy quark spin symmetry partners. The J(P) = 3/2(-) Lambda(c) (2625) should be viewed mostly as a dressed three-quark state, whose origin is determined by a bare state, predicted to lie very close to the mass of the resonance. The J(P) = 1/2(-) Lambda(c) (2595) seems to have, however, a predominant molecular structure. This is because it is either the result of the chiral Sigma(c)pi interaction, whose threshold is located much closer than the mass of the bare three-quark state, or because the light d.o.f. in its inner structure are coupled to the unnatural 0(-) quantum numbers. We show that both situations can occur depending on the renormalization procedure used. We find some additional states, but the classification of the spectrum in terms of heavy quark spin symmetry is difficult, despite having used interactions that respect this symmetry. This is because the bare quark-model state and the Sigma(c)pi threshold are located extraordinarily close to the Lambda(c) (2625) and Lambda(c) (2595), respectively, and hence they play totally different roles in each sector.  
  Address [Nieves, J.; Pavao, R.] Ctr Mixto CSIC UV, Inst Invest Paterna, Inst Fis Corpuscular, Apartado 22085, 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 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000509494900007 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 4272  
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 (up) 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 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 Du, M.L.; Hernandez, E.; Nieves, J. url  doi
openurl 
  Title Is the Lambda(c)(2625)(+) the heavy quark spin symmetry partner of the Lambda(c)(2595)(+) ? Type Journal Article
  Year 2022 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 106 Issue 11 Pages 114020 - 22pp  
  Keywords  
  Abstract (up) We use a O(alpha(s). Lambda(QCD)/m(c)) heavy quark effective theory scheme, where only O(Lambda(QCD)/mb) corrections are neglected, to study the matrix elements of the scalar, pseudoscalar, vector, axial-vector and tensor currents between the Lambda(b) ground state and the odd parity charm Lambda(c)(2595)(+) and Lambda(c)(2625)(+) resonances. We show that in the near-zero recoil regime, the scheme describes reasonably well, taking into account uncertainties, the results for the 24 form factors obtained in lattice QCD (LQCD) just in terms of only four Isgur-Wise (IW) functions. We also find some support for the possibility that the Lambda(c)(2595)(+) and Lambda(c)(2625)(+) resonances might form a heavy quark spin symmetry (HQSS) doublet. However, we argue that the available LQCD description of these two resonances is not accurate enough to disentangle the possible effects of the Sigma(c)pi and Sigma(c)*pi thresholds, located only a few MeV above their position, and that it cannot be ruled out that these states are not HQSS partners. Finally, we study the ratio d Gamma/[Lambda(b) -> Lambda(c,1/2)-*l (v) over bar (l)]/dq(2)/d Gamma/[Lambda(b) -> Lambda(c,3/2)-*l (v) over bar (l)]/dq(2) of the Standard Model differential semileptonic decay widths, with q the four-momentum transferred between the initial and final hadrons. We provide a natural explanation for the existence of large deviations, near the zero recoil, of this ratio from 1=2 (value predicted in the infinite heavy quark mass limit, assuming that the Lambda(c,1/2)- and Lambda(c,3/2)- are the two members of a HQSS doublet) based on S-wave contributions to the Lambda(b) -> Lambda(c,1/2)- decay amplitude driven by a subleading IW function.  
  Address [Du, Meng-Lin; Nieves, Juan] Inst Fis Corpuscular Ctr Mixto CSIC UV, Inst Invest Paterna, Apartado 22085, Valencia 46071, Spain, Email: du.ml@uestc.edu.cn;  
  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 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000905088600004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5454  
Permanent link to this record
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