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Author Lu, J.X.; Chen, H.X.; Guo, Z.H.; Nieves, J.; Xie, J.J.; Geng, L.S.
Title (down) Lambda(c)(2595) resonance as a dynamically generated state: The compositeness condition and the large N-c evolution Type Journal Article
Year 2016 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 93 Issue 11 Pages 114028 - 16pp
Keywords
Abstract Recent studies have shown that the well-established Lambda(c) (2595) resonance contains a large meson-baryon component, which can vary depending on the specific formalism. In this work, we examine such a picture by utilizing the compositeness condition and the large number of colors (N-c) expansion. We examine three different models fulfilling two body unitarily in coupled-channels, and adopting renormalization schemes where the mass of the Lambda(c)(2595) resonance is well described, but not necessarily its width, since we do not consider three body channels and work at the isospin symmetric limit. Both approximations might have an effect larger on the width than on the mass. In this context, our studies show that the compositeness of the Lambda(c)(2595) depends on the number of considered coupled channels, and on the particular regularization scheme adopted in the unitary approaches and, therefore, is model dependent. In addition, we perform an exploratory study of the Lambda(c)(2595) in the large N-c expansion, within a scheme involving only the pi Sigma(c) and K Xi(c)', channels, whose dynamics is mostly fixed by chiral symmetry. In this context and formulating the leading-order interaction as a function of N-c, we show that for moderate N-c > 3 values, the mass and width of the Lambda(c)(2595) deviate from those of a genuine qqq baryon, implying the relevance of meson-baryon components in its wave function. Furthermore, we study the properties of the Lambda(c)(2595), in the strict N-c -> infinity limit, using an extension of the chiral Weinberg-Tomozawa interaction to an arbitrary number of flavors and colors. This latter study hints at the possible existence of a (perhaps) subdominant qqq component in the Lambda(c)(2595) resonance wave function, which would become dominant when the number of colors gets sufficiently large.
Address [Lu, Jun-Xu; Chen, Hua-Xing; Geng, Li-Sheng] Beihang Univ, Sch Phys & Nucl Energy Engn, Beijing 100191, Peoples R China, Email: lisheng.geng@buaa.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:000378306600004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2745
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Author Nieves, J.; Pavao, R.; Sakai, S.
Title (down) 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 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
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Author Du, M.L.; Hernandez, E.; Nieves, J.
Title (down) 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 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
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Author Nieves, J.; Ruiz Simo, I.; Vicente Vacas, M.J.
Title (down) Inclusive charged-current neutrino-nucleus reactions Type Journal Article
Year 2011 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 83 Issue 4 Pages 045501 - 19pp
Keywords
Abstract We present a model for weak charged-current induced nuclear reactions at energies of interest for current and future neutrino oscillation experiments. This model is a natural extension of the work in Refs. [1,2], where the quasielastic contribution to the inclusive electron and neutrino scattering on nuclei was analyzed. The model is based on a systematic many-body expansion of the gauge boson absorption modes that includes one, two, and even three-body mechanisms, as well as the excitation of Delta isobars. The whole scheme has no free parameters, besides those previously adjusted to the weak pion production off the nucleon cross sections in the deuteron, since all nuclear effects were set up in previous studies of photon, electron, and pion interactions with nuclei. We have discussed at length the recent charged-current quasielastic MiniBooNE cross section data, and showed that two-nucleon knockout mechanisms are essential to describing these measurements.
Address [Nieves, J.] Univ Valencia, CSIC, Inst Invest Paterna, Inst Fis Corpuscular IFIC,Ctr Mixto, E-46071 Valencia, 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 0556-2813 ISBN Medium
Area Expedition Conference
Notes ISI:000289192700004 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 594
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Author Bourguille, B.; Nieves, J.; Sanchez, F.
Title (down) Inclusive and exclusive neutrino-nucleus cross sections and the reconstruction of the interaction kinematics Type Journal Article
Year 2021 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 04 Issue 4 Pages 004 - 42pp
Keywords Phenomenological Models
Abstract We present a full kinematic analysis of neutrino-nucleus charged current quasielastic interactions based on the Local Fermi Gas model and the Random Phase Approximation. The model was implemented in the NEUT Monte Carlo framework, which allows us to investigate potentially measurable observables, including hadron distributions. We compare the predictions simultaneously to the most recent T2K and MINERvA charged current (CC) inclusive, CC0 pi and transverse kinematic-imbalance variable results. We pursuit a microscopic interpretation of the relevant reaction mechanisms, with the aim to achieving in neutrino oscillation experiments a correct reconstruction of the incoming neutrino kinematics, free of conceptual biasses. Such study is of the utmost importance for the ambitious experimental program which is underway to precisely determine neutrino properties, test the three-generation paradigm, establish the order of mass eigenstates and investigate leptonic CP violation.
Address [Bourguille, B.] Univ Autonoma Barcelona, Inst Fis Altes Energies IFAE, Barcelona Inst Sci & Technol, Edifici Cn, Bellaterra, Barcelona, Spain, Email: bruno.bourguille@free.fr;
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 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000636427400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4774
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