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Author Yao, D.L.; Alvarez-Ruso, L.; Vicente Vacas, M.J.
Title Extraction of nucleon axial charge and radius from lattice QCD results using baryon chiral perturbation theory Type Journal Article
Year 2017 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 96 Issue 11 Pages (down) 116022 - 11pp
Keywords
Abstract We calculate the nucleon axial form factor up to the leading one-loop order in a covariant chiral effective field theory with the Delta(1232) resonance as an explicit degree of freedom. We fit the axial form factor to the latest lattice QCD data and pin down the relevant low-energy constants. The lattice QCD data, for various pion masses below 400 MeV, can be well described up to a momentum transfer of similar to 0.6 GeV. The Delta(1232) loops contribute significantly to this agreement. Furthermore, we extract the axial charge and radius based on the fitted values of the low-energy constants. The results are g(A) = 1.237(74) and < r(A)(2)> = 0.263(38) fm(2). The obtained coupling g(A) is consistent with the experimental value if the uncertainty is taken into account. The axial radius is below but in agreement with the recent extraction from neutrino quasielastic scattering data on deuterium, which has large error bars. Up to our current working accuracy, r(A) is predicted only at leading order, i.e., the one-loop level. A more precise determination might need terms of O(p(5)).
Address [Yao, De-Liang] CSIC, Ctr Mixto UVEG, Dept Fis Teor, E-46071 Valencia, Spain, Email: deliang.yao@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 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000418917900010 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 3437
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Author Guerrero Navarro, G.H.; Vicente Vacas, M.J.; Hiller Blin, A.N.; Yao, D.L.
Title Pion photoproduction off nucleons in covariant chiral perturbation theory Type Journal Article
Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 100 Issue 9 Pages (down) 094021 - 18pp
Keywords
Abstract Pion photoproduction off the nucleon close to threshold is studied in covariant baryon chiral perturbation theory at O(p(3)) in the extended-on-mass-shell scheme, with the explicit inclusion of the Delta(1232) resonance using the delta counting. The theory is compared to the available data of cross sections and polarization observables for all the charge channels. Most of the necessary low-energy constants arc well known from the analysis of other processes and the comparison with data constrains some of the still unknown ones. The Delta(1232) contribution is significant in improving the agreement with data, even at the low energies considered.
Address [Guerrero Navarro, Gustavo H.; Vacas, M. J. Vicente] UVEG, Ctr Mixto, CSIC, Dept Fis Teor, E-46071 Valencia, Spain, Email: gusguena@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 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000498060600002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4202
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Author Du, M.L.; Albaladejo, M.; Fernandez-Soler, P.; Guo, F.K.; Hanhart, C.; Meissner, U.G.; Nieves, J.; Yao, D.L.
Title Towards a new paradigm for heavy-light meson spectroscopy Type Journal Article
Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 98 Issue 9 Pages (down) 094018 - 8pp
Keywords
Abstract Since 2003 many new hadrons, including the lowest-lying positive-parity charm-strange mesons D*(s0) (2317) and D-s1 (2460), have been observed that do not conform with quark-model expectations. It was recently demonstrated that various puzzles in the charm-meson spectrum find a natural resolution if the SU(3) multiplets for the lightest scalar and axial-vector states, among them the D*(s0) (2317) and the D-s1 (2460), owe their existence to the nonperturbative dynamics of Goldstone-boson scattering off D-(s) and D*((s)) mesons. Most importantly the ordering of the lightest strange and nonstrange scalars becomes natural. We demonstrate for the first time that this mechanism is strongly supported by the recent high quality data on the B- -> D+ pi(-)pi(-) provided by the LHCb experiment. This implies that the lowest quark-model positive-parity charm mesons, together with their bottom counterparts, if realized in nature, do not form the ground-state multiplet. This is similar to the pattern that has been established for the scalar mesons made from light up, down, and strange quarks, where the lowest multiplet is considered to be made of states not described by the quark model. In a broader view, the hadron spectrum must be viewed as more than a collection of quark-model states.
Address [Du, Meng-Lin; Meissner, Ulf-G.] Univ Bonn, Helmholtz Inst Strahlen & Kernphys, D-53115 Bonn, Germany, Email: fkguo@itp.ac.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:000451000200003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3817
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Author Yao, D.L.; Alvarez-Ruso, L.; Hiller Blin, A.N.; Vicente Vacas, M.J.
Title Weak pion production off the nucleon in covariant chiral perturbation theory Type Journal Article
Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 98 Issue 7 Pages (down) 076004 - 25pp
Keywords
Abstract Weak pion production off the nucleon at low energies has been systematically investigated in manifestly relativistic baryon chiral perturbation theory with explicit inclusion of the Delta(1232) resonance. Most of the involved low-energy constants have been previously determined in other processes such as pion-nucleon elastic scattering and electromagnetic pion production off the nucleon. For numerical estimates, the few remaining constants are set to be of natural size. As a result, the total cross sections for single pion production on neutrons and protons, induced either by neutrino or antineutrino, are predicted. Our results are consistent with the scarce existing experimental data except in the nu(mu)n -> mu(-)n pi(+) channel, where higher-order contributions might still be significant. The Delta resonance mechanisms lead to sizeable contributions in all channels, especially in nu(mu)p -> mu(-) p pi(+), even though the considered energies are close to the production threshold. The present study provides a well-founded low-energy benchmark for phenomenological models aimed at the description of weak pion production processes in the broad kinematic range of interest for current and future neutrino-oscillation experiments.
Address [Yao, De-Liang; Alvarez-Ruso, Luis; Vicente Vacas, M. J.] UV, CSIC, Dept Fis Teor, Ctr Mixto,Inst Invest Paterna, E-46071 Valencia, Spain, Email: Deliang.Yao@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 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000446557200006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3752
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Author Wang, Y.F.; Yao, D.L.; Zheng, H.Q.
Title New insights on low energy pi N scattering amplitudes: comprehensive analyses at O (p(3)) level Type Journal Article
Year 2019 Publication Chinese Physics C Abbreviated Journal Chin. Phys. C
Volume 43 Issue 6 Pages (down) 064110 - 22pp
Keywords dispersion relations; pion-nucleon scattering; chiral perturbation theory
Abstract A production representation of partial-wave S matrix is utilized to construct low-energy elastic pion-nucleon scattering amplitudes from cuts and poles on complex Riemann sheets. Among them, the contribution of left-hand cuts is estimated using the O (p(3)) results obtained in covariant baryon chiral perturbation theory within the extendedon-nass-shell scheme. By fitting to data on partial-wave phase shifts, it is indicated that the existences of hidden poles in S-11 and P-11 channels, as conjectured in our previous paper [Eur. Phys. J. C, 78(7): 543 (2018)], are firmly established. Specifically, the pole mass of the S-11 hidden resonance is determined to be (895 +/- 81)-(164 +/- 23)i MeV, whereas, the virtual pole in the P-11 channel locates at (966 +/- 18) MeV. It is found that analyses at the O (p(3)) level improves significantly the fit quality, comparing with the previous O (p(2)) one. Quantitative studies with cautious physical discussions are also conducted for the other S- and P-wave channels.
Address [Wang, Yu-Fei; Zheng, Han-Qing] Peking Univ, Dept Phys, Beijing 100871, Peoples R China, Email: yaodeliang@pku.edu.cn
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1674-1137 ISBN Medium
Area Expedition Conference
Notes WOS:000468501700013 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4020
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