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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 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 (up) 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
Permanent link to this record
 

 
Author Yao, D.L.; Fernandez-Soler, P.; Guo, F.K.; Nieves, J.
Title New parametrization of the form factors in (B)over-bar -> Dl(nu)over-bar(l) decays Type Journal Article
Year 2020 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 101 Issue 3 Pages 034014 - 7pp
Keywords
Abstract A new model-independent parametrization is proposed for the hadronic form factors in the semileptonic (B) over bar -> Dl (nu) over bar (l) decay. By a combined consideration of the recent experimental and lattice QCD data, we determine precisely the Cabibbo-Kobayashi-Maskawa matrix element vertical bar V-cb vertical bar = 41.01(75) x 10(-3) and the ratio R-D = BR((B) over bar -> D tau(nu) over bar (tau))/BR((B) over bar -> Dl (nu) over bar (l)) = 0.301(5). The coefficients in this parametrization, related to phase shifts by sumrulelike dispersion relations and hence called phase moments, encode important scattering information of the (B) over bar (D) over bar interactions which are poorly known so far. Thus, we give strong hints about the existence of at least one bound and one virtual (B) over bar (D) over bar S-wave 0(+) states, subject to uncertainties produced by potentially sizable inelastic effects. This formalism is also applicable for any other semileptonic processes induced by the weak b -> c transition.
Address [Yao, De-Liang] Hunan Univ, Sch Phys & Elect, Changsha 410082, Hunan, Peoples R China
Corporate Author Thesis
Publisher (up) 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:000513217400004 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 4277
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Author Yao, D.L.; Alvarez-Ruso, L.; Vicente Vacas, M.J.
Title Neutral-current weak pion production off the nucleon in covariant chiral perturbation theory Type Journal Article
Year 2019 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 794 Issue Pages 109-113
Keywords
Abstract Neutral current single pion production induced by neutrinos and antineutrinos on nucleon targets has been investigated in manifestly relativistic baryon chiral perturbation theory with explicit Delta(1232) degrees of freedom up to O(p(3)). At low energies, where chiral perturbation theory is applicable, the total cross sections for the different reaction channels exhibit a sizable non-resonant contribution, which is not present in event generators of broad use in neutrino oscillation and cross section experiments such as GENIE and NuWro.
Address [Yao, De-Liang] Hunan Univ, Sch Phys & Elect, Changsha 410082, Hunan, Peoples R China, Email: yaodeliang@hnu.edu.cn;
Corporate Author Thesis
Publisher (up) 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 Medium
Area Expedition Conference
Notes WOS:000470065300017 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4043
Permanent link to this record
 

 
Author Wang, Y.F.; Yao, D.L.; Zheng, H.Q.
Title On the existence of N*(890) resonance in S-11 channel of N scatterings Type Journal Article
Year 2019 Publication Frontiers of Physics Abbreviated Journal Front. Phys.
Volume 14 Issue 2 Pages 24501 - 6pp
Keywords dispersion relations; N scatterings; nucleon resonance
Abstract Low-energy partial-wave N scattering data is reexamined with the help of the production representation of partial-wave S matrix, where branch cuts and poles are thoroughly under consideration. The left-hand cut contribution to the phase shift is determined, with controlled systematic error estimates, by using the results of O(p(3)) chiral perturbative amplitudes obtained in the extended-onmass- shell scheme. In S-11 and P-11 channels, severe discrepancies are observed between the phase shift data and the sum of all known contributions. Statistically satisfactory fits to the data can only be achieved by adding extra poles in the two channels. We find that a S-11 resonance pole locates at zr = (0:895-0:081)-(0:164-0:023)i GeV, on the complex s-plane. On the other hand, a P-11 virtual pole, as an accompanying partner of the nucleon bound-state pole, locates atzv = (0:966-0:018) GeV, slightly above the nucleon pole on the real axis below threshold. Physical origin of the two newly established poles is explored to the best of our knowledge. It is emphasized that the O(p(3)) calculation greatly improves the fit quality comparing with the previous O(p(2)) one.
Address [Wang, Yu-Fei; Zheng, Han-Qing] Peking Univ, Dept Phys, Beijing 100871, Peoples R China, Email: deliang.yao@ific.uv.es
Corporate Author Thesis
Publisher (up) Higher Education Press Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2095-0462 ISBN Medium
Area Expedition Conference
Notes WOS:000454564100001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3857
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Author Chen, Y.H.; Yao, D.L.; Zheng, H.Q.
Title A Study of rho-omega Mixing in Resonance Chiral Theory Type Journal Article
Year 2018 Publication Communications in Theoretical Physics Abbreviated Journal Commun. Theor. Phys.
Volume 69 Issue 1 Pages 50-58
Keywords Chiral Lagrangians; vector mesons; 1/N-C expansion
Abstract The strong and electromagnetic corrections to rho-omega mixing are calculated using an SU(2) version of resonance chiral theory up to next-to-leading orders in 1/N-C expansion, respectively. Up to our accuracy, the effect of the momentum dependence of rho-omega mixing is incorporated due to the inclusion of loop contributions. We analyze the impact of rho-omega mixing on the pion vector form factor by performing numerical fit to the data extracted from e(+)e(-) -> pi(+)pi(-) and tau -> nu(tau)2 pi, while the decay width of omega -> pi(+)pi(-) is taken into account as a constraint. It is found that the momentum dependence is significant in a good description of the experimental data. In addition, based on the fitted values of the involved parameters, we analyze the decay width of omega -> pi(+)pi(-), which turns out to be highly dominated by the rho-omega mixing effect.
Address [Chen, Yun-Hua] Univ Sci & Technol Beijing, Sch Math & Phys, Beijing 100083, Peoples R China, Email: yhchen@ustb.edu.cn;
Corporate Author Thesis
Publisher (up) 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 0253-6102 ISBN Medium
Area Expedition Conference
Notes WOS:000422832600010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3453
Permanent link to this record