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Author Alvarez-Ruso, L.; Ledwig, T.; Martin Camalich, J.; Vicente Vacas, M.J. url  doi
openurl 
  Title Nucleon mass and pion-nucleon sigma term from a chiral analysis of lattice QCD data Type Journal Article
  Year 2013 Publication (up) Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 88 Issue 5 Pages 054507 - 20pp  
  Keywords  
  Abstract The pion mass dependence of the nucleon mass within the covariant SU(2) baryon chiral perturbation theory both without and with explicit Delta(1232) degrees of freedom up to order p(4) is investigated. By fitting to a comprehensive set of lattice QCD data in 2 and 2 + 1 flavors from several collaborations, for pion masses M-pi < 420 MeV, we obtain low energy constants of natural size that are compatible with pion-nucleon scattering data. Our results are consistent with the rather linear pion mass dependence showed by lattice QCD. In the 2 flavor case we have also performed simultaneous fits to nucleon mass and sigma(pi N) data. As a result of our analysis, which encompasses the study of finite volume corrections and discretization effects, we report a value of sigma(pi N) = 41(5)(4) MeV in the 2 flavor case and sigma(pi N) = 52(3)(8) MeV for 2 + 1 flavors, where the inclusion of the Delta(1232) resonance changes the results by around 9 MeV. In the 2 flavor case we are able to set independently the scale for lattice QCD data, given by a Sommer scale of r(0) = 0.493(23) fm.  
  Address [Alvarez-Ruso, L.] Univ Valencia, Ctr Mixto, CSIC, Inst Fis Corpuscular IFIC, E-46071 Valencia, Spain, Email: alvarez@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 Medium  
  Area Expedition Conference  
  Notes WOS:000324636100005 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1603  
Permanent link to this record
 
 
Author Wang, E.; Alvarez-Ruso, L.; Hayato, Y.; Mahn, K.; Nieves, J. url  doi
openurl 
  Title Photon emission in neutral current interactions at the T2K experiment Type Journal Article
  Year 2015 Publication (up) Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 92 Issue 5 Pages 053005 - 8pp  
  Keywords  
  Abstract We have applied a microscopic model for single photon emission in neutral current interactions on nucleons and nuclei to determine the number and distributions of such events at the Super-Kamiokande detector, for the flux and beam exposure of the T2K experiment in neutrino mode. These reactions represent an effectively irreducible background in electron-(anti) neutrino appearance measurements aimed at a precise measurement of mixing angle theta(13) and the CP violating phase. We have obtained a total number of photon events that is twice as large as the one from the NEUT event generator (version 5.1.4.2) used in the analysis of T2K data. Detailed comparisons of energy and angular distributions for the nu μand (nu) over bar μfluxes have also been performed.  
  Address [Wang, E.] Zhengzhou Univ, Dept Phys, Zhengzhou 450001, Henan, Peoples R China  
  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:000361119300004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2380  
Permanent link to this record
 
 
Author Alvarez-Ruso, L.; Hernandez, E.; Nieves, J.; Vicente Vacas, M.J. url  doi
openurl 
  Title Watson's theorem and the N Delta(1232) axial transition Type Journal Article
  Year 2016 Publication (up) Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 93 Issue 1 Pages 014016 - 16pp  
  Keywords  
  Abstract We present a new determination of the N Delta axial form factors from neutrino induced pion production data. For this purpose, the model of Hernandez et al. [Phys. Rev. D 76, 033005 (2007)] is improved by partially restoring unitarity. This is accomplished by imposing Watson's theorem on the dominant vector and axial multipoles. As a consequence, a larger C-5(A) (0), in good agreement with the prediction from the off-diagonal Goldberger-Treiman relation, is now obtained.  
  Address [Alvarez-Ruso, L.; Nieves, J.] Ctr Mixto CSIC Univ Valencia, Inst Fis Corpuscular IFIC, Inst Invest Paterna, 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 1550-7998 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000368324700003 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 2521  
Permanent link to this record
 
 
Author Yao, D.L.; Alvarez-Ruso, L.; Vicente Vacas, M.J. url  doi
openurl 
  Title Extraction of nucleon axial charge and radius from lattice QCD results using baryon chiral perturbation theory Type Journal Article
  Year 2017 Publication (up) Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 96 Issue 11 Pages 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  
Permanent link to this record
 
 
Author Yao, D.L.; Alvarez-Ruso, L.; Hiller Blin, A.N.; Vicente Vacas, M.J. url  doi
openurl 
  Title Weak pion production off the nucleon in covariant chiral perturbation theory Type Journal Article
  Year 2018 Publication (up) Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 98 Issue 7 Pages 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  
Permanent link to this record
 
 
Author Alvarado, F.; Alvarez-Ruso, L. url  doi
openurl 
  Title Light-quark mass dependence of the nucleon axial charge and pion-nucleon scattering phenomenology Type Journal Article
  Year 2022 Publication (up) Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 105 Issue 7 Pages 074001 - 13pp  
  Keywords  
  Abstract The light-quark mass dependence of the nucleon axial isovector charge (gA) has been studied up to nextto-next-to-leading order, O(p4), in relativistic chiral perturbation theory using extended-on-mass-shell renormalization, without and with explicit Delta(1232) degrees of freedom. We show that in the Delta-less case, at this order, the flat trend of gA(MN) exhibited by state-of-the-art lattice QCD (LQCD) results cannot be reproduced using low energy constants extracted from pion-nucleon elastic and inelastic scattering. A satisfactory description of these LQCD data is only achieved in the theory with Delta. From this fit, we report gA(MN(phys)) = 1.260 1 0.012, close to the experimental result, and d16 = -0.88 1 0.88 GeV-2, in agreement with its empirical value. The large uncertainties are of theoretical origin, reflecting the difference between O(p3) and O(p4) that still persists at large MN in presence of the Delta.  
  Address [Alvarado, Fernando; Alvarez-Ruso, Luis] Inst Fis Corpuscular IFIC, E-46980 Valencia, Spain, Email: Fernando.Alvarado@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:000791214200001 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 5217  
Permanent link to this record
 
 
Author Alvarado, F.; An, D.; Alvarez-Ruso, L.; Leupold, S. url  doi
openurl 
  Title Light quark mass dependence of nucleon electromagnetic form factors in dispersively modified chiral perturbation theory Type Journal Article
  Year 2023 Publication (up) Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 108 Issue 11 Pages 114021 - 23pp  
  Keywords  
  Abstract The nucleon isovector electromagnetic form factors are calculated up to next-to-next-to-leading order by combining relativistic chiral perturbation theory (ChPT) of pion, nucleon, and Delta o1232 thorn with dispersion theory. We specifically address the light-quark mass dependence of the form factors, achieving a good description of recent lattice QCD results over a range of Q2 less than or similar to 0.6 GeV2 and M pi less than or similar to 350 MeV. For the Dirac form factor, the combination of ChPT and dispersion theory outperforms the pure dispersive and pure ChPT descriptions. For the Pauli form factor, the combined calculation leads to results comparable to the purely dispersive ones. The anomalous magnetic moment and the Dirac and Pauli radii are extracted.  
  Address [Alvarado, Fernando; Alvarez-Ruso, Luis] CSIC, Inst Fis Corpuscular IF, E-46980 Paterna, Valencia, Spain, Email: Fernando.Alvarado@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:001138524400003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5906  
Permanent link to this record
 
 
Author Belen Galan, M.; Alvarez-Ruso, L.; Rafi Alam, M.; Ruiz Simo, I.; Vicente Vacas, M.J. url  doi
openurl 
  Title Cabibbo suppressed hyperon production off nuclei induced by antineutrinos Type Journal Article
  Year 2024 Publication (up) Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 109 Issue 3 Pages 033001 - 13pp  
  Keywords  
  Abstract In this work, we study the production of E and A hyperons in strangeness -changing AS = -1 chargedcurrent interactions of muon antineutrinos on nuclear targets. At the nucleon level, besides quasielastic scattering, we consider the inelastic mechanism in which a pion is produced alongside the hyperon. Its relevance for antineutrinos with energies below 2 GeV is conveyed in integrated and differential cross sections. We observe that the distributions on the angle between the hyperon and the final lepton are clearly different for quasielastic and inelastic processes. Hyperon final -state interactions, modeled with an intranuclear cascade, lead to a significant transfer from primary produced E's into final A's. They also cause considerable energy loss, which is apparent in hyperon energy distributions. We have investigated A production off 40Ar in the conditions of the recently reported MicroBooNE measurement. We find that the A pi contribution, dominated by E*(1385) excitation, accounts for about one third of the cross section.  
  Address [Galan, M. Benitez; Simo, I. Ruiz] Univ Granada, Fac Ciencias, Dept Fis Atom Mol & Nucl, E-18071 Granada, Spain, Email: mbenitezgalan@ugr.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:001179626500005 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 6066  
Permanent link to this record
 
 
Author Wang, E.; Alvarez-Ruso, L.; Nieves, J. url  doi
openurl 
  Title Single photon events from neutral current interactions at MiniBooNE Type Journal Article
  Year 2015 Publication (up) Physics Letters B Abbreviated Journal Phys. Lett. B  
  Volume 740 Issue Pages 16-22  
  Keywords  
  Abstract The MiniBooNE experiment has reported results from the analysis of v(e) and (v) over bar (e) appearance searches, which show an excess of signal-like events at low reconstructed neutrino energies, with respect to the expected background. A significant component of this background comes from photon emission induced by (anti) neutrino neutral current interactions with nucleons and nuclei. With an improved microscopic model for these reactions, we predict the number and distributions of photon events at the MiniBooNE detector. Our results are compared to the MiniBooNE in situ estimate and to other theoretical approaches. We find that, according to our model, neutral current photon emission from single-nucleon currents is insufficient to explain the events excess observed by MiniBooNE in both neutrino and antineutrino modes.  
  Address [Wang, En; Alvarez-Ruso, Luis; Nieves, Juan] Univ Valencia, Ctr Mixto CSIC, Inst Fis Corpuscular IFIC, Inst Invest Paterna, E-46071 Valencia, Spain, Email: luis.alvarez@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 Medium  
  Area Expedition Conference  
  Notes WOS:000347046200003 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 2094  
Permanent link to this record
 
 
Author Ren, X.L.; Alvarez-Ruso, L.; Geng, L.S.; Ledwig, T.; Meng, J.; Vicente Vacas, M.J. url  doi
openurl 
  Title Consistency between SU(3) and SU(2) covariant baryon chiral perturbation theory for the nucleon mass Type Journal Article
  Year 2017 Publication (up) Physics Letters B Abbreviated Journal Phys. Lett. B  
  Volume 766 Issue Pages 325-333  
  Keywords Baryon chiral perturbation theory; Lattice QCD; Nucleon mass and sigma term  
  Abstract Treating the strange quark mass as a heavy scale compared to the light quark mass, we perform a matching of the nucleon mass in the SU(3) sector to the two-flavor case in covariant baryon chiral perturbation theory. The validity of the 19low-energy constants appearing in the octet baryon masses up to next-to-next-to-next-to-leading order[1] is supported by comparing the effective parameters (the combinations of the 19couplings) with the corresponding low-energy constants in the SU(2) sector[2]. In addition, it is shown that the dependence of the effective parameters and the pion-nucleon sigma term on the strange quark mass is relatively weak around its physical value, thus providing support to the assumption made in Ref.[2] that the SU(2) baryon chiral perturbation theory can be applied to study n(f) = 2 + 1lattice QCD simulations as long as the strange quark mass is close to its physical value.  
  Address [Ren, Xiu-Lei; Geng, Li-Sheng; Meng, Jie] Beihang Univ, Sch Phys & Nucl Energy Engn, Beijing 100191, Peoples R China, Email: lisheng.geng@buaa.edu.cn  
  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 Medium  
  Area Expedition Conference  
  Notes WOS:000396438300043 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3003  
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