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Author (down) 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 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 (down) 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 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 (down) 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 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 (down) Wang, E.; Alvarez-Ruso, L.; Nieves, J.
Title Photon emission in neutral-current interactions at intermediate energies Type Journal Article
Year 2014 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 89 Issue 1 Pages 015503 - 21pp
Keywords
Abstract Neutral-current photon emission reactions with nucleons and nuclei are studied. These processes are important backgrounds for nu(mu) -> nu(e) ((nu) over bar (mu) -> (nu) over bar (e)) appearance oscillation experiments where electromagnetic showers instigated by electrons (positrons) and photons are not distinguishable. At intermediate energies, these reactions are dominated by the weak excitation of the Delta(1232) resonance and its subsequent decay into N gamma. There are also nonresonant contributions that, close to threshold, are fully determined by the effective chiral Lagrangian of strong interactions. In addition, we have also included mechanisms mediated by nucleon excitations (N*) from the second resonance region above the Delta(1232). From these states, the contribution of the D-13 N*(1520) turns out to be sizable for (anti) neutrino energies above 1.5 GeV. We have extended the model to nuclear targets taking into account Pauli blocking, Fermi motion, and the in-medium Delta resonance broadening. We present our predictions for both the incoherent and coherent channels, showing the relevance of the nuclear corrections. We also discuss the target mass dependence of the cross sections. This study is important to reduce systematic effects in neutrino oscillation experiments.
Address [Wang, E.] Ctr Mixto Univ Valencia CSIC, Dept Fis Teor, 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 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000332159800010 Approved no
Is ISI yes International Collaboration
Call Number IFIC @ pastor @ Serial 1719
Permanent link to this record
 
 
Author (down) Wang, E.; Alvarez-Ruso, L.; Nieves, J.
Title Single photon events from neutral current interactions at MiniBooNE Type Journal Article
Year 2015 Publication 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 (down) Wang, E.; Alvarez-Ruso, L.; Hayato, Y.; Mahn, K.; Nieves, J.
Title Photon emission in neutral current interactions at the T2K experiment Type Journal Article
Year 2015 Publication 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 (down) Saul-Sala, E.; Sobczyk, J.E.; Rafi Alam, M.; Alvarez-Ruso, L.; Nieves, J.
Title Weak kaon production off the nucleon and Watson's theorem Type Journal Article
Year 2021 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 817 Issue Pages 136349 - 7pp
Keywords
Abstract We have improved the tree-level model of Ref.[1] for weak production of kaons off nucleons by partially restoring unitarity. This is achieved by imposing Watson's theorem to the dominant vector and axial-vector contributions in appropriate angular momentum and isospin quantum number sectors. The observable consequences of this procedure are investigated.
Address [Saul-Sala, E.; Alvarez-Ruso, L.; Nieves, J.] Univ Valencia, CSIC, Ctr Mixto, Inst Invest Paterna,Dept Fis Teor, E-46071 Valencia, Spain, Email: luis.alvarez@ific.uv.es
Corporate Author Thesis
Publisher Elsevier 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:000657652200060 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4867
Permanent link to this record
 
 
Author (down) Rocco, N.; Alvarez-Ruso, L.; Lovato, A.; Nieves, J.
Title Electromagnetic scaling functions within the Green's function Monte Carlo approach Type Journal Article
Year 2017 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 96 Issue 1 Pages 015504 - 12pp
Keywords
Abstract We have studied the scaling properties of the electromagnetic response functions of He-4 and C-12 nuclei computed by the Green's function Monte Carlo approach, retaining only the one-body current contribution. Longitudinal and transverse scaling functions have been obtained in the relativistic and nonrelativistic cases and compared to experiment for various kinematics. The characteristic asymmetric shape of the scaling function exhibited by data emerges in the calculations in spite of the nonrelativistic nature of the model. The results are mostly consistent with scaling of zeroth, first, and second kinds. Our analysis reveals a direct correspondence between the scaling and the nucleon-density response functions. The scaling function obtained from the proton-density response displays scaling of the first kind, even more evidently than the longitudinal and transverse scaling functions.
Address [Rocco, N.; Alvarez-Ruso, L.; Nieves, J.] Univ Valencia, CSIC, Ctr Mixto, Inst Fis Corpuscular IFIC, 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 2469-9985 ISBN Medium
Area Expedition Conference
Notes WOS:000406294000008 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3217
Permanent link to this record
 
 
Author (down) Ren, X.L.; Oset, E.; Alvarez-Ruso, L.; Vicente Vacas, M.J.
Title Antineutrino induced Lambda(1405) production off the proton Type Journal Article
Year 2015 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 91 Issue 4 Pages 045201 - 11pp
Keywords
Abstract We have studied the strangeness-changing antineutrino-induced reactions (v) over bar (l)p -> l(+)phi B, with phi B = K(-)p, (K) over bar (0)n, pi(0)Lambda, pi(0)Sigma(0), eta Lambda, eta Sigma(0), pi(+)Sigma(-), pi(-)Sigma(+), K+Xi(-), and K-0 Xi(0), using a chiral unitary approach. These ten coupled channels are allowed to interact strongly, using a kernel derived from the chiral Lagrangians. This interaction generates two Lambda(1405) poles, leading to a clear single peak in the pi Sigma invariant mass distributions. At backward scattering angles in the center-of-mass frame, (nu) over bar (mu)p -> mu(+)pi(0)Sigma(0) is dominated by the Lambda(1405) state at around 1420 MeV while the lighter state becomes relevant as the angle decreases, leading to an asymmetric line shape. In addition, there are substantial differences in the shape of pi Sigma invariant mass distributions for the three charge channels. If observed, these differences would provide valuable information on a claimed isospin I = 1, strangeness S = -1 baryonic state around 1400 MeV. Integrated cross sections have been obtained for the pi Sigma and (K) over barN channels and the impact of unitarization in the results has been investigated. The number of events with Lambda(1405) excitation in (nu) over bar μp collisions in the recent antineutrino run at the Main Injector Experiment for nu-A (MINER nu A) has also been obtained. We find that this reaction channel is relevant enough to be investigated experimentally and to be taken into account in the simulation models of future experiments with antineutrino beams.
Address [Ren, Xiu-Lei] Beihang Univ, Sch Phys & Nucl Energy Engn, Beijing 100191, Peoples R China, Email: xiulei.ren@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 0556-2813 ISBN Medium
Area Expedition Conference
Notes WOS:000352190300006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2191
Permanent link to this record
 
 
Author (down) Ren, X.L.; Alvarez-Ruso, L.; Geng, L.S.; Ledwig, T.; Meng, J.; Vicente Vacas, M.J.
Title Consistency between SU(3) and SU(2) covariant baryon chiral perturbation theory for the nucleon mass Type Journal Article
Year 2017 Publication 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
Permanent link to this record