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Author Alvarez-Ruso, L.; Ledwig, T.; Martin Camalich, J.; Vicente Vacas, M.J.
Title Nucleon mass and pion-nucleon sigma term from a chiral analysis of lattice QCD data Type Journal Article
Year 2013 Publication 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 (up) 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000324636100005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1603
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Author Gran, R.; Nieves, J.; Sanchez, F.; Vicente Vacas, M.J.
Title Neutrino-nucleus quasi-elastic and 2p2h interactions up to 10 GeV Type Journal Article
Year 2013 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 88 Issue 11 Pages 113007 - 10pp
Keywords
Abstract We extend to 10 GeV results from a microscopic calculation of charged-current neutrino-nucleus reactions that do not produce a pion in the final state. For the class of events coming from neutrino interactions with two nucleons producing two holes (2p2h), limiting the calculation to three-momentum transfers less than 1.2 GeV produces a two-dimensional distribution in momentum and energy transfer that is roughly constant as a function of energy. The cross section for 2p2h interactions approximately scales with the number of nucleons for isoscalar nuclei, similar to the quasi-elastic cross section. When limited to momentum transfers below 1.2 GeV, the cross section is 26% of the quasi-elastic cross section at 3 GeV, but 14% if we neglect a Delta(1232) resonance absorption component. The same quantities are 33% and 17% for antineutrinos. For the quasi-elastic interactions, the full nuclear model with long range correlations produces an even larger, but approximately constant distortion of the shape of the four-momentum transfer at all energies above 2 GeV. The 2p2h enhancement and long-range correlation distortions to the cross section for these interactions are significant enough they should be observable in precision experiments to measure neutrino oscillations and neutrino interactions at these energies, but also balance out and produce less total distortion than each effect does individually.
Address [Gran, R.] Univ Minnesota, Dept Phys, Duluth, MN 55812 USA
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 (up) 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000328692000001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1666
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Author Ledwig, T.; Martin Camalich, J.; Geng, L.S.; Vicente Vacas, M.J.
Title Octet-baryon axial-vector charges and SU(3)-breaking effects in the semileptonic hyperon decays Type Journal Article
Year 2014 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 90 Issue 5 Pages 054502 - 16pp
Keywords
Abstract The octet-baryon axial-vector charges and the g(1)/f(1) ratios measured in the semileptonic hyperon decays are studied up to O(p(3)) using the covariant baryon chiral perturbation theory with explicit decuplet contributions. We clarify the role of different low-energy constants and find a good convergence for the chiral expansion of the axial-vector charges of the baryon octet, g(1)(0), with O(p(3)) corrections typically around 20% of the leading ones. This is a consequence of strong cancellations between different next-to-leading- order terms. We show that considering only nonanalytic terms is not enough and that analytic terms appearing at the same chiral order play an important role in this description. The same effects still hold for the chiral extrapolation of the axial-vector charges and result in a rather mild quark-mass dependence. As a result, we report a determination of the leading-order chiral couplings, D = 0.623(61)(17) and F = 0.441(47)(2), as obtained from a completely consistent chiral analysis up to O(p(3)). Furthermore, we note that the appearance of an unknown low-energy constant precludes the extraction of the proton octet charge from semileptonic decay data alone, which is relevant for an analysis of the composition of the proton spin.
Address [Ledwig, T.; Vicente Vacas, M. J.] Univ Valencia, CSIC, Inst Invest Paterna, Dept Fis Teor, Paterna 46980, Spain, Email: ledwig@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 (up) 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000341264600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1899
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Author Alvarez-Ruso, L.; Hernandez, E.; Nieves, J.; Vicente Vacas, M.J.
Title Watson's theorem and the N Delta(1232) axial transition Type Journal Article
Year 2016 Publication 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 (up) 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000368324700003 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 2521
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Author Cabrera, D.; Hiller Blin, A.N.; Vicente Vacas, M.J.
Title phi meson self-energy in nuclear matter from phi N resonant interactions Type Journal Article
Year 2017 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 95 Issue 1 Pages 015201 - 9pp
Keywords
Abstract The phi-meson properties in cold nuclear matter are investigated by implementing resonant phi N interactions as described in effective approaches including the unitarization of scattering amplitudes. Several N*-like states are dynamically generated in these models around 2 GeV, in the vicinity of the phi N threshold. We find that both these states and the non-resonant part of the amplitude contribute sizably to the phi collisional self-energy at finite nuclear density. These contributions are of a similar strength as the widely studied medium effects from the KK cloud. Depending on model details (position of the resonances and strength of the coupling to phi N) we report a phi broadening up to about 40-50 MeV, to be added to the phi -> KK in-medium decay width, and an attractive optical potential at threshold up to about 35 MeV at normal matter density. The phi spectral function develops a double peak structure as a consequence of the mixing of resonance-hole modes with the phi quasiparticle peak. The former results point in the direction of making up for missing absorption as reported in phi nuclear production experiments.
Address [Cabrera, D.; Hiller Blin, A. N.; Vicente Vacas, M. J.] Univ Valencia, CSIC, Inst Fis Corpuscular, Inst Invest, Apartado Correos 22085, 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 (up) 2469-9985 ISBN Medium
Area Expedition Conference
Notes WOS:000391859600005 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 2920
Permanent link to this record