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Author  |
Alvarez-Ruso, L.; Ledwig, T.; Martin Camalich, J.; Vicente Vacas, M.J. |
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Title |
Nucleon mass and pion-nucleon sigma term from a chiral analysis of lattice QCD data |
Type |
Journal Article |
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Year |
2013 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
88 |
Issue |
5 |
Pages |
054507 - 20pp |
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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. |
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Address |
[Alvarez-Ruso, L.] Univ Valencia, Ctr Mixto, CSIC, Inst Fis Corpuscular IFIC, E-46071 Valencia, Spain, Email: alvarez@ific.uv.es; |
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Publisher |
Amer Physical Soc |
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Language |
English |
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Edition |
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ISSN |
1550-7998 |
ISBN |
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Expedition |
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Conference |
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Notes |
WOS:000324636100005 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
1603 |
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Author |
Hiller Blin, A.N.; Gutsche, T.; Ledwig, T.; Lyubovitskij, V.E. |
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Title |
Hyperon forward spin polarizability gamma(0) in baryon chiral perturbation theory |
Type |
Journal Article |
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Year |
2015 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
92 |
Issue |
9 |
Pages |
096004 - 9pp |
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Keywords |
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Abstract |
We present the calculation of the hyperon forward spin polarizability gamma(0) using manifestly Lorentz-covariant baryon chiral perturbation theory including the intermediate contribution of the spin-3/2 states. As at the considered order the extraction of. 0 is a pure prediction of chiral perturbation theory, the obtained values are a good test for this theory. After including explicitly the decuplet states, our SU(2) results have a very good agreement with the experimental data and we extend our framework to SU(3) to give predictions for the hyperons'. 0 values. Prominent are the Sigma(-) and Xi(-) baryons as their photon transition to the decuplet is forbidden in SU(3) symmetry and therefore they are not sensitive to the explicit inclusion of the decuplet in the theory. |
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Address |
[Hiller Blin, Astrid; Ledwig, Tim] Univ Valencia, Dept Fis Teor, Valencia 46071, Spain, Email: astrid.blin@ific.uv.es |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Language |
English |
Summary Language |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1550-7998 |
ISBN |
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Conference |
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Notes |
WOS:000364020300009 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
2451 |
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Author |
Hiller Blin, A.N.; Ledwig, T.; Vicente Vacas, M.J. |
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Title |
Delta(1232) resonance in the (gamma)over-right-arrowp -> p pi(0) reaction at threshold |
Type |
Journal Article |
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Year |
2016 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
93 |
Issue |
9 |
Pages |
094018 - 19pp |
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Keywords |
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Abstract |
We calculate the neutral pion photoproduction on the proton near threshold in covariant baryon chiral perturbation theory, including the Delta(1232) resonance as an explicit degree of freedom, up to chiral order p(7/2) in the delta counting. We compare our results with recent low-energy data from the Mainz Microtron for angular distributions and photon asymmetries. The convergence of the chiral series of the covariant approach is found to improve substantially with the inclusion of the Delta(1232) resonance. |
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Address |
[Hiller Blin, A. N.] Univ Valencia, CSIC, Inst Invest Paterna, Dept Fis Teor,Ctr Mixto, E-46071 Valencia, Spain, Email: astrid.blin@ific.uv.es |
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Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2470-0010 |
ISBN |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000376256400002 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
2694 |
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Author |
Hiller Blin, A.N.; Ledwig, T.; Vicente Vacas, M.J. |
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Title |
Chiral dynamics in the (gamma)over-right-arrowp -> p pi(0) reaction |
Type |
Journal Article |
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Year |
2015 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
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Volume |
747 |
Issue |
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Pages |
217-222 |
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Keywords |
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Abstract |
We investigate the neutral pion photoproduction on the proton near threshold in covariant chiral perturbation theory with the explicit inclusion of A degrees of freedom. This channel is specially sensitive to chiral dynamics and the advent of very precise data from the Mainz microtron has shown the limits of the convergence of the chiral series for both the heavy baryon and the covariant approaches. We show that the inclusion of the Delta resonance substantially improves the convergence leading to a good agreement with data for a wider range of energies. |
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Address |
[Vicente Vacas, M. J.] Univ Valencia, Ctr Mixto, CSIC, Dept Fis Teor,Inst Invest Paterna, E-46071 Valencia, Spain, Email: manuel.j.vicente@uv.es |
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Corporate Author |
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Thesis |
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Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0370-2693 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000358624800038 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
2330 |
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Author |
Ledwig, T.; Martin Camalich, J.; Geng, L.S.; Vicente Vacas, M.J. |
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Title |
Octet-baryon axial-vector charges and SU(3)-breaking effects in the semileptonic hyperon decays |
Type |
Journal Article |
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Year |
2014 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
90 |
Issue |
5 |
Pages |
054502 - 16pp |
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Keywords |
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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. |
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Address |
[Ledwig, T.; Vicente Vacas, M. J.] Univ Valencia, CSIC, Inst Invest Paterna, Dept Fis Teor, Paterna 46980, Spain, Email: ledwig@ific.uv.es; |
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Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1550-7998 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000341264600001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
1899 |
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