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Author Molina, R.; Ruiz de Elvira, J.
Title Light- and strange-quark mass dependence of the rho(770) meson revisited Type Journal Article
Year 2020 Publication (up) Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 11 Issue 11 Pages 017 - 74pp
Keywords Chiral Lagrangians; Lattice QCD
Abstract Recent lattice data on pi pi -scattering phase shifts in the vector-isovector channel, pseudoscalar meson masses and decay constants for strange-quark masses smaller or equal to the physical value allow us to study the strangeness dependence of these observables for the first time. We perform a global analysis on two kind of lattice trajectories depending on whether the sum of quark masses or the strange-quark mass is kept fixed to the physical point. The quark mass dependence of these observables is extracted from unitarized coupled-channel one-loop Chiral Perturbation Theory. This analysis guides new predictions on the rho (770) meson properties over trajectories where the strange-quark mass is lighter than the physical mass, as well as on the SU(3) symmetric line. As a result, the light- and strange-quark mass dependence of the rho (770) meson parameters are discussed and precise values of the Low Energy Constants present in unitarized one-loop Chiral Perturbation Theory are given. Finally, the current discrepancy between two- and three-flavor lattice results for the rho (770) meson is studied.
Address [Molina, R.] Ctr Mixto Univ Valencia CSIC, Dept Fis Teor, Inst Invest Paterna, Aptdo 22085, Valencia 46071, Spain, Email: raqumoli@ucm.es;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000591048300001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4615
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Author Pich, A.; Rodriguez-Sanchez, A.
Title SU(3) analysis of four-quark operators: K -> pi pi and vacuum matrix elements Type Journal Article
Year 2021 Publication (up) Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 06 Issue 6 Pages 005 - 43pp
Keywords Chiral Lagrangians; CP violation; Effective Field Theories; Kaon Physics
Abstract Hadronic matrix elements of local four-quark operators play a central role in non-leptonic kaon decays, while vacuum matrix elements involving the same kind of operators appear in inclusive dispersion relations, such as those relevant in tau -decay analyses. Using an SU(3)(L) circle times SU(3)(R) decomposition of the operators, we derive generic relations between these matrix elements, extending well-known results that link observables in the two different sectors. Two relevant phenomenological applications are presented. First, we determine the electroweak-penguin contribution to the kaon CP-violating ratio epsilon '/epsilon, using the measured hadronic spectral functions in tau decay. Second, we fit our SU(3) dynamical parameters to the most recent lattice data on K -> pi pi matrix elements. The comparison of this numerical fit with results from previous analytical approaches provides an interesting anatomy of the Delta I = 1/2 enhancement, confirming old suggestions about its underlying dynamical origin.
Address [Pich, A.] Univ Valencia, CSIC, IFIC, Dept Fis Teor, Edifici Inst Paterna,Apt Correus 22085, E-46071 Valencia, Spain, Email: Antonio.Pich@ific.uv.es;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000762295200001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5148
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Author Alarcon, J.M.; Hiller Blin, A.N.; Vicente Vacas, M.J.; Weiss, C.
Title Peripheral transverse densities of the baryon octet from chiral effective field theory and dispersion analysis Type Journal Article
Year 2017 Publication (up) Nuclear Physics A Abbreviated Journal Nucl. Phys. A
Volume 964 Issue Pages 18-54
Keywords Electromagnetic form factors; Chiral lagrangians; Dispersion relations; Hyperons; Charge distribution
Abstract The baryon electromagnetic form factors are expressed in terms of two-dimensional densities describing the distribution of charge and magnetization in transverse space at fixed light-front time. We calculate the transverse densities of the spin-1/2 flavor-octet baryons at peripheral distances b = O(M-pi(-1)) using methods of relativistic chiral effective field theory (chi EFT) and dispersion analysis. The densities are represented as dispersive integrals over the imaginary parts of the form factors in the timelike region (spectral functions). The isovector spectral functions on the two-pion cut t > 4 M-pi(2) are calculated using relativistic chi EFT including octet and decuplet baryons. The chi EFT calculations are extended into the rho meson mass region using an N / D method that incorporates the pion electromagnetic form factor data. The isoscalar spectral functions are modeled by vector meson poles. We compute the peripheral charge and magnetization densities in the octet baryon states, estimate the uncertainties, and determine the quark flavor decomposition. The approach can be extended to baryon form factors of other operators and the moments of generalized parton distributions.
Address [Alarcon, J. M.] Univ Bonn, Helmholtz Inst Strahlen & Kernphys, D-53115 Bonn, Germany, Email: alarcon@jlab.org
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 0375-9474 ISBN Medium
Area Expedition Conference
Notes WOS:000404199900002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3188
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Author Gomez Dumm, D.; Roig, P.; Pich, A.; Portoles, J.
Title tau -> pi pi pi nu(tau) decays and the a(1)(1260) off-shell width revisited Type Journal Article
Year 2010 Publication (up) Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 685 Issue 2-3 Pages 158-164
Keywords Hadron tau decays; Chiral Lagrangians; QCD; 1/N expansion
Abstract The tau -> pi pi pi nu(tau) decay is driven by the hadronization of the axial-vector current. Within the resonance chiral theory, and considering the large-N-C expansion, this process has been studied in Ref. [1] (D. Gomez Dumm, A. Pich, J. Portoles, 2004). In the light of later developments we revise here this previous work by including a new off-shell width for the lightest a(1) resonance that provides a good description of the tau -> pi pi pi nu(tau) spectrum and branching ratio. We also consider the role of the rho(1450) resonance in these observables. Thus we bring in an overall description of the tau -> pi pi pi nu(tau) process in excellent agreement with our present experimental knowledge.
Address [Pich, A.; Portoles, J.] Univ Valencia, CSIC, Dept Fis Teor, IFIC, E-46071 Valencia, Spain, Email: Jorge.Portoles@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 ISI:000275148800010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 488
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