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Author Bernard, V.; Passemar, E.
Title Chiral extrapolation of the strangeness changing scalar K pi form factor Type Journal Article
Year 2010 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 04 Issue 4 Pages 001 - 18pp
Keywords Lattice QCD; Chiral Lagrangians
Abstract (up) We perform a chiral extrapolation of lattice data on the scalar K pi form factor and the ratio of the kaon and pion decay constants within Chiral Perturbation Theory to two loops. We determine the value of the scalar form factor at zero momentum transfer, at the Callan-Treiman point and at its soft kaon analog as well as its slope. Results are in good agreement with their determination from experiment using the standard couplings of quarks to the W boson. The slope is however rather large. A study of the convergence of the chiral expansion is also performed.
Address [Bernard, Veronique] Univ Paris 11, Grp Phys Theor, IPN, CNRS, F-91406 Orsay, France, Email: bernard@ipno.in2p3.fr
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 1126-6708 ISBN Medium
Area Expedition Conference
Notes ISI:000277473100070 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 456
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Author Pich, A.; Rosell, I.; Sanz-Cillero, J.J.
Title One-loop calculation of the oblique S parameter in higgsless electroweak models Type Journal Article
Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 08 Issue 8 Pages 106 - 34pp
Keywords Higgs Physics; Beyond Standard Model; Chiral Lagrangians; Technicolor and Composite Models
Abstract (up) We present a one-loop calculation of the oblique S parameter within Higgsless models of electroweak symmetry breaking and analyze the phenomenological implications of the available electroweak precision data. We use the most general effective Lagrangian with at most two derivatives, implementing the chiral symmetry breaking SU(2)(L) circle times SU(2)(R) -> SU(2)(L+R) with Goldstones, gauge bosons and one multiplet of vector and axial-vector massive resonance states. Using the dispersive representation of Peskin and Takeuchi and imposing the short-distance constraints dictated by the operator product expansion, we obtain S at the NLO in terms of a few resonance parameters. In asymptotically-free gauge theories, the final result only depends on the vector-resonance mass and requires M-V > 1.8TeV (3.8TeV) to satisfy the experimental limits at the 3 sigma (1 sigma) level; the axial state is always heavier, we obtain M-A > 2.5TeV (6.6TeV) at 3 sigma (1 sigma). In strongly-coupled models, such as walking or conformal technicolour, where the second Weinberg sum rule does not apply, the vector and axial couplings are not determined by the short-distance constraints; but one can still derive a lower bound on S, provided the hierarchy M-V < M-A remains valid. Even in this less constrained situation, we find that in order to satisfy the experimental limits at 3 sigma one needs M-V,M-A > 1.8TeV.
Address [Pich, A.; Rosell, I.] Univ Valencia, CSIC, IFIC, Dept Fis Teor, 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 1126-6708 ISBN Medium
Area Expedition Conference
Notes WOS:000309883200063 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 1217
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Author Bernardoni, F.; Hernandez, P.; Necco, S.
Title Heavy-light mesons in the epsilon-regime Type Journal Article
Year 2010 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 01 Issue 1 Pages 070 - 30pp
Keywords Lattice QCD; Heavy Quark Physics; Chiral Lagrangians
Abstract (up) We study the finite-size scaling of heavy-light mesons in the static limit. We compute two-point functions of chiral current densities as well as pseudoscalar densities in the epsilon-regime of heavy meson Chiral Perturbation Theory (HMChPT). As expected, finite volume dependence turns out to be significant in this regime and can be predicted in the effective theory in terms of the infinite-volume low-energy couplings. These results might be relevant for extraction of heavy-meson properties from lattice simulations.
Address [Bernardoni, F.; Hernandez, P.] Univ Valencia, Dpto Fis Teor, E-46071 Valencia, Spain, Email: fabio.bernardoni@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 1126-6708 ISBN Medium
Area Expedition Conference
Notes ISI:000273717700041 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 510
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Author Albaladejo, M.; Oller, J.A.; Oset, E.; Rios, G.; Roca, L.
Title Finite volume treatment of pi pi scattering and limits to phase shifts extraction from lattice QCD Type Journal Article
Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 08 Issue 8 Pages 071 - 22pp
Keywords Lattice QCD; Chiral Lagrangians; Phenomenological Models
Abstract (up) We study theoretically the effects of finite volume for pi pi scattering in order to extract physical observables for infinite volume from lattice QCD. We compare three different approaches for pi pi scattering (lowest order Bethe-Salpeter approach, N/D and inverse amplitude methods) with the aim of studying the effects of the finite size of the box in the potential of the different theories, specially the left-hand cut contribution through loops in the crossed t, u-channels. We quantify the error made by neglecting these effects in usual extractions of physical observables from lattice ()CD spectrum. We conclude that for pi pi phase-shifts in the scalar-isoscalar channel up to 800 MeV this effect is negligible for box sizes bigger than 2,5m(pi)(-1) and of the order of 5% at around 1.5 – 2m(pi)(-1). For isospin 2 the finite size effects can reach up to 10% for that energy. We also quantify the error made when using the standard Luscher method to extract physical observables from lattice QCD, which is widely used in the literature but is an approximation of the one used in the present work.
Address [Albaladejo, M.; Oller, J. A.; Rios, G.; Roca, L.] Univ Murcia, Dept Fis, E-30100 Murcia, Spain, Email: albaladejo@um.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 1126-6708 ISBN Medium
Area Expedition Conference
Notes WOS:000309883600014 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 1214
Permanent link to this record