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Author Aguilar, A.C.; Binosi, D.; Papavassiliou, J.
Title QCD effective charges from lattice data Type Journal Article
Year 2010 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 07 Issue 7 Pages 002 - 24pp
Keywords Nonperturbative Effects; QCD
Abstract (down) We use recent lattice data on the gluon and ghost propagators, as well as the Kugo-Ojima function, in order to extract the non-perturbative behavior of two particular definitions of the QCD effective charge, one based on the pinch technique construction, and one obtained from the standard ghost-gluon vertex. The construction relies crucially on the definition of two dimensionful quantities, which are invariant under the renormalization group, and are built out of very particular combinations of the aforementioned Green's functions. The main non-perturbative feature of both effective charges, encoded in the infrared finiteness of the gluon propagator and ghost dressing function used in their definition, is the freezing at a common finite (non-vanishing) value, in agreement with a plethora of theoretical and phenomenological expectations. We discuss the sizable discrepancy between the freezing values obtained from the present lattice analysis and the corresponding estimates derived from several phenomenological studies, and attribute its origin to the difference in the gauges employed. A particular toy calculation suggests that the modifications induced to the non-perturbative gluon propagator by the gauge choice may indeed account for the observed deviation of the freezing values.
Address [Aguilar, A. C.] Fed Univ ABC, CCNH, BR-09210170 Santo Andre, Brazil, Email: arlene.aguilar@ufabc.edu.br
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:000281504500002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 384
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Author Blanton, T.D.; Hanlon, A.D.; Ben Horz; Morningstar, C.; Romero-Lopez, F.; Sharpe, S.R.
Title Interactions of two and three mesons including higher partial waves from lattice QCD Type Journal Article
Year 2021 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 10 Issue 10 Pages 023 - 59pp
Keywords Lattice QCD; Scattering Amplitudes
Abstract (down) We study two- and three-meson systems composed either of pions or kaons at maximal isospin using Monte Carlo simulations of lattice QCD. Utilizing the stochastic LapH method, we are able to determine hundreds of two- and three-particle energy levels, in nine different momentum frames, with high precision. We fit these levels using the relativistic finite-volume formalism based on a generic effective field theory in order to determine the parameters of the two- and three-particle K-matrices. We find that the statistical precision of our spectra is sufficient to probe not only the dominant s-wave interactions, but also those in d waves. In particular, we determine for the first time a term in the three-particle K-matrix that contains two-particle d waves. We use three N-f = 2 + 1 CLS ensembles with pion masses of 200, 280, and 340 MeV. This allows us to study the chiral dependence of the scattering observables, and compare to the expectations of chiral perturbation theory.
Address [Blanton, Tyler D.; Sharpe, Stephen R.] Univ Washington, Phys Dept, Seattle, WA 98195 USA, Email: blantonl@uw.edu;
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:000704432600004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4991
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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 (down) 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
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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 (down) 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 Coppola, M.; Gomez Dumm, D.; Noguera, S.; Scoccola, N.N.
Title Magnetic field driven enhancement of the weak decay width of charged pions Type Journal Article
Year 2020 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 09 Issue 9 Pages 058 - 19pp
Keywords QCD Phenomenology
Abstract (down) We study the effect of a uniform magnetic field B on the decays pi- > l- nu_l bar, where l(-)=e(-), μ(-), carrying out a general analysis that includes four pi (-) decay constants. Taking the values of these constants from a chiral effective Nambu-Jona-Lasinio (NJL) model, it is seen that the total decay rate gets strongly increased with respect to the B = 0 case, with an enhancement factor ranging from similar to 10 for eB = 0.1 GeV2 up to similar to 10(3) for eB = 1 GeV2. The ratio between electronic and muonic decays gets also enhanced, reaching a value of about 1 : 2 for eB = 1 GeV2. In addition, we find that for large B the angular distribution of outgoing antineutrinos shows a significant suppression in the direction of the magnetic field.
Address [Coppola, Maximo; Scoccola, Norberto N.] Consejo Nacl Invest Cient & Tecn, Rivadavia 1917, RA-1033 Buenos Aires, DF, Argentina, Email: coppola@tandar.cnea.gov.ar;
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:000570908100001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4534
Permanent link to this record