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Author Bertone, V.; Carrasco, N.; Ciuchini, M.; Dimopoulos, P.; Frezzotti, R.; Gimenez, V.; Lubicz, V.; Martinelli, G.; Mescia, F.; Papinutto, M.; Rossi, G.C.; Silvestrini, L.; Simula, S.; Tarantino, C.; Vladikas, A.
Title Kaon mixing beyond the SM from N-f=2 tmQCD and model independent constraints from the UTA Type Journal Article
Year 2013 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 03 Issue 3 Pages 089 - 53pp
Keywords Lattice QCD; Beyond Standard Model
Abstract We present the first unquenched, continuum limit, lattice QCD results for the matrix elements of the operators describing neutral kaon oscillations in extensions of the Standard Model. Owing to the accuracy of our calculation on Delta S = 2 weak Hamiltonian matrix elements, we are able to provide a refined Unitarity Triangle analysis improving the bounds coming from model independent constraints on New Physics. In our non-perturbative computation we use a combination of N-f = 2 maximally twisted sea quarks and Osterwalder-Seiler valence quarks in order to achieve both O(a)-improvement and continuum-like renormalization properties for the relevant four-fermion operators. The calculation of the renormalization constants has been performed non-perturbatively in the RI-MOM scheme. Based on simulations at four values of the lattice spacing and a number of quark masses we have extrapolated/interpolated our results to the continuum limit and physical light/strange quark masses.
Address Univ Freiburg, Inst Phys, D-79104 Freiburg, Germany, Email: valerio.bertone@cern.ch;
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:000317522400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1438
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Author Bernardoni, F.; Blossier, B.; Bulava, J.; Della Morte, M.; Fritzsch, P.; Garron, N.; Gerardin, A.; Heitger, J.; von Hippel, G.; Simma, H.; Sommer, R.
Title Decay constants of B-mesons from non-perturbative HQET with two light dynamical quarks Type Journal Article
Year 2014 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 735 Issue Pages 349-356
Keywords Lattice QCD; Heavy Quark Effective Theory; Bottom quarks; Meson decay
Abstract We present a computation of B-meson decay constants from lattice QCD simulations within the framework of Heavy Quark Effective Theory for the b-quark. The next-to-leading order corrections in the HQET expansion are included non-perturbatively. Based on N-f = 2 gauge field ensembles, covering three lattice spacings a approximate to (0.08-0.05) fm and pion masses down to 190 MeV, a variational method for extracting hadronic matrix elements is used to keep systematic errors under control. In addition we perform a careful autocorrelation analysis in the extrapolation to the continuum and to the physical pion mass limits. Our final results read f(B) = 186(13) MeV, f(Bs) = 224(14) MeV and f(Bs)/f(B) = 1.203(65). A comparison with other results in the literature does not reveal a dependence on the number of dynamical quarks, and effects from truncating HQET appear to be negligible.
Address [Bernardoni, Fabio; Simma, Hubert; Sommer, Rainer] NIC DESY, D-15738 Zeuthen, Germany
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 WOS:000340048900061 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1881
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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 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 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 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 Romero-Lopez, F.; Sharpe, S.R.; Blanton, T.D.; Briceno, R.A.; Hansen, M.T.
Title Numerical exploration of three relativistic particles in a finite volume including two-particle resonances and bound states Type Journal Article
Year 2019 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 10 Issue 10 Pages 007 - 43pp
Keywords Lattice QCD; Scattering Amplitudes
Abstract In this work, we use an extension of the quantization condition, given in ref. [1], to numerically explore the finite-volume spectrum of three relativistic particles, in the case that two-particle subsets are either resonant or bound. The original form of the relativistic three-particle quantization condition was derived under a technical assumption on the two-particle K matrix that required the absence of two-particle bound states or narrow two-particle resonances. Here we describe how this restriction can be lifted in a simple way using the freedom in the definition of the K-matrix-like quantity that enters the quantization condition. With this in hand, we extend previous numerical studies of the quantization condition to explore the finite-volume signature for a variety of two- and three-particle interactions. We determine the spectrum for parameters such that the system contains both dimers (two-particle bound states) and one or more trimers (in which all three particles are bound), and also for cases where the two-particle subchannel is resonant. We also show how the quantization condition provides a tool for determining infinite-volume dimer-particle scattering amplitudes for energies below the dimer breakup. We illustrate this for a series of examples, including one that parallels physical deuteron-nucleon scattering. All calculations presented here are restricted to the case of three identical scalar particles.
Address [Romero-Lopez, Fernando] Univ Valencia, CSIC, IFIC, Paterna 46980, Spain, Email: fernando.romero@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:000497979000001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4207
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Author Hansen, M.T.; Romero-Lopez, F.; Sharpe, S.R.
Title Generalizing the relativistic quantization condition to include all three-pion isospin channels Type Journal Article
Year 2020 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 07 Issue 7 Pages 047 - 49pp
Keywords Lattice QCD; Scattering Amplitudes
Abstract We present a generalization of the relativistic, finite-volume, three-particle quantization condition for non-identical pions in isosymmetric QCD. The resulting formalism allows one to use discrete finite-volume energies, determined using lattice QCD, to constrain scattering amplitudes for all possible values of two- and three-pion isospin. As for the case of identical pions considered previously, the result splits into two steps: the first defines a non-perturbative function with roots equal to the allowed energies, E-n(L), in a given cubic volume with side-length L. This function depends on an intermediate three-body quantity, denoted K-df;3, which can thus be constrained from lattice QCD input. The second step is a set of integral equations relating K-df,K-3 to the physical scattering amplitude, M-3. Both of the key relations, E-n(L) <-> K-df,K-3 and K-df,K-3 <-> M-3, are shown to be block-diagonal in the basis of definite three-pion isospin, I-pi pi pi, so that one in fact recovers four independent relations, corresponding to I-pi pi pi = 0; 1; 2; 3. We also provide the generalized threshold expansion of K-df,K-3 for all channels, as well as parameterizations for all three-pion resonances present for I-pi pi pi = 0 and I-pi pi pi = 1. As an example of the utility of the generalized formalism, we present a toy implementation of the quantization condition for I-pi pi pi = 0, focusing on the quantum numbers of the omega and h(1) resonances.
Address [Hansen, Maxwell T.] Univ Geneva, Theoret Phys Dept, CH-1211 Geneva 23, Switzerland, Email: maxwell.hansen@cern.ch;
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:000551981200002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4474
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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 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
Permanent link to this record
 

 
Author Romero-Lopez, F.; Rusetsky, A.; Schlage, N.; Urbach, C.
Title Relativistic N-particle energy shift in finite volume Type Journal Article
Year 2021 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 02 Issue 2 Pages 060 - 52pp
Keywords Lattice QCD; Lattice Quantum Field Theory
Abstract We present a general method for deriving the energy shift of an interacting system of N spinless particles in a finite volume. To this end, we use the nonrelativistic effective field theory (NREFT), and match the pertinent low-energy constants to the scattering amplitudes. Relativistic corrections are explicitly included up to a given order in the 1/L expansion. We apply this method to obtain the ground state of N particles, and the first excited state of two and three particles to order L-6 in terms of the threshold parameters of the two- and three-particle relativistic scattering amplitudes. We use these expressions to analyze the N-particle ground state energy shift in the complex phi (4) theory.
Address [Romero-Lopez, Fernando] Univ Valencia, CSIC, IFIC, Paterna 46980, Spain, Email: fernando.romero@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:000617678000002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4711
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Author Hansen, M.T.; Romero-Lopez, F.; Sharpe, S.R.
Title Decay amplitudes to three hadrons from finite-volume matrix elements Type Journal Article
Year 2021 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 04 Issue 4 Pages 113 - 44pp
Keywords Lattice QCD; Kaon Physics
Abstract We derive relations between finite-volume matrix elements and infinite-volume decay amplitudes, for processes with three spinless, degenerate and either identical or non-identical particles in the final state. This generalizes the Lellouch-Luscher relation for two-particle decays and provides a strategy for extracting three-hadron decay amplitudes using lattice QCD. Unlike for two particles, even in the simplest approximation, one must solve integral equations to obtain the physical decay amplitude, a consequence of the nontrivial finite-state interactions. We first derive the result in a simplified theory with three identical particles, and then present the generalizations needed to study phenomenologically relevant three-pion decays. The specific processes we discuss are the CP-violating K -> 3 pi weak decay, the isospin-breaking eta -> 3 pi QCD transition, and the electromagnetic gamma (*) -> 3 pi amplitudes that enter the calculation of the hadronic vacuum polarization contribution to muonic g – 2.
Address [Hansen, Maxwell T.] Univ Edinburgh, Sch Phys & Astron, Higgs Ctr Theoret Phys, Edinburgh EH9 3FD, Midlothian, Scotland, Email: maxwell.hansen@ed.ac.uk;
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:000640574400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4789
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Author Aguilar, A.C.; De Soto, F.; Ferreira, M.N.; Papavassiliou, J.; Rodriguez-Quintero, J.
Title Infrared facets of the three-gluon vertex Type Journal Article
Year 2021 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 818 Issue Pages 136352 - 7pp
Keywords QCD; Three-gluon vertex; Lattice QCD; Schwinger-Dyson equations
Abstract We present novel lattice results for the form factors of the quenched three-gluon vertex of QCD, in two special kinematic configurations that depend on a single momentum scale. We consider three form factors, two associated with a classical tensor structure and one without tree-level counterpart, exhibiting markedly different infrared behaviors. Specifically, while the former display the typical suppression driven by a negative logarithmic singularity at the origin, the latter saturates at a small negative constant. These exceptional features are analyzed within the Schwinger-Dyson framework, with the aid of special relations obtained from the Slavnov-Taylor identities of the theory. The emerging picture of the underlying dynamics is thoroughly corroborated by the lattice results, both qualitatively as well as quantitatively.
Address [Aguilar, A. C.; Ferreira, M. N.] Univ Estadual Campinas, Inst Phys Gleb Wataghin, UNICAMP, BR-13083859 Campinas, SP, Brazil, Email: jose.rodriguez@dfaie.uhu.es
Corporate Author Thesis
Publisher Elsevier 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 WOS:000662629500036 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4865
Permanent link to this record