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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 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
Permanent link to this record
 
 
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
Permanent link to this record
 
 
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
Permanent link to this record
 
 
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
Permanent link to this record
 
 
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
Permanent link to this record
 
 
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
Permanent link to this record
 
 
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 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
 
 
Author Ayala, C.; Cvetic, G.; Kogerler, R.
Title Lattice-motivated holomorphic nearly perturbative QCD Type Journal Article
Year 2017 Publication Journal of Physics G Abbreviated Journal J. Phys. G
Volume 44 Issue 7 Pages 075001 - 30pp
Keywords perturbative QCD; lattice QCD; QCD phenomenology; resummation
Abstract Newer lattice results indicate that, in the Landau gauge at low spacelike momenta, the gluon propagator and the ghost dressing function are finite non-zero. This leads to a definition of the QCD running coupling, in a specific scheme, that goes to zero at low spacelike momenta. We construct a running coupling which fulfills these conditions, and at the same time reproduces to a high precision the perturbative behavior at high momenta. The coupling is constructed in such a way that it reflects qualitatively correctly the holomorphic (analytic) behavior of spacelike observables in the complex plane of the squared momenta, as dictated by the general principles of quantum field theories. Further, we require the coupling to reproduce correctly the nonstrange semihadronic decay rate of tau lepton which is the best measured low-momentum QCD observable with small higher-twist effects. Subsequent application of the Borel sum rules to the V + A spectral functions of tau lepton decays, as measured by OPAL Collaboration, determines the values of the gluon condensate and of the V + A six-dimensional condensate, and reproduces the data to a significantly higher precision than the usual (MS) over bar running coupling.
Address [Ayala, Cesar] Univ Valencia, Dept Theoret Phys, E-46100 Valencia, Spain, Email: Gorazd.Cvetic@usm.cl
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0954-3899 ISBN Medium
Area Expedition Conference
Notes WOS:000402509800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3167
Permanent link to this record
 
 
Author Ren, X.L.; Alvarez-Ruso, L.; Geng, L.S.; Ledwig, T.; Meng, J.; Vicente Vacas, M.J.
Title Consistency between SU(3) and SU(2) covariant baryon chiral perturbation theory for the nucleon mass Type Journal Article
Year 2017 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 766 Issue Pages 325-333
Keywords Baryon chiral perturbation theory; Lattice QCD; Nucleon mass and sigma term
Abstract Treating the strange quark mass as a heavy scale compared to the light quark mass, we perform a matching of the nucleon mass in the SU(3) sector to the two-flavor case in covariant baryon chiral perturbation theory. The validity of the 19low-energy constants appearing in the octet baryon masses up to next-to-next-to-next-to-leading order[1] is supported by comparing the effective parameters (the combinations of the 19couplings) with the corresponding low-energy constants in the SU(2) sector[2]. In addition, it is shown that the dependence of the effective parameters and the pion-nucleon sigma term on the strange quark mass is relatively weak around its physical value, thus providing support to the assumption made in Ref.[2] that the SU(2) baryon chiral perturbation theory can be applied to study n(f) = 2 + 1lattice QCD simulations as long as the strange quark mass is close to its physical value.
Address [Ren, Xiu-Lei; Geng, Li-Sheng; Meng, Jie] Beihang Univ, Sch Phys & Nucl Energy Engn, Beijing 100191, Peoples R China, Email: lisheng.geng@buaa.edu.cn
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:000396438300043 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3003
Permanent link to this record