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Author Baeza-Ballesteros, J.; Hernandez, P.; Romero-Lopez, F.
Title A lattice study of pi pi scattering at large N-c Type Journal Article
Year 2022 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 06 Issue (down) 6 Pages 049 - 39pp
Keywords Hadronic Spectroscopy; Structure and Interactions; Lattice QCD; 1/N Expansion; Chiral Lagrangian
Abstract We present the first lattice study of pion-pion scattering with varying number of colors, N-c. We use lattice simulations with four degenerate quark flavors, N-f = 4, and N-c= 3 – 6. We focus on two scattering channels that do not involve vacuum diagrams. These correspond to two irreducible representations of the SU(4) flavor group: the fully symmetric one, SS, and the fully antisymmetric one, AA. The former is a repulsive channel equivalent to the isospin-2 channel of SU(2). By contrast, the latter is attractive and only exists for N-f >= 4. A representative state is (vertical bar D-s(+) pi(+)> – vertical bar D+ K+ >) /root 2. Using Lfischer's formalism, we extract the near-threshold scattering amplitude and we match our results to Chiral Perturbation Theory (ChPT) at large N-c. For this, we compute the analytical U(N-f) ChPT prediction for two-pion scattering, and use the lattice results to constrain the N-c scaling of the relevant low-energy couplings.
Address [Baeza-Ballesteros, Jorge; Hernandez, Pilar; Romero-Lopez, Fernando] Univ Valencia, CSIC, IFIC, Paterna 46980, Spain, Email: jorge.baeza@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:000809342900001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5258
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Author Fischer, M.; Kostrzewa, B.; Liu, L.M.; Romero-Lopez, F.; Ueding, M.; Urbach, C.
Title Scattering of two and three physical pions at maximal isospin from lattice QCD Extended Twisted Mass Collaboration Type Journal Article
Year 2021 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 81 Issue (down) 5 Pages 436 - 19pp
Keywords
Abstract We present the first direct N-f = 2 lattice QCD computation of two- and three-pi(+) scattering quantities that includes an ensemble at the physical point. We study the quark mass dependence of the two-pion phase shift, and the three-particle interaction parameters. We also compare to phenomenology and chiral perturbation theory (ChPT). In the two-particle sector, we observe good agreement to the phenomenological fits in s- and d-wave, and obtain M(pi)a(0) = -0.0481(86) at the physical point from a direct computation. In the three-particle sector, we observe reasonable agreement at threshold to the leading order chiral expansion, i.e. a mildly attractive three-particle contact term. In contrast, we observe that the energy-dependent part of the three-particle quasilocal scattering quantity is not well described by leading order ChPT.
Address [Fischer, Matthias; Ueding, Martin; Urbach, Carsten] Univ Bonn, Helmholtz Inst Strahlen & Kernphys, D-53115 Bonn, Germany, 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 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000680425500003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4900
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Author Baeza-Ballesteros, J.; Bijnens, J.; Husek, T.; Romero-Lopez, F.; Sharpe, S.R.; Sjo, M.
Title The isospin-3 three-particle K-matrix at NLO in ChPT Type Journal Article
Year 2023 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 05 Issue (down) 5 Pages 187 - 56pp
Keywords Chiral Lagrangian; Hadronic Spectroscopy; Structure and Interactions; Lattice QCD
Abstract The three-particle K-matrix, K-df,K-3, is a scheme-dependent quantity that parametrizes short-range three-particle interactions in the relativistic-field-theory three particle finite-volume formalism. In this work, we compute its value for systems of three pions at maximal isospin through next-to-leading order (NLO) in Chiral Perturbation Theory (ChPT). We compare the values to existing lattice QCD results and find that the agreement between lattice QCD data and ChPT in the first two coefficients of the threshold expansion of K-df,K-3 is significantly improved with respect to leading order once NLO effects are incorporated.
Address [Baeza-Ballesteros, Jorge] Univ Valencia, IFIC, CSIC, Paterna 46980, Spain, Email: jorge.baeza@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:000994292300001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5540
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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 (down) 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 Blanton, T.D.; Romero-Lopez, F.; Sharpe, S.R.
Title Implementing the three-particle quantization condition including higher partial waves Type Journal Article
Year 2019 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 03 Issue (down) 3 Pages 106 - 56pp
Keywords Lattice QCD; Lattice Quantum Field Theory; Scattering Amplitudes
Abstract We present an implementation of the relativistic three-particle quantization condition including both s- and d-wave two-particle channels. For this, we develop a systematic expansion of the three-particle K matrix, K-df,K-3, about threshold, which is the generalization of the effective range expansion of the two-particle K matrix, K-2. Relativistic invariance plays an important role in this expansion. We find that d-wave two-particle channels enter first at quadratic order. We explain how to implement the resulting multichannel quantization condition, and present several examples of its application. We derive the leading dependence of the threshold three-particle state on the two-particle d-wave scattering amplitude, and use this to test our implementation. We show how strong two-particle d-wave interactions can lead to significant effects on the finite-volume three-particle spectrum, including the possibility of a generalized three-particle Efimov-like bound state. We also explore the application to the 3 pi(+) system, which is accessible to lattice QCD simulations, where we study the sensitivity of the spectrum to the components of K-df,K-3. Finally, we investigate the circumstances under which the quantization condition has unphysical solutions.
Address [Blanton, Tyler D.; Sharpe, Stephen R.] Univ Washington, Dept Phys, 3910 15th Ave NE, Seattle, WA 98195 USA, Email: blanton1@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:000462325900001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3953
Permanent link to this record