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Author Garofalo, M.; Romero-Lopez, F.; Rusetsky, A.; Urbach, C.
Title (down) Testing a new method for scattering in finite volume in the phi(4) theory Type Journal Article
Year 2021 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 81 Issue 11 Pages 1034 - 5pp
Keywords
Abstract We test an alternative proposal by Bruno and Hansen (J High Energy Phys 2021(6), https://doi.org/10.1007/JHEP06(2021)043, 2021) to extract the scattering length from lattice simulations in a finite volume. For this, we use a scalar phi(4) theory with two mass nondegenerate particles and explore various strategies to implement this new method. We find that the results are comparable to those obtained from the Luscher method, with somewhat smaller statistical uncertainties at larger volumes.
Address [Garofalo, Marco; Rusetsky, Akaki; Urbach, Carsten] Rheinische Friedrich Wilhelms Univ Bonn, HISKP Theory, Nussallee 14-16, D-53115 Bonn, Germany, Email: garofalo@hiskp.uni-bonn.de
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:000722881700006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5035
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Author Drach, V.; Fritzsch, P.; Rago, A.; Romero-Lopez, F.
Title (down) Singlet channel scattering in a composite Higgs model on the lattice Type Journal Article
Year 2022 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 82 Issue 1 Pages 47 - 10pp
Keywords
Abstract We present the first calculation of the scattering amplitude in the singlet channel beyond QCD. The calculation is performed in SU(2) gauge theory with N-f = 2 fundamental Dirac fermions and based on a finite-volume scattering formalism. The theory exhibits a SU (4) -> Sp(4) chiral symmetry breaking pattern that is used to design minimal composite Higgs models currently tested at the LHC. Our results show that, for the range of underlying fermion mass considered, the lowest flavour singlet state is stable.
Address [Drach, Vincent; Fritzsch, Patrick; Rago, Antonio] Univ Plymouth, Ctr Math Sci, Plymouth PL4 8AA, Devon, England, 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:000744537400008 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5097
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Author Fischer, M.; Kostrzewa, B.; Liu, L.M.; Romero-Lopez, F.; Ueding, M.; Urbach, C.
Title (down) 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 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 Romero-Lopez, F.; Rusetsky, A.; Schlage, N.; Urbach, C.
Title (down) 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 Romero-Lopez, F.; Sharpe, S.R.; Blanton, T.D.; Briceno, R.A.; Hansen, M.T.
Title (down) 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