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Author Binosi, D.; Ibañez, D.; Papavassiliou, J.
Title Nonperturbative study of the four gluon vertex Type Journal Article
Year 2014 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 09 Issue 9 Pages 059 - 32pp
Keywords Nonperturbative Effects; QCD; Confinement
Abstract In this paper we study the nonperturbative structure of the SU(3) four-gluon vertex in the Landau gauge, concentrating on contributions quadratic in the metric. We employ an approximation scheme where “one-loop” diagrams are computed using fully dressed gluon and ghost propagators, and tree-level vertices. When a suitable kinematical configuration depending on a single momentum scale p is chosen, only two structures emerge: the tree-level four-gluon vertex, and a tensor orthogonal to it. A detailed numerical analysis reveals that the form factor associated with this latter tensor displays a change of sign (zero-crossing) in the deep infrared, and finally diverges logarithmically. The origin of this characteristic behavior is proven to be entirely due to the masslessness of the ghost propagators forming the corresponding ghost-loop diagram, in close analogy to a similar effect established for the three-gluon vertex. However, in the case at hand, and under the approximations employed, this particular divergence does not affect the form factor proportional to the tree-level tensor, which remains finite in the entire range of momenta, and deviates moderately from its naive tree-level value. It turns out that the kinematic configuration chosen is ideal for carrying out lattice simulations, because it eliminates from the connected Green's function all one-particle reducible contributions, projecting out the genuine one-particle irreducible vertex. Motivated by this possibility, we discuss in detail how a hypothetical lattice measurement of this quantity would compare to the results presented here, and the potential interference from an additional tensorial structure, allowed by Bose symmetry, but not encountered within our scheme.
Address (up) [Binosi, D.; Ibanez, D.] European Ctr Theoret Studies Nucl Phys & Related, I-38123 Villazzano, TN, Italy, Email: binosi@ectstar.eu;
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:000342215400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1954
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Author Binosi, D.; Papavassiliou, J.
Title Gauge invariant Ansatz for a special three-gluon vertex Type Journal Article
Year 2011 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 03 Issue 3 Pages 121 - 23pp
Keywords Nonperturbative Effects; QCD
Abstract We construct a general Ansatz for the three-particle vertex describing the interaction of one background and two quantum gluons, by simultaneously solving the Ward and Slavnov-Taylor identities it satisfies. This vertex is known to be essential for the gauge-invariant truncation of the Schwinger-Dyson equations of QCD, based on the pinch technique and the background field method. A key step in this construction is the formal derivation of a set of crucial constraints (shown to be valid to all orders), relating the various form factors of the ghost Green's functions appearing in the aforementioned Slavnov-Taylor identity. When inserted into the Schwinger-Dyson equation for the gluon propagator, this vertex gives rise to a number of highly non-trivial cancellations, which are absolutely indispensable for the self-consistency of the entire approach.
Address (up) [Binosi, D.] European Ctr Theoret Studies Nucl Phys & Related, I-38123 Villazzano, TN, Italy, Email: binosi@ect.it
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:000289295300049 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 624
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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 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 (up) [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
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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 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 (up) [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 Blanton, T.D.; Romero-Lopez, F.; Sharpe, S.R.
Title Implementing the three-particle quantization condition for pi(+)pi K-+(+) and related systems Type Journal Article
Year 2022 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 02 Issue 2 Pages 098 - 49pp
Keywords Lattice QCD; Lattice Quantum Field Theory
Abstract Recently, the formalism needed to relate the finite-volume spectrum of systems of nondegenerate spinless particles has been derived. In this work we discuss a range of issues that arise when implementing this formalism in practice, provide further theoretical results that can be used to check the implementation, and make available codes for implementing the three-particle quantization condition. Specifically, we discuss the need to modify the upper limit of the cutoff function due to the fact that the left-hand cut in the scattering amplitudes for two nondegenerate particles moves closer to threshold; we describe the decomposition of the three-particle amplitude K-df,K-3 into the matrix basis used in the quantization condition, including both s and p waves, with the latter arising in the amplitude for two nondegenerate particles; we derive the threshold expansion for the lightest three-particle state in the rest frame up to O(1/L-5); and we calculate the leading-order predictions in chiral perturbation theory for K-df,K-3 in the pi(+)pi K-+(+) and pi+K+K+ systems. We focus mainly on systems with two identical particles plus a third that is different (“2+1” systems). We describe the formalism in full detail, and present numerical explorations in toy models, in particular checking that the results agree with the threshold expansion, and making a prediction for the spectrum of pi(+)pi K-+(+) levels using the two- and three-particle interactions predicted by chiral perturbation theory.
Address (up) [Blanton, Tyler D.] Univ Maryland, Dept Phys, College Pk, MD 20742 USA, Email: blantonl@umd.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:000755933600005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5134
Permanent link to this record