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We exploit a method introduced recently to determine parton distribution amplitudes (PDAs) from minimal information in order to obtain light-quark pseudoscalar and vector meson PDAs from the limited number of moments produced by numerical…

We study QED in external electromagnetic fields using methods developed for simulating lattice QCD. Our first project is to simulate QED in a constant (in space and time) external magnetic field on a euclidean space-time lattice using the…

High Energy Physics - Lattice · Physics 2021-11-04 D. K. Sinclair , J. B. Kogut

Point-to-point vacuum correlation functions for spatially separated hadron currents are calculated in quenched lattice QCD on a $16^3\times 24$ lattice with $6/g^2=5.7$. The lattice data are analyzed in terms of dispersion relations, which…

High Energy Physics - Lattice · Physics 2008-11-26 M. -C. Chu , J. M. Grandy , S. Huang , J. W. Negele

We propose a lattice-QCD-suitable framework for computing the two-photon long-distance contribution to the complex $K_{\rm L}\rightarrow\mu^+\mu^-$ decay amplitude, where QED is treated perturbatively in the continuum and infinite-volume.…

High Energy Physics - Lattice · Physics 2023-12-22 En-Hung Chao , Norman H. Christ , Xu Feng , Luchang Jin

In lattice QCD it is possible, in principle, to determine the parameters in the effective chiral lagrangian (including weak interaction couplings) by performing numerical simulations in the $\epsilon$--regime, i.e. at quark masses where the…

High Energy Physics - Lattice · Physics 2011-07-19 L. Giusti , C. Hoelbling , M. Lüscher , H. Wittig

A new method based on the concept of probability distribution is proposed to analyze the finite volume energy spectrum in lattice QCD. Using synthetic lattice data, we demonstrate that for the channel with quantum numbers of the…

High Energy Physics - Lattice · Physics 2012-06-13 Veronique Bernard , Michael Lage , Ulf-G. Meißner , Akaki Rusetsky

A method for computing electromagnetic properties of hadrons in lattice QCD is applied to the extraction of electromagnetic properties of the octet baryons. This allows a determination of the full dependence of the baryon masses on the…

High Energy Physics - Lattice · Physics 2009-10-28 A. Duncan , E. Eichten , H. Thacker

Lattice QCD determinations appropriate to hadron spectroscopy are reviewed with emphasis on the glueball and hybrid meson states in the quenched approximation. Hybrids are discussed for heavy and for light quarks. The effects of sea quarks…

High Energy Physics - Phenomenology · Physics 2008-11-26 Chris Michael

We use lattice QCD calculations of the finite-volume spectra of systems of two and three mesons to determine, for the first time, three-particle scattering amplitudes with physical quark masses. Our results are for combinations of $\pi^+$…

A novel proposal is outlined to determine scattering amplitudes from finite-volume spectral functions. The method requires extracting smeared spectral functions from finite-volume Euclidean correlation functions, with a particular complex…

High Energy Physics - Lattice · Physics 2019-09-04 John Bulava , Maxwell T. Hansen

We demonstrate that the leading and next-to-leading finite-volume effects in the evaluation of leptonic decay widths of pseudoscalar mesons at $O(\alpha)$ are universal, i.e. they are independent of the structure of the meson. This is…

High Energy Physics - Lattice · Physics 2017-03-01 V. Lubicz , G. Martinelli , C. T. Sachrajda , F. Sanfilippo , S. Simula , N. Tantalo

The complex patterns of the hadronic spectrum have puzzled physicists since the early discovery of the "particle zoo" in the 1960s. Today, the properties of these myriad particles are understood to be the result of quantum chromodynamics…

High Energy Physics - Lattice · Physics 2011-11-23 Huey-Wen Lin

In this talk, I discuss methods that allow for a systematic and model-independent calculation of the hadron spectrum. These are lattice QCD and/or its corresponding Effective Field Theories. Assorted results are shown and I take the…

Nuclear Theory · Physics 2020-09-23 Ulf-G. Meißner

Lattice QCD is rapidly progressing toward being able to reliably compute the electric dipole moment of the neutron as a function of the strong CP-violating parameter theta. Present day calculations are performed at unphysical values of the…

High Energy Physics - Lattice · Physics 2014-11-17 Donal O'Connell , Martin J. Savage

We develop a method to compute inclusive semi-leptonic decay rate of hadrons fully non-perturbatively using lattice QCD simulations. The sum over all possible final states is achieved by a calculation of the forward-scattering matrix…

High Energy Physics - Lattice · Physics 2020-07-22 Paolo Gambino , Shoji Hashimoto

We calculate the spectrum of transfer matrix eigenvalues associated with Polyakov loops in finite-density lattice QCD with static quarks. These eigenvalues determine the spatial behavior of Polyakov loop correlations functions. Our results…

High Energy Physics - Lattice · Physics 2016-05-11 Hiromichi Nishimura , Michael C. Ogilvie , Kamal Pangeni

The computation of dynamical properties of nuclear matter, ranging from parton distribution functions of nucleons and nuclei to transport properties in the quark-gluon plasma, constitutes a central goal of modern theoretical physics. This…

High Energy Physics - Lattice · Physics 2023-08-03 Alexander Rothkopf

We present a non-perturbative lattice calculation of the form factors which contribute to the amplitudes for the radiative decays $P\to \ell \bar \nu_\ell \gamma$, where $P$ is a pseudoscalar meson and $\ell$ is a charged lepton. Together…

High Energy Physics - Lattice · Physics 2021-01-13 A. Desiderio , R. Frezzotti , M. Garofalo , D. Giusti , M. Hansen , V. Lubicz , G. Martinelli , C. T. Sachrajda , F. Sanfilippo , S. Simula , N. Tantalo

In Ref [1] we have presented the results of an exploratory lattice QCD computation of the long-distance contribution to the $K^+\to\pi^+\nu\bar{\nu}$ decay amplitude. In the present paper we describe the details of this calculation, which…

High Energy Physics - Lattice · Physics 2018-10-24 Ziyuan Bai , Norman H. Christ , Xu Feng , Andrew Lawson , Antonin Portelli , Christopher T. Sachrajda

We show that inconsistency between background field methods, which are relevant for lattice QCD spectroscopy, and effective field theory matching conditions, which are obtained from scattering amplitudes, can be resolved by augmenting…

High Energy Physics - Lattice · Physics 2014-11-05 Jong-Wan Lee , Brian C. Tiburzi