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The distribution of the sum of 1-dependent lattice vectors with supports on coordinate axes is approximated by a multivariate compound Poisson distribution and by signed compound Poisson measure. The local and $\ell_\alpha$-norms are used…

Probability · Mathematics 2020-09-11 V. Čekanavičius , P. Vellaisamy

The PAC-Bayesian approach is a powerful set of techniques to derive non- asymptotic risk bounds for random estimators. The corresponding optimal distribution of estimators, usually called the Gibbs posterior, is unfortunately intractable.…

Machine Learning · Statistics 2015-06-16 Pierre Alquier , James Ridgway , Nicolas Chopin

A unified set of predictions for pion and kaon elastic electromagnetic and gravitational form factors is obtained using a symmetry-preserving truncation of each relevant quantum field equation. A key part of the study is a description of…

High Energy Physics - Phenomenology · Physics 2023-11-28 Yin-Zhen Xu , Minghui Ding , Khépani Raya , Craig D. Roberts , José Rodríguez-Quintero , Sebastian M. Schmidt

Motivated by the planned measurements of the time-like electromagnetic proton form factors an exploratory study of the time-like electromagnetic pion form factor is presented in a formalism which describes mesons as Poincar\'e-invariant…

High Energy Physics - Phenomenology · Physics 2022-07-20 Reinhard Alkofer , Angel S. Miramontes , Helios Sanchis-Alepuz

A symmetry-preserving approach to the two valence-body continuum bound-state problem is used to calculate the elastic electromagnetic form factors of the $\rho$-meson and subsequently to study the evolution of vector-meson form factors with…

This exposition explains the basic ideas of Stein's method for Poisson random variable approximation and Poisson process approximation from the point of view of the immigration-death process and Palm theory. The latter approach also enables…

Probability · Mathematics 2007-05-23 Louis H. Y. Chen , Aihua Xia

We present an update on our lattice calculations of the Mellin moments of PDFs and GPDs for the pion and kaon, using momentum-boosted meson states. In particular, we focus on the calculation of the scalar and tensor local operators, and the…

High Energy Physics - Lattice · Physics 2024-01-09 Joseph Delmar , Constantia Alexandrou , Simone Bacchio , Ian Cloët , Martha Constantinou , Giannis Koutsou

The gradient expansion of the kinetic energy functional, when applied for atoms or finite systems, usually grossly overestimates the energy in the fourth order and generally diverges in the sixth order. We avoid the divergence of the…

Quantum Physics · Physics 2015-08-28 A. Sergeev , R. Jovanovic , S. Kais , F. H. Alharbi

In this paper we give a historical account of the development of Poisson approximation using Stein's method and present some of the main results. We give two recent applications, one on maximal arithmetic progressions and the other on…

Probability · Mathematics 2013-10-09 Louis H. Y. Chen , Adrian Röllin

A continuous approximation for the results of [1] is obtained. In this approximation the energy distribution is represented in the form of the product of the Gibbs factor and superstatistics factor. The mutual weights of the factors are…

Chemical Physics · Physics 2007-05-23 V. V. Ryazanov

An important task in computational statistics and machine learning is to approximate a posterior distribution $p(x)$ with an empirical measure supported on a set of representative points $\{x_i\}_{i=1}^n$. This paper focuses on methods…

The meson (pion and kaon) form factor is calculated in the perturbative framework with alternative forms for the running coupling constant and the gluon propagator in the infrared kinematic region. These modified forms are employed to test…

High Energy Physics - Phenomenology · Physics 2009-11-07 M. B. Gay Ducati , W. K. Sauter

We show that the evolution equation of the effective potential in the auxiliary mass method corresponds to a leading approximation of a certain series. This series is derived from an evolution equation of an effective action using a…

High Energy Physics - Phenomenology · Physics 2009-10-31 K. Ogure , J. Sato

A method to determine masses, widths and coupling constants of vector mesons, like phi(1020), omega(782) and rho0(770) recurrences is defined. Starting from data on decay rates and cross sections for the processes: phi -> M_I gamma, phi ->…

High Energy Physics - Phenomenology · Physics 2008-12-18 S. Pacetti

We obtain Stein approximation bounds for stochastic integrals with respect to a Poisson random measure over ${\Bbb R}^d$, $d\geq 2$. This approach relies on third cumulant Edgeworth-type expansions based on derivation operators defined by…

Probability · Mathematics 2018-06-04 Nicolas Privault

As is well known, in mathematics, any function could be approximated by the Pad\'e approximant. The Pad\'e approximant is the best approximation of a function by a rational function of given order. In fact, the Pad\'e approximant often…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-05 Hao Wei , Xiao-Peng Yan , Ya-Nan Zhou

We report results on the $\pi$-$\gamma$ transition form factor obtained within the hard scattering approach including transverse momentum effects and Sudakov corrections. The results clearly favor distribution amplitudes close to the…

High Energy Physics - Phenomenology · Physics 2009-09-25 R. Jakob , P. Kroll , M. Raulfs

We consider how to extract the pion form factors in the epsilon regime. Using the correlators with non-zero momenta and taking appropriate ratios of them, we eliminate the dominant finite volume effect from the zero-momentum pion mode. Our…

High Energy Physics - Lattice · Physics 2012-11-06 JLQCD Collaboration , H. Fukaya , S. Aoki , S. Hashimoto , T. Kaneko , H. Matsufuru , J. Noaki , T. Onogi , N. Yamada

Under the framework of the vector meson dominance model (VMD), the absolute scattering lengths of light vector mesons ($\phi$, $\omega$, and $\rho$) with the deuteron are calculated from the cross sections of vector meson photoproduction…

High Energy Physics - Phenomenology · Physics 2024-07-04 Xiao-Yun Wang , Chen Dong , Quanjin Wang

We construct a systematic expansion for full QCD. The leading term gives the valence (quenched) approximation.

High Energy Physics - Lattice · Physics 2008-02-03 J. Sexton , D. Weingarten