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Related papers: Pion Pressure in a Magnetic Field

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The magnetic polarisability is a fundamental property of hadrons, which provides insight into their structure in the low-energy regime. The pion magnetic polarisability is calculated using lattice QCD in the presence of background magnetic…

High Energy Physics - Lattice · Physics 2020-11-09 Ryan Bignell , Waseem Kamleh , Derek Leinweber

We explore the low-energy regime of quantum chromodynamics subjected to an external magnetic field by deriving the two-loop representations for the entropy density and the magnetization within chiral perturbation theory (CHPT). At fixed…

High Energy Physics - Phenomenology · Physics 2021-08-04 Christoph P. Hofmann

The pattern of chiral symmetry breaking is exploited to compute vector and axial-vector pion matrix elements in a uniform magnetic field. Our results are model independent, and thereby constitute low-energy theorems that must be obeyed by…

High Energy Physics - Phenomenology · Physics 2024-06-04 Prabal Adhikari , Brian C. Tiburzi

We consider the thermodynamics of three-flavor QCD in the pion-condensed phase at nonzero isospin chemical potential ($\mu_I$) and vanishing temperature using chiral perturbation theory in the isospin limit. The transition from the vacuum…

High Energy Physics - Phenomenology · Physics 2020-06-01 Prabal Adhikari , Jens O. Andersen

The fermionic dispersion relation in the presence of a background magnetic field and a high temperature QED plasma is calculated exactly in the external field, using the Hard Thermal Loop effective action. As the field strength increases…

High Energy Physics - Phenomenology · Physics 2009-10-28 Per Elmfors

The comparison of chiral perturbation theory formulae with data from lattice QCD simulations is discussed. Observables in the pion sector as well as in the baryon sector are considered, including the nucleon mass in a finite volume.

High Energy Physics - Lattice · Physics 2007-05-23 M. Göckeler

We present a formula that allows one to calculate the pion form factor in the timelike region 2mpi <= sqrt{s} <= 4mpi in lattice QCD. The form factor quantifies the contribution of two-pion states to the vacuum polarization. It must be…

High Energy Physics - Lattice · Physics 2012-04-04 Harvey B. Meyer

By extending the $\Phi$-derivable approach in Nambu-Jona-Lasinio model to finite magnetic field we calculate the properties of pion, $\sigma$ and $\rho$ mesons in a magnetic field at finite temperature in not only the quark-antiquark bound…

High Energy Physics - Phenomenology · Physics 2016-07-13 Rui Zhang , Wei-jie Fu , Yu-xin Liu

The magnetic polarizability of the neutral pion has been calculated in the background magnetic-field formalism of Lattice QCD. In this investigation, the chiral extrapolation of these lattice results is considered in a formalism preserving…

Nuclear Theory · Physics 2021-01-04 Fangcheng He , D. B. Leinweber , A. W. Thomas , P. Wang

We use dispersive techniques to address the behavior of the pion form factor as $Q^2 \to \infty$ and $Q^2 \to 0$. We perform the matching with the constraints of perturbative QCD and chiral perturbation theory in the high energy and low…

High Energy Physics - Phenomenology · Physics 2011-07-19 John F. Donoghue , Euy Soo Na

A review of photo-pion experiments on the nucleon in the near threshold region is presented. Comparisons of the results are made with the predictions of the low energy theorems of QCD calculated using chiral perturbation theory (ChPT) which…

Nuclear Experiment · Physics 2009-12-15 Aron M. Bernstein , Mohammad W. Ahmed , Sean Stave , Ying K. Wu , Henry R. Weller

We present a calculation of pion electromagnetic and scalar form factors in two-flavor QCD with the non-perturbatively O(a)-improved Wilson fermion. Chiral extrapolation of the corresponding charge radius is discussed based on the chiral…

A brief discussion of the elastic pion-pion scattering amplitude to two loops in chiral perturbation theory is given. Some technical details of the evaluation of two-loop diagrams are addressed, and results relevant for the pionium decay…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. E. Sainio

We study the combined effects of a finite volume and an external magnetic field on the charged two-pion correlation function. For these purposes, we consider a dilute system of pions where the finite volume effects are introduced computing…

High Energy Physics - Phenomenology · Physics 2022-03-14 Alejandro Ayala , Santiago Bernal-Langarica , Cristian Villavicencio

We derive a novel model-independent result for the pion susceptibility in QCD via the isovector-pseudoscalar vacuum polarisation. In the neighbourhood of the chiral-limit, the pion susceptibility can be expressed as a sum of two independent…

Nuclear Theory · Physics 2014-11-20 Lei Chang , Yu-Xin Liu , Craig D. Roberts , Yuan-Mei Shi , Wei-Min Sun , Hong-Shi Zong

We develop an extension of chiral perturbation theory to the $\Delta$(1232)-resonance energy region and apply it to investigate the pion electroproduction off the nucleon ($e^- N \to e^- N\pi$). We present a complete calculation of this…

High Energy Physics - Phenomenology · Physics 2008-11-26 Vladimir Pascalutsa , Marc Vanderhaeghen

We compute the electromagnetic form factor of a "pion" with mass m_pi=330MeV at low values of Q^2\equiv -q^2, where q is the momentum transfer. The computations are performed in a lattice simulation using an ensemble of the RBC/UKQCD…

High Energy Physics - Lattice · Physics 2009-01-06 P. A. Boyle , J. M. Flynn , A. Juttner , C. Kelly , H. Pedroso de Lima , C. M. Maynard , C. T. Sachrajda , J. M. Zanotti

The pion decay constant and mass are computed at low temperature within Chiral Perturbation Theory to two loops. The effects of the breaking of Lorentz Symmetry by the thermal equilibrium state are discussed. The validity of the Gell-Mann…

High Energy Physics - Phenomenology · Physics 2016-08-25 D. Toublan

We investigate the real-time dynamics of the chiral magnetic effect in quantum electrodynamics (QED) and quantum chromodynamics (QCD). We consider a field configuration of parallel (chromo)electric and (chromo)magnetic fields with a weak…

High Energy Physics - Theory · Physics 2015-03-20 Harmen J. Warringa

Chiral perturbation theory makes definitive predictions for the extrinsic behavior of hadrons in external electric and magnetic fields. Near the chiral limit, the electric and magnetic polarizabilities of pions, kaons, and nucleons are…

High Energy Physics - Lattice · Physics 2015-05-30 W. Detmold , B. C. Tiburzi , A. Walker-Loud