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Related papers: The pion-nucleon sigma term from Lattice QCD

200 papers

Consideration of the analytic properties of pion-induced baryon self-energies leads to new functional forms for the extrapolation of light baryon masses. These functional forms reproduce the leading non-analytic behavior of chiral…

High Energy Physics - Lattice · Physics 2009-07-09 D. B. Leinweber , A. W. Thomas , K. Tsushima , S. V. Wright

In this work, we employ the heavy hadron chiral perturbation theory (HHChPT) to calculate the $\Sigma_c\bar{D}^{(*)}$ potentials to the next-to-leading order. The contact, the one-pion exchange and the two-pion exchange interactions are…

High Energy Physics - Phenomenology · Physics 2019-08-07 Lu Meng , Bo Wang , Guang-Juan Wang , Shi-Lin Zhu

Chiral perturbation theory (ChPT) is an effective field theory that describes the properties of strongly-interacting systems at energies far below typical hadron masses. The degrees of freedom are hadrons instead of the underlying quarks…

High Energy Physics - Phenomenology · Physics 2022-12-27 Stefan Scherer , Matthias R. Schindler

We discuss the description of chiral imbalance imprint in pion matter. It is based on the Chiral Perturbation Theory supplemented by medium induced chiral chemical potential in the covariant derivative. Such an implementation of chiral…

High Energy Physics - Phenomenology · Physics 2019-07-02 A. A. Andrianov , V. A. Andrianov , D. Espriu

We employ a novel method to analyze Euclidean correlation functions entering the calculation of hadron energies in lattice QCD. The method is based on the sampling of all possible solutions allowed by the spectral decomposition of the…

High Energy Physics - Lattice · Physics 2015-06-23 C. Alexandrou , T. Leontiou , C. N. Papanicolas , E. Stiliaris

We review the failure of lowest order chiral $SU(3)_L \times SU(3)_R$ perturbation theory $\chi$PT$_3$ to account for amplitudes involving the $f_0(500)$ resonance and $O(m_K)$ extrapolations in momenta. We summarize our proposal to replace…

High Energy Physics - Phenomenology · Physics 2015-02-25 R. J. Crewther , Lewis C. Tunstall

Heavy baryon chiral perturbation theory including spin 3/2 delta resonances as effective degrees of freedom is reviewed. The theory admits a systematic expansion in the small scale $\epsilon$, where $\epsilon$ collectively denotes soft…

High Energy Physics - Phenomenology · Physics 2009-10-30 Joachim Kambor

I discuss low-energy pion-nucleon scattering in the framework of chiral perturbation theory. I argue that using this theoretical method one is able to handle the in some cases tremendous experimental accuracy (for the low partial waves). I…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ulf-G. Meißner

We investigate the excited states of the nucleon using $N_f=2$ twisted mass gauge configurations with pion masses in the range of about 270 MeV to 450 MeV and one ensemble of $N_f=2$ Clover fermions at almost physical pion mass. We use two…

High Energy Physics - Lattice · Physics 2014-02-12 C. Alexandrou , T. Korzec , G. Koutsou , T. Leontiou

Lattice QCD has matured to a degree where it is now possible to study excited hadrons as they truly appear in nature, as short-lived resonant enhancements decaying into multiple possible final states. Through variational analysis of…

High Energy Physics - Lattice · Physics 2018-09-21 Jozef J. Dudek

We examine the behavior of charged pions in neutron-rich matter using heavy-baryon chiral perturbation theory. This study is motivated by the prospect that pions, or pion-like excitations, may be relevant in neutron-rich matter encountered…

Nuclear Theory · Physics 2023-10-12 Bryce Fore , Norbert Kaiser , Sanjay Reddy , Neill C. Warrington

We study the effects of the $\Delta$(1232) resonance as an effective degree of freedom for charged and neutral pion photo-production on nucleons. Different observables have been calculated for these processes by using relativistic chiral…

High Energy Physics - Phenomenology · Physics 2019-11-27 Gustavo H. Guerrero Navarro

By employing a twisted mass term, we compare recent results from lattice calculations of Nf=2 dynamical Wilson fermions with Wilson Chiral Perturbation Theory (WChPT). The final goal is to determine some combinations of Gasser-Leutwyler Low…

High Energy Physics - Lattice · Physics 2010-12-23 L. Scorzato , F. Farchioni , P. Hofmann , K. Jansen , I. Montvay , G. Munster , M. Papinutto , E. E. Scholz , A. Shindler , N. Ukita , C. Urbach , U. Wenger , I. Wetzorke

We calculate finite size effects on nucleon masses in chiral perturbation theory. We confront the theoretical predictions with N_f=2 lattice results and discuss chiral extrapolation formulae.

High Energy Physics - Lattice · Physics 2009-09-29 A. Ali Khan , T. Bakeyev , M. Göckeler , T. R. Hemmert , R. Horsley , A. C. Irving , D. Pleiter , P. E. L. Rakow , G. Schierholz , H. Stüben

We use one-loop chiral perturbation theory (ChPT) to compare lattice results for the K+ to pi+ pi0 decay amplitude with the experimental value. Three systematic effects: quenching, finite-volume effects, and the use of unphysical values of…

High Energy Physics - Lattice · Physics 2009-10-30 Maarten Golterman , Ka Chun Leung

Among the sources of systematic error in nucleon structure calculations is contamination from unwanted excited states. In order to measure this systematic error, we vary the operator insertion time and source-sink separation independently.…

High Energy Physics - Lattice · Physics 2012-03-23 Jeremy Green , Stefan Krieg , John Negele , Andrew Pochinsky , Sergey Syritsyn

A non-zero signal $A_\gamma^\mathrm{np}=(-3.0\pm1.4\pm0.2)\times 10^{-8}$ of the gamma-ray asymmetry in the neutron-proton capture was recently reported by the NPDGamma Collaboration which provides the first determination of the $\Delta…

Nuclear Theory · Physics 2019-01-18 Feng-Kun Guo , Chien-Yeah Seng

I review recent progress made in the description of pion-nucleon scattering, the $\sigma$--term, the scalar form factor and the strangeness content of the nucleon in the framework of heavy baryon chiral perturbation theory. Other topics are…

High Energy Physics - Phenomenology · Physics 2011-04-15 Ulf-G. Meißner

In QCD with two massless quarks, the chiral phase transition is plausibly in the same universality class as the classical O(4) magnet. To test this hypothesis, critical exponents characterizing the behaviour of universal quantities near the…

High Energy Physics - Phenomenology · Physics 2016-11-03 Krishna Rajagopal

The talk contains a short introduction to mesonic Chiral Perturbation Theory (ChPT). In addition four disparate areas where some progress has been made in recent years are discussed. These are the last fit of the order $p^4$…

High Energy Physics - Phenomenology · Physics 2013-01-30 Johan Bijnens