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Related papers: Effective Field Theory Approach to Pionium

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In this work, the self energies of $\pi^0$ and $\pi^{\pm}$ up to one loop order have been calculated in the limit of weak external magnetic field. The effective masses are explicitly dependent on the magnetic field which are modified…

Nuclear Theory · Physics 2018-07-02 S. P. Adhya , M. Mandal , S. Biswas , P. K. Roy

A relativistic hadronic model for nuclear matter and finite nuclei, which incorporates nonlinear chiral symmetry and broken scale invariance, is presented and applied at the one-baryon-loop level to finite nuclei. The model contains an…

High Energy Physics - Phenomenology · Physics 2016-09-01 R. J. Furnstahl , Hua-Bin Tang , Brian D. Serot

We perform a relativistic chiral effective-field theory calculation of the pion electroproduction off the nucleon ($e^- N \to e^- N \pi$) in the Delta(1232)-resonance region. After fixing the three low-energy constants, corresponding to the…

High Energy Physics - Phenomenology · Physics 2014-11-18 Vladimir Pascalutsa , Marc Vanderhaeghen

These lectures introduce some of the basic notions of effective field theories, as used in particle physics. The topics discussed are the $\Delta S=1$ and $\Delta S =2$ weak interactions, and chiral perturbation theory as applied to mesons,…

High Energy Physics - Phenomenology · Physics 2007-05-23 Aneesh V. Manohar

We develop interactions from chiral effective field theory (EFT) that are tailored to the harmonic oscillator basis. As a consequence, ultraviolet convergence with respect to the model space is implemented by construction and infrared…

Nuclear Theory · Physics 2016-05-02 S. Binder , A. Ekström , G. Hagen , T. Papenbrock , K. A. Wendt

We consider the electroweak chiral Lagrangian, including a light scalar boson, in the limit of small $\xi=v^2/f^2$. Here $v$ is the electroweak scale and $f$ is the corresponding scale of the new strong dynamics. We show how the…

High Energy Physics - Phenomenology · Physics 2015-06-23 Gerhard Buchalla , Oscar Cata , Claudius Krause

An effective field theory approach is developed for calculating the thermodynamic properties of a field theory at high temperature $T$ and weak coupling $g$. The effective theory is the 3-dimensional field theory obtained by dimensional…

High Energy Physics - Phenomenology · Physics 2016-09-01 Eric Braaten , Agustin Nieto

In view of its relation to Big-Bang Nucleo-Synthesis and a reported discrepancy between nuclear models and data taken at S-DALINAC, electro-induced deuteron break-up 2H(e,e' p)n is studied at momentum transfer q<100MeV and close to…

Nuclear Theory · Physics 2008-11-26 Stefan Christlmeier , Harald W. Griesshammer

In this talk the $Q$ counting scheme to implement effective field theory is discussed. It is pointed out that there are two small mass scales in the problem $m_\pi$ and $1/a$ with $1/a \ll m_\pi$. It is argued that while the expansion based…

Nuclear Theory · Physics 2007-05-23 Thomas D. Cohen

Abst\-ract: A hierarchy of effective three-dimensional theories of finite temperature electroweak matter is studied. First an integration over non-static modes leads to an effective theory containing a gauge field $A_{i}^{a}$, an adjoint…

High Energy Physics - Phenomenology · Physics 2009-10-22 A. Jakovác , K. Kajantie , A. Patkós

The physics of pions within a finite volume is explored using lattice regularized chiral perturbation theory. This regularization scheme permits a straightforward computational approach to be used in place of analytical continuum…

High Energy Physics - Lattice · Physics 2009-11-10 B. Borasoy , R. Lewis

A system of fermions with short-range interactions at finite density is studied using the framework of effective field theory. The effective action formalism for fermions with auxiliary fields leads to a loop expansion in which…

Nuclear Theory · Physics 2009-11-07 R. J. Furnstahl , H. -W. Hammer

The properties of the effective field theory relevant for the low energy structure generated by the Goldstone bosons of a spontaneously broken symmetry are reexamined. It is shown that anomaly free, Lorentz invariant theories are…

High Energy Physics - Phenomenology · Physics 2009-10-22 H. Leutwyler

Progress in the Effective Field Theory of two and three nucleon systems is sketched, concentrating mainly on the low energy version in which pions are integrated out as explicit degrees of freedom. Examples given are: the extraction of…

Nuclear Theory · Physics 2009-11-07 Harald W. Griesshammer

We present an effective field theory of the $\Delta$-resonance as an interacting Weinberg's $(3/2,0)\oplus (0,3/2)$ field in the multi-spinor formalism. We derive its interactions with nucleons $N$, pions $\pi$ and photons $\gamma$, and…

High Energy Physics - Phenomenology · Physics 2021-06-18 Juan Carlos Criado , Abdelhak Djouadi , Niko Koivunen , Kristjan Müürsepp , Martti Raidal , Hardi Veermäe

In this paper, we employ chiral effective field theory to study the process of electron-positron annihilation into four pions in the low energy region within $E_{c.m.}\leq 0.6$ GeV. The prediction of the cross section is obtained through…

High Energy Physics - Phenomenology · Physics 2026-05-19 Jia-Yu Zhou , Hao-Xiang Pan , Ling-Yun Dai

We use chiral perturbation theory for SU(2) to compute the leading corrections to the thermal mass of the pions and the pion decay constant in the presence of the magnetic field in a low-temperature expansion. The magnetic field gives rise…

High Energy Physics - Phenomenology · Physics 2012-08-02 Jens O. Andersen

Low-energy nuclear structure and reactions can be described in a systematically improvable way using the framework of chiral effective field theory. This requires solving the quantum mechanical many-body problem with regularized nuclear…

Nuclear Theory · Physics 2023-12-22 Hermann Krebs , Evgeny Epelbaum

Lecture Notes, Summer School on Effective Theories and Fundamental Interactions, Erice, 1996. The application of effective field theory methods to the low energy structure of QCD is discussed. I emphasize the universal structure of the…

High Energy Physics - Phenomenology · Physics 2007-05-23 H. Leutwyler

Chiral perturbation theory is a much successful effective field theory of quantum chromodynamics at low energies. The effective Lagrangian is constructed systematically order by order in powers of the momentum $p^2$, and until now the…

High Energy Physics - Phenomenology · Physics 2020-06-18 Nils Hermansson-Truedsson