English
Related papers

Related papers: Studying chiral imbalance using Chiral Perturbatio…

200 papers

By bosonization of an extended NJL model we derive an effective meson theory which describes the interplay between chiral symmetry and heavy quark dynamics. This effective theory is worked out in the low-energy regime using the gradient…

High Energy Physics - Phenomenology · Physics 2009-10-28 D. Ebert , T. Feldmann , R. Friedrich , H. Reinhardt

I give an overview of the calculations done in three-flavour Chiral perturbation theory at next-to-next-to-leading order with an emphasis on those relevant for an improvement in the accuracy of the measurement of $V_{us}$. It is pointed out…

High Energy Physics - Phenomenology · Physics 2007-05-23 Johan Bijnens

The construction of effective Lagrangians commonly involves the application of the `classical equation of motion' to eliminate redundant structures and thus generate the minimal number of independent terms. We investigate this procedure in…

High Energy Physics - Phenomenology · Physics 2009-10-28 S. Scherer , H. W. Fearing

After a short status report on chiral perturbation theory, I review recent progress in determining some of the low-energy couplings by matching the effective theory to QCD. Consequences for K_{l3} decays and for the extraction of the CKM…

High Energy Physics - Phenomenology · Physics 2009-11-11 G. Ecker

Parameters of the effective chiral lagrangian (EChL) of orders $O(p^4)$ and $O(p^6)$ are extracted from low--energy behaviour of dual resonance models for $ \pi\pi$ and $\pi K$ scattering amplitudes. Dual resonance models are considered to…

High Energy Physics - Phenomenology · Physics 2009-10-28 M. V. Polyakov , V. V. Vereshagin

The chiral Lagrangians for singly heavy baryons are constructed up to the $\mathcal{O}(p^{4})$ order. The involved baryons may be in a flavor antitriplet with spin-1/2, a flavor sextet with spin-$1/2$, or a flavor sextet with spin-3/2 when…

High Energy Physics - Phenomenology · Physics 2023-08-01 Yuan-He Zou , Hao Liu , Yan-Rui Liu , Shao-Zhou Jiang

We apply the formalism of Chiral Perturbation Theory out of thermal equilibrium to describe explosive production of pions via the parametric resonance mechanism. To lowest order the lagrangian is that of the Nonlinear Sigma Model where the…

High Energy Physics - Phenomenology · Physics 2009-11-07 A. Gomez Nicola

Positivity constraints on the pion-nucleon scattering amplitude are derived in this article with the help of general S-matrix arguments, such as analyticity, crossing symmetry and unitarity, in the upper part of Mandelstam triangle, R.…

High Energy Physics - Phenomenology · Physics 2015-06-18 Juan Jose Sanz-Cillero , De-Liang Yao , Han-Qing Zheng

The branching ratios of the measured decay $K_L\to\pi^+\pi^-e^+e^-$ and of the still unmeasured decay $K^+\to\pi^+\pi^0e^+e^-$ are calculated to next-to-leading order in Chiral Perturbation Theory (CHPT). Recent experimental results are…

High Energy Physics - Phenomenology · Physics 2009-01-07 Hannes Pichl

The standard chiral perturbation theory is known to predict much weaker effects in magnetic field, than found in numerical lattice data. To overcome this disagreement we are using the effective chiral confinement Lagrangian, $L_{ECCL}$,…

High Energy Physics - Phenomenology · Physics 2018-12-05 M. A. Andreichikov , Yu. A. Simonov

The possibility of the formation of a local parity breaking (LPB) in a quark-hadron medium is examined as a result of chiral symmetry violation, i.e, the appearance of difference between the average densities of right- and left-handed…

High Energy Physics - Phenomenology · Physics 2019-10-23 A. A. Andrianov , V. A. Andrianov , D. Espriu , A. V. Iakubovich , A. E. Putilova

We investigate three-flavour chiral perturbation theory including virtual photons in a limit where the strange quark mass is much larger than the external momenta and the up and down quark masses, and where the external fields are those of…

High Energy Physics - Phenomenology · Physics 2008-11-26 Christoph Haefeli , Mikhail A. Ivanov , Martin Schmid

The hadronic sector of the standard model at low energies is described by a non--decoupling effective field theory, chiral perturbation theory. An introduction is given to the construction of effective chiral Lagrangians, both in the purely…

High Energy Physics - Phenomenology · Physics 2011-04-15 G. Ecker

We discuss the potential of Ginsparg-Wilson fermion simulations in the epsilon-regime of chiral perturbation theory, regarding the determination of the leading low energy constants of the effective chiral Lagrangian. It turns out to be very…

High Energy Physics - Lattice · Physics 2009-11-10 K. -I. Nagai , W. Bietenholz , T. Chiarappa , K. Jansen , S. Shcheredin

In this work, we construct the chiral Lagrangian for a light spin-1 boson $X$ possessing both vectorial and axial couplings to the light Standard Model quarks $u, d, s$. We then use it in order to describe the tree-level, model-independent…

High Energy Physics - Phenomenology · Physics 2024-01-11 Luca Di Luzio , Gabriele Levati , Paride Paradisi , Xavier Ponce Díaz

The main elements and methods of chiral perturbation theory, the effective field theory of the Standard Model below the scale of spontaneous chiral symmetry breaking, are summarized. Applications to the interactions of mesons and baryons at…

High Energy Physics - Phenomenology · Physics 2010-12-02 Gerhard Ecker

The dimensionless parameter $\xi' = M^2/(16 \pi^2 F^2)$, where $F$ is the pion decay constant in the chiral limit and $M$ is the pion mass at leading order in the quark mass, is expected to control the convergence of chiral perturbation…

High Energy Physics - Lattice · Physics 2009-02-11 D. J. Cecile , Shailesh Chandrasekharan

We examine the meson-baryon interaction in the strangeness S=-1 sector using an effective chiral Lagrangian. Potentials are derived from this Lagrangian and used in a coupled-channel calculation of the low energy observables. The potentials…

Nuclear Theory · Physics 2009-10-28 N. Kaiser , P. B. Siegel , W. Weise

We use heavy vector meson $SU(2)_L \times SU(2)_R$ chiral perturbation theory to predict differential decay distributions for $\tau \rightarrow \rho \pi \nu_\tau$ and $\tau \rightarrow K^* \pi \nu_\tau$ in the kinematic region where $p_V…

High Energy Physics - Phenomenology · Physics 2009-10-28 Hooman Davoudiasl , Mark B. Wise

We describe a rearrangement of the standard expansion of the symmetry breaking part of the QCD effective Lagrangian that includes into each order additional terms which in the standard chiral perturbation theory ($\chi$PT) are relegated to…

High Energy Physics - Phenomenology · Physics 2009-10-22 J. Stern , H. Sazdjian , N. H. Fuchs