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Related papers: $\pi\pi$ scattering at Large $N_\text{c}$

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We study the scaling with the number of colors $N_c$ of the weak amplitudes mediating kaon mixing and decay, in the limit of light charm masses ($m_u=m_d=m_s=m_c$). The amplitudes are extracted directly on the lattice for $N_c = 3-7$ (with…

High Energy Physics - Lattice · Physics 2018-04-18 Andrea Donini , Pilar Hernandez , Carlos Pena , Fernando Romero-Lopez

We analyse elastic-pion nucleon scattering to fourth order in heavy baryon chiral perturbation theory, extending the third order study published in Nucl. Phys. A640 (1998) 199. We use various partial wave analyses to pin down the low-energy…

High Energy Physics - Phenomenology · Physics 2009-10-31 Nadia Fettes , Ulf-G. Meißner

Isospin-1/2 $D\pi$ scattering amplitudes are computed using lattice QCD, working in a single volume of approximately $(3.6\; \mathrm{fm})^3$ and with a light quark mass corresponding to $m_\pi\approx239$ MeV. The spectrum of the elastic…

High Energy Physics - Lattice · Physics 2021-08-30 Luke Gayer , Nicolas Lang , Sinéad M. Ryan , David Tims , Christopher E. Thomas , David J. Wilson

The masses and widths of the broad scalar D_0^*(2400) and the axial D_1(2430) charmed-light resonances are extracted by simulating the corresponding D Pi and D* Pi scattering on the lattice. The resonance parameters are obtained using a…

High Energy Physics - Lattice · Physics 2024-04-24 Daniel Mohler , Sasa Prelovsek , R. M. Woloshyn

A meson-exchange model for pion-nucleon scattering was previously constructed using a three-dimensional reduction scheme of the Bethe-Salpeter equation for a model Lagrangian involving \pi, \eta, N, \Delta, \rho, and \sigma fields. We…

Nuclear Theory · Physics 2008-11-26 Guan Yeu Chen , S. S. Kamalov , Shin Nan Yang , D. Drechsel , L. Tiator

We calculate the two-pion wave function in the ground state of the I=2 $S$-wave system and find the interaction range between two pions, which allows us to examine the validity of the necessary condition for the finite-volume method for the…

We present results for the isospin-0 $\pi\pi$ s-wave scattering length calculated in twisted mass lattice QCD. We use three $N_f = 2$ ensembles with unitary pion mass at its physical value, 240~MeV and 330~MeV respectively. We also use a…

We present the scattering lengths for the $\pi\pi$ processes in the three flavour Chiral Perturbation Theory (ChPT) framework at next-to-next-to-leading order. We then combine this calculation with the determination of the parameters from…

High Energy Physics - Phenomenology · Physics 2011-03-22 Johan Bijnens , Pierre Dhonte , Pere Talavera

Using the method of asymptotic sum rules we estimated the size of $O(m_s p_\pi^4)$ and $O(m_s^2 p_\pi^2)$ corrections to $\pi K$ scattering amplitude in large $N_c$ limit. These corrections arise from the sixth order effective chiral…

High Energy Physics - Phenomenology · Physics 2016-09-01 A. A. Bolokhov , A. N. Manashov , M. V. Polyakov , V. V. Vereshagin

We examine the validity of the notion of the coherent state for pions and the quantum scattering effect in the final state of pion emission. When the number of particles is large, the effect caused by the small but finite mass difference…

High Energy Physics - Phenomenology · Physics 2010-01-08 Zheng Huang , Mahiko Suzuki

In this paper the phase structure of dense quark matter has been investigated in the presence of baryon, isospin and chiral isospin chemical potentials in the framework of (3+1)-dimensional Nambu--Jona-Lasinio model with two quark flavors.…

High Energy Physics - Phenomenology · Physics 2018-04-04 T. G. Khunjua , K. G. Klimenko , R. N. Zhokhov

We match the known chiral perturbation theory representation of the pi pi scattering amplitude to two loops with a phenomenological description that relies on the Roy equations. On this basis, the corrections to Weinberg's low energy…

High Energy Physics - Phenomenology · Physics 2011-05-05 G. Colangelo , J. Gasser , H. Leutwyler

The $\pi\pi$ scattering amplitude in the $\sigma$-channel is studied at finite baryonic density in the framework of a chiral unitary approach which successfully reproduces the meson meson phase shifts and generates the $f_0$ and $\sigma$…

Nuclear Theory · Physics 2011-02-09 D. Cabrera , E. Oset , M. J. Vicente Vacas

We present an analysis of isospin-breaking effects in threshold pion-nucleon scattering due to the light quark mass difference and the dominant virtual photon effects. We discuss the deviation from various relations, which are exact in the…

High Energy Physics - Phenomenology · Physics 2009-10-31 Nadia Fettes , Ulf-G. Meißner , Sven Steininger

$\pi\pi$ scattering length in the I=2 channel is calculated within quenched approximation using improved gauge and improved Wilson fermion actions on anisotropic lattices. The results are extrapolated towards the chiral, infinite volume and…

High Energy Physics - Lattice · Physics 2009-11-10 Xining Du , Guangwei Meng , Chuan Miao , Chuan Liu

We consider constraints on the isoscalar S-wave pi-N scattering length a+ from pi-deuteron scattering, to third order in small momenta and pion masses in chiral perturbation theory. To this order, the pi-deuteron scattering length is…

Nuclear Theory · Physics 2008-11-26 S. R. Beane , V. Bernard , T. -S. H. Lee , Ulf-G. Meißner

The effect of isoscalar S-wave processes $\pi\pi\to\pi\pi,K\overline{K},\eta\eta$ is considered in the analysis of data (from the ARGUS, CLEO, CUSB, Crystal Ball, Belle, BABAR collaborations) on the bottomonia decays ---…

High Energy Physics - Phenomenology · Physics 2015-12-09 Yu. S. Surovtsev , P. Bydžovský , T. Gutsche , R. Kamiński , V. E. Lyubovitskij , M. Nagy

In a recent paper by Xiu-Li Gao, Zhi-Hui Guo, Zhiguang Xiao, and Zhi-Yong Zhou, Phys. Rev. D 105, 094002 (2022), here referred to as I, $S$-wave $\pi\pi$ scattering phase shifts obtained in a lattice-QCD calculation are analyzed using…

High Energy Physics - Phenomenology · Physics 2023-03-10 Eef van Beveren , George Rupp

We present an investigation of the pion's electromagnetic form factor F_{\pi}(Q^2) in the spacelike region utilizing two new ingredients: (i) a double-humped, endpoint-suppressed pion distribution amplitude derived before via QCD sum rules…

High Energy Physics - Phenomenology · Physics 2014-11-17 A. P. Bakulev , K. Passek-Kumerički , W. Schroers , N. G. Stefanis

We perform an $\textit{ab initio}$ calculation of the $N_c$ scaling of the low-energy couplings of the chiral Lagrangian of low-energy strong interactions, extracted from the mass dependence of meson masses and decay constants. We compute…

High Energy Physics - Lattice · Physics 2019-10-24 Pilar Hernández , Carlos Pena , Fernando Romero-López