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Related papers: Isospin Breaking in the Pion-Nucleon Coupling from…

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We report measurements of the $\pi^- p \to \pi^o n$ differential cross sections at six momenta (104-143 MeV/c) and four angles (0-40 deg) by detection of $\gamma$-ray pairs from $\pi^o \to \gamma \gamma$ decays using the TRIUMF RMC…

Nuclear Experiment · Physics 2008-11-26 Y. Jia , T. P. Gorringe , M. D. Hasinoff , M. A. Kovash , M. Ojha , M. M. Pavan , S. Tripathi , P. A. Zolnierczuk

The charge-dependent nucleon-nucleon ($NN$) interactions are crucial in understanding the nuclear structure and reaction problems. This work explores the charge-dependent $NN$ interaction in covariant chiral effective field theory. By…

Nuclear Theory · Physics 2025-04-23 Yang Xiao , Jun-Xu Lu , Li-Sheng Geng

From the subsubleading chiral three-nucleon force [intermediate-range contributions, published in Phys. Rev. C\,87, 054007 (2013)] a density-dependent NN-interaction $V_\text{med}$ is derived in isospin-symmetric nuclear matter. Following…

Nuclear Theory · Physics 2021-02-01 N. Kaiser

pi-N and pi-pi interactions near threshold are uniquely sensitive to the chiral symmetry breaking part of the strong interaction. The pi-N sigma-term value with its implications for nucleon quark structure and the recent controversy…

High Energy Physics - Phenomenology · Physics 2015-06-25 D. Pocanic , E. Frlez

On the basis of a next-to-leading-order calculation in chiral perturbation theory, the first complete analysis of isospin breaking for direct CP violation in K^0 -> 2 pi decays is performed. We find a destructive interference between three…

High Energy Physics - Phenomenology · Physics 2009-11-10 V. Cirigliano , A. Pich , G. Ecker , H. Neufeld

We present a study of the strong isospin-breaking (IB) effect, due in QCD to the difference between $u$- and $d$-quark masses, in the leptonic decay constants of charmed and beauty pseudoscalar and vector mesons using the method of QCD sum…

High Energy Physics - Phenomenology · Physics 2017-01-17 Wolfgang Lucha , Dmitri Melikhov , Silvano Simula

We present a light-front determination of the pionic contribution to the nucleon self-energy, $\Sigma_\pi$, to second-order in pion-baryon coupling constants that allows the pion-nucleon vertex function to be treated in a model-independent…

Nuclear Theory · Physics 2013-05-30 Mary Alberg , Gerald A. Miller

New QCD sum rules for nucleons in nuclear matter are derived from a mixed correlation function of spin-1/2 and spin-3/2 interpolating fields. These sum rules allow a determination of the scalar self-energy of the nucleon independent of the…

Nuclear Theory · Physics 2007-05-23 Derek B. Leinweber , Xuemin Jin , R. J. Furnstahl

Effects of non-resonant photoproductions arising from two different $\pi NN$ couplings are investigated in the $\gamma N\to\pi\pi N$ reaction. We find that the pseudoscalar (PS) $\pi NN$ coupling is generally preferable to the pseudovector…

Nuclear Theory · Physics 2009-11-07 M. Hirata , N. Katagiri , T. Takaki

The effects of the symmetry potential and the isospin dependent in-medium nucleon-nucleon (NN) cross section on the number of proton(neutron) emissions N$_p(N_n$) are studied respectively within an isospin-dependent quantum molecular…

Nuclear Theory · Physics 2009-11-07 Jian-Ye Liu , Wen-Jun Guo , Yong-Zhong Xing , Wei Zuo , Xi-Guo Lee , Zeng-Hua Li

We calculate the nucleon parameters in isospin asymmetric nuclear matter using the QCD sum rules. The nucleon self-energies are expressed in terms of the in-medium values of QCD condensates. The simple approximate expressions for the…

Nuclear Theory · Physics 2009-11-10 E. G. Drukarev , M. G. Ryskin , V. A. Sadovnikova

Two new sets of QCD sum rules for the nucleon axial coupling constants are derived using the external-field technique and generalized interpolating fields. An in-depth study of the predicative ability of these sum rules is carried out using…

Nuclear Theory · Physics 2009-10-30 Frank X. Lee , Derek B. Leinweber , Xuemin Jin

The small mass difference $m_n-m_p=1.3 MeV$ between the proton and neutron leads to an excess of $n=\pi^- p$ over $p=\pi^+ n$ fluctuations which can be calculated by using a light-cone meson-baryon fluctuation model of intrinsic…

High Energy Physics - Phenomenology · Physics 2009-10-30 Bo-Qiang Ma

A measurement of parity-violating spin-dependent gamma proton Compton scattering will provide a theoretically clean determination of the parity-violating pion-nucleon coupling constant $h_{\pi NN}^{(1)}$. We calculate the leading…

Nuclear Theory · Physics 2009-10-31 Paulo F. Bedaque , Martin J. Savage

We analyze quark condensates and chiral (scalar) susceptibilities including isospin breaking effects at finite temperature $T$. These include $m_u\neq m_d$ contributions as well as electromagnetic ($e\neq 0$) corrections, both treated in a…

High Energy Physics - Phenomenology · Physics 2011-04-22 A. Gomez Nicola , R. Torres Andres

With the isovector coupling constants adjusted to reproduce the physical pion mass and lattice QCD results in baryon-free quark matter, we have carried out rigourous calculations for the pion condensate in the 3-flavor Nambu-Jona-Lasinio…

High Energy Physics - Phenomenology · Physics 2021-10-13 Lu-Meng Liu , Jun Xu , Guang-Xiong Peng

In this paper we investigate the phase structure of a (1+1)-dimensional schematic quark model with four-quark interaction and in the presence of baryon ($\mu_B$), isospin ($\mu_I$) and chiral isospin ($\mu_{I5}$) chemical potentials. It is…

High Energy Physics - Phenomenology · Physics 2017-01-04 D. Ebert , T. G. Khunjua , K. G. Klimenko

The nucleon-pion-state contributions to QCD 2- and 3-point functions used in the calculation of the nucleon axial charge are studied in chiral perturbation theory. For sufficiently small quark masses and large volumes the nucleon-pion…

High Energy Physics - Lattice · Physics 2015-08-06 Oliver Bar

In the supersymmetric models, the dominant sources of the hadronic flavor-diagonal CP violation at low energy are the theta term and the chromoelectric dipole moments of quarks. Using QCD sum rules, we estimate the preferred range and the…

High Energy Physics - Phenomenology · Physics 2009-11-07 Maxim Pospelov

From recent charge exchange measurements in the extreme forward direction, an independent and precise determination of the pion nucleon coupling constant is possible. This determination has reopened the debate on the value of this…

High Energy Physics - Phenomenology · Physics 2012-07-19 F. Myhrer