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Related papers: Strong $U_A(1)$ breaking in radiative $\eta$ decay…

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We explore patterns of effective restoration of the chiral U$_A$(1) symmetry using an extended three-flavor Nambu-Jona-Lasinio model that incorporates explicitly the axial anomaly through the 't Hooft interaction, and assuming that the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Pedro Costa , M. C. Ruivo , C. A. de Sousa , Yu. L. Kalinovsky

We study the anomalous decays $\pi^0, \eta \to\gamma\gamma$ in the framework of the three--flavor Nambu--Jona-Lasinio [NJL] model at finite temperature. The similarities and differences between these results and those obtained at zero…

High Energy Physics - Phenomenology · Physics 2007-05-23 Pedro Costa , M. C. Ruivo , Yu. L. Kalinovsky

New physics motivated by muonic puzzles (proton radius and muon $g-2$ discrepancies) is studied. Using a light scalar boson $\phi$, assuming Yukawa interactions, accounts for these muonic puzzles simultaneously. Our previous work limits the…

High Energy Physics - Phenomenology · Physics 2019-06-26 Yu-Sheng Liu , Ian C. Cloët , Gerald A. Miller

We present an improved measurement of the eta' meson energy spectrum in Upsilon(1S) decays, using 1.2 fb^{-1}} of data taken at the Upsilon(1S) center-of-mass energy with the CLEO III detector. We compare our results with models of eta'…

High Energy Physics - Experiment · Physics 2007-05-23 O. Aquines , CLEO Collaboration

We evaluate the decays $\ell_1^\pm \to \ell_2^\pm \gamma$, $Z \to \ell_1^+ \ell_2^-$, and $h \to \ell_1^+ \ell_2^-$, where $\ell_1$ and $\ell_2$ are charged leptons with different flavours and $h$ is the scalar particle with mass 125.25…

High Energy Physics - Phenomenology · Physics 2022-03-29 Darius Jurčiukonis , Luis Lavoura

The QCD formulae for the radiative decays $\eta,\eta'\to\c\c$, and the corresponding Dashen--Gell-Mann--Oakes--Renner relations, differ from conventional PCAC results due to the gluonic $U(1)_A$ axial anomaly. This introduces a critical…

High Energy Physics - Phenomenology · Physics 2009-11-11 G. M. Shore

We present results of an exploratory study of flavor SU(3) breaking effects in hyperon beta decays using domain wall fermions. From phenomenological point of view, the significance of this subject is twofold: (1) to extract the element…

High Energy Physics - Lattice · Physics 2008-11-26 Shoichi Sasaki , Takeshi Yamazaki

A generalized 3 flavor Nambu-Jona--Lasinio Lagrangian including the explicit chiral symmetry breaking interactions which contribute at the same order in the large $1/N_c$ counting as the $U_A(1)$ 't Hooft flavor determinant is considered to…

High Energy Physics - Phenomenology · Physics 2016-06-08 A. A. Osipov , B. Hiller , A. H. Blin , J. Moreira

We will show that the 3-3-1 model with new heavy right handed neutrinos as $SU(3)_L$ singlets can explain simultaneously the lepton flavor violating decays of the SM-like Higgs boson, charged lepton flavor violating decays $e_b\rightarrow…

High Energy Physics - Phenomenology · Physics 2022-09-22 T. T. Hong , N. H. T. Nha , T. Phong Nguyen , L. T. T. Phuong , L. T. Hue

The NA60 experiment has studied low-mass muon pairs production in proton-nucleus collisions at 400 GeV/$c$ at the CERN SPS. The mass spectrum is well described by the superposition of the two-body and Dalitz decays of the light neutral…

High Energy Physics - Experiment · Physics 2011-08-05 Antonio Uras , NA60 Collaboration

We study the mass spectra and decay process of $\sigma$ and $\pi_0$ mesons under strong external magnetic field. For this purpose, we deduce the thermodynamic potential in a two-flavor, hot and magnetized Nambu-Jona-Lasinio model. We…

High Energy Physics - Phenomenology · Physics 2022-04-14 Shuyun Yang , Meng Jin , Defu Hou

In this paper, we investigate the $\eta'N$ system using the three-flavor linear sigma model including the effect of flavor SU(3) symmetry breaking. The $\eta'N$ bound state is also found in the case including flavor symmetry breaking and…

Nuclear Theory · Physics 2017-02-28 Shuntaro Sakai , Daisuke Jido

In this paper, we investigate three symmetry breaking effects in strong and radiative decays of strange heavy mesons. We study 1/m_Q corrections within the heavy quark effect theory, as well as SU(3) and SU(2) symmetry breakings induced by…

High Energy Physics - Phenomenology · Physics 2016-02-17 Chi-Yee Cheung , Chien-Wen Hwang

This work is a follow up of recent investigations, where we study the implications of a generalized heat kernel expansion, constructed to incorporate non-perturbatively the effects of a non-commutative quark mass matrix in a fully covariant…

High Energy Physics - Phenomenology · Physics 2009-11-10 A. A. Osipov , H. Hansen , B. Hiller

Supersymmetric SO(10) grand unified models with renormalizable Yukawa couplings involving {\bf 10}, {\bf 126} and {\bf 120} Higgs fields have been shown to give a very economical theory for understanding quark-lepton flavor in a unified…

High Energy Physics - Phenomenology · Physics 2013-04-17 Bhaskar Dutta , Yukihiro Mimura , Rabindra N. Mohapatra

We present an improved measurement of the $\eta'$ meson energy spectrum in $\Upsilon(1S)$ decays, using 1.2 fb^{-1} of data taken at the $\Upsilon(1S)$ center-of-mass energy with the CLEO III detector. We compare our results with models of…

High Energy Physics - Experiment · Physics 2014-11-17 O. Aquines , CLEO Collaboration

CMS has reported indications (2.4\sigma) of the decay of the Higgs boson into \mu\tau. The simplest explanation for such a decay would be a general Two Higgs Doublet Model (2HDM). In this case, one would expect the heavy neutral Higgs…

High Energy Physics - Phenomenology · Physics 2016-03-23 Marc Sher , Keith Thrasher

We investigate the pp --> pp eta and pn --> pn eta reactions within an effective Lagrangian model for laboratory kinetic energies ranging from very close to eta meson production threshold to about 10 GeV. Production amplitudes include…

Nuclear Theory · Physics 2008-11-26 R. Shyam

We explore the possible values of the $\mu \to e \gamma$ branching ratio, $\text{BR}(\mu\rightarrow e\gamma)$, and the electron dipole moment (eEDM), $d_e$, in no-scale SU(5) super-GUT models with the boundary conditions that soft…

High Energy Physics - Phenomenology · Physics 2021-02-24 John Ellis , Jason L. Evans , Natsumi Nagata , Keith A. Olive , Liliana Velasco-Sevilla

Although eta-eta' mixing is qualitatively well understood as a consequence of the U(1)_A anomaly in QCD together with a broken SU(3) flavor symmetry, until recently the values of decay and mixing parameters of the eta and eta' were only…

High Energy Physics - Phenomenology · Physics 2009-10-31 Thorsten Feldmann