scholarly journals Linear seesaw model with a modular $S_4$ flavor symmetry

2022 ◽  
Author(s):  
Takaaki Nomura ◽  
Hiroshi Okada
Keyword(s):  
Neutrino Mass ◽  
High Energy Physics ◽  
Mass Matrix ◽  
High Energy ◽  
Mass Hierarchy ◽  
Creative Commons ◽  
Seesaw Model ◽  
Modern Physics ◽  
Normal Mass ◽  
Academy Of Sciences

Abstract We discuss a linear seesaw model with as minimum field content as possible, introducing a modular $S_4$ with the help of gauged $U(1)_{B-L}$ symmetries. Due to rank two neutrino mass matrix, we have a vanishing neutrino mass eigenvalue, and only the normal mass hierarchy of neutrinos is favored through the modular $S_4$ symmetry.In our numerical $\Delta \chi^2$ analysis, we especially find rather sharp prediction on sum of neutrino masses to be around $60$ meV in addition to the other predictions. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.

scholarly journals Annihilation diagram contribution to charmonium masses

2021 ◽  
Author(s):  
Renqiang 张仁强 Zhang ◽  
Ying Chen ◽  
Wei Sun ◽  
Zhaofeng Liu ◽  
Ming Gong ◽  
...  
Keyword(s):  
High Energy Physics ◽  
Charm Quark ◽  
High Energy ◽  
Mass Shift ◽  
Unitary Theory ◽  
Charm Quarks ◽  
Creative Commons ◽  
Anisotropic Lattices ◽  
Modern Physics ◽  
Academy Of Sciences

Abstract In this work, we generate gauge configurations with $N_f=2$ dynamical charm quarks on anisotropic lattices. The mass shift of $1S$ and $1P$ charmonia owing to the charm quark annihilation effect can be investigated directly in a manner of unitary theory. The distillation method is adopted to treat the charm quark annihilation diagrams at a very precise level. For $1S$ charmonia, the charm quark annihilation effect almost does not change the $J/\psi$ mass, but lifts the $\eta_c$ mass by approximately 3-4 MeV. For $1P$ charmonia, this effect results in positive mass shifts of approximately 1 MeV for $\chi_{c1}$ and $h_c$, but decreases the $\chi_{c2}$ mass by approximately 3 MeV. We have not obtain a reliable result for the mass shift of $\chi_{c0}$. In addition, it is observed that the spin averaged mass of the spin-triplet $1P$ charmonia is in a good agreement with the $h_c$, as expected by the non-relativistic quark model and measured by experiments. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.

scholarly journals Lattice calaulation of χc0→ 2γ decay width

2022 ◽  
Author(s):  
Zuoheng Zou ◽  
Yu Meng ◽  
Chuan 刘川 Liu
Keyword(s):  
Lattice Qcd ◽  
Decay Width ◽  
High Energy Physics ◽  
Form Factors ◽  
Statistical Error ◽  
High Energy ◽  
Creative Commons ◽  
Modern Physics ◽  
Gamma Decay ◽  
Academy Of Sciences

Abstract We perform a lattice QCD calculation of the $\chi_{c0} \rightarrow 2\gamma$ decay width using a model-independent method which does not require a momentum extrapolation of the corresponding off-shell form factors. The simulation is performed on ensembles of $N_f=2$ twisted mass lattice QCD gauge configurations with three different lattice spacings. After a continuum extrapolation, the decay width is obtained to be $\Gamma_{\gamma\gamma}(\chi_{c0})=3.65(83)_{\mathrm{stat}}(21)_{\mathrm{lat.syst}}(66)_{\mathrm{syst}}\, \textrm{keV}$. Albeit this large statistical error, our result is compatible with the experimental results within 1.3$\sigma$. Potential improvements of the lattice calculation in the future are also discussed. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.

scholarly journals P-wave $\Omega_{b}$ states: masses and pole residues

2021 ◽  
Author(s):  
Yong-Jiang XU ◽  
Yong-Lu Liu ◽  
Ming-Qiu Huang
Keyword(s):  
High Energy Physics ◽  
High Energy ◽  
Lhcb Collaboration ◽  
P Wave ◽  
Creative Commons ◽  
Chinese Academy Of Sciences ◽  
Modern Physics ◽  
The Masses ◽  
Academy Of Sciences ◽  
Energy Physics

Abstract In this paper, we consider all P-wave $\Omega_{b}$ states represented by interpolating currents with a derivative and calculate the corresponding masses and pole residues with the method of QCD sum rule. Due to the large uncertainties in our calculation compared with the small difference in the masses of the excited $\Omega_{b}$ states observed by the LHCb collaboration, it is necessary to study other properties of the P-wave $\Omega_{b}$ states represented by the interpolating currents investigated in the present work in order to have a better understanding about the four excited $\Omega_{b}$ states observed by the LHCb collaboration. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.

A multi-charged particle model with local $U(1)_{\mu - \tau}$ to explain muon $g-2$, flavor physics, and possible collider signature

2021 ◽  
Author(s):  
Nilanjana Kumar ◽  
Takaaki Nomura ◽  
Hiroshi Okada
Keyword(s):  
High Energy Physics ◽  
High Energy ◽  
Particle Model ◽  
Charged Scalar ◽  
Creative Commons ◽  
Lepton Flavor ◽  
Modern Physics ◽  
Z Boson Decays ◽  
Meson Mixing ◽  
Collider Signature

Abstract We consider a model with multi-charged particles including vector-like fermions and a charged scalar under a local $U(1)_{\mu - \tau}$ symmetry. We search for allowed parameter region explaining muon anomalous magnetic moment (muon $g-2$) and $b \to s \ell^+ \ell^-$ anomalies, satisfying constraints from the lepton flavor violations, $Z$ boson decays, meson anti-meson mixing and collider experiments. Carrying out numerical analysis, we explore the typical size of the muon $g-2$ and Wilson coefficients to explain $b \to s \ell^+ \ell^-$ anomalies in our model when all other experimental constraints are satisfied. We then discuss the collider physics of the multicharged vectorlike fermions, considering some benchmark points in the allowed parameter space. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.

scholarly journals On Yukawa Couplings in the Zee-Babu Model

2013 ◽  
Vol 23 (3) ◽  
pp. 193
Author(s):  
Hoang Ngoc Long ◽  
Vo Van Vien
Keyword(s):  
Exact Solution ◽  
Cp Violation ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Neutrino Mass Matrix ◽  
Mass Hierarchy ◽  
Yukawa Couplings ◽  
Neutrino Sector ◽  
Normal Mass

The exact solution for neutrino mass matrix of the Zee-Babu modelis derived. The tribimaximal mixing imposes  the conditions on the Yukawa couplings, from  which the normal mass hierarchy ispreferred. The derived conditions give a possibility of maximal \(CP\) violation in the neutrino sector.

Texture zeros of neutrino mass matrix with seesaw mechanism and leptogenesis

2014 ◽  
Vol 29 (08) ◽  
pp. 1450038 ◽  
Author(s):  
T. Phong Nguyen
Keyword(s):  
Neutrino Mass ◽  
High Energy Physics ◽  
Mass Matrix ◽  
High Energy ◽  
Baryon Asymmetry ◽  
Neutrino Mass Matrix ◽  
Lepton Asymmetry ◽  
Seesaw Mechanism ◽  
Current Observation ◽  
Charge Parity

We study the seesaw realization of seven textures of the neutrino mass matrix with two zeros, which were presented by Frampton, Glashow and Marfatia. It is found that once the Dirac neutrino mass matrix is fixed, only texture A2 out of the seven textures is realized by the seesaw with three different heavy Majorana right-handed neutrino (RHN) mass matrices. As a consequence of the seesaw mechanism, the out of equilibrium decay of the lightest RHN generates a lepton number asymmetry. By the leptogenesis process, this lepton asymmetry is converted to the Baryon Asymmetry of the Universe (BAU). By a proper choice of the parameter space of the model which satisfied the low energy experimental data, the BAU is successfully explained by both flavor dependent and flavor independent leptogenesis of the model. It is also shown that the predictions of Dirac charge parity (CP) violation phase, δ CP , for some fixed parameters of high energy physics can be constrained by the current observation of baryon asymmetry.

scholarly journals Neutrino mixing with nonzero θ13 in Zee–Babu model

2014 ◽  
Vol 29 (13) ◽  
pp. 1450072 ◽  
Author(s):  
Hoang Ngoc Long ◽  
Vo Van Vien
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Recent Experimental Data ◽  
Mass Hierarchy ◽  
Neutrino Mixing ◽  
Neutrino Mass Hierarchy ◽  
Mixing Angles ◽  
Yukawa Couplings ◽  
Neutrino Sector ◽  
Normal Mass

The exact solution for the neutrino mass matrix of the Zee–Babu model is derived. Tribimaximal mixing imposes conditions on the Yukawa couplings, from which the normal mass hierarchy is preferred. The derived conditions give a possibility of Majorana maximal CP violation in the neutrino sector. We have shown that nonzero θ13 is generated if Yukawa couplings between leptons almost equal to each other. The model gives some regions of the parameters where neutrino mixing angles and the normal neutrino mass hierarchy obtained are consistent with the recent experimental data.

scholarly journals Equal-time kinetic equations in a rotational field

2021 ◽  
Author(s):  
Shile Chen ◽  
Ziyue Wang ◽  
Peng-Fei 庄鹏飞 Zhuang
Keyword(s):  
High Energy Physics ◽  
Kinetic Equations ◽  
Dynamical Evolution ◽  
High Energy ◽  
Spin Coupling ◽  
Equal Time ◽  
Independent Components ◽  
Creative Commons ◽  
Modern Physics ◽  
Rotational Field

Abstract We investigate quantum kinetic theory for a massive fermion system under a rotational field. From the Dirac equation in curved space we derive the complete set of kinetic equations for the spin components of the covariant and equal-time Wigner functions. While the particles are no longer on a mass shell in general case due to the rotation-spin coupling, there are always only two independent components, which can be taken as the number and spin densities. With the help from the off-shell constraint we obtain the closed transport equations for the two independent components in classical limit and at quantum level. The classical rotation-orbital coupling controls the dynamical evolution of the number density, but the quantum rotation-spin coupling explicitly changes the spin density. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.

scholarly journals NEUTRINO MASSES, LEPTON FLAVOR MIXING AND LEPTOGENESIS IN THE MINIMAL SEESAW MODEL

2007 ◽  
Vol 16 (01) ◽  
pp. 1-50 ◽  
Author(s):  
WAN-LEI GUO ◽  
ZHI-ZHONG XING ◽  
SHUN ZHOU
Keyword(s):  
Beta Decay ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Majorana Neutrino ◽  
Double Beta Decay ◽  
Neutrino Mixing ◽  
Lepton Flavor ◽  
Seesaw Model ◽  
Flavor Mixing ◽  
Majorana Neutrinos

We present a review of neutrino phenomenology in the minimal seesaw model (MSM), an economical and intriguing extension of the Standard Model with only two heavy right-handed Majorana neutrinos. Given current neutrino oscillation data, the MSM can predict the neutrino mass spectrum and constrain the effective masses of the tritium beta decay and the neutrinoless double-beta decay. We outline five distinct schemes to parameterize the neutrino Yukawa-coupling matrix of the MSM. The lepton flavor mixing and baryogenesis via leptogenesis are investigated in some detail by taking account of possible texture zeros of the Dirac neutrino mass matrix. We derive an upper bound on the CP-violating asymmetry in the decay of the lighter right-handed Majorana neutrino. The effects of the renormalization-group evolution on the neutrino mixing parameters are analyzed, and the correlation between the CP-violating phenomena at low and high energies is highlighted. We show that the observed matter-antimatter asymmetry of the Universe can naturally be interpreted through the resonant leptogenesis mechanism at the TeV scale. The lepton-flavor-violating rare decays, such as μ→e+γ, are also discussed in the supersymmetric extension of the MSM.

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