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 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 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.

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.

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 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.

Autonomic Computing for a Complex Problem of Experimental Physics

2012 ◽  
pp. 97-107
Author(s):  
Tadeusz Wibig
Keyword(s):  
Neural Networks ◽  
High School Students ◽  
Data Analysis ◽  
Autonomic Computing ◽  
High Energy Physics ◽  
High Energy ◽  
Complex Problem ◽  
General Concept ◽  
School Students ◽  
Modern Physics

Standard experimental data analysis is based mainly on conventional, deterministic inference. The complexity of modern physics problems has become so large that new ideas in the field are received with the highest of appreciation. In this paper, the author has analyzed the problem of contemporary high-energy physics concerning the estimation of some parameters of the observed complex phenomenon. This article confronts the Natural and Artificial Networks performance with the standard statistical method of the data analysis and minimization. The general concept of the relations between CI and standard (external) classical and modern informatics was realized and studied by utilizing of Natural Neural Networks (NNN), Artificial Neural Networks (ANN) and MINUIT minimization package from CERN. The idea of Autonomic Computing was followed by using brains of high school students involved in the Roland Maze Project. Some preliminary results of the comparison are given and discussed.

The Fourth International Particle Accelerator Conference

2013 ◽  
Vol 02 (02) ◽  
pp. 19-21
Author(s):  
Zhentang Zhao
Keyword(s):  
High Energy Physics ◽  
High Energy ◽  
Particle Accelerator ◽  
Full Time ◽  
Applied Physics ◽  
Alphabetical Order ◽  
Chinese Academy Of Sciences ◽  
American Physical ◽  
Academy Of Sciences ◽  
Energy Physics

The fourth International Particle Accelerator Conference, IPAC'13, took place at the Shanghai International Conference Center, Shanghai, China from Sunday to Friday, 12 to 17 May, 2013. It was attended by close to 1000 full time delegates from approximately 30 different countries on all continents. Hosted by the Shanghai Institute of Applied Physics (SINAP) and the Institute of High Energy Physics (IHEP), Beijing, it was supported by the Asian Committee for Future Accelerators (ACFA), the American Physical Society Division of Physics of Beams (APS-DPB), the European Physical Society Accelerator Group (EPS-AG), the International Union of Pure and Applied Physics (IUPAP), the Chinese Academy of Sciences (CAS) and the National Natural Science Foundation of China (NSFC). Furthermore, the attendance of over 85 young scientists from all over the world was made possible through the sponsorship of societies, institutes and laboratories worldwide (in alphabetical order): ACFA, APS-DPB, CAS, EPSAG with contributions from ALBA-CELLS, Centro Fermi, CERN, CNRS-IN2P3, DESY, Diamond Light Source, ESRF, GSI, HZB, HZDR, IFIC, JAI, Max Lab, PSI, Synchrotron Soleil and STFC/Cockcroft Institute, and IUPAP. The organizers of IPAC'13 are grateful to all sponsors for their valuable support.

scholarly journals Gravitational waves from cosmic strings after a first-order phase transition

2021 ◽  
Author(s):  
Ligong Bian ◽  
Ruiyu 瑞雨 Zhou
Keyword(s):  
Phase Transition ◽  
Order Phase Transition ◽  
High Energy Physics ◽  
Cosmic Strings ◽  
High Energy ◽  
Wave Radiation ◽  
First Order ◽  
Creative Commons ◽  
First Order Phase Transition ◽  
First Order Phase

Abstract We study the possibility of probing high scale phase transitions that are unaccessible by LIGO. Our study shows that the stochastic gravitational-wave radiation from cosmic strings that are formed after the first-order phase transition can be detected by space-based interferometers when the phase transition temperature is $T_n\sim \mathcal{O}(10^{8-11})$ GeV. 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 ULTRA-LOW INTENSITY PROTON BEAMS FOR RADIATION RESPONSE RELATED EXPERIMENTS AT THE U-120M CYCLOTRON

2018 ◽  
Vol 14 ◽  
pp. 21
Author(s):  
Tomas Matlocha ◽  
Filip Krizek
Keyword(s):  
Proton Beam ◽  
Nuclear Physics ◽  
High Energy Physics ◽  
Tracking System ◽  
Operation Mode ◽  
High Energy ◽  
Ion Source ◽  
Alice Experiment ◽  
Physics Institute ◽  
Academy Of Sciences

The U-120M cyclotron at the Nuclear Physics Institute (NPI) of the Czech Academy of Sciences in Rez is used for radiation hardness tests of electronics for high-energy physics experiments. These tests are usually carried out with proton fluxes of the order of 10<sup>5</sup>–10<sup>9</sup> proton·cm<sup>−2</sup>·s<sup>−1</sup>. Some tests done for the upgrade of the Inner Tracking System of the ALICE experiment at CERN, however, required proton beam intensities several orders of magnitude lower. This paper presents a method which has been developed to achieve the proton beam flux of the order of 1 proton · cm<sup>−2</sup>·s<sup>−1</sup>. The method is mainly based on reduction of the discharge current in the cyclotron internal Penning type ion source. Influence of this new operation mode on the lifetime of ion source cathodes is discussed.

scholarly journals The place of elementary particle research in the development of modern physics

1964 ◽  
Vol 278 (1374) ◽  
pp. 290-302 ◽  
Keyword(s):  
Elementary Particle ◽  
Atomic Physics ◽  
Nuclear Physics ◽  
High Energy Physics ◽  
High Energy ◽  
Elementary Particles ◽  
Atomic Nuclei ◽  
Protons And Neutrons ◽  
Modern Physics ◽  
Energy Physics

The search for elementary particles is as old as science itself. It is always the most advanced part of physics which strives for an understanding of the fundamental constituents of matter. As physics progressed, the search for elementary particles moved on from chemistry to atomic physics, and then to nuclear physics. Not much more than a decade ago it separated from nuclear physics and became a new field, dealing no longer with the structure of atomic nuclei but with the structure of the constituents of nuclei, the protons and neutrons, and also with the structure of electrons and similar particles. This field is often referred to as high-energy physics because in it beams of particles of extremely high energy are needed for most of the relevant experiments. The purpose of this article is to present a bird’s-eye view of the new aspects which elementary particle research has recently created and to show how they fit into the framework of physics of this century.

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