Modern Physics Letters A

With the end of Daya Bay experimental operations in December 2020, I review the history, discoveries, measurements and impact of the Daya Bay reactor neutrino experiment in China.

This work is continuation of a stochastic quantization program reported earlier. In this paper, we propose a consistent scheme of doing computations directly in four dimensions using conventional quantum field theory methods.

The spectral energy distribution (SED) sequence for type Ia supernovae (SN Ia) is modeled by an artificial neural network. The SN Ia luminosity is characterized as a function of phase, wavelength, a color parameter and a decline rate parameter. After training and testing the neural network, the SED sequence could give both the spectrum with wavelength range from 3000 Åto 8000 Åand the light curve with phase from 20 days before to 50 days after the maximum luminosity for the supernovae with different colors and decline rates. Therefore, we call this the Artificial Neural Network Spectral Light Curve Template (ANNSLCT) model. We retrain the Joint Light-curve Analysis (JLA) supernova sample by using the ANNSLCT model and obtain the parameters for each supernova to make a constraint on the cosmological $\mathrm{\Lambda }$CDM model. We find that the best fitting values of these parameters are very close to those from the JLA sample trained with the Spectral Adaptive Lightcurve Template 2 (SALT2) model. It is expectable that the ANNSLCT model has potential to analyze more SN Ia multi-color light curves measured in future observation projects.

In this work, we analyze the motion properties of the test particle, that has a variable mass within the frame of Hénon–Heiles system. We derive the equations of motion of the test particle which varies its mass according to Jean’s law. We also determine the quasi-Jacobi integral which shows the effective variation due to variable mass parameters. Further, we studied the locations of stationary points and their stability, after using Meshcherskii spacetime inverse transformations.

A stellar model with an electrically charged anisotropic fluid as a source of matter is presented. The radial pressure is described by a Chaplygin state equation, $P_r(\rho )=\mu c^2\rho -\nu /(c^2\rho )$, while the anisotropy $\mathrm{\Delta }\equiv P_t-P_r=r^{2}f(r)$ is annulled in the center of the star $(f(r)$ is regular and $f(0)\ne 0)$, the electric field, is also annulled in the center. The density pressures and the tangential speed of sound are regular, while the radial speed of sound is monotonically increasing. The model is physically acceptable and meets the stability criteria of Harrison–Zeldovich–Novikov and in respect of the cracking concept the solution is unstable in the region of the center and potentially stable near the surface. A graphic description is presented for the case of an object with a compactness rate $u=0.27336$, mass $M=1.77M_{\odot }$ and radius $R=9.56$ km that matches the star Vela X-1. Also, the interval of the central density ${\rho }_c\in [1.176977292,1.308791129]10^{18}\mathrm{\text{kg}}/{\mathrm{\text{m}}}^3$, which is consistent with the expected magnitudes for this type of stars, which shows that the behavior is accurate for describing compact objects.

Thorium is the primary candidate fuel in Thorium-based Molten Salt Reactor (TMSR) and Accelerator Driven System (ADS). However, to utilize Thorium in the reactor and accelerator systems, nuclear data in the literature are not sufficient for neutron-induced fission reaction process. Therefore, we estimated neutron fission cross-section $\sigma$ (mb), independent $Y(A)$ and primary fission fragment yield $Y_I(A)$, mass-dependent average neutron multiplicity $\bar{\nu }(A)$, energy-dependent average neutron multiplicity $\bar{\nu }(E)$ and neutron emission multiplicity distribution $\nu$ of ${}^{232}\mathrm{\text{Th}}$ for different neutron incident energy values, 1 MeV, 1.5 MeV, 3 MeV, 5.5 MeV, 7.7 MeV, 10 MeV, 14.8 MeV and 20 MeV, where the energy region is important for the reactor and accelerator systems used in the industry. The obtained results are compared with experimental data obtained from the literature and are discussed for each energy value.

In this paper, we introduce an SU(1, 1) algebraic approach to study the (2 + 1)-Dirac oscillator in the presence of the Aharonov–Casher effect coupled to an external electromagnetic field in the Minkowski spacetime and the cosmic string spacetime. This approach is based on a quantum mechanics factorization method that allows us to obtain the su(1, 1) algebra generators, the energy spectrum and the eigenfunctions. We obtain the coherent states and their temporal evolution for each spinor component of this problem. Finally, for these problems, we calculate some matrix elements and the Schrödinger uncertainty relationship for two general SU(1, 1) operators.

In this paper, we propose a scheme where Alice shares an arbitrary m-particle unknown state with her agents, Bob and Charlie. Alice starts by distributing 2m Einstein–Podolsky–Rosen pairs with her agents and performs m joint three-particle Greenberger–Horne–Zeilinger state measurements on her particles. Bob, who acts as the controller, performs a product measurement ${\sigma }_x^1\otimes {\sigma }_x^2\otimes \cdots \otimes {\sigma }_x^m$ on his m qubit states while Charlie retrieves the original state by performing unitary operations on his m particles. Subsequently, we demonstrate our proposed scheme’s feasibility by applying it in electronic voting by sharing an arbitrary single-particle state.

The no-masking theories show that it is impossible to mask the set of all qubit states into the quantum correlation of bipartite qubit system or tripartite qubit system. In this paper, we give a new proof of the no-masking situation of the tripartite qubit system. Recent work has shown that there exists a universal masker which can mask an arbitrary set of qubit states in four-qubit systems perfectly by means of the maximum entangled states. Here we show that there exist more than one masking scheme even for the same multipartite qubit system. Basing on the maximum entangled states we give the deterministic masking scenario for N-qubit system. In practice, decoherence hinders us from obtaining the maximum entangled states. From this viewpoint, the masking scenario based on non-maximum entangled states becomes more universal. Furthermore, we provide an approximate quantum masking scenario and investigate the relation between approximate masking and quantum entanglement.