The decay channel ψ′→π⁺π^－J/ψ(J/ψ→γpp) is studied using a sample of 1.06×10⁸ ψ′ events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the pp invariant mass spectrum. The enhancement can be fitted with an...

The lepton-number-violating decays of singly-charged Higgs bosons H^± are investigated in the minimal type-(Ⅰ+Ⅱ) seesaw model with one SU(2)_L Higgs triplet Δ and one heavy Majorana neutrino N₁ at the TeV scale. We find that the branching ratios B (H+→...

In the paper we discuss the role of the axial U(1)_A symmetry in the chiral phase transition using the U(N_f)_R×U(N_f)_L linear sigma model with two massless quark flavors. It is expected that above a certain temperature the axial U(1)_A symmetry will be r...

We investigate the properties of spin-orbit interaction in the ground state and thermal entanglement of a two-qutrit Heisenberg XYZ system in the presence of an inhomogeneous magnetic field. Using negativity as entanglement measure, we give the depen...

The mirror nuclei ¹²N and ¹²B are separated by the Radioactive Ion Beam Line in Lanzhou (RIBLL) at HIRFL from the breakup of 78.6 MeV/u ¹⁴N on a Be target. The total reaction cross-sections of ¹²N at 34.9 MeV/u and ¹²B at 54.4 MeV/u on a Si target ha...

The binding energies ε_η and widths Γ_η of η-mesic nuclei are calculated. We parameterize the η self-energy in the nuclear medium as a function of energy and density. We find that the single-particle energies are sensitive to the scattering length, and...

We study the vector meson electro-production off the proton in a QCD inspired model. A calculation of the differential cross section is performed for the J/ψ, φ meson off the proton. The theoretical results are consistent with the experimental data, ...

We examine the space-time structure of particle-emitting source and two-pion interferometry in a smoothed hydrodynamic model with fluctuating initial conditions. An equation of state with a crossover transition between quark-gluon plasma and hadronic...

A novel Micro-pattern gaseous detector (MPGD), thick GEM with electrodes made of a resistive material (RETGEM) is presented. In this paper we mainly investigate the energy resolution of a RETGEM in Ar+CO₂ with different gas mixtures. The results indi...

Micromegas (MICRO MEsh GAseous Structure) is a position-sensitive gaseous
detector. It is widely used in particle physics. We present the results of full 3D Monte Carlo simulations of Micromegas performance, taking into account all the processes from ...

The fast luminosity monitor counting the γ photons above a given energy threshold emitted from radiative Bhabha scattering has been operated in the BEPCⅡ to measure the relative luminosity bunch by bunch for the first time and used successfully in be...

A NbTi 7 T superconducting magnet with a 338 mm bore system was rebuilt and the first experiment was carried out in Jan. 2009. The balancing-bridge method used for the quench detection system is analyzed and an improvement of the principle of balanci...

Experiment is carried out on the accelerator Sinus-700 to investigate the Relativistic Backward Wave Oscillator (RBWO) with a periodic guiding magnetic field. When the strength of the guiding magnetic field, whose period is 4.6 cm, is 0.54 T, a micro...

SFRFQ (Separated Function Radio Frequency Quadrupoles) accelerator is a new post accelerator of RFQ (Radio Frequency Quadrupoles) type, which has been developed since the beginning of the 1990s at Peking University. In order to demonstrate the possib...

The current design of the CSNS/RCS beam collimation system consists of a two-stage betatron collimation and a single momentum collimator. This paper summarizes various aspects of collimator design, including collimation principle and layout, material...

We present a design study of a free electron laser (FEL) oscillator for high power THz source experiments on the basis of the Shanghai femtosecond accelerator device. A circular groove guide is used as a new interaction structure. Plane metal meshes ...

A conception design of the Advanced Proton Therapy Facility (APTF) has been carried out. The system intentionally employs a slow-cycling synchrotron with a maximum energy of 250 MeV, two rotating gantries and two fixed beam nozzles for the treatment....