Jia Huan-Yu

Performance of the muon detector A under TIBET III array

In order to observe gamma rays in the 100 TeV energy region, the 4500 m(2) underground muon detector array using water Cherenkov technique is constructed, forming the TIBET III+MD hybrid array. Because the showers induced by primary gamma rays contain much fewer muons than those induced by primary hadrons, significant improvement of the gamma ray sensitivity for TIBET III+MD array is expected. In this paper, the design and performance of the MD-A detector with large Tyvek bag is reported.

Nonclassicality of photon-added squeezed vacuum states

By applying the bosonic creation operator to squeezed vacuum states, this paper introduces a new kind of quantum states: photon-added squeezed vacuum states. It also presents an experimental approach to prepare these states, and investigates their quantum statistical properties by the numerical method. The results indicate that these states reveal some interesting non-classical properties, such as anti-bunching effects, squeezing effects and negativities of the relevant Wigner functions.

Fano Resonance and Persistent Currents in a Mesoscopic Open Ring with a Flux Loop in Side-Branch

Persistent circulating currents in a mesoscopic open ring with side-branch structures are derived by transfer matrix method in the framework of quantum waveguide theory on networks. The behavior of transmission probability may show the Fano resonance in the presence of geometric scattering of side-branch structures. It is shown that persistent circulating currents in the main loop with equal length of both arms in the absence of magnetic flux occur near the Fermi wave vectors where the Fano resonance appears. The numerical results show that a larger persistent current is associated with a stronger Fano resonance. The persistent circulating currents can be controlled by the flux of side-branch structure.

Updated study on multi-TeV cosmic-ray modulation with the Tibet III air shower array using the east-west method

We study the sidereal and solar time modulation of multi-TeV cosmic rays using the east-west method with Tibet III air shower array data taken from November 1999 to December 2008. The statistics are twice the amount used in our previous paper. In this analysis, the amplitude of the observed sidereal time modulation is about 0.1%, and the modulation shows an excess from about 4 to 7 hours and a deficit around 12 hours in local sidereal time. The sidereal time modulation has a weak dependence on the primary energy of the cosmic rays. However, the solar time modulation shows a large energy dependence. We find that the solar time modulation is fairly consistent with the prediction of the Compton-Getting effect for high-energy samples (6.2 TeV and 12.0 TeV), but exceeds the prediction for the low-energy sample (4.0 TeV). Such a discrepancy may be due to the solar modulation or the characteristics of the experimental device in the near threshold energy.

Photon-added and photon-subtracted displaced Fock states and their non-classical properties

A new kind of quantum optical state, photon-added and -subtracted displaced Fock states, is introduced by applying the inverse of bosonic creation and annihilation operators to displaced Fock states. The quantum statistical properties of these states are investigated by numerical methods. Numerical results indicate that these states reveal some interesting non-classical properties, such as anti-bunching effects, sub-Poisson distributions and negativities of their Wigner functions.

Equation of State of Protoneutron Star with Trapped Neutrinos

The influence of trapped neutrinos on the proto-neutron star is studied in the framework of relativistic mean-field theory. The results show that trapped neutrinos increase proton fraction and make the equation of state of neutron star matter softer when neglecting hyperonic freedom, while suppress the appearance of hyperons and make the equation of state stiffer when including hyperons in the protoneutron star. The maximum mass, compared with cold neutron star which is in beta equilibrium, decreases by 0.06M⊙ for non-strange protoneutron star while increases by 0.21M⊙ for protoneutron star with hyperons when the relative number of trapped neutrino is 0.4.

Transition density of the large mass hyperon star

The difference between the transition density of a larger mass hyperon star (for example, the neutron star PSR J1614-2230) and that of a smaller mass hyperon star is investigated in the framework of the relativistic mean field theory. We see that the transition density ρ0H increases with the increase of xω (i.e. the mass of the neutron star). For the nucleons parts, the neutrons make the main contribution to the transition density as the baryon density ρ=ρ0H. With the increase of the xω (i.e. the mass of the neutron star), the relative particle number density of neutrons decreases while that of protons increases. For the parts of hyperons, the Λ and Ξ− make the main contributions to the transition density as the baryon density ρ=ρ0H. The relative particle number density of Λ decreases while that of Ξ− increases with the increase of the xω (i.e. the mass of the neutron star). For the hyperons Σ−, Σ0 and Σ−, the total contributions are less than 16 per cent.

A set of new nucleon coupling constants and the proto neutron star matter

Using a new set of nucleon coupling constants CZ11 the properties of a proto neutron star are examined within the framework of the relativistic mean-field theory for the baryon octet system. It is found that the relative number density of Λ, Ξ−, and Ξ0 for CZ11 are all smaller than those for GL97 and for both CZ11 and GL97, Σ−, Σ0, and Σ+ do not appear. It is also found that the pressure and the maximum mass for CZ11 are all smaller than those for GL97. The maximum mass for CZ11 decreases by approximately 9 percent compared with that for GL97.

Entangling a Series of Trapped Ions by Moving Cavity Bus

Entangling multiple qubits is one of the central tasks of quantum information processing. We propose an approach to entangle a number of cold ions (individually trapped in a string of microtraps) by a moved cavity. The cavity is pushed to include the ions one by one with a uniform velocity and thus the information stored in former ions could be transferred to the latter ones by such a moving cavity bus. Since the positions of the trapped ions are precisely located, the strengths and durations of the ion-cavity interactions can be exactly controlled. As a consequence, by properly setting the relevant parameters, typical multi-ion entangled states, e.g., W state for 10 ions, could be deterministically generated. The feasibility of the proposal is also discussed.

On the moment of inertia of a proto neutron star

The influences of σ* and Φ mesons, temperature and coupling constants of nucleons on the moment of inertia of the proto neutron star (PNS) are examined in the framework of relativistic mean field theory for the baryon octet {n, p, Λ, Σ−, Σ0, Σ+, Ξ−, Ξ0} system. It is found that, compared with that without considering σ* and Φ mesons, the moment of inertia decreases. It is also found that the higher the temperature, the larger the incompressibility and symmetry energy coefficient, and the larger the moment of inertia of a PNS. The influence of temperature and coupling constants of the nucleons on the moment of inertia of a PNS is larger than that of the σ* and Φ mesons.