arXiv subjects

Yuan Gao

Publications and source records attributed to Yuan Gao.

536 records · Page 30Linked to original sources

arXiv2013

The influence of the symmetry energy on the cone-azimuthal emission

In the framework of the isospin-dependent Boltzmann-Uehling-Uhlenbeck transport model, effects of the symmetry energy on the evolutions of free n/p ratio and charged pion ratio in the semi-central collision of $^{197}$Au+$^{197}$Au at an incident beam energy of 400 MeV/nucleon are studied. At the beginning of the reaction (before 11 fm/c) they are both affected by the low-density behavior of the symmetry energy but soon after are affected by the high-density behavior of the symmetry energy after nuclei are compressed (after 11 fm/c) and the effects of the symmetry energy are generally smaller compared with the central collision case. Interestingly, their dependences on the symmetry energy are shown to arise with increase of cone-azimuthal angle of the emitted particles. In the direction perpendicular to the reaction plane, the $π^{-}/π^{+}$ ratio or free n/p ratio especially at high kinetic energies exhibits significant sensitivity to the symmetry energy.

nucl-th↗

arXiv2012

Effect of the momentum dependence of nuclear symmetry potential on the transverse and elliptic flows

In the framework of the isospin-dependent Boltzmann-Uehling-Uhlenbeck transport model, effect of the momentum dependence of nuclear symmetry potential on nuclear transverse and elliptic flows in the neutron-rich reaction $^{132}$Sn+$^{124}$Sn at a beam energy of 400 MeV/nucleon is studied. We find that the momentum dependence of nuclear symmetry potential affects the rapidity distribution of the free neutron to proton ratio, the neutron and the proton transverse flows as a function of rapidity. The momentum dependence of nuclear symmetry potential affects the neutron-proton differential transverse flow more evidently than the difference of neutron and proton transverse flows as well as the difference of proton and neutron elliptic flows. It is thus better to probe the symmetry energy by using the difference of neutron and proton flows since the momentum dependence of nuclear symmetry potential is still an open question. And it is better to probe the momentum dependence of nuclear symmetry potential by using the neutron-proton differential transverse flow and the rapidity distribution of the free neutron to proton ratio.

nucl-th↗

arXiv2011

Initialization effect in heavy-ion collisions at intermediate energies

Based on the isospin-dependent Boltzmann-Uehling-Uhlenbeck transport model plus the Skyrme force parameters, initialization effect is studied in heavy-ion collision at intermediate energies. We find that there are moderate initialization effects in the observables of free neutron to proton ratio (n/p), pion-/pion + ratio, as well as neutron to proton differential flow (F^x_n-p). Effects of initialization are larger for charged pion-/pion ratios than n/p ratios. And the effects of initialization are more evident in nuclear reactions at lower incident beam energies. We do not see large effects of initialization for light reaction systems or large asymmetric (neutron-richer) reaction systems. We also see relatively large effects of initialization on the neutron to proton differential flow at relatively lower incident beam energies or with large impact parameters. These results may be useful for the delicate studies of Equation of Sate (EoS) of asymmetric nuclear matter.

nucl-th↗

arXiv2011

Effect of the momentum dependence of nuclear symmetry potential on pion-/pion+ ratio in heavy-ion collisions

In the framework of the isospin-dependent Boltzmann-Uehling-Uhlenbeck transport model, effect of the momentum dependence of nuclear symmetry potential on pion-/pion+ ratio in the neutron-rich reaction 132Sn+124Sn at a beam energy of 400 MeV/nucleon is studied. We find that the momentum dependence of nuclear symmetry potential affects the compressed density of colliding nuclei, numbers of produced pion- and pion+, as well as the value of pion-/pion+ ratio. The momentum dependent nuclear symmetry potential increases the compressed density of colliding nuclei, numbers of produced resonances delta(1232), N*(1440), pion- and pion+, as well as the value of pion-/pion+ ratio.

nucl-th↗

arXiv2010

Metropolitan all-pass and inter-city quantum communication network

We have demonstrated a metropolitan all-pass quantum communication network in field fiber for four nodes. Any two nodes of them can be connected in the network to perform quantum key distribution (QKD). An optical switching module is presented that enables arbitrary 2-connectivity among output ports. Integrated QKD terminals are worked out, which can operate either as a transmitter, a receiver, or even both at the same time. Furthermore, an additional link in another city of 60 km fiber (up to 130 km) is seamless integrated into this network based on a trusted relay architecture. On all the links, we have implemented protocol of decoy state scheme. All of necessary electrical hardware, synchronization, feedback control, network software, execution of QKD protocols are made by tailored designing, which allow a completely automatical and stable running. Our system has been put into operation in Hefei in August 2009, and publicly demonstrated during an evaluation conference on quantum network organized by the Chinese Academy of Sciences on August 29, 2009. Real-time voice telephone with one-time pad encoding between any two of the five nodes (four all-pass nodes plus one additional node through relay) is successfully established in the network within 60km.

quant-ph↗

arXiv2010

Transition Complexity of Incomplete DFAs

In this paper, we consider the transition complexity of regular languages based on the incomplete deterministic finite automata. A number of results on Boolean operations have been obtained. It is shown that the transition complexity results for union and complementation are very different from the state complexity results for the same operations. However, for intersection, the transition complexity result is similar to that of state complexity.

cs.FL↗

arXiv2010

State Complexity of Catenation Combined with Star and Reversal

This paper is a continuation of our research work on state complexity of combined operations. Motivated by applications, we study the state complexities of two particular combined operations: catenation combined with star and catenation combined with reversal. We show that the state complexities of both of these combined operations are considerably less than the compositions of the state complexities of their individual participating operations.

cs.FL↗

arXiv2010

State Complexity of Two Combined Operations: Reversal-Catenation and Star-Catenation

In this paper, we show that, due to the structural properties of the resulting automaton obtained from a prior operation, the state complexity of a combined operation may not be equal but close to the mathematical composition of the state complexities of its component operations. In particular, we provide two witness combined operations: reversal combined with catenation and star combined with catenation.

cs.FL↗

arXiv2010

State complexity of union and intersection combined with star and reversal

In this paper, we study the state complexities of union and intersection combined with star and reversal, respectively. We obtain the state complexities of these combined operations on regular languages and show that they are less than the mathematical composition of the state complexities of their individual participating operations.

cs.FL↗

arXiv2009

State Complexity Approximation

In this paper, we introduce the new concept of state complexity approximation, which is a further development of state complexity estimation. We show that this new concept is useful in both of the following two cases: the exact state complexities are not known and the state complexities have been obtained but are in incomprehensible form.

cs.FL↗

arXiv2009

Approximate homotopy symmetry method and homotopy series solutions to the six-order boussinesq equation

An approximate homotopy symmetry method for nonlinear problems is proposed and applied to the six-order boussinesq equation. We summarize the general formulas for similarity reduction solutions and similarity reduction equations of different orders, educing the related homotopy series solutions. The convergence region of homotopy series solutions can be adjusted by the auxiliary parameter. Series solutions and similarity reduction equations from approximate symmetry method can be retrieved from approximate homotopy symmetry method.

nlin.PS↗

arXiv2009

Nonsensitive nonlinear homotopy approach

Generally, natural scientific problems are so complicated that one has to establish some effective perturbation or nonperturbation theories with respect to some associated ideal models. In this Letter, a new theory that combines perturbation and nonperturbation is constructed. An artificial nonlinear homotopy parameter plays the role of a perturbation parameter, while other artificial nonlinear parameters, of which the original problems are independent, introduced in the nonlinear homotopy models are nonperturbatively determined by means of a principle minimal sensitivity. The method is demonstrated through several quantum anharmonic oscillators and a non-hermitian parity-time symmetric Hamiltonian system. In fact, the framework of the theory is rather general that can be applied to a broad range of natural phenomena. Possible applications to condensed matter physics, matter wave systems, and nonlinear optics are briefly discussed.

physics.comp-ph↗

arXiv2006

Topological structure of the vortex solution in Jackiw-Pi model

By using $ϕ$ -mapping method, we discuss the topological structure of the self-duality solution in Jackiw-Pi model in terms of gauge potential decomposition. We set up relationship between Chern-Simons vortices solution and topological number which is determined by Hopf index and and Brouwer degree. We also give the quantization of flux in the case. Then, we study the angular momentum of the vortex, it can be expressed in terms of the flux.

hep-th↗

arXiv2005

Density dependent relativistic hadron theory for hadron matter with inclusion of pentaquark $Θ^+$

The density dependent relativistic hadron field theory(DDRH) is extended to inclusions of pentaquark $Θ^+$. We investigate In-medium properties of $Θ^+$ and nucleons. As well as the neutron and proton,the effective $Θ^+$ mass decreases as the baryon density increases,and remains larger than nucleons'. The effective mass of $Θ^+$ is calculated,$M^*_{Θ^+}\simeq0.71M_{Θ^+}$ at normal nuclear density with the fraction of $Θ^+$ 0.2. The effective masses of all baryon increase with the increasing fraction of $Θ^+$. The binding energy is also studied. We find the binding energy is much larger than it in nuclear matter without $Θ^+$,and then discuss the stability of the system with conclusions of pentaquark $Θ^+$. It is shown that the system becomes bounder added small fraction of $Θ^+$. Finally we discuss the condition when the system is the most stable and calculate the minimum of binding energy and the fractions of all baryons as functions of baryon density.

nucl-th↗