Gluon saturation and pseudo-rapidity distributions of charged hadrons at RHIC energy regions

We modified the gluon saturation model by rescaling the momentum fraction according to saturation momentum and introduced the Cooper-Frye hydrodynamic evolution to systematically study the pseudo-rapidity distributions of final charged hadrons at different energies and different centralities for Au-Au collisions in relativistic heavy-ion collisions at BNL Relativistic Heavy Ion Collider (RHIC). The features of both gluon saturation and hydrodynamic evolution at different energies and different centralities for Au-Au collisions are investigated in this paper.Comment: 14 pages, 4 figure

A gauge invariant dressed holon and spinon description of the normal-state of underdoped cuprates

A partial charge-spin separation fermion-spin theory is developed to study the normal-state properties of the underdoped cuprates. In this approach, the physical electron is decoupled as a gauge invariant dressed holon and spinon, with the dressed holon behaving like a spinful fermion, and represents the charge degree of freedom together with the phase part of the spin degree of freedom, while the dressed spinon is a hard-core boson, and representing the amplitude part of the spin degree of freedom. The electron local constraint for single occupancy is satisfied. Within this approach, the charge and spin dynamics of the underdoped cuprates are studied based on the t-t'-J model. It is shown that the charge dynamics is mainly governed by the scattering from the dressed holons due to the dressed spinon fluctuation, while the scattering from the dressed spinons due to the dressed holon fluctuation dominates the spin dynamics.Comment: 10 pages, 7 figures, corrected typo

Enhanced spin injection efficiency in a four-terminal double quantum dot system

Within the scheme of quantum rate equations, we investigate the spin-resolved transport through a double quantum dot system with four ferromagnetic terminals. It is found that the injection efficiency of spin-polarized electrons can be significantly improved compared with single dot case. When the magnetization in one of four ferromagnetic terminals is antiparallel with the other three, the polarization rate of the current through one dot can be greatly enhanced, accompanied by the drastic decrease of the current polarization rate through the other one. The mechanism is the exchange interaction between electrons in the two quantum dots, which can be a promising candidate for the improvement of the spin injection efficiency.Comment: 10 pages and 5 figure

Development Power and Its Power Model: The Analytic Approach for Continuous Motivity of Economic Growth

Based on the Partial Distribution [F. Dai, 2001] and the theory of Development Power [F. Dai, 2004], this paper discusses the power model of relation between development power (DP) and productivity. The power model also supports the hypothesis [F. Dai, 2005] that there are three kinds of energy states in economy, i.e. normal state, strong state and super state, and DP is the continuous motivity to economic growth. By the power model of DP, we could interpret in analytic way that the diffusion of DP and the diversifications of economic development also might be occurred after the super state. Finally, the conclusions in this paper are researched in the empirical way, the results indicate the power model is better than the exponential model of DP in many cases, and we could get the inimitable outcomes in describing the macroeconomic process by the power model of DP.Development Power (DP), Partial Distribution, power model, macroeconomic analysis

The Logarithm Model of Development Power: A Tool to Analyze the Motivity of Economic Growth

After the discussions to exponential and power model [F. Dai, 2005], this paper points out there are three kinds of basic modes in the macroeconomic process, i.e., the exponential, power and logarithm mode, and discusses the logarithm model of Development Power (DP). By the analysis on logarithm model of DP, we will see the reasons, of which there are anomaly cycles in economic process, are just the alternate motion of DP accumulating and releasing. And that is also the reasons that there are the economic fluctuations in production markets. The logarithm model of DP can also describe the different characters of DP motion at the different stage, and indicates in analytic way that the diffusion of DP and the diversifications of economic productivity also might occur after an economic recession. The empirical researches are done about the conclusions in this paper, and the results express that the logarithm model is better than the power model and exponential model of DP in many cases. These three models of DP can not be replaced one another.Development Power (DP); Partial Distribution; logarithm model; macroeconomic analysis