Chiral expansion of the π0→γγ\pi^0\rightarrow\gamma\gamma decay width

A chiral field theory of mesons has been applied to study the contribution of the current quark masses to the $\pi^0\rightarrow\gamma\gamma$ decay width at the next leading order. $2\%$ enhancement has been predicted and there is no new parameter.Comment: 9 page

Sea flavor content of octet baryons and intrinsic five-quark Fock states

Sea quark contents of the octet baryons are investigated by employing an extended chiral constituent quark approach, which embodies higher Fock five-quark components in the baryons wave-functions. The well-known flavor asymmetry of the nucleon sea $\bar{d}-\bar{u}$, is used as input to predict the probabilities of $\bar{u}$, $\bar{d}$ and $\bar{s}$ in the nucleon, $\Lambda$, $\Sigma$ and $\Xi$ baryons, due to the intrinsic five-quark components in the baryons wave functions.Comment: 22 page

A novel micro-separator using the capillary separation effect with locally populated micro-pin-fin structure

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.Phase separation is an important process in many chemical engineering applications, such as reactive processes and thermal separation processes of components. In this paper, a novel micro-separator was proposed using the capillary separation effect. The micro-pin-fins are locally populated in a rectangular microchannel, forming an enclosed region with micro pores as the boundaries. Hence, the microchannel cross section is divided into two symmetrical side regions closed to the microchannel side wall and a center enclosed region. When a two-phase stream interacts with the enclosed region boundary with micro-pores, the gas phase is prevented from entering the center enclosed region to enforce the gas phase flowing in the two side regions. Meanwhile, the liquid phase is flowing towards the center enclosed region. As a result, the twophases are separated. The effect of the separator configuration parameters such as pin-fin size and distribution is also analyzed based on the computation results. The effect of phase separation is more obvious when the cross section area of side regions is decreased

Environment-dependent dissipation in quantum Brownian motion

The dissipative dynamics of a quantum Brownian particle is studied for different types of environment. We derive analytic results for the time evolution of the mean energy of the system for Ohmic, sub-Ohmic and super-Ohmic environments, without performing the Markovian approximation. Our results allow to establish a direct link between the form of the environmental spectrum and the thermalization dynamics. This in turn leads to a natural explanation of the microscopic physical processes ruling the system time evolution both in the short-time non-Markovian region and in the long-time Markovian one. Our comparative study of thermalization for different environments sheds light on the physical contexts in which non-Markovian dissipation effects are dominant.Comment: 10 pages, 6 figures, v2: added new references and paragraph

Critical Temperature Tc and Charging Energy Ec between B-B layers of Superconducting diboride materials MgB2 in 3D JJA model

The diboride materials MB2 (M = Mg, Be, Pb, etc.) are discussed on the basis of the 3D Josephson junction array (JJA) model due to Kawabata-Shenoy-Bishop, in terms of the B-B layers in the diborides analogous to the Cu-O ones in the cuprates. We propose a possibility of superconducting materials with the MgB2-type structure which exhibit higher critical temperature Tc over 39K of MgB2. We point out a role of interstitial ionic atoms (e.g., Mg in MgB2) as capacitors between the B-B layers, which reduce the charging coupling energy in JJA.Comment: 3 pages, 1 figure included; to be published in J. Phys. Soc. Jpn. 70, No.10 (2001

Entanglement enhancement and postselection for two atoms interacting with thermal light

The evolution of entanglement for two identical two-level atoms coupled to a resonant thermal field is studied for two different families of input states. Entanglement enhancement is predicted for a well defined region of the parameter space of one of these families. The most intriguing result is the possibility of probabilistic production of maximally entangled atomic states even if the input atomic state is factorized and the corresponding output state is separable.Comment: accepted for publication in J. Phys.