abstract

We compute the soft anomalous dimension (SAD) matrices for production of massive quarks \(Q\) and \(\bar {Q}\) in association with a gluon jet, from massless quarks \(q\) and antiquarks \(\bar {q}\): \(q\bar {q}\rightarrow Q\bar {Q}g\), and in the gluon scattering \(gg\rightarrow Q\bar {Q}g\). To analyse the behaviour of the eigenvalues of SAD matrices, we perform numerical studies of their eigensystems at two special kinematical configurations.

abstract

The effect of quark–antiquark potential on the dissociation energy and critical screening length of heavy meson such as \(b\bar {b}\) and \(c\bar {c}\) have been investigated when the respective meson is in Quark–Gluon Plasma (QGP). The different types of interquark potential have been used, which get screened in the QGP medium. The dissociation energy and critical screening length have been studied for both ground and excited states. It has been observed that the form of interquark potential has a substantial effect on the critical screening length when the meson is in QGP. A comparison with other theoretical studies is made.

abstract

A new event mixing constraint, namely invariant-mass/energy hierarchy correspondence (IMEHC) cut, is introduced for the low-multiplicity event mixing technique for the purpose of measuring Bose–Einstein correlations (BEC) in exclusive reactions with \(\pi \pi X\) final-state particles. The mixing cut is relevant to the hierarchy of the invariant mass of \(\pi X\) system and two bosons’ energy hierarchy. Numerical tests are performed to check the validity of the new mixing method. As long as the measurements of BEC parameters \(r_0\) and \(\lambda _2\) are considered, this new mixing method is effective to observe BEC effects, and the systematic bias of \(r_0\) and \(\lambda _2\) is smaller than the previously proposed mixing cut.

abstract

We show that the transition laws for a 2-connection can be recovered by discretizing the base 2-space of a 2-bundle into an Euclidean hypercubic lattice. The aim of this work is to serve as an example of how important results in higher gauge theory, which have been derived in a continuous setting, can also be derived in the lattice scheme.

abstract

A description of \(N\)-electron systems on the level of Dirac–Coulomb (DC) equation in many cases is either unfeasible or unnecessary. In this work, the \(N\)-particle DC equation has been simplified. The simplified DC Hamiltonians, defined on a reduced \(N\)-electron Dirac spinor space, are correct to the order of \(\alpha ^2\). Simplified DC equations retain linearity and do not introduce any inverse operators and singularities. The solutions of the corresponding eigenvalue problem are correct to \(\alpha ^2\), but they also contain terms of higher order. In the case of one-particle, the simplified DC Hamiltonian is equal to the exact Dirac one. As an example, the simplified eigenvalue problems have been solved for the case of two noninteracting electrons. The energies are more accurate than the ones derived from the Pauli approximation (due to the higher order terms). The method may be easily extended to obtain Hamiltonians correct to an arbitrary order in \(\alpha \).

abstract

Considering probability distribution as a function of the average density \(\bar {\rho }\) computed for 424 extrasolar planets, we identify three log-normal Gaussian population components. The two most populous components at \(\bar {\rho }\simeq 0.7\) g/cc and \(\bar {\rho }\simeq 7\) g/cc are the ice/gas giants and iron/rock super-Earths, respectively. A third component at \(\bar {\rho }\simeq 30\) g/cc is consistent with brown dwarfs, i.e. , electron degeneracy supported objects. We note presence of several extreme density planetary objects.

abstract

The adaptive dual synchronization of chaotic (hyperchaotic) complex systems with uncertain parameters has been investigated. The analytical control functions are derived using a theorem to synchronize the chaotic (hyperchaotic) solutions of these systems. The adaptive dual synchronization between the chaotic complex Chen and Lorenz systems is introduced as an example, and another example is used to test the validity of the technique of this paper. Other examples of chaotic or hyperchaotic complex systems can be similarly studied. Based on the up-to-date laws, the parameters of the drive systems can be identified. The image encryption technique based on the adaptive dual synchronization of chaotic complex Chen and Lorenz systems is presented for gray and color images in the same time. Meantime, in the receiver side, information can be recovered successfully by adaptive technique. The presented technique is robust with respect to different levels of white Gaussian noise. The communication channel as well as the effect of the increase of noise are big challenge which have not been considered. Numerical simulations are given to verify the feasibility of our proposed synchronization and better performance of image encryption technique in terms of histogram, robustness to noise and visual imperceptibility.

abstract

Virus capsids in interchromatin corrals of a cell nucleus are experimentally known to exhibit anomalous diffusion as well as normal diffusion, leading to the Gaussian distribution of the diffusion-exponent fluctuations over the corrals. Here, the sojourn-time distribution of the virus capsid in local areas of the corral, i.e. , probability distribution of the sojourn time characterizing diffusion in the local areas, is examined. Such an area is regarded as a virtual cubic block, the diffusion property in which is normal or anomalous. The distribution, in which the Gaussian fluctuation is incorporated, is shown to tend to slowly decay. Then, the block-size dependence of average sojourn time is discussed. A comment is also made on (non-)Markovianity of the process of moving through the blocks.