Regular Series


Vol. 50 (2019), No. 1, pp. 1 – 115

Piaski, Poland; September 1–7, 2019

Massive Abelian Gauge Bosons in Front-form Hamiltonians

abstract

It is shown how gauge bosons can be supplied with a mass term using the Higgs mechanism for the purpose of regulating Hamiltonians of Abelian gauge theories in the front form of quantum dynamics.


A New and Finite Family of Solutions of Hydrodynamics. Part I: Fits to Pseudorapidity Distributions

abstract

We highlight some of the interesting properties of a new and finite, exact family of solutions of \(1+1\) dimensional perfect fluid relativistic hydrodynamics. After reviewing the main properties of this family of solutions, we present the formulas that connect it to the measured rapidity and pseudorapidity densities and illustrate the results with fits to \(p+p\) collisions at 8 TeV and Pb+Pb collisions at \(\sqrt {s_{NN}} = 5.02\) TeV.


Transverse Momentum \(p_{\mathrm {T}}\) Spectra of Strange Particles Production in Different Collisions at \(\sqrt {s_{NN}}\) = 2.76, 5.02 and 7 TeV

abstract

We analyse the transverse momentum \(p_{\rm T}\) spectra of strange particles \(K^{0}_{\mathrm s}\), \({\mit \Lambda }\), and \({\mit \Xi }^{-}\) produced in Pb+Pb collision at \(\sqrt {s_{NN}}= 2.76\) TeV, \(p+{\rm Pb}\) collision at \(\sqrt {s_{NN}} = 5.02\) TeV, and \(p+p\) collision at \(\sqrt {s_{NN}}= 7\) TeV in different multiplicity events measured by the CMS experiment at the Large Hadron Collider. The \(p_{\rm T}\) spectra of strange particles are fitted by the Tsallis statistics and Boltzmann statistics, respectively. The fitting parameters are studied as a function of the multiplicity events for all systems. The Tsallis temperature (\(T_{\rm Ts}\)), Boltzmann temperature (\(T_{\rm Boltz}\)), and radius of the system (\(R\)) increase with both the mass and strangeness number of the particle and also increase with the multiplicity events. The non-extensive parameter (\(q\)) decreases with the increase in the mass of the particle and also decrease with the increase in the multiplicity events which means that the system tends to thermodynamic stabilization. The extracted temperatures from the two statistics for the strange particles exhibit a linear correlation.


A New Type Nuclear Reaction on \(^{159}\)Tb in the Outgoing Channel Considering Observation of a Bound Dineutron

abstract

A new type nuclear reaction on \(^{159}\)Tb with neutrons and protons in the incident channels and a bound dineutron (\(^{2}n\)) in the output channel is considered based on available experimental observations. The dineutron is assumed to be separated from the volume but not from the potential well of the residual nucleus. Such a configuration represents a nuclear system with a satellite dineutron located at a distance of few fm from the surface of the residual nucleus. Due to dineutron disintegration, the decay products are assumed to interact with the residual nuclei, leading to their transformations much faster than expected.


On Bogomolny Equations in the Skyrme Model

abstract

Using the concept of strong necessary conditions (CSNC), we derive a complete decomposition of the minimal Skyrme model into a sum of three coupled BPS submodels with the same topological bound. The bounds are saturated if corresponding Bogomolny equations, different for each submodel, are obeyed.


Phase Transitions in Percolation Phenomenon for a Tree Model

abstract

The stability of a tree model is studied by randomly and preferentially selecting edges, including adding and removing edges, respectively. Firstly, the critical point of the phase transition in the percolation phenomenon is determined according to the number of connected components with different sizes. Then the feature of the phase transition is distinguished according to the distribution of the connected components with respect to a cluster size at the critical point. The Monte-Carlo numerical results show that the phase transitions in the evolving and fragmentation processes for the Erdös–Rényi tree are continuous. For the product rule tree, however, the evolving process undergoes a discontinuous phase transition, while the phase transition in the fragmentation process is continuous.


Synchronization of Complex Network Based on the Theory of Gravitational Field

abstract

Based on the conception of gravitational field, the issue of synchronization of complex network turns to the interaction and motion of particles under a physical field. By the design of coupling factor based on velocity, the synchronization of complex network is obtained where the dynamics of those nodes may be discontinuous and different from each other. Unlike those common methods of synchronization, this new approach is not limited in any desired governing equation of motion. According to the idea of approximation, the conditions of network synchronization and the synchronous orbit equation in the gravitational field are pointed out. The speed of synchronization is positively related to the coefficient of gravity. Synchronization was obtained in complex network with 51 and 501 nodes of piecewise linear Chen systems, Sprott systems and Lorenz systems, which shows the effectiveness of the proposed method.


ERRATUM for Acta Phys. Pol. B 49, 1865 (2018)

Quark Binding Potential and QGP


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