Pramana最新文献

Recent research has indicated that the standard model (SM), while historically highly effective, is found to be insufficient due to its prediction of zero mass for neutrinos. With the exception of a few, the majority of the parameters related to neutrinos have been determined by neutrino oscillation experiments with excellent precision. Experiments on neutrino oscillation and neutrino mixing have shown that neutrinos are massive. To fill in gaps, discrete symmetries are becoming more common alongside continuous symmetries while describing the observed pattern of neutrino mixing. Here, we present a (T_7) flavour symmetry to explain the masses of charged leptons and neutrinos. The light neutrino mass matrix is derived using seesaw mechanism of type I, which involves the Dirac neutrino mass matrix as well as the right-handed neutrino mass matrix. For normal and inverted mass hierarchies, we estimate the Pontecorvo–Maki–Nakagawa–Sakata matrix ((U_{textrm{PMNS}})), three mixing angles, (theta _{12}), (theta _{23}) and (theta _{13}), the masses of three neutrinos, effective Majorana neutrino mass parameter (langle m_{ee} rangle ) and the other model parameters by using a powerful meta-heuristic and population-based optimisation algorithm, i.e. particle swarm optimisation (PSO).

This research extensively investigates the solitary wave solutions of the time-fractional Murray equation (TFME), a prevalent framework in diverse scientific and engineering disciplines. Three mathematical methods, the extended simple equation method, the modified extended auxiliary equation mapping method and the modified F-expansion method, are employed to derive analytical solutions in the form of trigonometric, hyperbolic, exponential and rational functions. To analyse the physical behaviour of the concerned model, some solutions are plotted in two and three dimensions by imparting particular values to the parameters under the constraint condition of each selective solution. Mathematica 13.0, the computational software, is used to handle all calculations as well as all plotted graphs of the concerned solutions. The derived results have numerous applications to understand the fluid dynamics and wave propagation, particularly in biological systems and potentially in modelling tsunami waves. Hence, this study has applications in nonlinear science. It is vital to perceive that our proposed methods are genuine, suitable and well-ordered for nonlinear fractional partial differential equations (NLFPDEs).

In this work, we study the E1 decay processes, (^3P_1) (rightarrow ) (^3S_1gamma ) and (^3S_1) (rightarrow ) (^3P_1gamma ), in the framework of Bethe–Salpeter equation and calculate their decay widths. We have used algebraic forms of the Salpeter wave functions obtained through the analytic solutions of the mass spectral equations for the ground and excited states of (^3S_1) and (^3P_1) equal mass charmonia in approximate harmonic oscillator basis to do analytic calculations of their decay widths. These decay widths have been compared with data and other models.

The nanofluids of the ternary hybrid provide one special benefit that reduces usage of energy, enhances machine production and increases cooling. In this study, the cooling structure of the cylindrical battery packs are explained and their flow models are set up. For this purpose, this article describes a laminar hybrid convectional inactive ternary hybrid’s point flow nanofluid in the presence of thermal emission. Used bvp4c method is used to solve transformed resulting partial differential equation (PDEs). Three types of nanofluids, (hbox {Fe}_{3}hbox {O}_{4})–(hbox {H}_{2})O, Zn–(hbox {H}_{2})O and (hbox {TiO}_{2})–(hbox {H}_{2})O, that have heat transfer properties, are analysed in depth. We identified that for the cylindrical battery pack, (hbox {Fe}_{3}hbox {O}_{4})–(hbox {H}_{2})O nanofluid is one of the excellent coolants. Further, there is a 73.2652% increase in rate of heat transfer in (hbox {Fe}_{3}hbox {O}_{4})–(hbox {H}_{2})O NFs, 68.441% increase in (hbox {Fe}_{3}hbox {O}_{4}+hbox {Zn}!!-!!hbox {H}_{2})O hybrid nanofluids (HNFs) and 64.9944% increase in (hbox {Fe}_{3}hbox {O}_{4}+hbox {Zn}+hbox {TiO}_{2}!!-!!hbox {H}_{2})O ternary hybrid nanofluids (THNFs).

The hybrid nanofluids (HNFs) have superior thermal impact and stability than traditional nanofluids, making them more suitable for peak thermal results in thermal systems and solar energy. Furthermore, artificial neural network (ANN) improves the accuracy and thermal aspects of HNF with optimised results. This analysis presents optimised thermal results associated with the flow of HNF due to the permeable porous surface with mass suction effects. Hybrid nanofluid properties are accounted for by using the suspension of gold (Au) and silver (Ag) nanoparticles with blood as the base liquid. The nonlinear applications of radiated phenomenon have been considered. The modification in heat and concentration equations are done by following the Cattaneo–Christov model. The concentration of HNF is observed using chemical reaction. Artificial neural network (ANN) simulations are performed to validate and optimise thermal results. Convective heat constraints are implemented to observe the thermal simulations. Computations are numerically simulated with the help of shooting scheme. The results for mono-nanofluid (MNF) and HNF are compared. It is observed that the suspension of HNF is more suitable for enhancing heat transfer systems. Temperature profile increases using suction phenomenon and porous media.

We show that the inverted versions of the Mathews–Lakshmanan and Higgs oscillator systems admit closed-form bound states within the Dunkl formalism. Conditions for the existence and number of bound states are derived.

The current study explores a fascinating plasma system in which ion-acoustic cnoidal waves arise and their dynamics is shaped by the interaction of positron, thermal and quantum processes. Degenerate electrons, positrons and warm ions in an unmagnetised environment make up the present plasma system. The Korteweg–de Vries (KdV) equation is developed using the reductive perturbation technique and modified for periodic waves by applying suitable boundary conditions. A preference for compressive ion-acoustic cnoidal waves is shown by the system’s support for hump-shaped (positive potential) periodic structures. Wave amplitude, frequency and wavelength correlations are shown by periodic solutions. The influence of several variables, including the ion temperature (sigma _{i}), positron temperature (sigma _{p}), positron density p and quantum parameter H, is examined in this work. The effects of these variables on the dispersion and nonlinear behaviour of the plasma system are investigated. When positron density (p), positron temperature ((sigma _{p})), thermal effects through ion temperature ((sigma _{i})) and quantum effects (H) are included, the amplitude of the cnoidal wave increases. It has been observed that the amplitude of moving waves increases both their frequency and wavelength. This implies that in this plasma structure, higher frequencies and longer wavelengths are linked to waves with bigger amplitudes.

This study examines the Painlevé integrability and complex dynamics of a dispersive coupled Burgers system, focussing on its fractal and chaotic structures. The Painlevé test is performed to determine the system’s integrability. Analytical solutions are derived using the Riccati method, while logarithmic, sine, cosine and Jacobi elliptic functions are employed to investigate the emergence of fractal structures. The chaotic nature of the system is further analysed through Poincaré section and Lyapunov exponent computations. The results provide valuable insights into the nonlinear wave interactions, pattern formation and turbulence modelling. This system has potential applications in fluid dynamics, particularly in describing shock waves and turbulence in compressible flows. Moreover, understanding the integrability, fractality and chaos in the present system can lead to advancement in predictive modelling across various scientific and engineering disciplines.

The E-gamma over spin (E-GOS) ratio, defined as (R_{mathrm {E-GOS}}(I)=E_{gamma }(Irightarrow I-2)/I), serves as a powerful tool in examining the transitions between vibrational and rotational structures. The mass region (100 le A le 112) has been recognised as a region of interest for such transitions, especially from (gamma )-soft/vibrational to rotational structures. However, recent studies of nuclei, such as (^{104})Pd and (^{106,108,110})Cd, have revealed an exotic interesting phenomenon: a transition from (gamma )-soft/vibrational to antimagnetic rotational behaviour along the yrast line. To explore this transition in a systematic manner, we have calculated two quantities: the average of the E-GOS ratio (({overline{R}}_{mathrm{E-GOS}})) and the gradient of the E-GOS ratio ((g=frac{triangle R_{mathrm{E-GOS}}}{triangle I})) at the band-head for both (gamma )-soft/vibrational and antimagnetic rotational modes within a specific spin range.

Processes that take place in the participant and spectator regions of interacting nuclei poses a significant obstacle to comprehend the nucleus–nucleus (A–A) interactions, given the central character of the reactions. An essential parameter for gaining a thorough understanding of the response processes in A–A interactions is the analysis of angular distributions (ADs) in the final-state particles in the target fragmentation zone. By offering a full 4(pi ) angular coverage, nuclear emulsion detectors (NEDs) enable almost thresholdless detection of shower, black and grey particles, referred to as fast target protons (FTP). The ADs of the FTP released in contact with emulsion nuclei at 1 A GeV of (^{84})Kr are reported. These ADs are examined using the modified Maxwell–Boltzmann statistical (MBS) model for a range of (N_{h})-values (target sizes) and Q-values (projectile spectator charges). It is evident that the ADs of these target protons satisfy the nuclear limiting fragmentation (NLF) theory, which is unaffected by the (N_{h})-values and Q-values. It is also observed that all event group ADs have maxima located at around (60^{circ }). For each collection of events, the forward–backward asymmetry ratio (F/B) is examined together with the computed statistical moments ((M=langle theta rangle ), (sigma ^{2}), (chi _{0}), (omega )) of the distributions. Results presented by other physicists are compared with the ADs of FTP.