We present an analytical investigation of the creation of neutral scalar particle–antiparticle pair in the spacetime of a cosmic string under the combined influence of Coulomb-type interactions and a KG-oscillator–type nonminimal coupling. The scalar field is described by a modified Klein–Gordon equation including scalar, minimally coupled vector, and nonminimally coupled vector interactions. Exact solutions for the field modes are obtained, allowing the Bogoliubov coefficients, particle production probability, and number density to be derived explicitly. Our analysis reveals that the nontrivial topology of the cosmic string spacetime, together with the confining effect of the KG-oscillator–type nonminimal coupling, plays a crucial role in enhancing vacuum instability. We show that Coulomb-type interactions introduce an additional control mechanism that can significantly amplify particle creation, even in regimes where minimal coupling alone does not lead to vacuum decay. The dependence of the production rate on the cosmic string parameter and the quantum numbers is analyzed in detail. These results provide a unified analytical framework for understanding scalar pair creation in topologically nontrivial spacetimes and may be relevant to early-universe particle generation as well as analogue gravity systems.
The concept of self-similarity in the internal structure of the proton, rooted in scale invariance and fractal geometry, provides an intriguing framework for understanding the behaviour of parton distribution functions (PDFs), particularly in the small x region probed in deep inelastic scattering (DIS). Phenomenological models based on self-similarity have been shown to reproduce key features of experimental data, suggesting that recursive scaling patterns may play an important role in partonic dynamics. In this work, we present an overview of scale-invariant descriptions of proton structure, focusing on self-similar models developed in earlier studies and their phenomenological implications for structure functions and parton distributions. We then explore possible conceptual connections between these fractal-inspired descriptions and modern holographic approaches to QCD, particularly within the framework of light-front holographic QCD. By comparing the scaling behaviour appearing in phenomenological models with the geometric structure underlying holographic QCD, we highlight qualitative correspondences that suggest a broader role of scale invariance in proton structure. Although the connection remains interpretive rather than derivational, it offers a complementary perspective of how fractal-like scaling observed in DIS may relate to geometric scaling in holographic descriptions of QCD.
We investigate the phenomenological consequences of a dimension-6 operator H dagger H3/Lambda 2, Lambda is the effective scale at which new physics takes over, which modifies the scalar potential of the standard model and can induce a strong first-order electroweak phase transition (SFOEWPT). We estimate the lower limit on the effective scale Lambda to be 515 GeV from the di-Higgs production cross section measured by the LHC. We analyze the associated collider and cosmological signatures in a unified framework, emphasizing the complementarity between gravitational wave (GW) observations and multi-Higgs production at hadron colliders. Using one-loop and finite-temperature effective potential techniques, we identify the parameter space where SFOEWPT occurs and compute the resulting stochastic GW spectra. We show that for cutoff scales Lambda less than or similar to 750 GeV, the predicted GW signal lies within the sensitivity reach of future interferometers such as LISA, DECIGO, and BBO. At the same time, such low-scale scenarios also enhance di-Higgs and tri-Higgs production cross sections, making them testable at the HL-LHC, HE-LHC, and FCC-hh. We derive current bounds on Lambda from Run-II di-Higgs searches and demonstrate how future multi-Higgs measurements can probe the same region favored by GW observability. Our results highlight the power of combining collider and GW experiments to probe extended scalar interactions and the nature of electroweak symmetry breaking.
In this paper, we presented an approximate analytical treatment of the Coulomb plus logarithmic potential using perturbation theory to investigate the mass spectra of bottomonium and charmonium mesons for the low-order quantum states. The derived energy equation, to first-order corrections, was employed to model the free potential parameters through fitting to experimental data of the Particle Data Group. The proposed potential successfully reproduces asymptotic freedom at short distances through one-gluon exchange interactions and quark confinement at large distances, which are the essential features of the strong interactions in Quantum chromodynamics theory. The calculated bottomonium masses exhibited excellent agreement with experimental values, yielding an absolute percentage average deviation (APAD) of 0.24
In this work, the radial Schrodinger equation with a nonrelativistic quark potential model (NRQPM) is solved numerically by employing the shooting method. Calculated numerical wave functions (or solutions) are used to compute the masses, root mean square (RMS) radii, E1, M1 radiative transition widths, annihilation decay widths, and branching ratios of S, P, D, and F states of toponium tt & strns;. Calculated results are compared with recently available theoretical data. This work will be helpful for experimentalists in gaining a deeper understanding of quasibound toponium states.
