Modern Physics Letters A

In this paper, we examine the radially excited states of B-mesons: $B^{\pm },B^{\pm \ast },B_s^{0\ast },B_s^0,B_c^{\pm \ast }$ and $B_c^{\pm }$-mesons. Our investigation uses the relativistic independent quark model, which relies on a flavor-independent average potential expressed in the scalar and vector square root form. We make phenomenological fit the potential model parameters, $a=0.885$ GeV, $U_0=-1.070$ GeV for calculation of 1S state of B-mesons: $B^{\pm }(5.272\mathrm{\text{GeV}}),B^{\pm \ast }$ (5.329GeV), $B_s^0(5.360\mathrm{\text{GeV}}),B_s^{0\ast }(5.429\mathrm{\text{GeV}}),B_C^{\pm }(6.0593\mathrm{\text{GeV}}),$ $B_C^{\pm \ast }(6.2604\mathrm{\text{GeV}})$, which aligns well with theoretical and experimental data. For higher radially excited states (2S, 3S, 4S, 5S), we adjust $U_0=-1.344$ GeV while keeping “a” fixed, yielding results consistent with other theoretical models. With these parameters, we compute the pseudoscalar and vector meson decay constants, magnetic transition rates, non-leptonic decay widths, branching fractions, rare decay widths, and semileptonic decay widths and branching fractions of the B-mesons. Our findings show reasonable agreement with lattice QCD calculations, experimental results and other theoretical predictions. For instance, our predicted radiative decay width for $B_c^{\ast }$ (1S) $\to$ $B_c$(1S)$\gamma$, sensitive to the $B_c^{\ast }$ and $B_c$, mass difference, can aid in experimentally determining the $B_c^{\ast }$, mass. Predicted non-leptonic branching fractions, such as $B^0\to D^{-}{\rho }^{+}(6.393\times {10}^{-3}),$ $B^0\to D^{-}{k}^{+}(2.148\times {10}^{-4})$ and $B_S^0\to D_S^{-}{k}^{+}(2.188\times {10}^{-4})$, align with PDG values of $(7.6\pm 1.2)\times {10}^{-3},(2.05\pm 0.08)\times {10}^{-4}$ and $(2.25\pm 0.12)\times {10}^{-4}$. Additionally, we calculate the dileptonic decays of $B^0\to {\mu }^{+}{\mu }^{-}(2.245\times {10}^{-10})$ and $B_S^0\to {\mu }^{+}{\mu }^{-}(3.506\times {10}^{-9})$, which agrees with CMS, LHCb and PDG results. Our semileptonic decays of $B^0$ and $B_S^0$ mesons are computed and compared with PDG results. Furthermore, the results obtained for mass difference, $\mathrm{\Delta }M(0.509{\mathrm{\text{ps}}}^{-1}$ and $17.699{\mathrm{\text{ps}}}^{-1})$, mixing parameters, $x_q(0.771$ and $26.82)$, ${\chi }_q$ (0.1866 and 0.4993) of $B^0-{\bar{B}}^0$ and $B_S^0-{\bar{B}}_S^0$ oscillations, shows good agreement with PDG data, validating our model.

In this study, we investigated quintessence and tachyon field dark energy (DE) models for the inhomogeneous and anisotropic Ruban universe in $f(R,T)$ gravitation theory. We utilized the Hubble parameter in the field equations as $\frac{\beta }{\sqrt{t+\alpha }}$ for the solutions. Since DE candidates are classified according to the $\frac{p}{\rho }$ values of the EoS parameter $\omega$, we obtained the p and $\rho$ solutions for each DE candidate and analyzed the scalar field (SF) and scalar potential solution. We also talked about the model’s physical characteristics and parameters with the help of a various of graphics for redshift z and cosmic time t. Additionally, the statefinder parameters, which are essential tools for distinguishing various dark energy models, have been explored.

In this paper, we quantitatively examine the dynamics of quantum resources, such as quantum coherence, degree of mixedness, fidelity, and the atomic entropy squeezing, in a quantum system of a two-level atom (TLA) driven by a phase noise laser (PNL) within the context of non-Markovian dynamics. The $l_1$ norm is used to quantify coherence, linear entropy to measure the degree of TLA mixedness, and entropy to detect the atomic squeezing. We demonstrate how these quantum resources can be controlled through a suitable selection of model parameters. Furthermore, we provide the optimal conditions required to manipulate these quantum resources based on changes in the damping coupling. Finally, we discuss the relationships among the quantum resources in the present quantum model.

In this paper, we investigate the effect of repulsive interaction between hadrons on the susceptibilities of conserved charges, namely baryon number (B), electric charge (Q) and strangeness (S). We estimate second-, fourth- and sixth-order susceptibilities of conserved charges, their differences, ratios and correlations within ambit of mean-field hadron resonance gas (MFHRG) model. We consider repulsive mean-field interaction among meson pairs, baryon pairs and antibaryon pairs separately and constrain them by confronting the results of various susceptibilities with the recent lattice quantum chromodynamics (LQCD) data. We find that the repulsive interactions between baryon–baryon pairs and antibaryon–antibaryon pairs are sufficient to describe the baryon susceptibilities of hadronic matter at temperatures below QCD transition temperature. However, small but finite mesonic repulsive interaction is needed to describe electric charge and strangeness susceptibilities. We finally conclude that the repulsive interaction between hadrons play a very important role in describing the thermodynamic properties of hadronic matter, especially near the quark–hadron phase transition temperature ($T_c$). The mean-field parameter for baryons ($K_B$) should be constrained in the range $0.40\le K_B\le 0.450\mathrm{\text{GeV}}{\mathrm{\text{fm}}}^3$ to get a good agreement of baryon susceptibilities with the LQCD results, whereas meson mean-field parameter $K_M\sim 0.05\mathrm{\text{GeV}}{\mathrm{\text{fm}}}^3$ must be included with $K_B$ to get a reasonable agreement of MFHRG model with the LQCD results for electric charge and strangeness susceptibilities.

In this paper, we consider a heavy quarkonium state in a hot QCD medium, namely the ground state of charmonium and bottomonium. The quark–antiquark potential is proposed in the form of a temperature-dependent Cornell potential, and is extended to include a temperature-dependent parameter. Then, for the proposed potential with different parametrizations of the Debye mass, the N-dimensional Schrödinger equation is analytically solved using the biconfluent Heun equation. The obtained energy eigenvalues and wave functions are employed to study the flavor dependence, the effect of dimensionality and the influence of the additional term on the mass and binding energy of 1S state of charmonium and bottomonium at finite temperature. The findings of this research are compared to those from past studies. We concluded that this work provides a simple and consistent description of quarkonium states at finite temperature in a hot QCD medium, highlighting the effect of noncompact extra dimensions and the flavor dependence of the binding energies of heavy quarkonia.

In this paper, we examine the stability condition of $f(T)$ gravity theory where T is the Torsion scalar using interacting and non-interacting models with the help of dynamical system. We let the $f(T)$ function be $f(T)=\alpha T+\beta$, where T is Torsion scalar and $\alpha$ and $\beta$ are the arbitrary constants. We calculated the critical points and study the stability behavior for this model. We analyze the system’s phase graphs and examined the physical interpretation. We demonstrate all of the cosmological parameters including ${\mathrm{\Omega }}_m$, ${\mathrm{\Omega }}_{\varphi }$, q, and ${\omega }_{\mathrm{\text{Tot}}}$ at each critical point and contrast them with values from observations. Then, we assume hybrid scale factor and transform it into the equation of redshift and time. Using this equation, we convert all the parameters into terms of redshift and analyze their behavior. Our model illustrates the Universe’s accelerating expansion. The energy conditions are examined in terms of redshift for the model. As a result, we conclude that our $f(T)$ model is stable and all the observed values are in agreement with observations.

In this paper, we study pair production of $\psi [1S]$ and $\psi [2S]$ charmonium states in the forward rapidity region of the LHCb experiment at the $\sqrt{s}=13$TeV using the improved color evaporation model and the parton Reggeization approach, which is a gauge invariant version of the $k_T$–factorization approach. Taking into account single and double parton scattering mechanisms and using the set of model parameters which have been fixed early, we compare our theoretical predictions with the recent LHCb experimental data as well as with another theoretical predictions. The numerical calculations are performed using the parton–level Monte–Carlo event generator KaTie and modified KMRW model for unintegrated parton distribution functions. We have found absolutely dominant role of the double parton scattering mechanism in the charmonium pair production at the LHCb.

The radiative capture ${}^{14}$C(p, $\gamma$)${}^{15}$N is analyzed within the framework of potential model (PM) and R-matrix framework. The capture cross-section was analyzed for non-resonant and resonant transitions within the pathways that involve radiative capture via electric dipole ($E1$), and magnetic dipole ($M1$) transitions. The non-resonant transitions include $E1$ via s- and d-wave capture. The resonant transitions include electric dipole ($E1$), and magnetic dipole ($M1$) from the three dominant resonant states above the threshold of p+${}^{14}$C to the ground state of ${}^{15}$N. Based on the total cross-section, the rates associated with p+${}^{14}$C $\to$${}^{15}$N+$\gamma$ have been analyzed. In this paper, the resonant capture rates dominate compared to the existing data because, at resonant energies the amplitude of the cross-sections have a dominant effect on the radiative capture rates within the T₉ = 1.