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The paper studies a strong coupling constant between π meson and octet baryon using the hard-wall AdS/QCD model, which considers SU(3)f symmetry-breaking effects. Briefly mentioned are profile functions for pseudoscalar meson and baryon fields. The obtained baryon coupling constants are in agreement with those obtained in theoretical calculations. [ABSTRACT FROM AUTHOR]

We look at the mass spectra of the D ± , D ± ∗ , D s ± ∗ , D s ± , B ± , B ± ∗ , B s 0 ∗ , B s 0 , B c ± ∗ , B c ± , ρ , π , and ω mesons using a relativistic square root potential. Before looking at the mass spectra, we have to figure out the model parameters, which are U 0 = − 1. 1 1 5 GeV and a = 0. 8 8 5 GeV. The calculated result of D ± (1. 8 6 1 GeV) , D ± ∗ (2. 0 1 0 GeV) , D s ± (1. 9 0 3 GeV) , D s ∗ ± (2. 1 1 2 GeV) , B ± (5. 2 6 4 GeV) , B ± ∗ (5. 3 2 7 GeV) , B s 0 (5. 3 4 5 GeV) , B s 0 ∗ (5. 4 2 3 GeV) , B C ± (5. 9 5 6 GeV) , B C ± ∗ (6. 2 7 7 GeV) , findings of this study exhibit a notable concurrence with the experimental observations and pertinent theoretical projections. We estimate the decay constant, leptonic decay width, semileptonic decay width, and branching fractions of pseudoscalar and vector mesons, specifically B and D mesons, while keeping the model parameters unchanged. The pseudoscalar decay constants and partial decay widths of "B and D-mesons" reasonably agree with the theoretical predictions, lattice quantum chromodynamics (LQCD) calculations, and experimental data. Moreover, we have efficiently found the values for these mesons' leptonic decay width and branching fraction, matching the experimental findings and theoretical forecasts. The calculated values of semileptonic decays are D 0 → π − e + ν e (2. 8 9 2 × 1 0 − 3) , D + → π 0 e + ν e (3. 6 6 9 × 1 0 − 3) , D + → ρ 0 e + ν e (1. 6 5 9 × 1 0 − 3) and D + → η ′ e + ν e (3. 1 7 × 1 0 − 4) , D S + → φ e + ν e (2. 5 9 9 × 1 0 − 2) , D S + → η e + ν e (2. 3 0 3 × 1 0 − 2) , the proximity of the observed results to experimental and certain theoretical models is evident. [ABSTRACT FROM AUTHOR]

This article elucidates the pivotal role of b-mesons and bottomonium states in exploring the existence and properties of hot QCD matter (commonly known as quark-gluon-plasma (QGP) produced within the crucible heavy-ion collision experiments). Owing to the complex and confounding nature of strong interaction force the direct detection of probing the hot QCD matter is not feasible. In light of this, investigating the dynamics of b-quarks and anti-quarks within the hot QCD medium emerges as an invaluable indirect probe. The impact of b-quarks and the mesons spans a spectrum of interesting domains regarding the physics of QCD at finite temperature, encompassing the QCD phase transition, color screening, quarkonia dissociation, heavy quark energy loss and collective flow, anisotropic aspects, and strongly coupled nature of hot QCD medium. These aspects underscore the indispensable nature of B-mesons in the quest to create and explore the complex nature of strong interaction force through the QGP/hot QCD matter. In this context, we mainly focus on works related to transport studies of b-mesons in hot QCD medium, lattice QCD, and effective field theory studies on bottomonium states, and finally, open quantum system frameworks to quarkonia to explore the properties of hot QCD medium in relativistic heavy-ion collision experiments. [ABSTRACT FROM AUTHOR]

Belle II collects data at the asymmetric electron-positron collider SuperKEKB, which operates with a centre-of-mass energy at, or close to, the mass of the Υ (4 S) resonance. The Υ (4 S) lies just above the kinematic threshold for B-meson-pair production, so Belle II collects a large sample of B + B - and B 0 B ¯ 0 pairs that are unaccompanied by other particles. The low-multiplicity final state and constrained kinematics allow many measurements with missing energy and neutral mesons in the final state that complement the B-physics measurements made by LHCb. In addition to B mesons, this center-of-mass energy has a similar cross section for electron-positron annihilation to c c ¯ and τ + τ - pairs, meaning Belle II also makes measurements of charm hadron and tau lepton properties. Finally, unique searches for hypothesized dark-sector particles with masses in the range 100 MeV–10 GeV are possible. This article reviews the current results from the Belle II experiment. [ABSTRACT FROM AUTHOR]

We overview the current status and future perspectives of the QCD-based method of light-cone sum rules. The two main versions of these sum rules, using light-meson and B-meson distribution amplitudes are introduced and the most important applications of the method are discussed. We also outline open problems and future perspectives of this method. [ABSTRACT FROM AUTHOR]

We discuss the main issues in dealing with heavy quarks on the lattice and shortly present the different approaches used. We discuss a selection of computations covering first the b-quark mass and the B (s) meson decay constants as the consolidated results (neglecting isospin breaking corrections). In the second part, we consider recent calculations of form factors for tree-level semileptonic decays with emphasis on the tensions between the results produced by different collaborations. We propose benchmark quantities and tests suited to investigate the origin of such tensions. Finally, we review computations of the bag parameters parameterising neutral meson mixing and provide an overview on a few recent developments in the field. [ABSTRACT FROM AUTHOR]

The Schwinger confinement mechanism stipulates that a massless fermion and a massless antifermion are confined as a massive boson when they interact in the Abelian QED interaction in (1+1)D.If we approximate light quarks as massless and apply the Schwinger confinement mechanism to quarks, we can infer that a light quark and a light antiquark interacting in the Abelian QED interaction are confined as a QED meson in (1+1)D. Similarly, a light quark and a light antiquark interacting in the QCD interaction in the quasi-Abelian approximation will be confined as a QCD meson in (1+1)D. The QED and QCD mesons in (1+1)D can represent physical mesons in (3+1)D when the flux tube radius is properly taken into account. Such a theory leads to a reasonable description of the masses of π 0 , η , and η ′ , and its extrapolation to the unknown QED sector yields an isoscalar QED meson at about 17 MeV and an isovector QED meson at about 38 MeV. The observations of the anomalous soft photons, the hypothetical X17 particle, and the hypothetical E38 particle bear promising evidence for the possible existence of the QED mesons. Pending further confirmation, they hold important implications on the properties on the quarks and their interactions. [ABSTRACT FROM AUTHOR]

The two-body leptonic decays of both light and heavy-charged mesons X l 2 ± are investigated in the first Born approximation in the presence of a monochromatic and circularly polarized laser field. As a result of using Volkov functions, the analytic study of these processes has brought a change in the parameters associated with each decay process. The decay width, lifetime, and branching ratio of each decay process are affected by increasing the classical parameter ξ of the meson. A comparison between the matter decay X l 2 + and that of the anti-matter X l 2 - in the presence of a circularly polarized laser wave, indicates that increasing laser field strength (increasing the classical parameter ξ ) can induce a slight dominance of matter over antimatter or vise versa. [ABSTRACT FROM AUTHOR]

The medium mass modification may lead to a squeezing effect. In the baryonic medium, the mass of D meson was expected to reduce and the in-medium masses of D + and D − may show a splitting effect, and the chemical potential of D meson may be not zero. We study the squeezing effect on the yield ratio D + ∕ D − with nonzero chemical potential. Due to the in-medium mass splitting, the squeezing effect on the momentum distributions of D + and D − are different. Without the squeezing effect, the yield ratio D + ∕ D − remains constant as the transverse momentum increases. The yield ratio D + ∕ D − is affected by the squeezing effect, resulting in a dependence on transverse momentum. An increase in transverse momentum leads to a decrease in the yield ratio, especially when there is a high chemical potential. Additionally, the in-medium mass splitting amplifies this phenomenon. The yield ratio D + ∕ D − with nonzero chemical potential approaches 1 when there is a large average in-medium mass reduction, which becomes more evident at higher transverse momentum. The study of the squeezing effect on the yield ratio D + ∕ D − with nonzero chemical potential may be meaningful for the CBM and PANDA experiments of the FAIR project at GSI. [ABSTRACT FROM AUTHOR]

The neutron skin of atomic nuclei impacts the structure of neutron-rich nuclei, but its accurate measurement is quite challenging. We present predictions for neutron skins and proton radii for light to medium mass nuclei by employing Covariant Density Functional Theory (CDFT) based on density-dependent meson-exchange interaction. Using our microscopic predictions, we find a linear correlation between the neutron skin and the isospin asymmetry. The calculations are also extended to find a linear relationship between proton and neutron radii of mirror nuclei. Using the charge symmetry property of nuclear forces, a correlation between the neutron skin of neutron-rich nuclei and difference between the proton radii of the corresponding mirror pair has also been investigated. The inclusion of ISB term is found to affect the mirror difference charge radii of 4 8 Ca- 4 8 Ni mirror pair. [ABSTRACT FROM AUTHOR]

In this note we study the tensor and vector exchange contributions to the elastic reactions involving the pseudoscalars mesons π + π - , K + K - and D + D - . In the case of the tensor-exchange contributions we assume that an intermediate tensor f 2 (1270) is dynamically generated from the interaction of two virtual ρ mesons, with the use of a pole approximation. The calculation of the two-loop amplitude is facilitated since the triangle loops can be factorized and computed separately. The results show very small contributions coming from the tensor-exchange mechanisms when compared with those from the vector-exchange processes. We compare our results for π π and K K ¯ scattering with those obtained in other works where the f 2 (1270) is considered as an ordinary q q ¯ meson. Our picture provides a smaller contribution but of similar order of magnitude for pion scattering and stabilizes the results in the case of K K ¯ , allowing us to make estimates for D D ¯ scattering. [ABSTRACT FROM AUTHOR]

We calculate the spectrum and wave functions (WFs) of various states of bottomonium( b b ¯ ) mesons using a non-relativistic quark potential model (NRQPM). The calculated WFs are used to compute the radiative widths of various states of b b ¯ . The strong decays widths of bottomonium states are also calculated using 3 P 0 model by choosing simple harmonic oscillator wave functions (SHOWFs). The β of SHOWFs for various states of the mesons are measured by fitting the numerical wave functions. The radiative and strong decay widths are used to calculate the branching ratios of b b ¯ mesons. We also compare our calculated masses and widths with available experimental data. On basis of this comparison, it is suggested that Υ (10860) is the 5S state of b b ¯ mesons. [ABSTRACT FROM AUTHOR]

In this paper, we study the mass spectra of heavy quarkonia and heavy-light mesons in a curved space-time with conical geometry induced by a topological defect. The interactions between particles are modeled by an extended version of the Cornell potential, namely the singularized harmonic potential. To compute energy levels as well as the corresponding wave functions, the Hamiltonian operator is constructed within a torsion free space-time with a point-like global monopole. Then the full spectrum is obtained by solving the Schrödinger equation using the bi-confluent Heun equation. It is found that the energy spectra and wave functions of each meson differ from their flat Minkowski space-time counterparts. To check the efficiency of our model, we use the results of calculation to reproduce the mass spectra of heavy quarkonia such as b b ¯ , c c ¯ and some heavy-light mesons such as b ¯ c and c s ¯ . The mass spectra are calculated up to 4 S state at different values of the topological defect, then compared with experimental data and some relevant theoretical works. Decay constants are also computed for the selected mesons. The effect of the topological defect is also analyzed in details. It is observed that, for small values of the parameter α , our predictions approach the experimental data, especially when α = 0.39 . Whereas for α close to unity, the mass spectrum of the system gives values quite far from the experiment. [ABSTRACT FROM AUTHOR]

The production cross-section of J/ψ pairs in proton-proton collisions at a centre-of-mass energy of s = 13 TeV is measured using a data sample corresponding to an integrated luminosity of 4.2 fb−1 collected by the LHCb experiment. The measurement is performed with both J/ψ mesons in the transverse momentum range 0 < pT< 14 GeV/c and rapidity range 2.0 < y < 4.5. The cross-section of this process is measured to be 16.36 ± 0.28 (stat) ± 0.88 (syst) nb. The contributions from single-parton scattering and double-parton scattering are separated based on the dependence of the cross-section on the absolute rapidity difference ∆y between the two J/ψ mesons. The effective cross-section of double-parton scattering is measured to be σeff = 13.1 ± 1.8 (stat) ± 2.3 (syst) mb. The distribution of the azimuthal angle ϕCS of one of the J/ψ mesons in the Collins-Soper frame and the pT-spectrum of the J/ψ pairs are also measured for the study of the gluon transverse-momentum dependent distributions inside protons. The extracted values of ⟨cos 2ϕCS⟩ and ⟨cos 4ϕCS⟩ are consistent with zero, but the presence of azimuthal asymmetry at a few percent level is allowed. [ABSTRACT FROM AUTHOR]

Based on recent progress in the systematic analysis of C and CP violation in the light-meson sector, we calculate the C-odd transition amplitudes η → π0ℓ+ℓ− and η′ → ηℓ+ℓ−. Focusing on long-distance contributions driven by the lowest-lying hadronic intermediate states, we work out the correlations between these beyond-the-Standard-Model signals and the Dalitz-plot asymmetries in η → π0π+π− and η′ → ηπ+π−, using dispersion theory. [ABSTRACT FROM AUTHOR]

Recent developments in the Standard Model analysis of semileptonic charged-current processes involving light quarks have revealed ~ 3σ tensions in Cabibbo universality tests involving meson, neutron, and nuclear beta decays. In this paper, we explore beyond the Standard Model explanations of this so-called Cabibbo Angle Anomaly in the framework of the Standard Model Effective Field Theory (SMEFT), including not only low-energy charged current processes ('L'), but also electroweak precision observables ('EW') and Drell-Yan collider processes ('C') that probe the same underlying physics across a broad range of energy scales. The resulting 'CLEW' framework not only allows one to test explanations of the Cabibbo Angle Anomaly, but is set up to provide near model-independent analyses with minimal assumptions on the flavor structure of the SMEFT operators. Besides the global analysis, we consider a large number of simpler scenarios, each with a subset of SMEFT operators, and investigate how much they improve upon the Standard Model fit. We find that the most favored scenarios, as judged by the Akaike Information Criterion, are those that involve right-handed charged currents. Additional interactions, namely oblique operators, terms modifying the Fermi constant, and operators involving right-handed neutral currents, play a role if the CDF determination of the W mass is included in the analysis. [ABSTRACT FROM AUTHOR]

This work presents the results of developing a set of electronic and chemical reactions for a plasma discharge in octafluoropropane (C3F8). Electronic reactions were obtained using the most relevant set of cross sections at the moment, taking into account experimentally known dissociation and ionization channels. Based on the dissociation products obtained during electronic reactions, a set of chemical reactions was adapted by analogy with the C4F8 reaction scheme from the literature. Next, the resulting complete set of reactions was tested against published experimental data on the concentration of electrons, negative ions, and electronegativity in a capacitive plasma discharge at different gas pressures and discharge input powers. For this purpose, a one-dimensional hydrodynamic drift-diffusion model was used. Reasonable agreement was obtained between the model and experimental data on electronegativity. Eventually, the resulting set of reactions was adapted for a two-dimensional hydrodynamic drift-diffusion model of an ICP discharge. The results of the calculations are two-dimensional distributions of radicals and ions, radical and ion composition of fluxes onto the substrate under conditions typical for industrial reactors. [ABSTRACT FROM AUTHOR]

There are two stages in the process of low-temperature nuclear fusion. The first stage corresponds to the bringing together of nuclei due to attraction to the negative charge in the internuclear space. This charge is formed by massive electron pairs located in a circular orbit. According to hadronic mechanics, the attraction of electrons (with opposite spins) is ensured by contact interaction. The second stage corresponds to the exchange of nuclei by pions, which begins when the nuclei approach each other to a distance equal to the strong interaction radius Rs, To estimate the maximum value of Rs*, the concepts of hadron mechanics about the πn0 - meson as a bound electron - positron (e- e 1+ pair are used. The main attention is paid to the visual interpretation of the electromagnetic interaction (e- e+) - pairs with nuclei, promoting the attraction of nuclei. [ABSTRACT FROM AUTHOR]

Based on recent progress in the systematic analysis of C and CP violation in the light-meson sector, we calculate the C-odd transition amplitudes η → π0ℓ+ℓ− and η′ → ηℓ+ℓ−. Focusing on long-distance contributions driven by the lowest-lying hadronic intermediate states, we work out the correlations between these beyond-the-Standard-Model signals and the Dalitz-plot asymmetries in η → π0π+π− and η′ → ηπ+π−, using dispersion theory. [ABSTRACT FROM AUTHOR]

Flavour changing neutral current (FCNC) processes are described by loop diagrams in the Standard Model (SM), while in 331 models, based on the gauge group SU (3) C × SU (3) L × U (1) X , they are dominated by tree-level exchanges of a new heavy neutral gauge boson Z ′ . By exploiting this feature, observables related to FCNC decays of K, B d and B s mesons can be considered in several variants of 331 models. The variants are distinguished by the value of a parameter β that plays a key role in this framework. Imposing constraints on the Δ F = 2 observables, we select possible ranges for the mass of the Z ′ boson in correspondence to the values β = ± k / 3 , with k = 1 , 2 . The results are used to determine the impact of 331 models on b → s processes and on the correlations among them, in the light of new experimental data recently released. [ABSTRACT FROM AUTHOR]

In this paper, we perform a complete non-relativistic study of the improved class of inversely quadratic Yukawa plus Hulthén potential (ICIQYHP) model in the context of three-dimensional non-relativistic non-commutative quantum phase-space (3D-NRNCPS) symmetries impacted by perturbed spin–orbit interaction and the external magnetic fields for the homogeneous (N2 and O2) and heterogeneous (CO and NO) diatomic molecules and the heavy meson systems, such as charmonium (cc) and bottomonium (bb) using generalized Bopp's shifts method and standard perturbation theory with the Greene–Aldrich approximation to the centrifugal barrier. The new non-relativistic energy equation and eigenfunction for the ICIQYHP in the presence of deformation phase–space are obtained to be sensitive to the atomic quantum numbers (j , l , s , and m), the mixed potential depths ( V 0 1 , V 2 1 , V 1 1 and V 3 1 ), the screening parameter δ 0 , and non-commutativity parameters (Φ / η ¯ , χ / χ ¯ and ζ / ζ ¯). The critical particular cases in 3D-NRNCPS symmetries have been obtained by adjusting the parameters of the ICIQYHP, such as the improved Hulthén potential, the improved Coulomb potential, and the improved inversely quadratic Yukawa potential. We have also studied the spin-averaged mass spectra of the heavy mesons and the thermo-magnetic properties under the class of inversely quadratic Yukawa plus Hulthén potential model in 3D-NRQM and 3D-NRNCPS symmetries. This research can potentially be applied to atomic, condensed matter, nuclear, molecular physics, and chemical physics. [ABSTRACT FROM AUTHOR]

The mass spectrum of heavy mesons using the Cornell potential is used for studying the quark–antiquark interaction. By appropriately modifying the potential parameters, the established potential models such as Kratzer's potential and the anharmonic one are applied in the Pekeris approximation. The Schrodinger equation for the Cornell potential setting is solved in this paper via the Nikiforov–Uvarov method. We acquire the confined-state energy spectrum to verify whether the outcome produced by this approach is accurate. The spectrum of energy formulation is used to determine the mass spectra of heavy quarkonium compounds, including charmonium and bottomonium. There is a comparison with various theoretical stances. The outcomes align well with both experimental data and other researchers' findings. [ABSTRACT FROM AUTHOR]

Flavour physics is one of the essential elements of the Standard Model (SM). Experimental studies of weak decays of B and D mesons at B factories have, together with the discovery of the Higgs boson at LHC, provided the final confirmation of the validity of the SM. The present generation of precision flavour physics experiments is looking for departures from the SM. We discuss studies of anomalies in b hadron decays, and studies of rare decays, which are a very promising method for searching for new physics. This article is part of the theme issue 'The particle-gravity frontier'. [ABSTRACT FROM AUTHOR]