International Journal of Modern Physics A

In this study, singly charm baryons ${\mathrm{\Lambda }}_c$, ${\mathrm{\Sigma }}_c$, ${\mathrm{\Xi }}_c$ and ${\mathrm{\Omega }}_c$ have been studied. The known hypercentral Constituent Quark Model (hCQM) has been subjected to an addition of second-order correction term to the mass in spin-dependent term. This has allowed to observe the expected spin-splitting in the correct order and modify the previous findings to a new level. All the other properties have been obtained ranging from magnetic moment to strong decay width along with the linearly observed Regge trajectories.

The goal of this study is to check which, if any, of the published versions of the pion and kaon fragmentation functions (FFs) is compatible with the STAR data on semi-inclusive pion and kaon production in proton–proton collisions, and on the basis of this analysis to make reliable predictions for the $p_T$ spectra of the pions and kaons in inclusive pion and kaon production at the future NICA proton–proton collider. The calculations are carried out in next-to-leading order (NLO) of perturbative quantum chromodynamics (pQCD), using the well-tested CTEQ6 parton distributions. We consider the following pion and kaon FFs — DSEHS-14 [D. de Florian, R. Sassot, M. Epele, R. J. Hernández-Pinto and M. Stratmann, Phys. Rev. D 91, 014035 (2015), 1410.6027], DSEHS-17 [D. de Florian, M. Epele, R. J. Hernandez-Pinto, R. Sassot and M. Stratmann, Phys. Rev. D 95, 094019 (2017), 1702.06353], LSS-15 [E. Leader, A. V. Sidorov and D. B. Stamenov, Phys. Rev. D 93, 074026 (2016), 1506.06381], HKNS-07 [M. Hirai, S. Kumano, T. H. Nagai and K. Sudoh, Phys. Rev. D 75, 094009 (2007), hep-ph/0702250] and AKK-08 [S. Albino, B. A. Kniehl and G. Kramer, Nucl. Phys. B 803, 42 (2008), 0803.2768]. Our analysis shows that within the experimental errors all tested sets of FFs provide a good fit to STAR data at the c.m. energy $\sqrt{S}=200\mathrm{\text{GeV}}$, and the best ones are both LSS-15 and DSEHS-14 for pions and DSEHS-17 for kaons. From comparison of the LO and NLO results it is clear that the latter fit data much better, specially in the region of small $p_T$. The NLO cross-sections are also less scale-$Q^2$ dependent, where $p_T/2\le Q\le 2p_T$, than the LO ones. In order to make predictions for NICA energies, we compare the NLO pQCD results with the existing experimental BES STAR data on semi-inclusive hadron production in the most peripheral Au+Au collisions where the nuclear effects can be neglected. The comparison for lower energy scales, like at NICA, shows that a purely pQCD approach is inadequate and suggests the necessity to take into account also higher-order effects of initial-state soft-gluon radiation. Nevertheless, these data on the $p_T$ spectra of ${\pi }^{+}$, $K^{+}$ and also the ratios ${\pi }^{-}/{\pi }^{+}$ and $K^{-}/K^{+}$ seem to favor LSS-15 and DSEHS-14 FFs for pions and DSEHS-17 for kaons, similarly as at the energy scale $\sqrt{S}=200$GeV.

We construct a supersymmetric quantum mechanical model in which the energy eigenvalues of the Hamiltonians are the products of Riemann zeta functions. We show that the trivial and nontrivial zeros of the Riemann zeta function naturally correspond to the vanishing ground state energies in this model. The model provides a natural form of supersymmetry.

The Duffin–Kemmer–Petiau (DKP) particle with spin 0 interacts with the Aharonov–Bohm (AB) magnetic vector potential and scalar Coulomb-type potential in the cosmic string space–times under the framework of rainbow gravity (RG). By using Bethe–Ansatz method, we obtain the energy eigenvalue and approximate solution to the wave function of the DKP particle with spin 0. We select two sets of rainbow functions and analyze their influence on the energy eigenvalue and wave functions. We find that the energy eigenvalue is determined by the parameters of the rainbow function. It further shows that the rainbow function affects the properties of the space–time where the DKP particle located, and also affects the distribution probability of DKP particles in the space.

In this work, we examined chromo-natural inflation in the context of warm inflation with constant and variable dissipation coefficients. We studied the cosmological perturbation theory in this model and obtained the scalar and tensor power spectra in each case. The sources of density fluctuations in this model are mainly the thermal fluctuations of the inflaton field like a general warm inflationary model. Finally, cosmological observables, namely, the spectral index and tensor-to-scalar ratio are calculated. It is found that the cosmological observables are consistent with observational Planck 2018 and BICEP bounds for sub-Planckian values of axion decay constant $f$ in case of temperature–inflaton-dependent dissipation coefficient. In case of the constant and temperature-dependent dissipation coefficient, the values of axion decay constant $f$ can be lowered below the GUT scale.

We explore the mathematical relationship between holographic Wilsonian renormalization group (HWRG) and stochastic quantization (SQ) of scalar field theory with its generic mass, self-interaction and $n$-multiple-trace deformation on the $d$-dimensional conformal boundary defined in AdS${}_{d+1}$ space–time. We understand that once we define our Euclidean action, $S_E$ as $S_E\equiv -2S_B$, then the stochastic process will reconstruct the HWRG data via solving Langevin equation and computing stochastic correlation functions. The $S_B$ is given by $S_B=S_{\mathrm{\text{ct}}}+S_{\mathrm{\text{def}}}$, where $S_{\mathrm{\text{ct}}}$ is the boundary counter term and $S_{\mathrm{\text{def}}}$ is the boundary deformation which gives a boundary condition. In our study, we choose the boundary condition adding (marginal)$n$-multiple-trace deformation to the holographic dual field theory. In this theory, we establish maps between fictitious time, $t$ evolution of stochastic $n$-point, ($2n-2$)-point correlation functions and the (AdS)radial, $r$ evolution of $n$-multiple-trace and ($2n-2$)-multiple-trace deformations, respectively, once we take identifications of $r=t$ and between some of the constants appearing in both sides.

In this paper, the constrained dispersionless BKP hierarchy are given by restricting the formal Laurent series ${ℒ}$ of the dispersionless BKP hierarchy to ${ℒ}=k+\frac{\mu (t)}{k-\rho (t)}+\frac{\mu (t)}{k+\rho (t)}$. Its additional symmetries are given by introducing vital formal Laurent series ${{𝒴}}_{2n+1}$. The additional flows form the nonabelian $\mathbb{Z}$-grading Lie algebra. Furthermore, the additional flows acting on $\mu (t)$ and $\rho (t)$ are presented.

We have investigated a model of colliding plain gravitational waves, proposed by Szekeres, whose structure of singularities is determined. We have evaluated a total energy of matter as a volume integral of the energy–momentum tensor (EMT), whose contributions arise only at these singularities. The total matter energy is conserved before a collision of two plane gravitational waves but decreases during the collision and becomes zero at the end of the collision. We thus interpret that this model of colliding plane gravitational waves is a space–time describing a pair annihilation of plan gravitational waves. We have also calculated a matter conserved charge proposed by the present author and his collaborators. The matter charge is indeed conserved but is zero due to a cancelation between two plain gravitational waves. This seems natural since nothing remains after a pair annihilation, and gives a hint on a physical interpretation of the conserved charge, which we call the gravitational charge. By modifying the space–time for the pair annihilation, we newly construct two types of a scattering plane gravitational wave and a pair creation of plane gravitational waves, and combining all, a Minkowski vacuum bottle, a Minkowski space–time surrounded by two moving plane gravitational waves.