Narrow Results

The thermal mass spectra of scalar and pseudo-scalar mesons are studied in an IR-improved soft-wall AdS/QCD model. The Reissner–Nordstrom AdS black hole metric is introduced to describe both the finite temperature and density effects. The thermal spectral function is computed, which shows that the position of peak moves toward a smaller value and the width of peak also broadens to a larger value as the temperature increases. The critical temperature at which the peaks are completely dissolved has been found to be around T_c≃160~200 MeV. The effect of chemical potential is shown to be the same as the one caused by the temperature. It is found that when the temperature approaches to zero T≈0, the melting down of mesons occurs at the scaled critical chemical potential μ₀/κ≈2.2~2.4 GeV.

An application of the recently introduced method [M. Çapak et al., J. Math. Phys. 52, 102102 (2011)] to the bound-state eigenvalue problem in the elementary quarkonium potential V(r) = -a/r + br + cr² is described, proved and illustrated for and systems. The quasi- and conditionally-exactly solvable spin-averaged mass spectra of heavy quarkonia are obtained in compact forms. The comparison of the present predictions with those of other theories in the related literature, together with the available data, has shown the success of the model used in this work and also revealed that the use of different confinings in the perturbed Coulomb potential descriptions has no considerable effect on the mass spectra of such systems.

In this paper, we study the mass spectra of D_s mesons, such as D_s, and D_s1. In the simulation, we use N_f = 2 twisted mass lattice QCD gauge configurations generated by the European Twisted Mass Collaboration (ETMC). The simulation is performed on lattices with lattice spacings a = 0.067 fm and lattice size 32³×64, and a = 0.085 fm and lattice size 24³×48, respectively. Our numerical results for the mass spectra of D_s mesons reached impressive agreement with the experimental data.

Heavy $c\bar{c}$ and $b\bar{b}$ quarkonia are considered as systems confined within a hard-wall potential shaped after a linear combination of a cotangent — with a square co-secant function. Wave functions and energy spectra are then obtained in closed forms in solving by the Nikiforov–Uvarov method the associated radial Schrödinger equation in the presence of a centrifugal term. The interest in this potential is that in one parametrization, it can account for a conformal symmetry of the strong interaction, and in another for its perturbation, a reason for which we here employ it to study status of conformal symmetry in the heavy flavor sector. The resulting predictions on heavy quarkonia mass spectra and root mean square radii are compared with the available experimental data, as well as with predictions by other theoretical approaches. We observe that a relatively small conformal symmetry perturbing term in the potential suffices to achieve good agreement with data.

Here, analytical expressions of energy eigenvalues and eigen functions for a generalized Cornell potential are obtained by solving the non-relativistic Schrodinger equation using the Nikiforov–Uvarov functional analysis method along with Greene–Aldrich approximation. Energy spectra of three physically important potentials viz the pseudoharmonic, the Kratzer and the Coulomb perturbed potentials are derived from the general results. Further, within the framework of the Kratzer potential, energy eigenvalue spectra of diatomic molecules $\mathrm{\text{CO}}$, $\mathrm{\text{NO}}$, ${\mathrm{\text{O}}}_2$, $\mathrm{\text{LiH}}$ and $\mathrm{\text{HCl}}$ are computed. The mass spectra of two heavy mesons are also investigated using the Coulomb perturbed potential, a form of the generalized Cornell potential. The obtained results are in good agreement with the results of others studies. The study is further extended to calculate and draw the partition function and other associated thermodynamic quantities for heavy mesons.

The mass spectrum of $b\bar{b}$ states has been obtained using the phenomenological relativistic quark model (RQM). The Hamiltonian used in the investigation has confinement potential and confined one gluon exchange potential (COGEP). In the framework of RQM a study of $M1$ and $E1$ radiative decays of $b\bar{b}$ states has been made. An overall agreement is obtained with the experimental masses and decay widths. The possibility that some of the excited $s$ wave $b\bar{b}$ states being exotic states is explored.

Based on the relativistic quark model and the infinitesimally shifted Gaussian basis function method, we investigate the mass spectra of double-bottom baryons systematically. In the $\rho$-mode which appears lower in energy than the other excited modes, we obtain the allowed quantum states and perform a systematic study of the mass spectra of the ${\mathrm{\Xi }}_{bb}$ and ${\mathrm{\Omega }}_{bb}$ families. We analyze the root mean square radii and quark radial probability density distributions to deeply understand the structure of the heavy baryons. Meanwhile, the mass spectra allow us to successfully construct the Regge trajectories in the $(J,M^2)$ plane. We also predict the masses of the ground states of double-bottom baryons and discuss the differences between the structures of our spectra and those from other theoretical methods. At last, the shell structure of the double-bottom baryon spectra is shown from which one could get a bird’s-eye view of the mass spectra. In this paper, we also make a hypothesis that the heavy baryon excitation may be dominated by the excitation of heavy quarks in the heavy quark limit. It could help to deepen the understanding of heavy baryons structure.

In this paper, we determine the radial and orbital states mass spectra of the triply heavy baryon ${\mathrm{\Omega }}_{bbc}$ with total spin $S=1∕2$ and 3/2 using the hypercentral constituent quark model (hCOM). The mass spectra are obtained by incorporating the color Coulomb plus linear confining term and the harmonic oscillator potential with first-order correction. Additionally, we considered spin–spin, spin-orbit and tensor interactions for hyperfine splitting calculation. Our computed mass spectra of the ${\mathrm{\Omega }}_{bbc}$ baryon is compared with existing literature. Further, we establish Regge trajectories of this baryon in ($n,M^2$) and ($J,M^2$) planes which are helpful in determining the unknown quantum number and $J^P$ values.

We present an exploratory study on the radiative transition for the charm-strange meson: $D_s^{\ast }\to D_s\gamma$ using $N_f=2$ twisted mass lattice quantum chromodynamics gauge configurations. The form factor for $D_s$ meson is also determined. The simulation is performed on lattices with lattice spacings $a=0.067$ fm and lattice size $32^3\times 64$, and $a=0.085$ fm and lattice size $24^3\times 48$, respectively. Our numerical results for radiative decay width and the experimental data overlap within the margin of error.

In this paper, we enumerated ground and excited state masses of singly heavy bottom-strange baryons using the hypercentral constituent quark model (hCQM). The screening potential is used with color-Coulomb potential, as the confining potential. We determine the possible $J^P$ values to recently observed excited states like, ${\mathrm{\Xi }}_b(6100)$, ${\mathrm{\Xi }}_b(6227)$, ${\mathrm{\Xi }}_b(6327)$, ${\mathrm{\Xi }}_b(6333)$ and four ${\mathrm{\Omega }}_b(6316,6330,6340,6350)$ states. The Regge trajectories are plotted in $(J,M^2)$ plane to assign the $J^P$ values and quantum numbers to recently observed states. Using the calculated spectroscopic data, properties such as magnetic moment, transition magnetic moment, radiative decay width, and strong decay width are also investigated for all singly heavy bottom-strange baryonic system.

In this paper, we study the properties of triply charm and triply bottom baryon. The mass spectra of these baryons are calculated in nonrelativistic constituent quark model with Coulomb plus screened potential. Several states $S$, $P$, $D$ and $F$ of the ${\mathrm{\Omega }}_{ccc}$ and ${\mathrm{\Omega }}_{bbb}$ baryons with quantum number $J^P={\frac{1}{2}}^{\pm }$, ${\frac{3}{2}}^{\pm }$, ${\frac{5}{2}}^{\pm }$, ${\frac{7}{2}}^{\pm }$ are determined. Regge trajectories are also plotted to determine the quantum number of baryons. Moreover, the magnetic moments are calculated for $J^P={\frac{3}{2}}^{+}$.

In this paper, we investigate the mass spectra of bottom-charm baryons systematically, where the relativistic quark model and the infinitesimally shifted Gaussian basis function method are employed. Our calculation shows that the $\rho$-mode appears lower in energy than the other excited modes. According to this feature, the allowed quantum states are selected and a systematic study of the mass spectra for ${\mathrm{\Xi }}_{bc}^{\prime }$ (${\mathrm{\Xi }}_{bc}$) and ${\mathrm{\Omega }}_{bc}^{\prime }$ (${\mathrm{\Omega }}_{bc}$) families is performed. The root mean square radii and quark radial probability density distributions of these baryons are analyzed as well. Next, the Regge trajectories in the $(J,M^2)$ plane are successfully constructed based on the mass spectra. At last, we present the structures of the mass spectra, and analyze the difficulty and opportunity in searching for the ground states of bottom-charm baryons in experiment.

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.

Recently, the BESIII Collaboration reported that there exist two explicit enhancement structures near 2.25GeV, one has the mass of $M=2232\pm 19\pm 27$MeV and the width of $\mathrm{\Gamma }=93\pm 53\pm 20$MeV and another structure has the mass of $M=2200\pm 11\pm 17$MeV and the width of $\mathrm{\Gamma }=74\pm 20\pm 24$MeV when analyzing the cross section of subprocesses. Earlier, the BESIII Collaboration reported the existence of the $X(2220)$, with a mass of $2222\pm 7\pm 2$MeV and width of $59\pm 30\pm 6$MeV. Based on these experimental results, we carried out a study. We present the comparison of the mass spectrum between theoretical and experimental masses and examine the two-body strong decays of these states within two different approaches to the ${}^3{P}_0$ model. We find that the newly discovered states are most likely to be an $\omega (3\mathrm{\text{D}})$ state. This discovery could be useful in establishing entire $\omega$ mesons.

In this paper, we investigate the mass spectra and decay properties of $B$, $B_s$ and $B_c$ mesons using the relativistic potential model with confining potential $V_q(r)=\frac{1}{2}(1+{\gamma }^0)(a^{2}r+V_0)$. The calculated mass spectra of $B$, $B_s$ and $B_c$ accord to the findings of the experiments and other theoretical forecasts. Using the same parameters, we calculate possible radiative decay widths of $V(ns)\to P(ns)\gamma$ and $P(ns)\to V(ns)\gamma$, $n=1,2,3$ and weak leptonic decay constants of $B$, $B_s$ and $B_c$ mesons. Our results, in most cases, generally agree with experimental and other theoretical predictions. Finally, we also investigate mixing parameters $x_q$, $y_q$ and ${\chi }_q$ for $B_q^0-{\overline{B}}_q^0$$(qϵd,s)$ mesons, where our calculated values reasonably agree with the experiment.

In the last few years, the experimental evidence of charmed mesons is increasing remarkably. In this work, we systematically studied the D meson by employing Regge phenomenology. By assuming the existence of the quasilinear Regge trajectories, several relations between Regge slope, intercept and meson masses have been extracted. With the aid of these derived relations, Regge parameters are evaluated in both the ($J,M^2$) and ($n,M^2$) planes to obtain the mass spectra of D meson. In the forthcoming years, we believe that more candidates will be reported and our predictions could provide useful information for future experimental evidences.

Significant efforts have been made in recent years to measure the properties of charmed baryons. In this work, we study the ${\mathrm{\Xi }}_c^{\prime }$ and ${\mathrm{\Omega }}_c$ baryons in the relativistic flux tube model with a quark–diquark picture of a baryon. The modified Regge relation between mass and angular momentum is used to predict the spin-average masses. The spin-dependent interactions are also included to compute the spin-dependent splitting. We calculate the masses of states belonging to the $1F$-wave and $1G$-wave of ${\mathrm{\Xi }}_c^{\prime }$ and ${\mathrm{\Omega }}_c$ baryons, which are not yet detected experimentally. Our mass predictions can offer valuable insights to experimental facilities in their search to discover the higher excited states of ${\mathrm{\Xi }}_c^{\prime }$ and ${\mathrm{\Omega }}_c$ baryons.

This study focuses on baryons that consists of one heavy quark and two light quarks. This paper explores the mass spectra of radial and excited states for all singly heavy baryons, employing the Hypercentral Constituent Quark Model (hCQM). In this model, we incorporated higher-order corrections, including second-order corrections in mass, specifically considering spin-dependent terms. This methodology enables a more accurate observation of the correct spin splitting order. We have determined important properties, including magnetic moment, transition magnetic moment, radiative decay width and strong decay width.

This work is devoted to the study of charmonium S-states by solving the Schrödinger equation with Cornell plus spin–spin interaction term via the artificial neural network (ANN) approach. From the solutions provided by ANN approach, we propose possible assignments for some of the recently discovered charmonium-like resonances. For simplicity purpose, we restricted the study to the ground and radially excited S-states of charmonium. The charmonium wave function is represented by the feed forward ANN and its inputs are assimilated to coordinate values. We calculated the masses, hyperfine splittings, spin-averaged mass spectrum and Regge trajectories of pseudoscalar and vector charmonium states. Overall, our results are in good accordance with the available experimental data and past studies of the mass spectrum of $J^{\mathrm{\text{PC}}}=1^{--}$ and $J^{\mathrm{\text{PC}}}=0^{-+}$ charmonium states. Further, we propose a possible assignment for some of the recently discovered charmonium-like mesons. We concluded that ${\eta }_c(3S)$, ${\eta }_c(4S)$, $\psi (4S)$, ${\eta }_c(5S)$ and $\psi (6S)$ are, respectively, good candidates of $X(3940)$, $X(4160)$, $Y(4260)$, $\psi (4415)$ and $Y(4660)$ charmonium-like resonances.

The mass spectra and decay properties of $B$ and $B_s$ mesons are obtained using the nonrelativistic potential model by applying the variational approach. The quark–anti-quark potential used in our model consists of a Hulthen potential and a confining linear potential. The hyper-fine interaction is introduced to obtain the splittings of the spin-singlet and triplet states, while the spin–orbit and tensor interactions provide the fine structure splittings. The model parameters and the wave functions that reproduce the mass spectra are used to investigate the decay properties of $B$ and $B_s$ mesons. The mass spectra of $B$ and $B_s$ mesons have been enhanced using coupled channel effects.