Searcharxiv⌕ Search

arXiv subjects

P C Vinodkumar

Publications and source records attributed to P C Vinodkumar.

At least 19 recordsLinked to original sources
arXiv2026

Mass and Decay Properties of Toponium Using SUSY QM Factorization Method

The Supersymmetric quantum mechanics (SUSY QM) factorization method is applied to study the Cornell potential in the context of toponium $(t\bar{t})$, the heaviest quarkonium system. The method is successfully applied to determine the mass, binding energy, and spin-dependent hyperfine splitting, giving pseudoscalar $(η_t)$ and vector $(Θ_t)$ state masses of 344.114 GeV and 344.141 GeV, respectively. The decay properties of both the pseudoscalar and vector states are also investigated through their respective decay widths, highlighting the crucial role of the bound-state wavefunction. Among the decay channels, the di-gluonic $(η_t\rightarrow gg)$ mode is found to be dominant, with an estimated decay width of 2.57 MeV. In addition, the spatial characteristics of toponium are examined by evaluating the mean radius, root-mean-square (RMS) radius, and most probable radius, all of which are found to lie within the range of $0.015\text{--}0.025\,\mathrm{fm}$.

hep-ph↗
arXiv2025

Strong decays of newly observed charm-strange meson states based on a relativistic model

The mass spectra of charm-strange mesons including ground, radial and orbital excitations have been calculated within a relativistic Dirac framework. The predicted masses of the ground state $1S$ and the first orbital excited state $1P$ exhibits excellent agreement with values reported by the PDG. Utilizing these mass predictions and an effective Lagrangian approach based on heavy quark and chiral symmetries, we have computed the OZI allowed two body strong decay widths of higher excited state candidates of charm-strange sector. The resulting partial widths and branching ratios enable the assignment of spin-parity quantum numbers to several newly observed charm-strange states. In particular, we identify $D_{sJ}(2700)$ as the $2^3S_1$, $D_{s0}(2590)$ as the $2^1S_0$, $D_{sJ}(2860)$ as the $1^3D_3$, $D_{s1}(2860)$ as the $1^3D_1$, and $D_{sJ}(3040)$ as the $2^1P_1$ states. The effective coupling constants $g_T$, $g_X$, $g_Y$, $\tilde{g}_S$ and $\tilde{g}_H$ extracted from present analysis. Furthermore, the $D^*K$ decay channel emerges as the most promising mode for the experimental search of the missing $1^3D_2$ and $1^1D_2$ states, while the $2^3P_0$ state is more likely to be observed through the $DK$ channel.

hep-ph↗
arXiv2019

Spectroscopy and decay properties of bottomonium using instanton induced potential from QCD vacuum

Ground state and radial excitation mass spectra of bottomonium states are computed using the Instanton Induced $q \bar{q}$ Potential obtained from Instanton Liquid Model for QCD vacuum. The Schrodinger equation is solved for two body problem using variational method. Hyperfine interactions are incorporated to remove the degeneracy between spin singlet and spin triplet states of $S$ wave masses. Spin-orbit and tensor interactions through one gluon exchange has been added to the spin average masses of P and D wave states. The vector decay constants and pseudoscalar decay constants are also estimated using the Van Royan Weiskopff formula within non-relativistic limit. The di-leptonic, di-gamma, di-gluon decays of the bottomonium states are predicted without and with QCD corrections up to the lowest order using numerical values of the wave function at origin. Tri-gluon decays of respective $S$, $P$ and $D$ states are also studied. Other annihilation decay channels of bottomonium states into $γgg$ , $γγγ$ , $q\bar{q} + g $ are also computed. The radiative transitions of first order like electric dipole transitions (E1) and magnetic dipole transitions (M1) are estimated. Our estimations of the mass spectra and decay properties for bottomonium found to be in excellent agreement with the average experimental values reported by particle data group.

hep-ph↗
arXiv2018

Status of quarkonia - like negative and positive parity states in a relativistic confinement scheme

Properties of quarkonia - like states in the charm and bottom sector have been studied in the frame work of relativistic Dirac formalism with a linear confinement potential. We have computed the mass spectroscopy and decay properties (vector decay constant and leptonic decay width) of several quarkonia - like states. Present study is also intended to identify some of the unexplained states as mixed P-wave and mixed S-D wave states of Charmonia and Bottomonia. The results indicate that the X(4140) state can be an admixture of two P states of charmonium. And the charmonium like states X(4630) and X(4660) are the admixed state of S - D waves. Similarly, the $X(10610)$ state recently reported by Belle II can be a mixed P - states of bottomonium. In the relativistic framework we have computed vector decay constant and the leptonic decay width for S wave charmonium and bottomonium. The leptonic decay width for the $J^{PC} = 1^{--}$ mixed states are also predicted. Further, both the masses and the leptonic decay width are considered for the identification of the quarkonia-like states.

hep-ph↗
arXiv2016

Tetraquark states in the bottom sector and the status of the $Y_b$(10890) state

We have done the exploratory study of bottom tetraquarks ($[bq\bar b \bar q];{q\in u,d}$) in the diquark-antidiquark framework with the inclusion of spin hyperfine, spin-orbit and tensor components of the one gluon exchange interaction. Our focus here is on the $Y_b$(10890) and other exotic states in the bottom sector. We have predicted some of the bottom counterparts to the charm tetraquark candidates. Our present study shows that if $Z_b(10610)$ and $Z_b(10650)$ are diquark-diantiquark states then they have to be first radial excitations only and we have predicted $Z_b(10650)$ state as first radial excitation of tetraquark state $X_b$ (10.143-10.230). We have identified $X_b$ state with $J^{PC}= 1^{+-}/0^{++}$ as being the analogue of $Z_c(3900)$. An observation of the $X_b$ will provide a deeper insight into the exotic hadron spectroscopy and is helpful to unravel the nature of the states connected by the heavy quark symmetry. We particularly focus on the lowest P wave $[bq][\bar b\bar q]$ states with $J^{PC}=1^{--}$ by computing their leptonic, hadronic and radiative decay widths to predict the status of still controversial $Y_b$(10890) state. Apart from this, we have also shown here the possibility of mixing of P wave states. In the case of mixing of $1^{--}$ state with different spin multiplicities, we found that predicted masses of the mixed P states differ from $Y_b$(10890) state only by $\pm20$ MeV energy difference which can be helpful to resolve further the structure of $Y_b$(10890).

hep-ph↗
arXiv2014

Mass spectra of four quark states in hidden charm sector

Masses of the low lying four quark states in the hidden charm sector ($cq\bar c \bar q; q\in u,d$) are calculated within the framework of a non-relativistic quark model. The four body system is considered as two two-body systems such as diquark-antidiquark ($Qq-\bar Q \bar q$) and quark antiquark-quark antiquark ($Q\bar q -\bar Qq$) molecular-like four quark states. Here, Cornell type potential has been used for describing the two body interactions among $Q-q$, $\bar Q-\bar q$, $Q-\bar q$, $Qq-\bar Q \bar q$ and $Q\bar q-\bar Qq$, with appropriate string tensions. Our present analysis suggests the following exotic states, $X(3823)$, $Z_c(3900)$, $X(3915)$, $Z_c(4025)$, $ψ(4040)$, $Z_1(4050)$ and $X(4160)$ as $Q\bar q-\bar Qq$ molecular-like four quark states while $Z_c(3885)$, $X(3940)$ and $Y(4140)$ as the diquark-antidiquark four quark states. We have been able to assign the $J^{PC}$ values for many of the recently observed exotic states according to their structure. Apart from this, we have identified the charged state $Z(4430)$ recently confirmed by LHCb as the first radial excitation of $Zc(3885)$ with G=+1 and $Y(4360)$ state as the first radial excitation of $Y(4008)$ with $G=-1$ and the state $ψ(4415)$ as the first radial excitation of the $ψ(4040)$ state.

hep-ph↗
arXiv2014

Mass spectra and decay properties of $D_s$ Meson in a relativistic Dirac formalism

The mass spectra of $D_s$ meson is obtained in the framework of relativistic independent quark model using Martin like potential for the quark confinement. The predicted excited states are in good agreement with the experimental results as well as with the lattice and other theoretical predictions. The spectroscopic parameters are employed further to compute the decay constant, electromagnetic transition and leptonic decay widths. The present result for its decay constant, $f_P$ (252.82 MeV) is in excellent agreement with the value 252.6 $\pm$ 11.1 MeV reported by CLEO-c and the predicted branching ratios for $(D_s \rightarrow τ\barν_τ, μ\barν_μ)$ ($5.706 \times 10^{-2}, 5.812 \times 10^{-3}$) are in close agreement with the PDG values ($ (5.43 \pm 0.31)\times 10^{-2}, (5.90 \pm 0.33)\times 10^{-3} $) respectively.

hep-ph↗
arXiv2013

Status of $ψ$ (3686), $ψ$ (4040), $ψ$ (4160), Y (4260), $ψ$ (4415) and X (4630) charmonia like states

We examine the status of charmonia like states by looking into the behaviour of the energy level differences and regularity in the behaviour of the leptonic decay widths of the excited charmonia states. The spectroscopic states are studied using a phenomenological Martin-like confinement potential and their radial wave functions are employed to compute the di-leptonic decay widths. Their deviations from the expected behaviour provide a clue to consider them as admixtures of the nearby S and D states. The present analysis strongly favour \$$\backslash$psi \$ (3686) as admixture of $c \bar{c}$ (2S) and $c \bar{c}$g (4.1 GeV) hybrid, \$$\backslash$psi \$ (4040) and \$$\backslash$psi \$ (4160) as admixture states of charmonia (3S, 3D) states with mixing angle \$$\backslash$theta \$ = 11$^\circ$ and 45$^\circ$ respectively. We identify Y (4260) as a pure $c \bar{c}$ (4S) state whose leptonic decay is predicted as 0.65 keV. While X(4630) is closer to the $c \bar{c}$ (6S) state. The status of \$$\backslash$psi \$ (4415) is still not clear as it does not fit to be pure or admixture state.

hep-ph↗
arXiv2012

Semileptonic decay of $B_c$ meson into $c\bar c$ states in a quark model

The exclusive semileptonic decay form factors and widths of $B_c$ meson in the $c\bar c\ (η_c,J/ψ)$ states based on heavy quark effective theory are computed. The spectroscopic parameters of $B_c$ and the $c\bar c$ states deduced using the phenomenological coulomb plus power form of the $q-\bar q$ potential $(CPP_ν)$ with power index $ν$ have been employed to compute the Isgur wise function as well as the decay form factors. The universal behaviour of the Isgur-wise function at the maximum momentum transfer has been observed for different choices of $ν$ between 0.5 to 2.0. However, such an universality is not observed for the choice of $ν<0.5$. Our predictions for the branching ratio $B_c\rightarrowη_c\ell^+ν_\ell$ lie 0.50 $%$ - 0.56 $%$ while that for $B_c\rightarrow J/ψ\ell^+ν_\ell$ lie 1.8 $%$ - 2.0 $%$ for the choice of the potential index in the range $0.5\leqν\leq2.0$.

hep-ph↗
arXiv2011

Two-Photon, Two-gluon and Radiative Decays of Heavy Flavoured Mesons

Here we present the two-photon and two-gluon decay widths of the S-wave ($η_{Q\in c,b}$) and P-wave ($χ_{Q\in c,bJ}$) charmonium and bottonium states and the radiative transition decay widths of $c\bar c$, $b\bar b$ and $c\bar b$ systems based on Coulomb plus power form of the inter-quark potential ($CPP_ν$) with exponent $ν$. The Schr$\ddot{o}$dinger equation is solved numerically for different choices of the exponent $ν$. We employ the masses of different states and their radial wave functions obtained from the study to compute the two-photon and two-gluon decay widths and the E1 and M1 radiative transitions. It is found that the quarkonia mass spectra and the E1 transition can be described by the same interquark model potential of the $CPP_ν$ with $ν=1.0$ for $c\bar c$ and $ν=0.7$ for $b\bar b$ systems, while the M1 transition (at which the spin of the system changes) and the decay rates in the annihilation channel of quarkonia are better estimated by a shallow potential with $ν<1.0$.

hep-ph↗
arXiv2009

Decay Properties of $D$ and $D_s$ mesons

The decay rates and spectroscopy of the $D$ and $D_s$ mesons are computed in a nonrelativistic phenomenological quark-antiquark potential of the type $V(r)=-{4/3}\frac{α_s}{r}+A r^ν$ with different choices of $ν$. Numerical method to solve the Schrödinger equation has been used to obtain the spectroscopy of $q\bar{Q}$ mesons. The spin hyperfine, spin-orbit and tensor components of the one gluon exchange interactions are employed to compute the spectroscopy of the excited $S$ states, low lying $P$-waves and $D$-waves. The numerically obtained radial solutions are employed to obtain the decay constant and leptonic decay widths. It has been observed that predictions of the spectroscopy and the decay widths are consistent with other model predictions as well as with the known experimental values.

hep-ph↗
arXiv2009

Raditive decay of single charmed baryons

The electromagnetic transitions between ($J^{P}={3/2}^{+}$) and ($J^{P}={1/2}^{+}$) baryons are important decay modes to observe new hadronic states experimentally. For the estimation of these transitions widths, we employ a non-relativistic quark potential model description with color coulomb plus linear confinement potential. Such a description has been employed to compute the ground state masses and magnetic moments of the single heavy flavor baryons. The magnetic moments of the baryons are obtained using the spin-flavor structure of the constituting quark composition of the baryon. Here, we also define an effective constituent mass of the quarks (ecqm) by taking into account the binding effects of the quarks within the baryon. The radiative transition widths are computed in terms of the magnetic moments of the baryon and the photon energy. Our results are compared with other theoretical models.

hep-ph↗
arXiv2008

Properties of $Q\bar Q$ mesons in non-relativistic QCD formalism

The decay rates of $Q \bar Q$ mesons ($Q \varepsilon {c, b}$) are studied in the NRQCD formalism in terms of their short distance and long distance coefficients. The long distance coefficients are obtained through phenomenological potential model description of the mesons. The model parameters that reproduces the mass spectrum of the $c \bar c$, $b \bar b$ and $c \bar b$ mesons are employed to study the decay widths of these mesons. We extract the mass spectrum as well as the reproduces the respective radial wave functions from the different potential models as well as from non-relativistic phenomenological quark antiquark potential of the type $V(r)=-\frac{α_c}{r}+A r^ν$, with $ν$ varying from 0.5 to 2. The spin hyperfine and spin-orbit interactions are employed to obtain the masses of the pseudoscalar and vector mesons. The decay constants with QCD corrections are computed in this model as well as in the case of other potential models for comparison. The digamma and dileptonic decays of $c \bar c$, and $b \bar b$ mesons are investigated using some of the known potential models without and with radiative corrections up to the lowest order. These decay width are also computed within the NRQCD formalism up to $O(v^4)$ by making uses of the respective spectroscopic parameters of the models. Our theoretical predictions of the decays of the $c \bar c$, and $b \bar b$ mesons and the results obtained from some of the other potential schemes are compared with the experimental values. The partial widths and life time of the $B_c$ meson are also computed using the model parameters and are found to be in good accordance with the experimental values.

hep-ph↗
arXiv2008

Properties of doubly charmed baryons in the quark-diquark model

Baryons containing two heavy quarks are important and interesting systems to study the quark-diquark structure of baryons and to understand the dynamics of QCD at hadronic scale. The Selex Collaboration has recently reported the discovery of $Ξ_{cc}$ with a mass of 3.519 Ge$V$. However, other groups such as Babar, Belle and Focus have all failed to confirm this state. So there is a demand to review this state both theoretically and experimentally. We report here the spectra and magnetic moments of $ccq(q\in u,d,s)$ systems using coulomb plus Martin potential. Here the two heavy quarks are considered for the diquark states. The same potential form is used for the diquark interaction as well as for the quark-diquark interaction. The chromomagnetic one gluon exchange interaction are perturbatively treated here to get the masses of $J^P={1/2}^{+}$ and $J^P={3/2}^{+}$ states. Accordingly, we obtain $Ξ^{++}_{cc}$ (3519, 3555), $Ξ^{+}_{cc}$ (3527, 3562) and $Ω^{+}_{cc}$ (3648,3688) states of the $ccq$ $({1/2}^{+},{3/2}^{+})$ combinations. Our predictions are in accordance with the SELEX result for $Ξ^{++}_{cc}$ (3519) and other model predictions. Predictions of other properties of these $ccq$ systems will be presented in detail.

hep-ph↗
arXiv2008

Open flavour Charmed Mesons

We present here recent results on the investigations of the mass spectrum (S-states and P-states), decay constants, decay widths and life time of the D, $D_s$,and $B_c$mesons within the framework of phenomenological potential models.We also present the binding energy and the masses of the di-meson molecular systems with one or more charm meson combinations. Many of the newly found experimental open charm states are identified with the orbital excitations of the conventional open charm mesons while others like X(3872), Y(3930), $D_{sJ}$(2632, 2700) \emph{etc.}, are identified as molecular like states.

hep-ph↗