arXiv subjects

Kaushal Thakkar

Publications and source records attributed to Kaushal Thakkar.

15 recordsLinked to original sources

arXiv2026

Static and dynamic properties of Triply Heavy Baryons

In this study, we investigate the ground-state masses, magnetic moments, transition magnetic moments, radiative decays, and heavy-to-heavy semileptonic decay rates, including their corresponding branching fractions of triply heavy baryons (THBs). The ground-state masses of the involved baryons are evaluated by numerically solving the six-dimensional hyperradial Schrödinger equation within the hypercentral constituent quark model (hCQM), incorporating both hyper-Coulomb and linear confinement potentials along with spin-dependent interactions. The electromagnetic properties are calculated using the spin-flavour wave functions and the effective constituent quark masses of the baryon. The semileptonic $b \rightarrow c$ decay widths are computed using the Isgur--Wise function within the heavy-quark spin symmetry, from which the corresponding branching ratios and lepton flavour universality ratios are also determined.

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arXiv2026

Semileptonic decay form factors of $Ξ_b^0 \rightarrow Ξ_c^+\ell\barν_{\ell}$ in HQET

Heavy-to-heavy semileptonic decays, particularly the bottom-to-charm quark transitions, are essential for testing the Standard Model (SM) and extracting the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements. These decays have been extensively studied using various theoretical approaches. In this work, we investigate the semileptonic decay $Ξ_b^0 \rightarrow Ξ_c^+\ell\barν_{\ell}$ (where $\ell = e$, $τ$) using a phenomenological quark model. We compute the ground-state masses of the initial and final baryons to get the wave function, which is then used to calculate the form factors, including corrections up to order $1/m_Q$ within the framework of Heavy Quark Effective Theory (HQET). The obtained form factors are implemented in the helicity formalism to evaluate the differential decay rates, total decay width and branching ratio. We compare our results for the form factors at both the maximum and minimum recoil points with previous theoretical studies, finding good agreement. We observe that the form factors depend on the transferred momentum $q^2$ and their magnitude gradually increases with increasing $q^2$. The dominant form factors are $f_1$ and $g_1$, and they also exhibit similar $q^2$ dependencies. Additionally, we calculate the lepton flavour universality (LFU) ratio $R(Ξ_c) \approx 0.3$, which is in agreement with existing theoretical predictions.

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arXiv2026

Semileptonic decay and form factors of $Ω_b^- \rightarrow Ω_c^0\,e\,\bar{ν_e}$

We investigated the heavy-to-heavy semileptonic decay $Ω_b^- \rightarrow Ω_c^0 e \bar{ν_e}$ within the framework of the Hypercentral Constituent Quark Model (HCQM). The ground-state masses of the involved baryons were evaluated by numerically solving the six-dimensional hyperradial Schrödinger equation, incorporating both hyper-Coulomb and linear confinement potentials along with spin-dependent interactions. The Heavy Quark Effective Field Theory (HQET) form factors are computed up to the subleading order, incorporating $1/m_Q$ corrections that account for finite mass effects beyond the heavy-quark symmetry limit. These form factors were then employed to analyse the heavy-to-heavy semileptonic decay rate via helicity formalism. The decay width and branching ratio results were compared to those obtained using various theoretical approaches.

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arXiv2025

Electromagnetic and weak decay of singly Heavy Baryons (Qqq)

The heavy-to-heavy exclusive semileptonic transitions of singly heavy baryons (SHBs) are investigated within the framework of the Hypercentral Constituent Quark Model (hCQM). The six-dimensional hyperradial Schrödinger equation is solved in the variational approach to calculate the ground state masses of bottom and charmed baryons. The transition magnetic moments and radiative $M1$ decay widths are calculated using the spin-flavour wave function and the effective quark masses of constituent baryon. The Isgur-Wise function (IWF) is determined at zero recoil to compute the $b \rightarrow c$ semileptonic decay. Additionally, the branching ratios, as well as the slope and convexity parameters of IWF are evaluated and compared with results from other studies.

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arXiv2025

Transition properties of Doubly Heavy Baryons

In this study, we have investigated the radiative and semileptonic decay of doubly heavy baryons. Our focus is to determine the static and dynamic properties such as ground state masses, magnetic moment, transition magnetic moment, radiative decay and heavy-to-heavy semileptonic decay rates including their corresponding branching fractions. The ground state masses are calculated by solving the six-dimensional hyperradial Schrödinger equation. The magnetic moments and transition magnetic moments for $J^P=\frac{1}{2}^+$ and $J^P=\frac{3}{2}^+$ baryons are also calculated. In addition, radiative M1 decay widths are computed from the transition magnetic moment. We have employed the Isgur-Wise function(IWF) to analyse the semileptonic decay widths of the doubly heavy baryons. The obtained results are compared with other theoretical predictions.

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arXiv2020

Semileptonic Transition of $Λ_{b}$ Baryon

The semileptonic transition of $Λ_b$ baryon is studied using the Hypercentral constituent quark model. The six-dimensional hyperradial $Schr\ddot{o}dinger$ equation is solved in the variational approach to get masses and wavefunctions of heavy baryons. The matrix elements of weak decay are written in terms of the overlap integrals of the baryon wave function. The Isgur-Wise function is determined to calculate exclusive semileptonic decay $Λ_b$ $\rightarrow$ $Λ_c$ $\ell$ $\barν$. The calculated decay rate and the branching ratio of $Λ_b$ baryon are consistent with other theoretical predictions and with the available experimental observations.

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arXiv2017

Excited State Mass spectra and Regge trajectories of Bottom Baryons

We present the mass spectra of radial and orbital excited states of singly heavy bottom baryons; $Σ_{b}^{+}, Σ_{b}^-, Ξ_b^-, Ξ_b^0, Λ_b^0$ and $Ω_b^-$. The QCD motivated hypercentral quark model is employed for the three body description of baryons and the form of confinement potential is hyper coulomb plus linear. The first order correction to the confinement potential is also incorporated in this work. The semi-electronic decay of $Ω_b$ and $Ξ_b$ are calculated using the spectroscopic parameters of the baryons. The computed results are compared with other theoretical predictions as well as with the available experimental observations. The Regge trajectories are plotted in (n, $M^2$) plane.

nucl-th↗

arXiv2016

Mass spectra and Regge trajectories of $Λ_{c}^{+}$, $Σ_{c}^{0}$, $Ξ_{c}^{0}$ and $Ω_{c}^{0}$ Baryons

We calculate the mass spectra of the singly charmed baryons ($Λ_{c}^{+}$, $Σ_{c}^{0}$, $Ξ_{c}^{0}$ and $Ω_{c}^{0}$) using Hypercentral constituent quark model(hCQM). The hyper color coloumb plus linear potential is used to calculate the masses of positive(upto $J^{p}=\frac{7}{2}^{+}$) and negative parity(upto $J^{p}=\frac{9}{2}^{-}$) excited states. The spin-spin, spin-orbital and tensor interaction terms are also incorporated for mass spectra. We have compared our results with other theoretical predictions and Lattice QCD for each baryons. Moreover, the known experimental results are also reasonably closed to our predicted masses. By using the radial and orbital excitation, we construct Regge trajectories for the baryons in (n,$M^{2}$) plane and find their slopes and intercepts. The other properties like, magnetic moments, radiative transitions and radiative decay widths of these baryons are also calculated successfully.

nucl-th↗

arXiv2016

Magnetic Moments of Baryons containing all heavy quarks in Quark-Diquark Model

The triply heavy flavour baryons are studied using the Quark-diquark description of the three-body system. The confinement potential for present study of triply heavy flavour baryons is assumed as coulomb plus power potential with power index $ν$. We have solved Schrodinger equation numerically to calculate the masses of triply heavy flavour baryons. The masses and magnetic moments of triply heavy flavour baryons are computed for different power indices, $ν$, starting from 0.4 to 1.0. The predicted masses and magnetic moments are in good agreement with other theoretical predictions.

hep-ph↗

arXiv2016

Excited State Mass spectra of doubly heavy baryons $Ω_{cc}$, $Ω_{bb}$ and $Ω_{bc}$

We discuss the mass spectrum of $Ω$ baryon with two heavy quarks and one light quark (\textit{ccs, bbs and bcs}). The main goal of the paper is to calculate the ground state masses and after that, the positive and negative parity excited states masses are also obtained within a Hypercentral Constituent quark model, using coulomb plus linear potential framework. We also added first order correction to the potential. The mass spectra upto 5S for radial excited states and 1P-5P, 1D-4D and 1F-2F states for orbital excited states are computed for $Ω_{cc}$, $Ω_{bb}$ and $Ω_{bc}$ baryons. Our obtained results are compared with other theoretical predictions which could be a useful complementary tool for the interpretation of experimentaly unknown heavy baryon spectra. The Regge trajectory is constructed in both ($n_r$, $M^{2}$) and ($J$, $M^{2}$) planes for $Ω_{cc}$,$Ω_{bb}$ and $Ω_{bc}$ baryons and their slopes and intercepts are also determined. Magnetic moments of doubly heavy $Ω'$s are also calculated.

hep-ph↗

arXiv2016

Excited State Mass spectra of Singly Charmed Baryons

Mass spectra of excited states of the singly charmed baryons are calculated using the hypercentral description of three body system. The baryon consist of a charm quark and light quarks (u, d and s) are studied in the framework of QCD motivated constituent quark model. The form of confinement potential is hyper coloumb plus power potential with potential index $ν$, varying from 0.5 to 2.0. The first order correction to the confinement potential is also incorporated in this approach. The radial as well as orbital excited state masses of $Σ_{c}^{++}, Σ_{c}^+, Σ_{c}^0, Ξ_c^+, Ξ_c^0, Λ_c^+, Ω_c^0$ baryons, are reported in this paper. We have incorporated spin-spin, spin-orbit and tensor interactions perturbatively in the present study. The semi-electronic decay of $Ω_c$ and $Ξ_c$ are also calculated using the spectroscopic parameters of these baryons. The computed results are compared with other theoretical predictions as well as with the available experimental observations. We also construct the Regge trajectory in ($n_r$, $M^{2}$) and (J, $M^{2}$) plane for these baryons.

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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

Electromagnetic transition properties of $Δ\rightarrow Nγ$ in a hypercentral scheme

The electromagnetic transition properties of the decuplet to octet baryon ($Δ\rightarrow Nγ$) is studied within the frame work of a hypercentral quark model. The confinement potential is assumed as hypercentral coloumb plus linear potential. The transition magnetic moment and transition amplitude $f_{M_1}$ for the $Δ\rightarrow Nγ$ are in agreement with other theoretical predictions. The present result of the radiative decay width is found to be in excellent agreement with the experimental values reported by the particle data group over other theoretical model predictions.

hep-ph↗

arXiv2011

Properties of Light Flavour Baryons in Hypercentral quark model

The light flavour baryons are studied within the quark model using the hyper central description of the three-body system. The confinement potential is assumed as hypercentral coulomb plus power potential ($hCPP_ν$) with power index $ν$. The masses and magnetic moments of light flavour baryons are computed for different power index, $ν$ starting from 0.5 to 1.5. The predicted masses and magnetic moments are found to attain a saturated value with respect to variation in $ν$ beyond the power index $ν>$ 1.0. Further we computed transition magnetic moments and radiative decay width of light flavour baryons. The results are in good agreement with known experimental as well as other theoretical models.

hep-ph↗

arXiv2011

Spectroscopy and decay properties of $Σ_{b}, Λ_{b}$ baryons in quark-diquark model

Properties of single beauty baryons ($Σ_{b},Λ_{b}$) are studied based on the quark-diquark structure. The confinement potential is assumed as two body colour coulomb plus power potential with exponent $ν$. We find a strong correlation between the choice of the heavy quark mass parameter ($m_{b}$), strong coupling constant ($α_{s}$) and the potential exponent ($ν$) for getting the experimental mass spilt of $m_{Σ^{*}_{b}}- m_{Σ_{b}}=21.2\pm2.0 $ MeV. The resultant spectroscopic parameters are used for computing magnetic moments, the electromagnetic radiative decay, strong hadronic decay and semileptonic decay widths of $Σ_{b}, Λ_{b}$ systems. Our predictions on the radiative decay width correspond to $Σ^{*0}_{b}\rightarrowΛ_{b}γ$ are in agreement with the QCD sum rule prediction. The present results on the semileptonic decay widths of $Λ_{b}\rightarrow Λ_{c}lν_{l}$ (2.50-4.73) $ *10^{10} s^{-1}$ are in agreement with the experimental value of $3.59^{+1.234}_{-0.936} *10^{10} s^{-1}$ reported by (PDG 2010).

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