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Chetan Lodha

Publications and source records attributed to Chetan Lodha.

7 recordsLinked to original sources
arXiv2026

A Unified Study of Hidden-Charm and Hidden-Bottom Mesons

We present a unified phenomenological analysis of hidden-charm and hidden-bottom mesons, treating the \(c\bar c\) and \(b\bar b\) sectors within a common screened-potential and QCD sum-rule framework. The mass spectra are obtained from a screened Coulomb-plus-confining interaction with spin-dependent corrections, while the short-distance decay constants, annihilation widths and electromagnetic transition form factors are organized through two-point and three-point QCD sum rules. The same calculated states are then used to study E1 and M1 radiative transitions, Regge trajectories and finite-spectrum thermodynamic observables constructed from excitation energies relative to the corresponding ground states. The results are discussed together rather than as disconnected outputs: the mass spectra determine the state assignments, the Regge plots test the global level ordering, the radiative widths probe orbital and spin-flip overlap integrals, and the QCD sum-rule quantities connect the spectrum to current-coupled observables. The comparison of the two hidden-flavour sectors shows the expected compression and stronger spin suppression in bottomonium, while charmonium remains more sensitive to fine-structure, radial-node and medium-related effects. The resulting picture provides a coherent vacuum benchmark for \(c\bar c\) and \(b\bar b\) spectroscopy, radiative transitions and QCD sum-rule observables.

hep-ph↗
arXiv2026

A unified study of the \(B_c\) meson: from spectrum and form factors to weak and radiative decays

The $B_c$ meson constitutes a unique system for investigating heavy-hadron dynamics, since it exhibits quarkonium-like bound-state structure while decaying predominantly through weak interactions. In this work, we present a unified study of $B_c$-meson spectroscopy, decay constants, weak decays, radiative transitions, and Regge trajectories within a single framework. The mass spectrum is computed in a screened potential model including relativistic kinetic-energy corrections and spin-dependent interactions, from which we obtain both spin-averaged and spin-resolved states together with the corresponding pseudoscalar and vector decay constants. Using these spectroscopic inputs, we then analyze weak decays within a mass-updated three-point QCD sum-rule framework for transitions to $S$-, $P$-, and $D$-wave charmonium states, as well as to final states containing charmonium and $D^{(*)}_{(s)}$ mesons. In this part of the analysis, the hadronic thresholds, Borel-window prescriptions, Lorentz decompositions, and decay-width expressions of the underlying sum-rule formulations are retained, while the heavy-quark masses are updated to $m_c=1.48~\mathrm{GeV}$ and $m_b=4.90~\mathrm{GeV}$, leading to a controlled refit of the overall normalization rather than a full rederivation of all perturbative and condensate contributions. We further investigate purely leptonic decay widths and radiative $E1$ and $M1$ transitions, and examine the Regge behavior of the resulting spectrum. The present study therefore provides a coherent description of the $B_c$ meson in which the spectroscopic wave functions determine the short-distance couplings that enter both weak and electromagnetic observables, while the Regge analysis serves as a complementary global consistency test of the same dynamical picture.

hep-ph↗
arXiv2026

Compact $cs\bar{s}\bar{s}$ Tetraquarks in the Charm--Strange Sector: Mass Spectra, Rearrangement Decays and Regge Trajectories with $D_s$ Threshold Inputs

This work presents a spectroscopy-focused study of the compact open-charm, multi-strange tetraquark configuration \(cs\bar{s}\bar{s}\), modeled as an axial diquark-antidiquark system \([cs][\bar{s}\bar{s}]\). The conventional \(D_s\) meson spectrum is retained as a calibration sector for the model parameters and as a reference for the dominant two-meson thresholds; however, the primary emphasis is placed on the mass spectrum, threshold structure, rearrangement decay mechanisms, and Regge systematics of the \(cs\bar{s}\bar{s}\) tetraquark. The spectrum is computed within a Cornell-potential framework using both semi-relativistic and non-relativistic treatments, with the \(\bar{\mathbf{3}}-\mathbf{3}\) and \(\mathbf{6}-\bar{\mathbf{6}}\) color configurations analyzed separately. Owing to the presence of two identical strange antiquarks, Pauli symmetry imposes restrictions on the \([\bar{s}\bar{s}]\) antidiquark, favoring axial-vector building blocks as the natural low-lying degrees of freedom for the \(J^P=0^+,1^+,2^+\) tetraquark multiplet. The strong-decay sector is formulated in terms of the rearrangement topology \(cs\bar{s}\bar{s}\rightarrow(c\bar{s})(s\bar{s})\), with the \(D_s^{(*)}\eta\), \(D_s^{(*)}\eta'\), and \(D_s^{(*)}\phi\) modes identified through spin-color Fierz recoupling and normalized using two-point and three-point QCD-sum-rule amplitudes. Orbital and radial Regge trajectories are constructed to characterize the excitation patterns of the compact tetraquark and to benchmark them against the calibrated \(D_s\) spectrum. This framework provides a dedicated phenomenological basis for identifying \(cs\bar{s}\bar{s}\) candidates in hidden-strangeness open-charm final states.

hep-ph↗
arXiv2025

Probing Kaons as Light-Strange Tetraquarks through Spectral and Decay Dynamics

Motivated by the discovery of several kaon-like states observed at BESIII and LHCb, this study explores S-wave and P-wave tetraquark states with quark contents $ss\bar{s}\bar{q}$ and $sq\bar{q}\bar{q}$ using potential-based phenomenology. The tetraquarks are modeled as diquark-antidiquark systems in antitriplet-triplet and sextet-antisextet color configurations. The mass spectra are calculated using the Cornell potential, while decay properties are analyzed through Fierz rearrangement. A comparison with experimentally observed states is provided to enhance our understanding of light-light tetraquark systems with non-homogeneous quark compositions.

hep-ph↗
arXiv2024

Investigation of Mass and Decay Characteristics of the Light-Strange Tetraquark

Motivated by recent developments in tetraquark studies, we investigate the mass spectra and decay properties of light-strange tetraquarks ($sq\bar{s}\bar{q},ss\bar{q}\bar{q}$) in diquark-antidiquark formalism. By considering different internal quark structures and internal color structures, mass spectra are generated in semi-relativistic and non-relativistic frameworks. For decay widths, the annihilation model and spectator model have been incorporated. Several resonances have been explored as potential candidates for these tetraquarks. Concurrently, mass spectra and several decay channels of kaons ($s\bar{q},q\bar{s}$) are also investigated. This study is carried out in the hope of helping improve the understanding of tetraquarks in the light-light sector.

hep-ph↗
arXiv2024

Investigation of Mass and Decay Characteristics of the All-light Tetraquark

We investigate the mass spectra and decay properties of pions and all light tetraquarks using both semi-relativistic and non-relativistic frameworks. By applying a Cornell-like potential and a spin-dependent potential, we generate the mass spectra. The decay properties of tetraquarks are evaluated using the annihilation model and the spectator model. Potential tetraquark candidates are interpreted for quantum numbers $J^{PC} = 0^{++}, 0^{-+}, 1^{-+}, 1^{+-}, 1^{--}, 2^{+-}, 2^{-+},$ and $2^{--}$. Additionally, we compare our results with existing experimental data and theoretical predictions to validate our findings. This study aims to enhance the understanding of tetraquarks in the light-light sector.

hep-ph↗
arXiv2022

Mass Spectra and Regge Trajectories of $Δ$ Baryons

In contrast to past studies, the current paper is focused on baryons, and all four isospin states have been independently generated using u and d quarks with various constituent masses. The hypercentral Constituent Quark Model (hCQM) serves as the theoretical foundation for computing the resonance masses. The spin-dependent and first order correction terms are added to the confining potential, which is assumed to be in linear form. The resulting results have been contrasted with a wide range of methodologies and experimentally practicable states. Regge trajectories for (n,M^2) and (J,M^2) have also been displayed in addition to mass spectra.

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