arXiv subjects

M. Shekari Tousi

Publications and source records attributed to M. Shekari Tousi.

5 recordsLinked to original sources

arXiv2026

Examining possible doubly topped baryon configurations

We present a comprehensive theoretical assessment of the masses of possible baryonic configurations characterized by the presence of two heavy top quarks, including $Ξ_{ttu}$, $Ξ_{ttd}$, $Ω_{tts}$, $Ω_{ttc}$, and $Ω_{ttb}$ systems. This analysis is rigorously executed within the specialized framework of two-point $\mathrm{QCD}$ sum rules, focusing on their predicted ground state masses. Our interest in these systems arises from recent CMS and ATLAS reports indicating a pseudoscalar excess close to $t\bar{t}$ threshold. Our evaluation incorporates both perturbative terms and nonperturbative effects, including condensate contributions up to dimension eight. Based on our results, the extracted central masses for all channels are slightly above the sum of the constituent quark masses, which is consistent with the inherent uncertainties of the method. These quantitative predictions provide a useful first-principle theoretical reference, which may help future experimental searches for such heavy configurations at the LHC and inform sensitivity studies at next-generation facilities such as the FCC.

hep-ph↗

arXiv2026

Doubly heavy spin-$\frac {3}{2} $ baryons spectrum in the ground and excited states

This study employs QCD sum rules to predict the masses and residues of spin-$\frac {3}{2} $ doubly heavy baryons including two heavy quarks (c and/or b) and one light quark, specifically focusing on $ Ξ_{cc}^*$, $ Ξ_{bc}^*$, $ Ξ_{bb}^*$, $ Ω_{cc}^*$, $ Ω_{bc}^*$ and $ Ω_{bb}^*$. Our study provides results for the ground state ($1S$), first orbital excitation ($1P$), and the first radial excitation ($2S$), within a consistent theoretical framework. In addition to mass spectra, we provide residue calculations as well. The calculated residues are essential for estimating the decay widths and branching ratios of these baryons at different decay channels. Our analysis incorporates nonperturbative QCD effects through operators up to dimension ten, leading to improved precision in the mass and residue calculations. These predictions offer crucial guidance for ongoing and future experimental searches, particularly in light of the current lack of empirical data for the ground and excited states, and provide a basis for comparison with future experimental data.

hep-ph↗

arXiv2025

Semileptonic decays of doubly charmed or bottom baryons to single heavy baryons

We investigate the semileptonic decays of baryons containing double charm or double bottom quarks, focusing on their transitions to single heavy baryons through three-point QCD sum rule framework. In our calculations, we take into account nonperturbative operators with mass dimensions up to five. We calculate the form factors associated with these decays, emphasizing the vector and axial-vector transition currents in the corresponding amplitude. By applying fitting functions for the form factors based on the squared momentum transfer, we derive predictions for decay widths and branching ratios in their possible lepton channels. These findings offer valuable insights for experimentalists exploring semileptonic decays of doubly charm or bottom baryons. Perhaps they can be validated in upcoming experiments like LHCb. These investigations contribute to a deeper understanding of the decay mechanisms in these baryonic channels.

hep-ph↗

arXiv2024

Investigation of the semileptonic decay $ Ξ^{++}_{cc}\rightarrow Ξ^+_{c} \bar{\ell}ν_{\ell}$ within QCD sum rules

We study the semileptonic decay of the doubly heavy baryon $ Ξ^{++}_{cc} $ into the singly heavy baryon $ Ξ^+_{c}$ within the three-point QCD sum rule approach in two possible lepton channels. Our analysis includes perturbative as well as nonperturbative condensation contributions up to dimension 5. We evaluate the form factors of this semileptonic decay entering the amplitude described by the vector and axial vector transition currents. The fit functions of the form factors with respect to the transferred momentum squared are utilized to predict the decay widths and branching ratios of the $ Ξ^{++}_{cc}\rightarrow Ξ^+_{c} \bar{\ell}ν_{\ell}$ channels. We compare our findings with other predictions in the literature. Our outcomes can be useful for experimental groups in their search for the weak decays of doubly heavy baryons and may be checked via future experiments such as LHCb.

hep-ph↗

arXiv2024

Properties of doubly heavy spin-$\frac{1}{2}$ baryons: The ground and excited states

We determine the masses and residues of the ground and excited spin-$\frac {1}{2} $ baryons consist of two heavy b or c quark utilizing the QCD sum rule formalism. In the calculations, we consider the nonperturbative operators up to ten mass dimensions in order to increase the accuracy compared to the previous calculations. We report the obtained results for both the symmetric and anti-symmetric currents defining the doubly heavy baryons of the ground state (1S), first orbitally excited state (1P) and first radially excited state (2S). We compare our results with the predictions of other nonperturbative approaches as well as existing experimental data which is available only for the ground state of $ Ξ_{cc}$ channel. These predictions can help the experimental groups in their searches for all members of the doubly heavy baryons in their ground and exited states.

hep-ph↗