arXiv subjects

Nopmanee Supanam

Publications and source records attributed to Nopmanee Supanam.

5 recordsLinked to original sources

arXiv2025

Radiative decay of $χ_{c1}$ states in effective Lagrangian approach

The $χ_{c1}(3872)$ state, first observed by the Belle collaboration with its quantum numbers identified as $J^{PC} = 1^{++}$, has been the subject of extensive research due to its intriguing properties. Several theoretical interpretations have been proposed to explain its unique characteristics, including the $χ_{c1}(2P)$ assignment, a molecular $\bar{D}^{*}D/\bar{D}D^{*}$ configuration, a coupled-channel framework incorporating $c\bar{c}$ and di-meson degrees of freedom, and the compact tetraquark hypothesis. However, challenges remain in reconciling its mass coincidence with the threshold and the observed isospin violation within both the pure $c\bar{c}$ and compact tetraquark models. In this study, we examine the radiative decays of the $χ_{c1}(1P)$ and $χ_{c1}(3872)$ states in an effective field theory framework, incorporating triangle loops of $D$ and $D^{*}$ mesons. The model parameters are calibrated based on the observed branching fraction of the radiative decay mode $χ_{c1}(1P) \to J/ψγ$. Utilizing these fixed parameters, we predict the branching fractions $R_{χ_{c1}(3872) \to J/ψγ} \sim 10^{-1}$ and $R_{χ_{c1}(3872) \to ψ(2S) γ} \sim 10^{-2}$, and the relative fraction $\mathcal{R}_{Ψγ} \approx 0.109$. The work supports the argument that the $χ_{c1}(3872)$ is unlikely a $c\bar{c}$ state.

hep-ph↗

arXiv2025

Revisiting the two-zero texture Majorana neutrino mass matrix

It has long been pointed out that there are seven different two-zero texture neutrino mass matrices compatible with neutrino oscillation data. We perform an updated analysis with the recently published Nu-Fit 6.0 results. We also subject the seven two-zero textures to constraints on neutrino mass from cosmology, end point of beta decay spectrum, and neutrinoless double beta decay experiments. We find that all seven textures are compatible with the new oscillation parameters. However, we find five textures, whose 1-1 entry is nonvanishing, are in severe tension with the constraints from cosmology and neutrinoless double beta decay. With the next generation experiments, these five textures could be decisively ruled out. For the remaining two textures, one of them could be ruled out, or severely constrained, if the octant of $θ_{23}$ is determined.

hep-ph↗

arXiv2025

Upper limit on dark matter mass in the inert doublet model

We study the upper limit on dark matter mass in the context of the inert double model. We derive analytic expression for the upper bound as a function of the mass squared differences between dark matter and other new particles. We find that the upper limit varies between 20$-$80 TeV depending on the mass squared splitting.

hep-ph↗

arXiv2022

Estimation of coupling constants for D-meson, charmed, and light baryons in effective Lagrangian approach and quark model

We estimate coupling constants for effective Lagrangians of $D$-meson, charmed, and light baryons from charmed baryon decay processes. First, we calculate decay widths for the processes $Λ_{c} \to DN$, $Σ_{c} \to D Δ$, $Σ_{c} \to D^{*} Δ$, and $Λ_{c} \to D^{*}N$ in effective Lagrangian method and quark model picture with $^{3}P_{0}$ model. By employing the coupling constants for $D^{*} Λ_{c} N$ interaction from several literatures, the strength parameter $λ$ for $^{3}P_{0}$ quark model is fixed in the decay process $Λ_{c} \to D^{*}N$. Then, the coupling constants for the effective Lagrangians of $DΛ_{c}N$, $DΣ_{c}Δ$, and $D^{*}Σ_{c}Δ$ interactions are estimated in the decay channels $Λ_{c} \to DN$, $Σ_{c} \to D Δ$, and $Σ_{c} \to D^{*} Δ$, respectively. These coupling constants will be useful for further studies of charm hadrons.

hep-ph↗

arXiv2010

Baryon chiral perturbation theory with virtual photons and leptons

We construct the general pion-nucleon SU(2) Lagrangian including both virtual photons and leptons for relativistic baryon chiral perturbation theory up to fourth order. We include the light leptons as explicit dynamical degrees of freedom by introducing new building blocks which represent these leptons.

hep-ph↗