arXiv subjects

Jia-Xin Lin

Publications and source records attributed to Jia-Xin Lin.

9 recordsLinked to original sources

arXiv2026

Signatures of the $\Omega(2012)^{-}$ state in $\Xi^*\bar K$ Correlation Functions

We investigate the $\Omega(2012)$ resonance in the strangeness $S=-3$ sector within a coupled-channel chiral unitary approach and present the first quantitative predictions for femtoscopic correlation functions directly sensitive to its dynamics. The $\Omega(2012)$ is dynamically generated as a quasi-bound $\Xi^{\ast}\bar K$-$\Omega\eta$ molecular state, with its coupling to the $\Xi\bar{K}$ channel driven by $d$-wave transitions. Model parameters are constrained by the measured mass, width, and the Belle determination of the branching fraction $\mathcal R^{\Xi\bar K\pi}_{\Xi\bar K}$, yielding $M_{\Omega(2012)}=(2012.53\pm0.73)$ MeV and $\Gamma_{\Omega(2012)}=(4.05\pm0.13)$ MeV. Within this framework, we compute the femtoscopic correlation functions of the $\Xi^{\ast0}K^-$, $\Xi^{\ast-}\bar K^0$, and $\Omega^-\eta$ systems. The $\Xi^{\ast}\bar K$ correlation functions exhibit pronounced near-threshold structures that arise from the proximity of the $\Omega(2012)$ pole, demonstrating an exceptional sensitivity to its position and coupled-channel composition. In particular, the $\Xi^{\ast0}K^-$ correlation function is identified as a clean and highly selective probe of the $\Omega(2012)$ resonance. These results establish femtoscopic correlation measurements as powerful tools for extracting resonance properties beyond conventional invariant-mass analyses and provide concrete theoretical benchmarks for upcoming experimental studies aimed at elucidating the molecular nature of the $\Omega(2012)$.

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arXiv2025

Signatures of Odd-Parity $s$-wave $\Xi^*$ States in Femtoscopic Correlation Functions

We investigate the $\Xi^*$ resonances within the molecular picture, where these states are dynamically generated as poles in the unitarized scattering amplitudes arising from the coupled-channel interactions of $K^{*-} \Lambda$, $K^{*-} \Sigma^0$, $\rho^- \Xi^0$, $\overline{K}{}^{*0} \Sigma^-$, $\rho^0 \Xi^-$, $\omega \Xi^-$, and $\phi \Xi^-$. The interaction kernel is derived from the local hidden gauge formalism, while the unitarization procedure employs a hybrid method that combines cutoff and dimensional regularizations in the evaluation of the loop function. From a detailed spectroscopic analysis, we identify two $S = -2$ baryon states whose properties are compatible with some of the $\Xi^*$ resonances listed in the Review of Particle Physics. To explore their possible experimental signatures, we compute the femtoscopic correlation functions for all the vector-baryon pairs considered in the present study, using realistic estimates of production weights and varying source sizes $R = 1, 1.1, 1.2, 1.3, 1.5$ fm.

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arXiv2025

Testing the nature of the $\Sigma^*(1430)$

We study the feasibility of having the $\Sigma^*(1430)$ state, predicted within the chiral unitary approach and recently reported by the Belle Collaboration, as corresponding to a state of non-molecular nature. Starting from this assumption, since the state is observed in the $\pi \Lambda$ channel, we allow the coupling to this state and relate the coupling to $\bar K N$ and $\pi \Sigma$ using $SU(3)$ symmetry arguments. We find that it is possible to have such a state with negligible coupling to the molecular components with a bare mass of the state very close to the physical mass of the $\Sigma^*(1430)$. Yet, this has consequences on other observables, since the width obtained is extremely small and incompatible with the Belle observations, and it leads to abnormally large values of the $\bar K N$ effective range. Conversely, such mismatches do not appear for large values of the bare mass of the state, but in this case we observe that the state develops large molecular components. While one can rule out a largely non-molecular nature for this state, its properties and detailed nature will need further experimental developments which one can anticipate will be coming in the near future.

hep-ph↗

arXiv2024

Determination of the $K^{+}\bar{K}^{0}$ scattering length and effective range and its relation to the $a_{0}^{+}(980)$ from the $\chi_{c1}\to\pi^{+}\pi^{-}\eta$ reaction

We analyze the clean cusp, seen in the $\eta \pi$ mass distribution with high precision of the $\chi_{c1} \to \eta \pi^+ \pi^-$ reaction in the BESIII experiment, with the aim of making a precise determination of the scattering length $a$ and effective range $r_0$ of $K^+ \bar{K}^{0}$. For that, we follow a previous theoretical work that gave a good reproduction of these data using the chiral unitary approach for the meson-meson interaction, and allow some flexibility in the input to carry a better fit to the data. The important task of determining the uncertainties in the scattering parameters is done using the resampling method and an accuracy in $a$ and $r_0$ is obtained better than $20\%$. The effective range is determined for the first time with this analysis.

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arXiv2024

$\bar{B}_s^0 \to D_{s1}(2460)^+ K^-, D_{s1}(2536)^+ K^-$ and the nature of the two $D_{s1}$ resonance

Starting from the molecular picture for the $D_{s1}(2460)$ and $D_{s1}(2536)$ resonances, which are dynamically generated by the interaction of coupled channels, the most important of which are the $D^*K$ for the $D_{s1}(2460)$ and $DK^*$ for the $D_{s1}(2536)$, we evaluate the ratio of decay widths for the $\bar{B}_s^0 \to D_{s1}(2460)^+ K^-$ and $\bar{B}_s^0 \to D_{s1}(2536)^+ K^-$ decays, the latter of which has been recently investigated by the LHCb collaboration, and we obtain a ratio of the order of unity. The present results should provide an incentive for the related decay into the $D_{s1}(2460)$ resonance to be performed, which would provide valuable information on the nature of these two resonances.

hep-ph↗

arXiv2024

$J/ψ$ decays into $ω(ϕ) f_1(1285)$ and $ω(ϕ) \,''f_1(1420)''$

We perform a theoretical study of the $J/ψ\to ω(ϕ) K^* \bar{K} + c.c. \to ω(ϕ) K^0 π^+ K^-$ reactions with the assumption that the $f_1(1285)$ is dynamically generated from a single channel $K^* \bar{K} + c.c$ interaction in the chiral unitary approach. Two peaks in the $K^0 π^+ K^-$ invariant mass distribution are observed, one clear peak locates at the $f_1(1285)$ nominal mass, the other peak locates at around $1420\; \rm MeV$ with about $70 \;\rm MeV$ width. We conclude that the former peak is associated with the $f_1(1285)$ and the latter peak is not a genuine resonance but a manifestation of the kinematic effect in the higher energy region caused by the $K^* \bar{K} + c.c.$ decay mode of the $f_1(1285)$.

hep-ph↗

arXiv2024

Molecular pentaquark states with open charm and bottom flavors

We study the possibly-existing molecular pentaquark states with open charm and bottom flavors, {\it i.e.}, the states with the quark contents $c\bar{b}qqq$ and $b\bar{c}qqq$ ($q=u,d,s$). We investigate the meson-baryon interactions through the coupled-channel unitary approach within the local hidden-gauge formalism, and extract the poles by solving the Bethe-Salpeter equation in coupled channels. These poles qualify as molecular pentaquark states, which are dynamically generated from the meson-baryon interactions through the exchange of vector mesons. Our results suggest the existence of the $Σ_c^{(*)} B^{(*)}$ and $Σ_b^{(*)} \bar{D}^{(*)}$ molecular states with isospin $I=1/2$, the $Ξ_c^{(\prime,*)} B^{(*)}$ and $Ξ_b^{(\prime,*)} \bar{D}^{(*)}$ molecular states with isospin $I=0$ and $I=1$, as well as the $Ω_c^{(*)} B^{(*)}$ and $Ω_b^{(*)} \bar D^{(*)}$ molecular states with isospin $I=1/2$.

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arXiv2023

The $\bar B_s^0 \to J/ψπ^0 η$ decay and the $a_0(980)-f_0(980)$ mixing

We study the $\bar B_s^0 \to J/ψf_0(980)$ and $\bar B_s^0 \to J/ψa_0(980)$ reactions, and pay attention to the different sources of isospin violation and mixing of $f_0(980)$ and $a_0(980)$ resonances where these resonances are dynamically generated from meson-meson interaction. We find that the main cause of isospin violation is the isospin breaking in the meson-meson transition $T$ matrices, and the other source is that the loops involving kaons in the production mechanism do not cancel due to the different masses of the charged and neutral kaons. We obtain a branching ratio for $a_0(980)$ production of the order of $5 \times 10^{-6}$. Future experiments can address this problem, and the production rate and shape of the $π^0 η$ mass distribution will definitely help to better understand the nature of scalar resonances.

hep-ph↗

arXiv2021

The $D_s^+ \to a_0(980) e^+ ν_e$ reaction and the $a_0(980)-f_0(980)$ mixing

We perform a study of the $D_s^+ \to a_0(980)(f_0(980)) e^+ ν_e$ reactions investigating the different sources of isospin violation which make the production of the $a_0(980)$ possible. We find that loops involving kaons in the production mechanism provide a source of isospin violation since they do not cancel due to the different mass of charged and neutral kaons, but we also find that the main source comes from the breaking of isospin in the meson-meson transition $T$ matrices, which contain information on the nature of the low lying scalar mesons. The reaction is thus very sensitive to the nature of the $a_0(980)$ and $f_0(980)$ resonances. Our results are consistent with the present upper bound for $a_0(980)$ production and only a factor three smaller, indicating that future runs with more statistics should find actual numbers for this reaction from where we can learn more about the origin of the scalar resonances and their nature.

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