arXiv subjects

Yi-Yao Li

Publications and source records attributed to Yi-Yao Li.

8 recordsLinked to original sources

arXiv2026

The $Ω(2380)$ as a partner of the $Ω(2012)$

We present a study of the $Ω(2380)$ resonance and show that it is consistent with a dynamically generated state arising from the $\bar{K}^*Ξ^*$, $ωΩ$, and $ϕΩ$ interactions. In this picture, the $Ω(2380)$ is analogous to the $Ω(2012)$, which is generated from the $\bar{K}Ξ^*$ and $ηΩ$ channels. The resulting mass, total width, and partial decay widths into the $\bar{K}Ξ^*$ and $\bar{K}^*Ξ$ channels are compatible with the available experimental data. We also discuss possible experimental observables that could provide further insight into the nature of this state.

hep-ph↗

arXiv2025

On the $π^+π^-$ and $D^+_sπ^{\pm}$ mass spectra in the $D_{s1}(2536) \to D^+_sπ^+π^-$ decays

We have carried out an evaluation of the $π^+ π^-$ and $D_s^+ π^+$ mass distributions in the $D_{s1}(2536)$ decay to $D_s^+ π^+ π^-$, from the perspective that the $D_{s1}(2536)$ is a molecular state, mostly made from $K^*D$ in $I=0$. We are able to obtain, not only the mass distributions, but the branching ratio of this decay. The shape of the mass distributions differ appreciably from those of the analogous reaction $D_{s1}(2460)\to D_s^+ π^+ π^-$, which has been measured by the LHCb collaboration and analyzed theoretically from the perspective that the $D_{s1}(2460)$ is a molecular state of $D^*K$, showing a good agreement with the data. In spite of the analogy with the $D_{s1}(2460)$ decay, the dynamical differences in the decay mechanism are important, since now the $f_0(500)$ resonance is not generated, while it was the dominant mechanism in the $D_{s1}(2460)\to D_s^+ π^+ π^-$ decay. Nonetheless, we find striking differences in the mass distributions compared with phase space as a consequence of the decay mechanism. The branching ratio obtained is an order of magnitude bigger than the one of the $D_{s1}(2460)\to D_s^+ π^+ π^-$ reaction, mostly due to the larger available phase space. We also show that the shape of the distributions obtained from the molecular picture are quite different from those obtained based on a $q\bar{q}$ picture. We conclude that measuring the shape of the mass distributions and the total strength of the decay mode, should be very valuable to learn about the structure of the $D_{s1}(2536)$.

hep-ph↗

arXiv2025

$a_0(980)$ and $f_0(980)$ excitation in the $D^+ \to π^+ ηη$ decay

We have made a thorough study of the $D^+ \to π^+ ηη$ reaction, recently measured by the BESIII collaboration, which shows an abnormal strength at high invariant masses in the $πη$ mass distribution. We studied in detail the triangle mechanism and the $f_0(1370)$ excitation modes that have been suggested to explain this abnormal feature, and concluded that they are too small to have any important role in the solution to that problem. We have also studied other possible solutions evaluating the contribution of excitations of other $f_0$, $a_0$ and $f_2$ resonances and reached the same conclusion. Unexpectedly, the solution to the problem is found considering the $f_0(980)$ excitation, with the $f_0(980)$ decaying to two $η$, which is tied to the $a_0(980)$ production, and well under control. At the same time, the consideration of the $f_0(980)$ excitation solves another non reported problem, which is the $ηη$ mass distribution that comes when only the $a_0(980)$ resonance is allowed to be excited, which produces a large deficiency at low invariant masses compared with experiment.

hep-ph↗

arXiv2025

Revisiting the $Λ_c^+\rightarrow\bar{K}^0ηp$ reaction: the role of $N^(1535),~ N^(1650)$ and $Σ(1620)$

We perform a theoretical study of the weak decay $Λ_c^+ \rightarrow \bar{K}^0 ηp$ using a coupled-channel chiral unitary approach that incorporates both pseudoscalar-baryon and vector-baryon interactions. Our framework includes contributions from both internal and external weak emission mechanisms, as well as strong final state interactions. We assume that the $N^*(1535)$ and $N^*(1650)$ resonances are dynamically generated through meson-baryon scattering and they appear as distinct structures in the $ηp$ invariant mass distributions. {A clear peak also appears in the $\bar{K}^0 p$ invariant mass distribution around 1620~MeV, associated with the dynamically generated $Σ(1620)$ resonance.} Notably, this work provides the first theoretical description of the simultaneous observation of these two related $N^*$ resonances in the same meson-baryon final state. Our results highlight the crucial role of final state interaction and the interplay between different weak decay topologies in shaping the resonance patterns. These findings offer new insights into the nature of nucleon excitations and support the interpretation of $N^*(1535)$ and $N^*(1650)$ as dynamically generated states. {Moreover, the identification of the $Σ(1620)$ further supports the picture of hadronic molecular structures emerging from meson-baryon interactions in the non-perturbative QCD regime.}

hep-ph↗

arXiv2025

Molecular states with bottom mesons and multistrange baryons systems

We investigate molecular states formed by bottom mesons and multistrange baryons from both octet and decuplet flavor representations, using the local hidden gauge approach combined with coupled-channel Bethe-Salpeter equations. Focusing on strangeness sectors $S = -1$ to $-4$, we predict several bound states in the $S=-1, I=1/2,~3/2$ and $S=-2, I=0$ sectors. No bound states are found in other isospin channels, where the interaction is repulsive, nor in higher strangeness sectors. The binding energies are analyzed under different values of the cutoff regularization parameters, providing estimates of theoretical uncertainties. This study provides concrete predictions to support future experimental investigations and improve understanding of heavy-flavor multistrange exotic hadrons.

hep-ph↗

arXiv2025

The $Λ_c^+\toΛπ^+π^+π^-$ reaction, and a triangle singularity producing the $Σ^*(1430)$ state

We study the decay $Λ_c^+ \to Λπ^+ π^+ π^-$, focusing on the production of the $Σ^*(1430)$ resonance observed by the Belle Collaboration. Interpreted as a dynamically generated state from meson-baryon interactions in the chiral unitary approach, the $Σ^*(1430)$ signal is shown to be enhanced by a triangle singularity involving intermediate $K^{*-}$, $p$, and $\bar K^0$ states. This mechanism leads to a sharp peak near 1434 MeV in the $π^+ Λ$ invariant mass distribution, in agreement with the experimental observations, and predicts a secondary peak around 1875 MeV in the $π^- Σ^*(1430)$ spectrum tied to the triangle singularity. We also estimate the branching ratio of $Λ_c^+ \to π^+ π^- Σ^*(1430)$ to be about $3.5 \times 10^{-4}$. The results for the branching ratio and the $π^- Σ^*(1430)$ mass distributions are predictions of the theoretical approach, which could be tested with reanalysis of existing data.

hep-ph↗

arXiv2024

Revealing the mystery of the double charm tetraquark in $pp$ collision

A novel approach is proposed to probe the nature of the double charm tetraquark through the prompt production asymmetry between $T_{\bar{c}\bar{c}}^-$ and $T_{cc}^+$ in $pp$ collisions. When comparing two theoretical pictures, i.e. the compact tetraquark and hadronic molecular pictures, we find that the former one exhibits a significantly larger production asymmetry, enabling the unambiguous determination of the tetraquark's internal structure. Additionally, distinctive differences in the transverse momentum and rapidity distributions of $T_{\bar{c}\bar{c}}^-$ and $T_{cc}^+$ cross sections emerge, particularly at $p_\mathrm{T}\approx 2~\mathrm{GeV}$ and $y\approx \pm 6$ at a center-of-mass energy of 14$~\mathrm{TeV}$. The insignificant asymmetry in hadronic molecular picture is because that hadronic molecules are produced in hadronic phase, where the phase space of their constituents needs to be taken into account rigorously. Our work can be extended to the exploration of other double heavy tetraquark candidates, offering a versatile approach to advance our understanding of exotic hadrons.

hep-ph↗

arXiv2024

The pole structures of the $X(1840)/X(1835)$ and the $X(1880)$

Whether the $N\bar{N}$ interaction could form a state or not is a long standing question, even before the observation of the $p\bar{p}$ threshold enhancement in 2003. The recent high statistic measurement in the $J/ψ\to γ3(π^+π^-)$ channel would provide a good opportunity to probe the nature of the peak structures around the $p\bar{p}$ threshold in various processes. By constructing the $N\bar{N}$ interaction respecting chiral symmetry, we extract the pole positions by fitting the $p\bar{p}$ and $3(π^+π^-)$ invariant mass distributions of the $J/ψ\to γp \bar p$ and $J/ψ\to γ3(π^+π^-)$ processes. The threshold enhancement in the $p\bar{p}$ invariant mass distribution is from the pole on the third Riemann sheet, which more couples to the isospin triplet channel. The broader structure in the $3(π^+π^-)$ invariant mass comes from the pole on the physical Riemann sheet, which more couples to the isospin singlet channel. Furthermore, the large compositeness indicates that there should exit $p\bar{p}$ resonance based on the current experimental data. In addition, we also see a clear threshold enhancement in the $n\bar{n}$ channel, but not as significant as that in $p\bar{p}$ channel, which is useful and compared with further experimental measurement.

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