arXiv subjects

Shi-Chen Xue

Publications and source records attributed to Shi-Chen Xue.

6 recordsLinked to original sources

arXiv2026

Revisiting the $Λ_c^+ \to nπ^+η$ decay in light of the BESIII measurement

Motivated by the latest BESIII measurements on $Λ_c^+\to nπ^+η$, we perform a systematic theoretical study of this decay. We take into account contributions from the $N(1535)$ state dynamically generated by $S$-wave pseudoscalar meson-octet baryon interactions, the $a_0(980)$ resonance originating from the $S$-wave pseudoscalar meson-pseudoscalar meson interactions, together with the intermediate states $N(1440)$ and $a_2(1320)$. Our results indicate that $a_0(980)$ provides a significant contribution to this process. The inclusion of $a_2(1320)$ hardly improves the fitting quality, while the nucleon resonances play a crucial role in describing the experimental behavior of the $π^+η$ invariant mass spectrum in both low and high energy regions. Restricted by insufficient experimental statistics and a coarse bin size of 33 MeV, the precise contribution fraction of $a_0(980)$ cannot be reliably extracted. We propose future higher-precision and higher-statistics experimental measurements of $Λ_c^+\to nπ^+η$, which can help reveal the intrinsic nature of $a_0(980)$ and quantify the roles of different excited nucleon states in this decay.

hep-ph↗

arXiv2026

Semi-leptonic decays $B \to D^{(*)}(1S,2S)\ell ν_{\ell}$ within the covariant light-front approach

We present a systematic analysis of the semi-leptonic decays $B_{(s)}\to D_{(s)}(1S,2S)\ellν_\ell$ and $B_{(s)}\to D^*_{(s)}(1S,2S)\ellν_\ell$ with $\ell=e,μ,τ$ within the covariant light-front quark model (CLFQM). Using the form factors of the transitions $B_{(s)}\to D_{(s)}(1S,2S)$ and $B_{(s)}\to D^*_{(s)}(1S,2S)$, we calculate the branching ratios of the relevant semi-leptonic decays and find that $Br(B_{(s)}\to D_{(s)}\ell^\primeν_{\ell^\prime})$ and $Br(B_{(s)}\to D^*_{(s)}\ell^\primeν_{\ell^\prime})$ with $\ell^\prime=e,μ$ are agree well with the data, while $Br(B_{(s)}\to D_{(s)}τν_τ)$ and $Br(B_{(s)}\to D^*_{(s)}τν_τ)$ are systematically smaller than the experimental measurements. This naturally gives rise to the so-called $\mathcal{R}(D)$ and $\mathcal{R}(D^*)$ anomalies. Our predictions $\mathcal{R}(D)=0.261\pm0.013$ and $\mathcal{R}(D^*)=0.228\pm0.026$ show $3.1σ$ and $2.1σ$ deviations from the current experimental world averages compiled by the Heavy Flavor Averaging Group (HFLAV), respectively, yet only deviate by $0.16σ$ and $1.5σ$ from the latest LHCb measurements. For the decays $B_{(s)}\to D_{(s)}(2S)\ellν_\ell$ and $B_{(s)}\to D^*_{(s)}(2S)\ellν_\ell$, their branching ratios lie in the range $10^{-4}\sim10^{-3}$, which are much larger than the results from the Bethe Salpeter (BS) equation , but agree with the relativistic quark model (RQM) calculations. Furthermore, we also calculate the forward-backward asymmetries $\mathcal{A}_{FB}$ and longitudinal polarization fractions $f_L$ for the corresponding decays. Our predictions are consistent with most other theoretical results and experimental data

hep-ph↗

arXiv2022

Transverse momentum weighted Sivers asymmetries in SIDIS and Drell-Yan processes at COMPASS

We investigate the transverse momentum weighted Sivers asymmetries in the processes with transversely polarized proton target, including the $\frac{P_{hT}}{zM_p}\sin (ϕ_h-ϕ_S)$ weighted asymmetry in charged hadron production in semi-inclusive deeply inelastic scattering (SIDIS) and the $\frac{q_T}{M_p}\sin (ϕ_S)$ weighted asymmetry in $π^- p$ Drell-Yan process. Due to the integration over the transverse momentum, the weighted asymmetries can be expressed as the product of the transverse-moments of the transverse momentum dependent (TMD) parton distribution functions (PDFs) and fragmentation functions (FFs). Using the parametrization for the Sivers function of the proton, the unpolarized PDFs of proton and pion, and the unpolarized FF of charged hadron, we present the numerical calculation for weighted Sivers asymmetries in SIDIS and Drell-Yan processes at the kinematics of COMPASS, and compare them with experimental data. We find that our prediction on the weighted Sivers asymmetry in SIDIS process is in agreement with the recent COMPASS measurement. Due to the relatively large uncertainties of the preliminary data from COMPASS Drell-Yan program, high precision experimental data are needed to test the sign change property of the Sivers function between SIDIS and Drell-Yan processes and to constrain the sea quark Sivers function.

hep-ph↗

arXiv2020

The Collins asymmetry in electroproduction of Kaon at the electron ion colliders within TMD factorization

We apply the transverse momentum dependent factorization formalism to investigate the transverse single spin dependent Collins asymmetry with a $\sin(ϕ_h+ϕ_s)$ modulation in the semi-inclusive production of Kaon meson in deep inelastic scattering process. The asymmetry is contributed by the convolutions of the transversity distribution function $h_1(x)$ of the target proton and the Collins function of the Kaon in the final state. We adopt the available parametrization of $h_1(x)$ as well as the recent extracted result for the Kaon Collins function. To perform the transverse momentum dependent evolution, the parametrization of the nonperturbative Sudakov form factor of the proton and final state Kaon are utilized. We numerically predict the Collins asymmetry for charged Kaon production at the electron ion colliders within the accuracy of next-to-leading-logarithmic order. It is found that the asymmetry is sizable and could be measured. We emphasize the importance of planned electron ion colliders in the aspect of constraining sea quark distribution functions as well as accessing the information of the nucleon spin structure and the hadronization mechanism.

hep-ph↗

arXiv2018

The possible members of the $5^1S_0$ meson nonet

The strong decays of the $5^1S_0$ $q\bar{q}$ states are evaluated in the $^3P_0$ model with two types of space wave functions. Comparing the model expectations with the experimental data for the $π(2360)$, $η(2320)$, $X(2370)$, and $X(2500)$, we suggest that the $π(2360)$, $η(2320)$, and $X(2500)$ can be assigned as the members of the $5^1S_0$ meson nonet, while the $5^1S_0$ assignment for the $X(2370)$ is not favored by its width. The $5^1S_0$ kaon is predicted to have a mass of about 2418 MeV and a width of about 163 MeV or 225 MeV.

hep-ph↗

arXiv2018

Strong decays of the higher isovector scalar mesons

Under the assignment of $a_0(1450)$ as the ground isovector scalar meson, the strong decays of $a_0(1950)$ and $a_0(2020)$ are evaluated in the $^3P_0$ model. Our calculations suggest that $a_0(1950)$ and $a_0(2020)$ can be regarded as the same resonance referring to $a_0(3^3P_0)$. The masses and strong decays of $a_0(2^3P_0)$ and $a_0(4^3P_0)$ are also predicted, which can be useful in the search for radially excited scalar mesons in the future.

hep-ph↗