arXiv subjects

Yongjie Deng

Publications and source records attributed to Yongjie Deng.

3 recordsLinked to original sources

arXiv2026

Higher-twist effect in inclusive electron-positron annihilation

We establish a comprehensive theoretical framework for the electron-positron single-inclusive annihilation (SIA) process that incorporates higher-twist contributions up to twist-4 and demonstrate that these effects should be considered in low-energy reactions. Through a systematic collinear expansion of the hadronic tensor, we derive the complete set of structure functions in terms of collinear fragmentation functions (FFs), explicitly including multi-parton correlators up to the four-parton level. To evaluate the impact of these power corrections, we estimate the twist-4 unpolarized FF using a spectator model and compute the normalized differential cross section for $π^0$ production. Our numerical analysis reveals that the interplay between kinematic hadron mass corrections and dynamical twist-4 effects improves the theoretical description of recent BESIII data at relatively low-$z$ region. Furthermore, the $Q$-dependence confirms that higher-twist corrections are dominant at intermediate energy scales. These findings indicate that standard leading-twist global analyses must be extended to include these power corrections for precise studies of hadronization dynamics.

hep-ph↗

arXiv2025

The Sivers asymmetry of vector meson production in semi-inclusive deep inelastic scattering

The transverse single-spin asymmetry for $ρ^0$ production in semi-inclusive deep inelastic scattering was recently reported by the COMPASS Collaboration. Using the Sivers functions extracted from pion and kaon productions, we perform a calculation of the Sivers asymmetry within the transverse momentum dependent factorization. Our results are consistent with the COMPASS data, confirming the universality of the Sivers functions within current experimental uncertainties. While various global analyses of Sivers functions can equally well describe the current data, we obtain very different predictions on the Sivers asymmetry of $ρ$ and $K^*$ productions at electron-ion colliders, which therefore are expected to provide further constraints.

hep-ph↗

arXiv2025

Testing Lepton Flavor Universality at the Electron-Ion Collider

Measurements of $b\to cτ^-\barν_τ$ transitions at colliders are highly motivated for testing lepton flavor universality (LFU), a cornerstone hypothesis of the Standard Model (SM). Potential observations of LFU violation could provide significant evidence for physics beyond the SM (BSM). The substantial production of $b$-hadrons at the Electron-Ion Collider (EIC) would highlight its potential to support LFU testing and complement studies conducted at other experimental facilities. In this paper, we study the production of $b$-hadrons in deep inelastic scattering processes at the EIC with $\sqrt{s}=100\,\rm GeV$. We estimate the $b$-hadron yields at the EIC to reach $\mathcal O(10^9)$ with an integrated luminosity of up to $10^3\,{\rm fb}^{-1}$. Furthermore, we perform a systematic study on various $b$-hadron decays, exploring the sensitivities of LFU-violating observables, including $R_{J/ψ}$, $R_{D_s^{(\ast)}}$ and $R_{Λ_c}$. Detailed strategies for track-based event reconstruction are investigated for these observables. We also include a discussion of the annihilation process $B_c^+ \to τ^+ν_τ$. Finally, we provide a theoretical interpretation of the projected sensitivities within the framework of low energy effective field theory (LEFT). Our analysis indicates that the EIC has the potential to constrain the relevant Wilson coefficients at $\mathcal O(0.1)$, offering complementary insights to other measurements.

hep-ph↗