arXiv subjects

Yiqi Geng

Publications and source records attributed to Yiqi Geng.

5 recordsLinked to original sources

arXiv2026

Two-nucleon systems at $m_{\pi}\approx292$ MeV from lattice QCD

Nucleon-nucleon systems in the $^3S_1$ and the $^1S_0$ channels are studied in lattice quantum chromodynamics at a pion mass of approximately $m_{\pi}\approx292$ MeV, employing three $N_f = 2+1$ ensembles with the same pion mass and lattice spacing $a=0.10530(18)$ fm but different spatial volumes. Finite-volume energies of the nucleon-nucleon systems are determined in both the rest frame and a moving frame. The distillation quark smearing method is applied to improve the precision and to ensure the symmetric correlators by using the same interpolating operators at sink and source. The scattering amplitudes are extracted from the finite-volume spectra using the L\"uscher's finite-volume method. At the studied pion mass, both the $^3S_1$ (deuteron) and $^1S_0$(di-neutron) channels exhibit a virtual state pole, with binding energies of $6^{+5}_{-3}$ MeV and $11^{+6}_{-5}$ MeV, respectively. To investigate the effects of the left-hand cut, an alternative method -- the Non-Perturbative Hamiltonian framework (NPHF) -- is used for the scattering analysis and yields consistent results with those from the L\"uscher method.

hep-lat↗

arXiv2025

Parton Distribution Function of a Deuteron-like Dibaryon System from Lattice QCD

We report a lattice QCD calculation of the parton distribution function (PDF) of a deuteron-like dibaryon system using large-momentum effective theory. The calculation is done on three Wilson Clover ensembles with a fixed lattice spacing a=0.105 fm and two pion masses. The lattice matrix elements are computed at proton momenta up to 2.46 GeV with the signal of high momentum modes being improved by applying the momentum smearing technique. The state-of-the-art renormalization, matching and extrapolation are then applied to obtain the final result of the light-cone PDF. A comparison between the result of the dibaryon system and the sum of the proton and neutron PDFs is also given.

hep-lat↗

arXiv2025

Lattice QCD study of $Λ_c Λ_c$ scattering

We present the first lattice result of the near threshold $Λ_cΛ_c$ scattering with $I(J^P) = 0(0^+)$. The calculation is performed on two $N_f = 2+1$ Wilson-Clover ensembles with pion mass $m_π\sim 303$\,MeV and lattice spacing $a = 0.07746$\,fm. The Lüscher's finite volume method is utilized to extract the scattering parameters from the finite-volume spectrum. The coupled channel $Ξ_{cc}N$ is ignored in the scattering analysis based on the observation that the energy levels computed from the $Λ_cΛ_c$ and $Ξ_{cc}N$ operators do not mix. The $Σ_cΣ_c$ channel is not included either since the energy range explored in this study is well below its threshold. Our results indicate that the interaction in the $Λ_cΛ_c$ single channel is repulsive, and the scattering length is determined to be $a_0 = -0.21(4)(8)$\,fm, where the first error is the statistical error and the second is the systematic error.

hep-lat↗

arXiv2024

Polarization and quantum entanglement effects in $B^\pm_c\to J/ψ+π^\pm +π^0$ process

Motivated by the very recent observation of the $B^+_c\to J/ψ+π^+ +π^0$ decay using proton-proton collision data by the LHCb collaboration, we study the four-body angular distributions and the quantum entanglement effects in the $B^+_c\to J/ψ+π^+ +π^0$ associated with $J/ψ\to μ^++μ^-$. The helicity angular distributions are given in the QCD effective theory and the von Neumann entropy is obtained in $B^\pm_c\to J/ψ(\to μ^+μ^-)+ρ^\pm(\to π^\pm π^0)$ decay process.

hep-ph↗

arXiv2023

Distinguishing Low-lying Vector Beauty-charm Meson via Polarization Analysis

To distinguish the low-lying vector beauty-charm meson, we systematically study the $B_c^*\to B_c+γ$, $B_c^*\to \ell+ν_{\ell}$ and $B_c^{(*)}\to J/ψ+nh$ processes within effective theory by the helicity decomposition method. The significant difference of polarization asymmetry in $B_c^{(*)}\to J/ψ+nh$ indicates a general law in vector-to-vector and pseudoscalar-to-vector transition processes, which can be tested in current and future LHC experiments. In the end, we discuss the experiment search and discovery potential for the low-lying vector beauty-charm meson.

hep-ph↗