arXiv subjects

Jinfei Wu

Publications and source records attributed to Jinfei Wu.

5 recordsLinked to original sources

arXiv2026

Measurement of $\Xi^-/\bar{\Xi}^{+}$ production in jets from $Z$ boson decays with the DELPHI open data

The production rates of $\Xi^{-}/\bar{\Xi}^{+}$ baryons in energy-ranked jets produced in $Z\to\text{hadrons}$ decays are measured using $3.2$ million hadronic $Z$ events recorded by the DELPHI experiment. Jets are reconstructed using the Durham algorithm with $y_{\text{cut}}=0.005$. Quark- and gluon-enriched jet samples are obtained by ranking the jet energies in three-jet events. The softest jet are found to produce fewer $\Xi^{-}/\bar{\Xi}^{+}$ and less energetic baryons than the other jets. The ratio of $\Xi^{-}/\bar{\Xi}^{+}$ production rates in gluon and quark jets, each normalized to the corresponding mean charged-particle multiplicity, is measured to be $1.21 \pm 0.18~\mathrm{(stat.)} \pm 0.26~\mathrm{(syst.)}$. The result is consistent with the JETSET expectation and the OPAL measurements of $K_S^0$ and $\Lambda$ productions in $Z$ decays. This study presents the first measurement of the gluon-to-quark production ratio for baryons containing two $s$ quarks, providing new insights into strange-quark production and hadronization. Future $e^{+}e^{-}$ colliders such as CEPC and FCCee will provide much larger $Z$-boson samples and will allow far more precise studies of the subject.

hep-ex↗

arXiv2025

Determination of the Strong Coupling Constant $α_s$ from Inclusive Semi-leptonic $B$ Meson Decays

We demonstrate the feasibility of determining the strong coupling constant, $α_s$, from the inclusive semileptonic decay width of $B$ mesons. We express the semileptonic $B$ decay width as a function of $α_s(5\mathrm{\,GeV})$, the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cb}|$, $b$- and $c$-quark masses in the $\overline{\mathrm{MS}}$ scheme. We fit $α_s(5\mathrm{\,GeV})$ to current world averages of the $B^{\pm}$ and $B^{0}$ semileptonic decay widths. This yields $α_s(5\mathrm{\,GeV}) = 0.245 \pm 0.009$, corresponding to a 5-flavor extrapolation of $α_s(m_{Z}) = 0.1266 \pm 0.0023$. The primary uncertainty contributions arise from the uncertainty on the perturbative expansion and the value of $|V_{cb}|$. Future advancements including higher-order perturbative calculations, and precise measurements of $|V_{cb}|$ and $B$ decay widths from upcoming $B$ and $Z$ factories, could enable this method to determine $α_s(m_{Z})$ with a competitive precision of $Δα_s(m_{Z}) \sim 0.0018$. This precision is comparable to the current accuracy of $α_s(m_{Z})$ measurements from $τ$-lepton decays, which is regarded as the most precise experimental approach.

hep-ph↗

arXiv2025

Determination of Strong Coupling Constant from Inclusive Semileptonic Decays of Charmed Mesons

Employing the heavy quark expansion model with the kinetic scheme, we evaluate $α_S(m_c^2)$, the strong coupling constant at the charm quark mass $m_c$ with data on inclusive semileptonic decays of charmed mesons. Using the experimental values of semileptonic decay widths of the $D^0$ and the $D^+$, the value of $α_{s}(m_c^{2})$ is determined to be $0.445\pm0.009\pm0.114$, where the first uncertainty is experimental and the second systematic. This reported $α_{s}(m_c^{2})$ is in good agreement with the value of $α_{s}(m_c^{2})$ calculated by running $α_S(m_Z^2)$ at the $Z^0$ boson mass $m_Z$ with the renormalization group evolution equation. In addition, values of $α_{s}(m_c^{2})$ obtained individually from each of the $D^0$, $D^+$, and $D_s^+$ mesons are found to be consistent being of the same origin.

hep-ph↗

arXiv2025

Measurements of decay branching fractions of the Higgs boson to hadronic final states at the CEPC

The Circular Electron Positron Collider (CEPC) is a large-scale particle accelerator designed to collide electrons and positrons at high energies. One of the primary goals of the CEPC is to achieve high-precision measurements of the properties of the Higgs boson, facilitated by the large number of Higgs bosons that can be produced with significantly low contamination. The measurements of Higgs boson branching fractions into $b\overline{b} /c\overline{c} /gg$ and $τ\overlineτ /WW^{*} /ZZ^{*} $, where the $W$ or $Z$ bosons decay hadronically, are presented in the context of the CEPC experiment, assuming a scenario with 5600 fb$^{-1}$ of collision data at a center-of-mass energy of 240 GeV. In this study the Higgs bosons are produced in association with a $Z$ boson, with the $Z$ boson decaying into a pair of muons $(μ^{+}μ^{-})$, which have high efficiency and high resolution. In order to separate all decay channels simultaneously with high accuracy, the Particle Flow Network (PFN), a graph-based machine learning model, is considered. The precise classification provided by the PFN is employed in measuring the branching fractions using the migration matrix method, which accurately corrects for detector effects in each decay channel. The statistical uncertainty of the measured branching ratio is estimated to be 0.55% in $H\to b\overline{b}$ final state, and approximately 1.5%-16% in $H\to c\overline{c} /gg/τ\overlineτ/WW^{*} /ZZ^{*} $ final states. In addition, the main sources of systematic uncertainties to the measurement of the branching fractions are discussed.

hep-ex↗

arXiv2024

Radiative Leptonic Decay of Heavy Quarkonia

This study examines the properties of heavy quarkonia $X$ by treating them as bound states of $Q$ and $\bar{Q}$ at the LO level within the NRQCD framework, where $Q$ represents either a charm or a bottom quark. The branching ratios for the radiative leptonic decays $X\rightarrow γl^{+} l^{-}$ are revisited and the angular and energy/momentum distributions of the final state particles are analyzed in the rest frame of $X$. Furthermore, we apply Lorentz transformations from the rest frame of $X$ to the center-of-mass frame of $l^+ l^-$ to establish the connection between the widths ${Γ_{X \rightarrow γl^{+} l^{-}}}$ and ${Γ_{X \rightarrow l^{+} l^{-}}}$. When comparing the connection with those documented in the literature (divided by $2π$) for various $X$ states, such as $J/Ψ$, $Ψ(2S)$, $Υ(1S)$, and $Υ(2S)$, relative differences typically around or below 10\% can be found, which is comparable to the NLO corrections of $O(α)$ and $O(v^4)$. However, we observe a significant disparity in the ratio between ${Γ_{Ψ(2S) \to γτ^+ τ^-}}$ and ${Γ_{Ψ(2S) \to τ^+ τ^-}}$, with our prediction being four times larger than those in the literature. The outcomes derived from this study held practical implications in describing the QED radiative processes and contribute to the investigation of QCD processes associated with the decays of heavy quarkonia and the searches for new physics.

hep-ph↗