arXiv subjects

Huijing Li

Publications and source records attributed to Huijing Li.

2 recordsLinked to original sources

arXiv2022

Feasibility Study of $D_s^+ \to τ^+ ν_τ$ Decay and Test of Lepton Flavor Universality with Leptonic $D_s^+$ Decays at STCF

We report a sensitive study of $D_s^+ \to τ^+ ν_τ$ decay via $τ^+ \to e^+ ν_e \barν_τ$ with an integrated luminosity of 1 ab$^{-1}$ at the center-of-mass energy of $4.009$ GeV at a future Super Tau Charm Facility (STCF). Under the help of the fast simulation software package, the statistical sensitivity for the absolute branching fraction of $D_s^+ \to τ^+ ν_τ$ is determined to be $2\times10^{-4}$. Combining with our previous prospect of $D_s^+ \to μ^+ ν_μ$, the ratio of the branching fractions for $D_s^+ \to τ^+ ν_τ$ over $D_s^+ \to μ^+ ν_μ$ can achieve a relative statistical precision of 0.5%, which will provide the most stringent test of the $τ$-$μ$ lepton flavor universality in heavy quark decays. Taking the decay constant $f_{D_s^+}$ from lattice QCD calculations or the CKM matrix element $|V_{cs}|$ from the CKMfitter group as an input, the relative statistical uncertainties for $|V_{cs}|$ and $f_{D_s^+}$ are estimated to be 0.3% and 0.2%, respectively.

hep-ex↗

arXiv2021

Prospects of CKM elements $|V_{cs}|$ and decay constant $f_{D_{s}^+}$ in $D_s^+\to\mu^+\nu_\mu$ decay at STCF

We report a feasibility study of pure leptonic decay $D_s^+\to\mu^+\nu_\mu$ by using a fast simulation software package at STCF. With an expected luminosity of $1~\mathrm{ab}^{-1}$ collected at STCF at a center-of-mass energy of 4.009 GeV, the statistical sensitivity of the branching fraction is determined to be 0.3\%. Combining this result with the $c\rightarrow s$ quark mixing matrix element $|V_{cs}|$ determined from the current global Standard Model fit, the statistical sensitivity of $D_s^+$ decay constant, $f_{D_s^+}$, is estimated to be 0.2\%. Alternatively, combining the current results of $f_{D_s^+}$ calculated by lattice QCD, the statistical sensitivity of $|V_{cs}|$ is determined to be 0.2\%, which helps probe possible new physics beyond. The unprecedented precision to be achieved at STCF will provide a precise calibration of QCD and rigorous test of Standard Model.

hep-ex↗