论文标题
中性媒介介子的四级衰减
Four-lepton decays of neutral vector mesons
论文作者
论文摘要
我们研究了中性矢量介子的罕见电磁衰变（以$ j/ψ$，$差，$ρ^0 $，$ω，$ω，ϕ $，\ ldots）为四个带电的leptons（$ 2（e^+e^+e^ - ）$，$ 2（$ 2（$ 2） $ e^+e^-μ^+μ^ - $，$ e^+e^+e^ - τ^+τ^ - $，\ ldots）在QED中的最低顺序。与将媒介中膜衰减成一对瘦素相反，必须将Lepton质量保留在这四局衰减通道中以截断质量奇异性。由于更明显的共线增强，媒介中的分支分数衰减为$ 2（E^+E^ - ）$要大得多，大得多，比衰减的$ 2（μ^+μ^ - ）$要大得多。预测衰减通道$ j/ψ（υ）\至2（e^+e^ - ），e^+e^+e^-μ^+μ^ - $的$被预测具有$ 10^{ - 5} $的分支分数，似乎具有{\ tt besiii}，{\ ttt belle 2} and c and and and and and and and and and c。
We investigate the rare electromagnetic decays of neutral vector mesons (exemplified by $J/ψ$, $Υ$, $ρ^0$, $ω,ϕ$, \ldots) into four charged leptons ($2(e^+e^-)$, $2(μ^+μ^-)$, $2(τ^+τ^-)$, $e^+e^-μ^+μ^-$, $e^+e^-τ^+τ^-$, \ldots) at lowest order in QED. In contrast to the case of vector meson decay into a single pair of leptons, the lepton mass must be retained in these four-lepton decay channels to cutoff the mass singularity. Owing to more pronounced collinear enhancement, the branching fractions of vector mesons decays into $ 2(e^+e^-)$ are considerably greater than those for decays into $2(μ^+μ^-)$. The decay channels $J/ψ(Υ)\to 2(e^+e^-), e^+e^-μ^+μ^-$ are predicted to have branching fractions of order $10^{-5}$, which appear to have bright observation prospect at {\tt BESIII}, {\tt Belle 2} and {\tt LHC} experiments.
