论文标题
罕见的两肢腐烂，将顶部夸克变成底部的介子，以及一个或魅力夸克
Rare two-body decays of the top quark into a bottom meson plus an up or charm quark
论文作者
论文摘要
顶级夸克的罕见两体腐烂成中性的底部Quark Meson，以及上或魅力的Quark：$ t \ to {\ overline b}^0+ u，c $; $ t \ to {\ overline b}^0_ {s}+ c，u $;首次研究$ t \ to到υ（NS）+ C，U $。相应的部分宽度是在非相关QCD框架中以领先顺序计算的。所有两体分支比率的总和相当于$ \ MATHCAL {B}（t \ to {\ overline B}^0+ {\ rm jet}）\近似\ Mathcal {b}（t \ t \ t \ to {\ overline b}^0_ $ \ mathcal {b}（t \ to告诉（ns）+ {\ rm jet}）\大约2 \ cdot 10^{ - 9} $。观察$ t \ to {\ overline b}^0 _ {（s）}+{\ rm jet} $衰减的可行性是在proton-proton碰撞中在$ \ sqrt {s} = 14，100 $ tev in lhc and fcc和fcc中分别估计的。 Combining many exclusive hadronic ${\overline B}^0_{(s)}$ decays, with $J/ψ$ or $D^{0,\pm}$ final states, about 50 (16000) events are expected in 3 (20) ab$^{-1}$ of integrated luminosity at the LHC (FCC), after typical selection criteria, acceptance, and efficiency losses.在有趣的$ t \ to b（\ rm {jet}）+c（\ rm {jet}）$ dijet最终状态中，也可以实现对两体顶级衰败的观察，其中$ {\ overline b}^0 _ {（s）} $ decay产品与500300次乘以53300 cots procests，其中$ {\ overline b}^0 _ {（s）} $ decay产品在500300上进行了预期。 LHC和FCC分别。这种独特的最终状态提供了一种新的直接方法，可以通过简单的2体不变质量分析精确地测量顶级质量。
Rare two-body decays of the top quark into a neutral bottom-quark meson plus an up- or charm-quark: $t\to {\overline B}^0+ u, c$; $t\to {\overline B}^0_{s}+ c,u$; and $t \to Υ(nS)+ c,u$, are studied for the first time. The corresponding partials widths are computed at leading order in the non-relativistic QCD framework. The sums of all two-body branching ratios amount to $\mathcal{B}(t \to {\overline B}^0+ {\rm jet}) \approx \mathcal{B}(t \to {\overline B}^0_{s}+ {\rm jet}) \approx 4.2\cdot 10^{-5}$ and $\mathcal{B}(t \to Υ(nS)+ {\rm jet}) \approx 2\cdot 10^{-9}$, respectively. The feasibility to observe the $t\to {\overline B}^0_{(s)}+{\rm jet}$ decay is estimated in top-pair events produced in proton-proton collisions at $\sqrt{s} = 14, 100$ TeV at the LHC and FCC, respectively. Combining many exclusive hadronic ${\overline B}^0_{(s)}$ decays, with $J/ψ$ or $D^{0,\pm}$ final states, about 50 (16000) events are expected in 3 (20) ab$^{-1}$ of integrated luminosity at the LHC (FCC), after typical selection criteria, acceptance, and efficiency losses. An observation of the two-body top-quark decay can also be achieved in the interesting $t\to b(\rm{jet})+c(\rm{jet})$ dijet final state, where the ${\overline B}^0_{(s)}$ decay products are reconstructed as a jet, with 5300 and 1.4 million signal events above backgrounds expected after selection criteria at the LHC and FCC, respectively. Such unique final states provide a new direct method to precisely measure the top-quark mass via simple 2-body invariant mass analyses.
