"Figure 3a" of "Search for $CP$ violation in ttH and tH production in multilepton channels in proton-proton collisions at $\sqrt{s}$ = 13 TeV"

M_ttH which is one of the input variables to the XGBoost used for CP discrimination in 2lss + 0tau channel, defined in table 4.

M_ttH是用于2同号轻子+0τ轻子分析道的CP鉴别所用XGBoost模型的输入变量之一，其定义详见表4。