论文标题
$ d^+\toπ^ - π^+π^+$衰减的振幅分析和$π^-π^+$ s波振幅的测量
Amplitude analysis of the $D^+\toπ^- π^+π^+$ decay and measurement of the $π^-π^+$ S-wave amplitude
论文作者
论文摘要
对$ d^+ \至π^ - π^+π^+ $衰减的振幅分析是在$ 1.5 \ rm fb^{ - 1} $相对应的$ pp $ collisions的$ 1.5 \ rm fb^{ - 1} $的样本中进行的，该样本在一个中centre $ \ sqrt $ \ sqrt {s} = 8 $ tev coltitation inty prockation tect coltitation coltitation coltitation tem conterty conterty collection tection conteriation coltions coltions。信号纯度为$ 95 \％$。通过拟合达利兹图研究了谐振结构，其中$π^-π^+$ s波振幅作为$π^-π^+$质量的函数提取，而Spin-1和Spin-2共振通过ISOBAR模型相干地包括在内。发现S波组件是主导的，其次是$ρ（770）^0π^+$和$ f_2（1270）π^+$组件。 $ω（782）\toπ^-π^+ $衰减的小贡献是在$ d^+ \toπ^-π^-π^+π^+ $衰减中首次看到的。
An amplitude analysis of the $D^+ \to π^- π^+ π^+$ decay is performed with a sample corresponding to $1.5\rm fb^{-1}$ of integrated luminosity of $pp$ collisions at a centre-of-mass energy $\sqrt{s}=8$ TeV collected by the LHCb detector in 2012. The sample contains approximately six hundred thousand candidates with a signal purity of $95\%$. The resonant structure is studied through a fit to the Dalitz plot where the $π^- π^+$ S-wave amplitude is extracted as a function of $π^-π^+$ mass, and spin-1 and spin-2 resonances are included coherently through an isobar model. The S-wave component is found to be dominant, followed by the $ρ(770)^0π^+$ and $f_2(1270)π^+$ components. A small contribution from the $ω(782)\toπ^-π^+$ decay is seen for the first time in the $D^+ \to π^- π^+ π^+$ decay.
