论文标题
$ x（3872）$和$ψ（2s）$生产的研究$ p \ bar {p} $ collisions at 1.96 TEV
Studies of $X(3872)$ and $ψ(2S)$ production in $p\bar{p}$ collisions at 1.96 TeV
论文作者
论文摘要
我们介绍了基于10.4 fb $^{ - 1} $的$ x（3872）$和$ψ（2s）$状态的各种属性，由d0实验在tevatron $ p \ bar p $ collisisions in $ \ sqrt {s} $ = 1.96 $ = 1.96 tev中收集。对于这两种状态，我们都会测量由于$ B $含量的Hadron的衰减而导致的包容性生产率的非项目分数$ f_ {np} $。我们在LHC在LHC上获得的$ f_ {np} $ valuess找到$ f_ {np} $值。 $ f_ {np} $分数$ψ（2s）$随横向动量增加而增加，而对于x（3872），它在大型不确定性中是恒定的，与LHC结果一致。提示与非项目的$ψ（2s）$生产的比率，$（1-f_ {np}） / f_ {np} $的比率仅略微减小，从tevatron略微减少到LHC，但对于$ x（3872）$，该比率降低了3个。通过研究$ x（3872）$的生产作为$ x（3872）$的动能的函数和$ x（3872）π$质量中心框架中的动力，这是魅力 - 梅森对。对于与迅速生产一致的子样本，结果与$ x（3872）$的小动能的$ x（3872）$的生产相当不兼容，而$ x（3872）π$中心的$ x $ x $ x $+x $+soft-+soft-+soft-+toff-pion生产机构中的$ x（3872）$和$π$。对于与$ B $ HADRON的衰减相一致的事件，没有明显证据表明软态效应，而是其在预期的0.17 MEV的预期水平上的存在，而动量尺度$λ= m（π）$不排除。
We present various properties of the production of the $X(3872)$ and $ψ(2S)$ states based on 10.4 fb$^{-1}$ collected by D0 experiment in Tevatron $p \bar p$ collisions at $\sqrt{s}$ = 1.96 TeV. For both states, we measure the nonprompt fraction $f_{NP}$ of the inclusive production rate due to decays of $b$-flavored hadrons. We find the $f_{NP}$ values systematically below those obtained at the LHC. The $f_{NP}$ fraction for $ψ(2S)$ increases with transverse momentum whereas for the X(3872) it is constant within large uncertainties, in agreement with the LHC results. The ratio of prompt to nonprompt $ψ(2S)$ production, $(1 - f_{NP}) / f_{NP}$, decreases only slightly going from the Tevatron to the LHC, but for the $X(3872)$ this ratio decreases by a factor of about 3. We test the soft-pion signature of the $X(3872)$ modeled as a weakly-bound charm-meson pair by studying the production of the $X(3872)$ as a function of the kinetic energy of the $X(3872)$ and the pion in the $X(3872)π$ center-of-mass frame. For a subsample consistent with prompt production, the results are incompatible with a strong enhancement in the production of the $X(3872)$ at small kinetic energy of the $X(3872)$ and the $π$ in the $X(3872)π$ center-of-mass frame expected for the $X$+soft-pion production mechanism. For events consistent with being due to decays of $b$ hadrons, there is no significant evidence for the soft-pion effect but its presence at the level expected for the binding energy of 0.17 MeV and the momentum scale $Λ=M(π)$ is not ruled out.
