论文标题
$ \ sqrt {s} = 5 \ \ rm {tev} $的$ pp $碰撞中$υ$生产的测量
Measurement of $Υ$ production in $pp$ collisions at $\sqrt{s}=5 \ \rm{TeV}$
论文作者
论文摘要
$υ$梅森的生产横截面，即$υ（1s）$，$υ（2s）$和$υ（3s）$，$ pp $ collisions in $ \ sqrt {s} = 5 \ \ \ \ \ \ \ \ \ rm {tev} $，用数据示例与$ 9.13的数据相应地测量\ rm {pb}^{ - 1} $由LHCB检测器收集。 $υ$介子是在衰减模式中重建的$υ\toμ^+μ^ - $。双差分横截面时间分支分支，作为横向动量$ p _ {\ rm {t}} $的功能和$υ$梅森的快速$ y $，以$ p _ {\ rm {t}}} <20 \ \ \ \ \ \ \ \ \ rm {geev} <4。5 <4. 5 <4. 5.5在这些$ p _ {\ rm {t}} $和$ y $范围内集成的结果 $σ（1S））\ times \ nathcal {b}（υ（1s）\toμ^+μ^ - ）= 2101 \ pm33 \ pm83 \ pm83 \ \ rm {pb}，$ $σ（2S））\ times \ times \ Mathcal {b}（2s）\toμ^+μ^ - ）= 526 \ pm20 \ pm21 \ pm21 \ \ \ rm {pb}，$ $σ（3S））\ times \ times \ Mathcal {b}（υ（3S）\toμ^+μ^ - ）= 242 \ pm16 \ pm10 \ pm10 \ \ \ \ rm {pb}，$ 第一个不确定性是统计的，第二个是系统的。确定了两个不同的$υ$状态的测量和不同质量中心能量的测量之间的横截面比率。也使用此分析的直接测量的横截面结果，更新了$ \ sqrt {s} = 5 \ \ rm {tev} $的核修饰因子$υ（1s）$。
The production cross-sections of $Υ$ mesons, namely $Υ(1S)$, $Υ(2S)$ and $Υ(3S)$, in $pp$ collisions at $\sqrt{s}=5 \ \rm{TeV}$ are measured with a data sample corresponding to an integrated luminosity of $9.13\pm{0.18} \ \rm{pb}^{-1}$ collected by the LHCb detector. The $Υ$ mesons are reconstructed in the decay mode $Υ\to μ^+ μ^-$. Double differential cross-sections times branching fractions, as functions of the transverse momentum $p_{\rm{T}}$ and the rapidity $y$ of the $Υ$ mesons, are measured in the range $p_{\rm{T}} < 20 \ \rm{GeV}/c$ and $2.0<y<4.5$. The results integrated over these $p_{\rm{T}}$ and $y$ ranges are $σ(Υ(1S)) \times\mathcal{B}(Υ(1S)\to μ^+ μ^-) = 2101\pm33\pm83 \ \rm{pb},$ $σ(Υ(2S)) \times\mathcal{B}(Υ(2S)\to μ^+ μ^-) = 526\pm20\pm21 \ \rm{pb},$ $σ(Υ(3S)) \times\mathcal{B}(Υ(3S)\to μ^+ μ^-) = 242\pm16\pm10 \ \rm{pb},$ where the first uncertainties are statistical and the second are systematic. The ratios of cross-sections between measurements of two different $Υ$ states and between measurements at different center-of-mass energies are determined. The nuclear modification factor of $Υ(1S)$ at $\sqrt{s}=5 \ \rm{TeV}$ is updated as well using the directly measured cross-section results from this analysis.
