论文标题
升级的爱丽丝内部跟踪系统中的PB $ -PB碰撞中的重型风味测量
Heavy Flavour measurements in Pb$-$Pb collisions with the upgraded ALICE Inner Tracking System
论文作者
论文摘要
在第二次LHC长时间关闭（LS2）期间，Alice的内部跟踪系统（ITS）（一个大离子对撞机实验）将被七层CMOS单层主动像素传感器（MAPS）代替。硅成像技术的最新创新允许构建大型的超薄硅晶片，可以进一步提高爱丽丝追踪器的能力。用于建造新的顶点探测器的研究和开发研究已经开始。已经提出了针对第三个LHC长关闭（LS3）的探测器安装，在此期间，三个最内向的层应被大型弯曲的CMOS Wafers的三个圆柱层代替。此升级（ITS3）将进一步提高影响参数分辨率和低动量颗粒的跟踪效率。最内向的一层将位于交互点，将材料预算降低至0.05 $ \％x_0 $每层。 ITS2设计中简化ITS3几何形状的Monte Carlo模拟表明，影响参数分辨率和跟踪效率有所改善，这对于测量重型燃料载体至关重要。此贡献显示了$λ_ {\ mathrm {b}} $的示例的性能的改进，该$根据这些MC模拟提取其测量的重要性。与ITS2相比，低动量区域的显着改善几乎三倍。
During the second LHC long shutdown (LS2) the Inner Tracking System (ITS) of ALICE (A Large Ion Collider Experiment) will be replaced by seven layers of CMOS Monolithic Active Pixel Sensors (MAPS). The latest innovations in silicon imaging technology allow for the construction of large, ultra-thin silicon wafers which can further improve the capabilities of the ALICE tracker. The research and development studies towards the construction of a novel vertex detector have started. The detector installation has been proposed for the third LHC long shutdown (LS3) during which the three innermost layers shall be replaced by three cylindrical layers of large curved CMOS wafers. This upgrade (ITS3) will further improve the impact parameter resolution and the tracking efficiency of low momentum particles. The innermost layer will be positioned closer to the interaction point and the material budget will be reduced down to 0.05$\%X_0$ per layer. Monte Carlo simulations of a simplified ITS3 geometry within the ITS2 design indicate an improvement in the impact parameter resolution and the tracking efficiency, which are of crucial importance for measurements of heavy-flavour hadrons. This contribution shows the improved performance for the example of the $Λ_{\mathrm{b}}$, for which the significance of its measurement is extracted based on these MC simulations. A significant improvement by almost a factor of three in the low momentum region compared to the ITS2 is observed.
