"$\mathrm{D^{0}}$ jets in pp 5.02 TeV, R = 0.3" of "Measurement of the production of charm jets tagged with ${\rm D^0}$ mesons in pp collisions at $\sqrt{s}$ = 5.02 and 13 TeV"

The measurement of the production of charm jets, identified by the presence of a $\mathrm{D^0}$ meson in the jet constituents, is presented in proton--proton collisions at centre-of-mass energies of $\sqrt{s}=5.02$ and $13$ TeV with the ALICE detector at the CERN LHC.The $\mathrm{D^0}$ mesons were reconstructed from their hadronic decay $\mathrm{D^0}\rightarrow\mathrm{K}^{-}\mathrm{\pi}^{0}$ and the respective charge conjugate. Jets were reconstructed from $\mathrm{D^0}$-meson candidates and charged particles using the anti-$k_\text{T}$ algorithm, in the jet transverse momentum range $5 < p_{\mathrm{T,ch\ jet}}< 50$ GeV/$c$, pseudorapidity $|\eta_{\mathrm{ch\ jet}}| < 0.9-R$, and with the jet resolution parameters $R = 0.2$, $0.4$, $0.6$. The distribution of the jet momentum fraction carried by a $\mathrm{D^0}$ meson along the jet axis ($z^{\mathrm{ch}}_{||}$) was measured in the range $0.4< z^{\mathrm{ch}}_{||} <1.0$ in four ranges of the jet transverse momentum.Comparisons of results for different collision energies and jet resolution parameters are also presented. The measurements are compared to predictions from Monte Carlo event generators based on leading-order and next-to-leading-order perturbative quantum chromodynamics calculations. A generally good description of the main features of the data is obtained in spite of a few discrepancies at low $p_{\mathrm{T,ch\ jet}}$. Measurements were also done for $R=0.3$ at $\sqrt{s}=5.02$ TeV and are shown along with their comparisons to theoretical predictions in an appendix to this paper.本文报道了在欧洲核子研究中心（CERN）大型强子对撞机（LHC）上利用ALICE探测器，于质心系能量√s=5.02 TeV与13 TeV的质子-质子碰撞中，对以喷注内部组分包含D⁰介子为标识的粲喷注产生过程的测量结果。D⁰介子通过其强衰变道D⁰→K⁻π⁰及其对应的电荷共轭过程完成重建。本次分析采用anti-k_T算法，从D⁰介子候选体与带电粒子出发重建喷注，选取的带电喷注横动量范围为5 < p_{T,ch jet} < 50 GeV/c，赝快度满足|η_{ch jet}| < 0.9 - R，并采用了R=0.2、0.4、0.6三种喷注分辨参数。测量了D⁰介子沿喷注轴携带的喷注动量份额（z^{ch}_{||}）的分布，在四个带电喷注横动量区间内，该分布的测量区间为0.4 < z^{ch}_{||} < 1.0。本文还对不同碰撞能量与不同喷注分辨参数下的测量结果进行了对比。将本次测量结果与基于领头阶（leading-order, LO）和次领头阶（next-to-leading-order, NLO）微扰量子色动力学计算的蒙特卡洛事件产生器给出的理论预言进行了对比，尽管在低带电喷注横动量区间存在少量偏差，但理论预言总体上能够较好地描述实验数据的主要特征。此外，本文还针对√s=5.02 TeV下R=0.3的情况完成了测量，相关结果及其与理论预言的对比将在本文附录中展示。