大型强子对撞机(LHC)上J/ψ的产生截面和极化的计算

Computations of the Differential Cross Section and Polarization for J/ψat the LHC (Large Hadron Collider)

本文介绍了重夸克偶素产生在实验和理论上的重要性,以及计算QCD(Quantum Chromo Dynamics)修正的意义。我们列出了J/ψ、ψ(2S)、Γ(1S,2S,3S)完整的prompt产生的各个过程,每个过程的费曼图的个数,计算的目标参量,各种输入参数等。通过分析理论计算的计算规模,精度要求及精度对结果的影响,指出在超级计算机上进行计算的必要性。为能够有效地利用超级计算机的资源,我们做了在深腾7000上的效率的测试,并给出部分测试结果。针对已有的计算结果,我们分析了这些数据所使用的计算量。最后,我们给出了FDC(Feynman Diagram Calculation)系统在超级计算机上计算的一些新成果。

The heavy-quarkonium production is very important for both experimental measurement and theoretical computation. The discrepancy between experiments and LO QCD computation demands NLO QCD corrections. We give the processes of complete prompt productionfor J/ψ,ψ（2S）,ψ （1S, 2S, 3S）, the number of Feynman diagrams for each process, the physical observations, and input parameters, etc. The computation scale and precision indicates the requirement of super computer. To make good use of the super computer （Scmp7000）, we have done some tests about the efficiency （or speedup ratio）, and summarize the test results. In addition, a detailed analyzing of the calculation time for our recent work is shown in the figure. Finally, we give some new progress for our FDC computation on Scmp7000.