Next-to-next-leading order correction to 3-jet rate and event-shape distribution

Pramana

Tooraj Ghaffary¹  Alireza Sepehri¹  Parvin Eslami¹  Mohammad Ebrahim Zomorrodian1¹ 

[1] Department of Physics, Ferdowsi University of Mashhad, Mashhad 91775-1436, Khorasane, Razavi, Iran$$

关键词: Transverse momenta;    three-jet rate;    event shapes.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

The hadronic events from the 𝑒+ 𝑒− annihilation data at the centre-of-mass energies ranging from 60 to 197 GeV were studied. The AMY and OPAL Collaborations offered a unique opportunity to test QCD by measuring the energy dependence of different observables. The coupling constant, 𝛼𝑠, was measured by two different methods: first by employing the three-jet observables. Combining all the data, the value of as at next-to-next leading order (NNLO) was determined to be 0.117 ± 0.004(hard) ± 0.006(theo). Secondly, from the event-shape distributions, the strong coupling constant, 𝛼𝑠, was extracted at NNLO and it’s evaluation was tested with the energy scale. The results were consistent with the running of 𝛼𝑠, expected from QCD predictions. Averaging over different observables, 𝛼𝑠 was determined to be 0.115 ± 0.007(hard) ± 0.003(theo).

【 授权许可】

Unknown