In this paper we present the QED photonic radiative corrections of the e+ e- → tt¯ process by using the factorization of ISR and GRACE system as a numerical calculation method. | PHOTONIC RADIATIVE CORRECTIONS OF e+ e− → t¯ t PROCESS QUACH ANH TAI College of Education, Hue University YOSHIMASA KURIHARA - QUACH MY UYEN NHI High Energy Accelerator Research Organization (KEK), Tsukuba, Japan Abstract: In this paper we present the QED photonic radiative corrections of the e+ e− → tt¯ process by using the factorization of ISR and GRACE system as a numerical calculation method. The results exported from GRACE system are compared with the exact O(α2 ) theoretical calculations, and good agreement is found. We consider the beam polarization and the angular distribution as well. The δISR is given to evaluate the effect of ISR. Finally, the deviation between O(α2 ) and O(α2 ) is also discussed. Keywords: radiative corrections, cross section, GRACE system, electron-positron annihilation processes. 1 INTRODUCTION Radiative corrections are really important for precise prediction of the cross sections for the study on high-energy e+ e− → tt¯ annihilation processes. Among various corrections from the electro-weak interactions, photonic radiative corrections are known as the corrections to the initial-state particles which give a significant contribution. The final state corrections result just have a small contribution in the total cross section [1], [2]. To investigate the initial-state radiation (ISR) of e+ e− → tt¯ annihilation process, we use the factorization of ISR as theoretical calculation method. After calculating out the ISR function, we inspect the order O(α) and O(α2 ) corrections by re-summed formula. In this study, we focus on the electroweak correction contribution in the case that it is the dominant part where as QED correction is controllable. Thus, we apply the numerical calculation using GRACE system to evaluate the total cross section of all diagrams of e+ e− → tt¯ process in the center-of-mass energy range from 350 GeV to 1 TeV. The results exported from GRACE system are compared with the exact O(α2 ) theoretical calculations, and .
