2024/10/29 by Jiang Jun, Jiang, Jun, P.-C. Lu +7 · 2 citations
Physics and Astronomy · #Advanced Frequency and Time Standards #Atomic and Subatomic Physics Research #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph)
paper · pdf · doi:10.48550/arxiv.2410.21963
openalex publication_date 2024/10/29 · openalex created_date 2024/11/14 · openalex updated_date 2026/07/28
We study the next-to-leading order (NLO) electroweak (EW) corrections to the γγ→ τ+ τ- process in Pb-Pb ultraperipheral collision (UPC). We find that the EW correction δσEW decreases the total cross section σNLO = σLO + δσEW by -3% at Pb-Pb center-of-mass energy √sNN=5.02 TeV. The weak correction plays significant role whose contribution is about -4 times of that of QED. The CMS and ATLAS collaborations use the reaction γγ→ τ+ τ- in Pb-Pb and proton-proton UPC to constrain tau's anomalous magnetic moment aτ. By parameterizing the γττ vertex with two form factors F1,2, the cross section can be written as σaτ = σLO + δσaτ, where δσaτ is proportional to aτ. The impact of NLO EW corrections on aτ bounds in Pb-Pb UPC is limited, as the current experimental bounds are loose. We also find that various differential distributions of the two ratios d σNLO/ d σLO and d σaτ/ d σLO have different lineshapes. This work is significant to precisely study the interaction of γττ via γγ→ τ+ τ- process.