Two-Loop Electroweak Corrections with Fermion Loops to e^{+}e^{-}→ZH.

Area of Science:

• High-energy particle physics
• Quantum field theory
• Electroweak interactions

Background:

• Precise theoretical predictions are crucial for interpreting experimental results at particle colliders.
• Electroweak corrections are essential for understanding particle interactions, particularly in electron-positron collisions.
• Previous calculations have not fully incorporated next-to-next-to-leading order electroweak corrections with closed fermion loops.

Purpose of the Study:

• To perform a complete calculation of next-to-next-to-leading electroweak corrections involving closed fermion loops for the process e^{+}e^{-}→ZH.
• To provide precise numerical predictions for the differential and integrated cross sections.
• To assess the impact of these higher-order corrections on the predicted cross section.

Main Methods:

• Employed a seminumerical technique for evaluating two-loop vertex and box diagrams.
• Utilized Feynman parameters and dispersion relations for subloop calculations.
• Applied suitable subtraction terms to handle ultraviolet (UV) divergences.

Main Results:

• Successfully computed the next-to-next-to-leading electroweak corrections, including closed fermion loops.
• Obtained numerical results for the unpolarized differential and integrated cross section at a center-of-mass energy of 240 GeV.
• Determined that the new corrections increase the predicted cross section by 0.7%.

Conclusions:

• The inclusion of higher-order electroweak corrections significantly refines theoretical predictions for e^{+}e^{-}→ZH.
• The calculated corrections provide a more accurate theoretical baseline for experimental searches and measurements.
• The findings contribute to a deeper understanding of electroweak interactions in high-energy physics.