RT Journal Article
T1 QCD anomalies in electromagnetic processes: A solution to the  γ → 3 π  puzzle
A1 Xing, Zanbin
A1 Dang, Hao
A1 Sultan, M. Atif
A1 Raya, Khépani
A1 Chang, Lei
AB In this work, the γ→3π form factor is calculated within the Dyson-Schwinger equations framework using a contact interaction model within the so-called modified rainbow ladder truncation. The present calculation takes into account the pseudovector component in the pion Bethe-Salpeter amplitude (BSA) and π−π scattering effects, producing a γ→3π anomaly that is 1+6R2π larger than the low energy prediction. Here Rπ is the relative ratio of the pseudovector and pseudoscalar components in the pion BSA; with our parameters’ input, this correction raises the γ→3π anomaly by around 10%. The main outcome of this work is the unveiling of the origin of such a correction, which could be a possible explanation of the discrepancy between the existing experimental data and the low energy prediction. Moreover, it is highlighted how the magnitude of the anomaly is affected in effective theories that require an irremovable ultraviolet cutoff. We find that for both the anomalous processes π→2γ and γ→3π, the missing contribution to the anomaly can be compensated by the additional structures related with the quark anomalous magnetic moment.
PB American Physical Society
SN 2470-0010
SN 2470-0029 (electrónico)
YR 2024
FD 2024-03
LK https://hdl.handle.net/10272/23631
UL https://hdl.handle.net/10272/23631
LA eng
NO Xing, Z., Dang, H., Sultan, M. A., Raya, K., & Chang, L. (2024). QCD anomalies in electromagnetic processes: A solution to the γ → 3 π puzzle. In Physical Review D (Vol. 109, Issue 5). American Physical Society (APS). https://doi.org/10.1103/physrevd.109.054028
NO This work was supported by National Natural ScienceFoundation of China (Grant No. 12135007). K. R. issupported by the Spanish MICINN Grant No. PID2022-140440NB-C22, and regional Andalusian Project No. P18-FR-5057.
DS Repositorio Institucional de la Universidad de Huelva
RD 30 may 2026