Pion to photon transition form factor: Beyond valence quarks

by Xiaoyi Wu (IMP)

Wednesday Oct 9, 2024, 9:50 PM → 10:35 PM Asia/Shanghai

We investigate the singly virtual transition form factor (TFF) for the π0→γ∗γprocess in the space-like region using the hard-scattering formalism within the Basis Light-Front Quantization (BLFQ) framework. This form factor is expressed in terms of the perturbatively calculable hard-scattering amplitudes (HSAs) and the light-front wave functions (LFWFs) of the pion. We obtain the pion LFWFs by diagonalizing the light-front QCD Hamiltonian, which is determined for its constituent quark-antiquark and quark-antiquark-gluon Fock sectors with a three-dimensional confinement. We employ the HSAs up to next-to-leading order (NLO) in the quark-antiquark Fock sector and leading order (LO) in the quark-antiquark-gluon Fock sector. The NLO correction to the TFF in the quark-antiquark Fock sector is of the same order as the LO contribution to the TFF in the quark-antiquark-gluon Fock sector. We find that while the quark-antiquark-gluon Fock sector has minimal effect in the large momentum transfer (Q2) region, it has a noteworthy impact in the low-Q2 region. Our results show that, after accounting for both Fock sectors, the TFF within the BLFQ framework aligns well with existing experimental data, particularly in the low Q2 region.

 

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ZOOM ID:84390108770

Password: 482223

Meeting link
https://us02web.zoom.us/j/84390108770?pwd=0WXWMctbLWFvEb6HmcXpULUvrmUgbf.1