Fragmentation functions of charged hadrons at next-to-next-to-leading order and constraints on proton PDFs

Abstract: We present the first global analysis of fragmentation functions (FFs) for light charged hadrons ($\pi^{\pm}$, $K^{\pm}$) at full next-to-next-to-leading order in Quantum Chromodynamics (QCD), incorporating world data from both single-inclusive electron-positron annihilation and semi-inclusive deep-inelastic scattering. The collinear factorization has been tested with low-momentum-transfer data and has demonstrated success at high hadron momenta. Additionally, we perform a joint determination of both parton distribution functions (PDFs) and FFs. Our findings indicate that the current global data on hadron production favor a reduced asymmetry in the strange (anti-) quark PDFs, as compared to the asymmetry predicted by state-of-the-art PDFs derived from inclusive data.