Transeverse-Momentum Subtraction for Semi-Inclusive Deep-Inelastic Scattering

Abstract

Semi-Inclusive Deep-Inelastic Scattering provides unique access to the three-dimensional momentum and spin structure of the proton, enabling precise studies of parton dynamics and hadronization in QCD. We present a transverse-momentum subtraction approach applied to the detected hadron that enables efficient and precise calculation of higher-order QCD corrections to identified hadron production in Semi-Inclusive Deep-Inelastic Scattering. We demonstrate the success of the method through a next-to-next-to-leading order QCD calculation and provide fully differential phenomenological applications, which provide important ingredients for global analyses of fragmentation functions. Our method is applicable to next-to-next-to-next-to-leading order QCD corrections for both unpolarized and polarized semi-inclusive deep-inelastic scattering.

Figures (4)

• Figure 1: NNLO QCD corrections to the differential cross section at the EIC for charged pion production, with $x=0.2$, $y=0.3$, and $0.2<z<0.8$, as a function of the slicing parameter. The resolved, unresolved, and full contributions are represented by the dotted, dash-dotted, and solid lines, respectively. The dashed line is analytical calculations for different partonic channels Bonino:2024qbhGoyal:2024tmo. The lower panel shows the cross sections for different partonic channels.
• Figure 2: Differential cross section as functions of the hadron energy fraction $x_p$ for charged pion production at the EIC at various orders in QCD together with scale variations.
• Figure 3: Multiplicity distribution as functions of the hadron energy fraction $x_p$ for unidentified charged hadron production at the HERA at various orders in QCD together with scale variations, compared to the ZEUS data ZEUS:2010mrq.
• Figure 4: Transverse-momentum $P_h^T$ distribution of the charged pion at the EIC with $\sqrt{s}=141$ GeV. The bands indicate the scale uncertainties. The orange histogram represents the results from PYTHIA. The red band denotes the N$^4$LL-resummed result matched with NNLO fixed-order prediction.