Abstract:
We present recent work on the transverse momentum dependence of hadrons in semi-inclusive deep inelastic scattering, based on the two complementary factorization frameworks applicable at low and high transverse momentum. These approaches offer critical insight into the partonic structure of the nucleon. Focusing on observables such as the $\cos\phi$ azimuthal modulation, we explore...
Previous studies have shown that certain observables at massless $e^+e^−$ colliders producing primary top quarks can be used to measure the top quark mass with an uncertainty smaller than $\Lambda_{\text{QCD}}$. The maximal sensitivity to the top mass is attained in the peak of the distribution, where Effective Field Theories (EFTs) enable the factorization of the differential cross section...
In this talk, we present new results for double quarkonium production in (un)polarized hadronic collisions at fixed-target experiments. Our approach incorporates the transverse momentum dependent factorization in combination with the Color-Singlet Model. We present new analytical expressions for the angular structure of the cross section for the $q \bar q$ induced channel, and provide...
Fragmentation Function (FF) plays a crucial role in describing the hadronization process. In this talk, we report the measurements of normalized differential cross sections of inclusive hadron production as a function of hadron momentum with $q^2$ transfer from 5 to 13 GeV$^2$ in the $e^+e^-$ annihilations in the BESIII experiment at BEPCII. These results would provide unique information on...
In this talk I present a new determination of the unpolarised fragmentation functions (FFs) for Lambda production from single-inclusive e+e- annihilation and semi-inclusive deep-inelastic scattering. The analysis is done at both next-to-leading order (NLO) and next-to-next-to-leading order (NNLO). We extract the unpolarised FFs defining a parametrisation in terms of a neural network and...
The HERMES experiment has collected a wealth of data using the 27.6 GeV longitudinally polarized HERA lepton beam and various polarized and unpolarized gaseous targets. This allows for a series of unique measurements of observables sensitive to the multidimensional (spin) structure of the nucleon, in particular semi-inclusive deep-inelastic scattering (SIDIS) measurements, for which the HERMES...
Recently we have extended the string+3P0 model of polarized string fragmentation to include the production and decay of spin-1/2 baryons by using a quark-diquark model for the baryon and assuming that string breakings can occur via the tunneling of diquark-antidiquark pairs with vacuum quantum numbers. In this talk we present the implementation of the model in the Pythia event generator for...
Spin asymmetries in semi-inclusive dihadron production have been measured at CLAS12 in several channels. These analyses provide the most comprehensive catalog of dihadron fragmentation to date, exploring novel fragmentation phenomena stemming from the interferences of s- and p-wave dihadron production. First measurements of $\pi^{\pm}\pi^{0}$ beam-spin asymmetries show non-zero signals in...
The COMPASS experiment at CERN has studied the three-dimensional structure of nucleons by making unique measurements of several processes. This presentation focuses on measurements of hadron pair production in SIDIS with the 160 GeV muon beam and unpolarized and polarized proton and deuteron targets. The most recent results are reviewed, with particular attention to the measurements of...
