Speaker
Description
Precision measurement of the Standard Model (SM) and detection of the New Physics (NP) are the primary goals in current collider phenomenology. Spin effects offer a powerful avenue for advancing these goals, with transverse spin polarization serving as a particularly sensitive probe of chirality-flip interactions. This talk presents our recent works on NP detection via novel transverse spin approaches at EIC, exploiting transversity PDF of nucleon and dihadron fragmentation functions. Firstly, we propose to investigate the semi-leptonic scalar/tensor four-fermion operators of electron and quarks through the transverse double spin asymmetry at EIC, where both the electron and proton beams could be highly transversely polarized. Then, we propose a novel method to probe light-quark dipole moments by examining the azimuthal asymmetries between a collinear pair of hadrons in semi-inclusive deep inelastic lepton scattering off an unpolarized proton target at EIC. These asymmetries provide a means to observe transversely polarized quarks, which arise exclusively from the quantum interference between the NP and the SM interactions, thereby depending linearly on the NP couplings. We demonstrate that this novel approach can enhance current constraints on NP operators by an order of magnitude, free from contamination of other NP effects. Furthermore, it allows for a simultaneous determination of both the real and imaginary parts of the NP couplings, offering a new avenue for investigating potential $CP$-violating effects at high energies.