Beam Spin Asymmetry in Semi-Inclusive Electroproduction of Hadron Pairs

A first measurement of the longitudinal beam spin asymmetry ALU in semi-inclusive electroproduction pairs charged pions is reported. a higher-twist observable and offers cleanest access to nucleon twist-3 parton distribution function e(x). Data have been collected Hall-B at Jefferson Lab by impinging 5.498-GeV electron on liquid-hydrogen target, reconstructing scattered pion pair with CLAS detector. One-dimensional projections ALUsin?R moments are extracted for kinematic variables interest valence quark region. The understanding dihadron production essential interpretation observables single-hadron DIS, pioneering measurements single-spin asymmetries open new avenue studies QCD dynamics.Received 26 October 2020Revised 23 December 2020Accepted 12 January 2021DOI:https://doi.org/10.1103/PhysRevLett.126.062002Published American Physical Society under terms Creative Commons Attribution 4.0 International license. Further this work must maintain attribution author(s) published article’s title, journal citation, DOI. Funded SCOAP3.Published SocietyPhysics Subject Headings (PhySH)Research AreasDeep inelastic scatteringFragmentation into hadronsParticles & FieldsAccelerators BeamsNuclear Physics