The STAR Collaboration reports measurements of the transverse single-spin asymmetries, A(N), for inclusive jets and identified "hadrons within jets" production at midrapidity from transversely polarized pp collisions at root s = 200 GeV, based on data recorded in 2012 and 2015. The inclusive jet asymmetry measurements include A(N) for inclusive jets and A(N) for jets containing a charged pion carrying a momentum fraction z > 0.3 of the jet momentum. The identified hadron within jet asymmetry measurements include the Collins effect for charged pions, kaons, and protons, and the Collins-like effect for charged pions. The measured asymmetries are determined for several distinct kinematic regions characterized by the jet transverse momentum p(T) and pseudorapidity eta, as well as the hadron momentum fraction z and momentum transverse to the jet axis j(T). These results probe higher momentum scales (Q(2) up to similar to 900 GeV2) than current, semi-inclusive deep-inelastic scattering measurements, and they provide new constraints on quark transversity in the proton and enable tests of evolution, universality, and factorization breaking in the transverse-momentum-dependent formalism.
Azimuthal transverse single-spin asymmetries of inclusive jets and identified hadrons within jets from polarized collisions at
S. FazioMembro del Collaboration Group
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2022-01-01
Abstract
The STAR Collaboration reports measurements of the transverse single-spin asymmetries, A(N), for inclusive jets and identified "hadrons within jets" production at midrapidity from transversely polarized pp collisions at root s = 200 GeV, based on data recorded in 2012 and 2015. The inclusive jet asymmetry measurements include A(N) for inclusive jets and A(N) for jets containing a charged pion carrying a momentum fraction z > 0.3 of the jet momentum. The identified hadron within jet asymmetry measurements include the Collins effect for charged pions, kaons, and protons, and the Collins-like effect for charged pions. The measured asymmetries are determined for several distinct kinematic regions characterized by the jet transverse momentum p(T) and pseudorapidity eta, as well as the hadron momentum fraction z and momentum transverse to the jet axis j(T). These results probe higher momentum scales (Q(2) up to similar to 900 GeV2) than current, semi-inclusive deep-inelastic scattering measurements, and they provide new constraints on quark transversity in the proton and enable tests of evolution, universality, and factorization breaking in the transverse-momentum-dependent formalism.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.