2026/02/19 by LHCb collaboration, R. Aaij, A. S. W. Abdelmotteleb +1174 · 1 voice
Physics and Astronomy · #hep-ex
The first measurement of the polarization of charm baryons by the LHCb experiment recorded in fixed-target mode is presented. The polarization of Λc baryons is studied in collisions of protons, at an energy of 2.51 TeV, incident on a gaseous target of neon, at a nucleon-nucleon center-of-mass energy of 68.6 GeV. The world's first measurement of separate-charge polarizations for Λ+c and Λ-c baryons is performed, determining PΛ+c = ( 24 ± 9 ± 2 )% , P_Λ-c = (-8 ± 12 ± 3 ) % , where the first uncertainty is statistical and the second systematic. The polarization is also measured in intervals of baryon transverse momentum and the Feynman-x variable.