Polarization measurement of ${\Lambda }_c^{+}$ and $\overline{\Lambda }{}_c^{-}$ baryons in $p$Ne collisions at $\sqrt{s_{NN}}=68.6$ GeV

Abstract

The first measurement of the polarization of charm baryons by the LHCb experiment recorded in fixed-target mode is presented. The polarization of ${\Lambda }_c$ 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 ${\Lambda }_c^{+}$ and $\overline{\Lambda }{}_c^{-}$ baryons is performed, determining $$P_{{\Lambda }_c^{+}}=(24\pm 9\pm 2)\%,$$ $$P_{\overline{\Lambda }{}_c^{-}}=(-8\pm 12\pm 3)\%,$$ 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.

All figures and tables, along with any supplementary material and additional information, are available at https://lhcb-glance.cern.ch/alcm/public/analysis/full-details/5290