2026-10-19T01:18:13Zhttps://ebyu-rdlopen.rawdatalibrary.net/oai/requestoai:ebyu-rdlopen.rawdatalibrary.net:ebyu/107792026-10-18T20:25:55Zopenairedrivercom_ebyu_10000col_ebyu_10001Observation of (Formula presented) Hyperon Local Polarization in (Formula presented)-Pb Collisions at (Formula presented)Hayrapetyan, A.Tumasyan, A.Adam, W.Andrejkovic, J.W.Benato, L.Bergauer, T.Chatterjee, S.Damanakis, K.Dragicevic, M.Hussain, P.S.Jeitler, M.Krammer, N.Li, A.Liko, D.Mikulec, I.Schieck, J.Schöfbeck, R.Schwarz, D.Sonawane, M.Waltenberger, W.Wulz, C.-E.Janssen, T.Van Laer, T.Van Mechelen, P.Breugelmans, N.D’Hondt, J.Dansana, S.De Moor, A.Delcourt, M.Heyen, F.Lowette, S.Makarenko, I.Müller, D.Tavernier, S.Tytgat, M.Van Onsem, G.P.Van Putte, S.Vannerom, D.Bilin, B.Clerbaux, B.Das, A.K.De Bruyn, I.De Lentdecker, G.Evard, H.Favart, L.Gianneios, P.Jaramillo, J.Khalilzadeh, A.Khan, F.A.Lee, K.AstrophysicsHeavy ionsParticle detectorsTellurium compoundsA-centerAzimuthal dependenceBeam directionCenter-of-mass energiesCentre-of-mass energiesCMS detectorsHyperon polarizationIntegrated luminosityLocal polarizationSpin-polarizationarticlepolarizationSpin polarizationThe polarization of the (Formula presented) and (Formula presented) hyperons along the beam direction has been measured in proton-lead ((Formula presented)) collisions at a center-of-mass energy per nucleon pair of 8.16 TeV. The data were obtained with the CMS detector at the LHC and correspond to an integrated luminosity of (Formula presented). A significant azimuthal dependence of the hyperon polarization, characterized by the second-order Fourier sine coefficient (Formula presented), is observed. The (Formula presented) values decrease as a function of charged particle multiplicity, but increase with transverse momentum. A hydrodynamic model that describes the observed (Formula presented) values in nucleus-nucleus collisions by introducing vorticity effects does not reproduce either the sign or the magnitude of the (Formula presented) results. These observations pose a challenge to the current theoretical implementation of spin polarization in heavy ion collisions and offer new insights into the origin of spin polarization in hadronic collisions at LHC energies. © 2025 CERN, for the CMS Collaboration.American Physical Society2025Articlehttps://rdlopen.rawdatalibrary.net/r/ebyu/10779https://doi.org/10.1103/6ywq-gm610031-9007enPhysical Review Lettersinfo:eu-repo/semantics/openAccessinfo:eu-repo/semantics/articlehttps://ebyu-rdlopen.rawdatalibrary.net/tr/items/ebyu/10779