# Impact of LHC vector boson production in heavy ion collisions on strange PDFs

Kusina, A.; Ježo, T.; Clark, D. B.; Duwentäster, P.; Godat, E.; Hobbs, T. J.; Kent, J.; Klasen, M.; Kovařík, K.; Lyonnet, F.; Muzakka, K. F.; Olness, F. I.; Schienbein, I.; Yu, J. Y.

##### Abstract:
The extraction of the strange quark parton distribution function (PDF) poses a long-standing puzzle. Measurements from neutrino-nucleus deep inelastic scattering (DIS) experiments suggest the strange quark is suppressed compared to the light sea quarks, while recent studies of W^\pm /Z boson production at the LHC imply a larger strange component at small x values. As the parton flavor determination in the proton depends on nuclear corrections, e.g. from heavy-target DIS, LHC heavy ion measurements can provide a distinct perspective to help clarify this situation. In this investigation we extend the nCTEQ$_{15}$ nPDFs to study the impact of the LHC proton-lead W^\pm /Z production data on both the flavor differentiation and nuclear corrections. This complementary data set provides new insights on both the LHC W^\pm /Z proton analyses and the neutrino-nucleus DIS data. We identify these new nPDFs as nCTEQ$_{15}$WZ. Our calculations are performed using a new implementation of the nCTEQ code (nCTEQ++) based on C++ which enables us to easily interface to external programs such as HOPPET, APPLgrid and MCFM. Our results indicate that, as suggested by the proton data, the small x nuclear strange sea appears larger than previously expected, even when the normalization of the W^{\pm }/Z data is accommodated in the fit. ... mehr

 Zugehörige Institution(en) am KIT Institut für Theoretische Physik (ITP) Publikationstyp Zeitschriftenaufsatz Publikationsmonat/-jahr 10.2020 Sprache Englisch Identifikator ISSN: 1434-6044, 1434-6052 KITopen-ID: 1000128930 Erschienen in The European physical journal / C Verlag Springer Verlag Band 80 Heft 10 Seiten Art.Nr. 968 Vorab online veröffentlicht am 19.10.2020 Nachgewiesen in ScopusWeb of ScienceDimensions
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