PT Journal AU LHCb Collaboration (Aaij, Rea Garcia Martin, LM Henry, L Jashal, BK Martinez-Vidal, F Oyanguren, A Remon Alepuz, C Ruiz Vidal, J Sanchez Mayordomo, C TI Constraints on the K-S(0) -> mu(+) mu(-) Branching Fraction SO Physical Review Letters JI Phys. Rev. Lett. PY 2020 BP 231801 - 10pp VL 125 IS 23 DI 10.1103/PhysRevLett.125.231801 LA English AB A search for the decay K-S(0) -> mu(+) mu(-) is performed using proton-proton collision data, corresponding to an integrated luminosity of 5.6 fb(-1) and collected with the LHCb experiment during 2016, 2017, and 2018 at a center-of-mass energy of 13 TeV. The observed signal yield is consistent with zero, yielding an upper limit of B(K-S(0) -> mu(+) mu(-)) < 2.2 x 10(-10) at 90% C.L.. The limit reduces to B(K-S(0) -> mu(+) mu(-)) < 2.1 x 10(-10) at 90% C.L. once combined with the result from data taken in 2011 and 2012. ER