This Letter presents the observation of the rare Z boson decay Z→ ψ ℓ+ ℓ−. Here, ψ
represents contributions from direct J/ψ and ψ (2 S)→ J/ψ X, ℓ+ ℓ− is a pair of electrons or …

This Letter presents the observation of the rare Z boson decay Z→ ψ ℓ+ ℓ-. Here, ψ
represents contributions from direct J/ψ and ψ (2 S)→ J/ψ X, ℓ+ ℓ-is a pair of electrons or …

This Letter presents the observation of the rare Z boson decay Z-> psi l (+) l (-). Here, psi
represents contributions from direct J/psi and psi (2S)-> J/psi X, l (+) l (-) is a pair of electrons …

This Letter presents the observation of the rare Z boson decay Z $\to\psi\ell^+\ell^-$. Here,
$\psi $ represents contributions from direct J/$\psi $ and $\psi $(2S) $\to $ J/$\psi X …

A search is presented for decays of ZZ and Higgs bosons to a J/ψ J/ψ meson and a photon,
with the subsequent decay of the J/ψ J/ψ to μ^+ μ^-μ+ μ-. The analysis uses data from proton …

A bstract The first observation of the Z boson decaying to four leptons in proton-proton
collisions is presented. The analyzed data set corresponds to an integrated luminosity of …

A study of the associated production of a ZZ boson and a charm quark jet (Z+ c Z+ c), and a
comparison to production with abb quark jet (Z+ b Z+ b), in pp pp collisions at a centre-of …

The J= ψ→ μ+ μ− μ+ μ− decay has been observed with a statistical significance in excess of
five standard deviations. The analysis is based on an event sample of proton-proton …

A search for decays of the Higgs and Z boson to pairs of J/ψ or Y (nS)(n= 1, 2, 3) mesons,
with their subsequent decay to μ+ μ− pairs, is presented. The analysis uses data from proton …

The J/ψ→ µ+ µ− µ+ µ− decay has been observed with a statistical significance in excess of
five standard deviations. The analysis is based on an event sample of proton-proton …