The production of J/$\psi$ pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has been observed using an integrated luminosity of 37.5 pb$^{-1}$ collected with the LHCb detector. The production cross-section for pairs with both $J/\psi$ in the rapidity range $2 < y^{J/\psi} < 4.5$ and transverse momentum $p_T^{J/\psi} < 10 {\rm GeV}/c$ is $\sigma^{J/\psi J/\psi} = 5.1 \pm 1.0 \pm 1.1$ nb, where the first uncertainty is statistical and the second systematic.The production of $J/\psi$ pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has been observed using an integrated luminosity of $37.5 pb^{-1}$ collected with the LHCb detector. The production cross-section for pairs with both \jpsi in the rapidity r...
See paper for full list of authors - 10 pages, 3 figuresThe production of $J/\psi$ pairs in proton-p...
The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has be...
See paper for full list of authors - 10 pages, 3 figuresThe production of $J/\psi$ pairs in proton-p...
The production of J/Psi pairs in proton\u2013proton collisions at a centre-of-mass energy of 7 TeV h...
The production of J/Psi pairs in proton–proton collisions at a centre-of-mass energy of 7 TeV has be...
The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has be...
The production of $J/\psi$ pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has...
The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has be...
The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has be...
The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has be...
The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has be...
The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has be...
The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has be...
The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has be...
The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has be...
See paper for full list of authors - 10 pages, 3 figuresThe production of $J/\psi$ pairs in proton-p...
The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has be...
See paper for full list of authors - 10 pages, 3 figuresThe production of $J/\psi$ pairs in proton-p...
The production of J/Psi pairs in proton\u2013proton collisions at a centre-of-mass energy of 7 TeV h...
The production of J/Psi pairs in proton–proton collisions at a centre-of-mass energy of 7 TeV has be...
The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has be...
The production of $J/\psi$ pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has...
The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has be...
The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has be...
The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has be...
The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has be...
The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has be...
The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has be...
The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has be...
The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has be...
See paper for full list of authors - 10 pages, 3 figuresThe production of $J/\psi$ pairs in proton-p...
The production of J/psi pairs in proton-proton collisions at a centre-of-mass energy of 7 TeV has be...
See paper for full list of authors - 10 pages, 3 figuresThe production of $J/\psi$ pairs in proton-p...