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[en] Superconducting pairing in cuprates is widely believed to be driven by a magnetic mechanism. Recent experiments with underdoped cuprates, meanwhile, proved the existence of a magnetic quantum critical point (QCP), separating phases with no static magnetic order and with magnetic order. The QCP for YBa2Cu3Oy is located at a doping of x ≈ 0.1, which is quite close to the optimal doping of x ≈ 0.15, where maximum of Tc(x) reaches. The idea is that superconducting pairing can be significantly influenced by magnetic criticality, which has been recently considered by Wang, and Chubukov in the context of electron doped cuprates. A common approach to such problems is to treat electrons in the normal state as a Fermi liquid with a large Fermi surface, implying a weak coupling regime. However, a large Fermi surface, to a significant extent, diminishes the importance of the magnetic criticality. In the present work, we consider a “rigid” 2D Mott insulator with two immobile fermions injected, so in essence our approach implies a small Fermi surface and therefore strong coupling limit. As a model system we consider a 2D bilayer antiferromagnet that is close to the O(3) magnetic quantum critical point (QCP), separating magnetically ordered and disordered phases. Focusing on the disordered phase in the vicinity of the QCP, we demonstrate that the criticality results in a strong long range attraction between the fermions, with a potential V(r) ∝ 1/r0.75, where r is the separation between the fermions. The mechanism of the enhanced attraction is similar to the Casimir effect and it is also closely related to the spin-charge separation at the QCP. So we suggest a mechanism of magnetic critical enhancement of pairing in cuprates.