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We study the LHC discovery potential of the double-bottom tetraquarks bbūd, bbūs and bbds, the lightest of which having J P = 1 + , called T {bb} [ūd] , T {bb} [ūs] and T {bb} [ds] , are expected to be stable against strong decays. Employing the Monte Carlo generators MadGraph5 aMC@NLO and Pythia6, we simulate the process pp →bbbb + X and calculate the bb-diquark jet configurations, specified by the invariant mass interval M bb < M T {bb} [qq ′ ] + ∆M . Estimates of ∆M from the measured product σ(pp → B + c + X)B(B + c → J/ψπ + ) are presented and used to get the bb-diquark jet cross sections in double-bottom hadrons σ(pp → H {bb} + X), where H {bb} represent tetraquarks and baryons. This is combined with the LHCb data on the fragmentation b → Λ b and b → B to obtain σ(pp → T {bb} [ūd] +X) = (2.8 +1.0 −0.7 ) nb at √ s = 13 TeV, and about a quarter of this for the T {bb} [ūs] and T {bb} [ds] , each. We also present estimates of the production cross sections for the mixed bottom-charm tetraquarks, bcūd, bcūs and bcds, obtaining σ(pp → T [bc] [ūd] + X) = (103 +39 −25 ) nb at √ s = 13 TeV, and the related ones having T [bc] [ūs] and T [bc][ds] . They have excellent discovery potential at the LHC, as their branching ratios in various charge combinations of BD (s) (γ) are anticipated to be large. PACS numbers:Introduction: The discovery of X(3872), followed by well over a dozen related mesonic states, X, Y , Z, and two baryonic states P c (4380) and P c (4450), has opened a second layer of "extraordinary" hadrons in QCD, containing four and five valence quarks and antiquarks [1]. However, their dynamics is not yet deciphered and is under intense study. The competing theoretical models put forward can be roughly classified into two categories: those reflecting the residual QCD long-distance effects, dominated by meson exchanges, and those reflecting genuine short-distance interactions, dominated by gluon exchanges. Their spectroscopy, production and decay characteristics are discussed in a number of reviews [2-6].

baryons and tetraquarks may be viewed as diquark-quark and diquark-antidiquark objects, respectively, with the diquarks having well-defined color, spin and flavor quantum numbers. Indeed, if tetraquarks, which are stable against strong and radiative decays, could be found in experiments, this would provide an irrefutable evidence of compact diquarks as building blocks of hadronic matter.The objects of our interest in this paper are the doublebottom J P = 1 + tetraquarks T {bb} [ūd] , and the related ones T {bb} [ūs] and T {bb} [ds] collected in Fig. 1, which have evoked lately a lot of theoretical and phenomenological interest [6][7][8][9][10][11], though the possibility of stable multiquark states was already pointed out a long time ago [12,13]. Likewise, estimates of the tetraquark masses with two heavy quarks carried out in quark models well over a decade ago also predicted stable tetraquarks [14].Concentrating on the T {bb} [ūd] state, which is a J P = 1 + , I = 0 tetraquark, consisting of the S-wave bound axialvector {bb} diquark and the scalar light [ūd] antidiquark, its mass is pitched at (10389 ± 21) MeV [6], lying about 215 MeV below the BB * threshold. Other esti-