Discovery potential of stable and near-threshold doubly heavy tetraquarks at the LHC

We study the LHC discovery potential of the double-bottom tetraquarks bbu¯d¯, bbu¯s¯ and bbd¯s¯, the lightest of which having JP=1+, called T[u¯d¯]{bb}, T[u¯s¯]{bb} and T[d¯s¯]{bb}, are expected to be stable against strong decays. Employing the Monte Carlo generators [email protected] and Pythia6, we simulate the process pp→b¯bb¯b+X and calculate the bb-diquark jet configurations, specified by the invariant mass interval Mbb<MT[q¯q¯′]{bb}+ΔM. Estimates of ΔM from the measured product σ(pp→Bc++X)B(Bc+→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→Λb and b→B to obtain σ(pp→T[u¯d¯]{bb}+X)=(2.8−0.7+1.0)nb at s=13 TeV, and about a quarter of this for the T[u¯s¯]{bb} and T[d¯s¯]{bb}, each. We also present estimates of the production cross sections for the mixed bottom-charm tetraquarks, bcu¯d¯, bcu¯s¯ and bcd¯s¯, obtaining σ(pp→T[u¯d¯][bc]+X)=(103−25+39)nb at s=13 TeV, and the related ones having T[u¯s¯][bc] and T[d¯s¯][bc]. 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.