Production of singlet P-wave cc̅ and bb̅ states

No spin-singlet bb̅ quarkonium state has yet been observed. In this paper we discuss the production of the singlet P-wave bb̅ and cc̅ ¹P₁ states h_b and h_c. We consider two possibilities. In the first the ¹P₁ states are produced via the electromagnetic cascades Υ(3S)→η_b(2S)+γ⃗h_b+γγ⃗η_b+γγγ and ψ^′→η_c^′+γ⃗h_c+γγ⃗η_c+γγγ. A more promising process consists of single pion transition to the ¹P₁ state followed by the radiative transition to the 1¹S₀ state: Υ(3S)→h_b+π⁰→η_b+π⁰+γ and ψ^′→h_c+π⁰→η_c+π⁰+γ. For a million Υ(3S) or ψ^′’s produced we expect these processes to produce several hundred events.