Possibility of observation of hidden-bottom pentaquark resonances in bottomonium photoproduction on protons and nuclei near threshold

We study the $\Upsilon(1S)$ meson photoproduction on protons and nuclei at near-threshold center-of-mass energies below 11.4 GeV (or at the corresponding photon laboratory energies $E_{\gamma}$ below 68.8 GeV). We calculate the absolute excitation functions for the nonresonant and resonant photoproduction of $\Upsilon(1S)$ mesons off protons at incident photon laboratory energies of 63-68 GeV by considering direct ( ${\gamma}p \to {\Upsilon(1S)}p$ ) and two-step ( ${\gamma}p \to P^+_b(11080) \to {\Upsilon(1S)}p$ , ${\gamma}p \to P^+_b(11125) \to {\Upsilon(1S)}p$ , ${\gamma}p \to P^+_b(11130) \to {\Upsilon(1S)}p$ ) $\Upsilon(1S)$ production channels within different scenarios for the nonresonant total cross section of the elementary reaction ${\gamma}p \to {\Upsilon(1S)}p$ and for branching ratios of the decays $P^+_b(11080) \to {\Upsilon(1S)}p$ , $P^+_b(11125) \to {\Upsilon(1S)}p$ , and $P^+_b(11130) \to {\Upsilon(1S)}p$ . We also calculate an analogous function for the photoproduction of $\Upsilon(1S)$ mesons on the ¹²C and ²⁰⁸Pb target nuclei in the near-threshold center-of-mass beam energy region of 9.0-11.4 GeV by considering the respective incoherent direct ( ${\gamma}N \to {\Upsilon(1S)}N$ ) and two-step ( ${\gamma}p \to P^+_b(11080) \to {\Upsilon(1S)}p$ , ${\gamma}p \to P^+_b(11125) \to {\Upsilon(1S)}p$ , ${\gamma}p \to P^+_b(11130) \to {\Upsilon(1S)}p$ and ${\gamma}n \to P^0_b$ $ (11080) \to{\Upsilon(1S)}n $ , ${\gamma}n \to P^0_b(11125) \to {\Upsilon(1S)}n$ , ${\gamma}n \to P^0_b(11130) \to {\Upsilon(1S)}n$ ) $\Upsilon(1S)$ ) production processes using a nuclear spectral function approach. We demonstrate that a detailed scan of the $\Upsilon(1S)$ total photoproduction cross section on proton and nuclear targets in the near-threshold energy region in future high-precision experiments at the proposed high-luminosity electron-ion colliders EIC and EicC in the US and China should provide a definite result for or against the existence of the nonstrange hidden-bottom pentaquark states $P_{bi}^+$ and $P_{bi}^0$ ( $i$ =1, 2, 3) as well as clarify their decay rates.