“…The axial-vector meson b 1 , which is identified as a 1 P 1 state in the quark model, was first observed by the HBC Collaboration in 1963 [7]. Before 1994, it was studied in pp [8,9], γp [10], and pπ [11][12][13][14][15][16][17][18][19] reactions, where the focus was on mass and width measurements. Later, it was widely observed in hadronic decays of D, B, and charmonium states [3].…”