Observation of High Momentumη′Production inBDecays

We report the first observation of B{r_arrow}{eta}{sup {prime}}X transitions with high momentum {eta}{sup {prime}} mesons. We observe 39.0{plus_minus}11.6 B decay events with 2.0{lt}p{sub {eta}{sup {prime}}}{lt}2.7 GeV/c , the high momentum region where background from b{r_arrow}c processes is suppressed. We discuss the physical interpretation of the signal, including the possibility that it is due to b{r_arrow}sg{sup {asterisk}} transitions. Given that interpretation, we find B(B{r_arrow}{eta}{sup {prime}}X{sub s} )=[6.2{plus_minus}1.6(stat){plus_minus} 1.3(syst){sup +0.0}{sub {minus}1.5} (bkg)]{times}10{sup {minus}4} for 2.0{lt}p{sub {eta}{sup {prime}}}{lt}2.7 GeV/c . {copyright} {ital 1998} {ital The American Physical Society }