Search for light tetraquark states in ?(1S) and ?(2S) decays

Abstract

We search for the JPC = 0?? and 1�? light tetraquark states with masses up to 2.46 GeV=c2 in ?�1S� and ?�2S� decays with data samples of �102 2� million and �158 4� million events, respectively, collected with the Belle detector. No significant signals are observed in any of the studied production modes, and 90% credibility level (C.L.) upper limits on their branching fractions in ?�1S� and ?�2S� decays are obtained. The inclusive branching fractions of the ?�1S� and ?�2S� decays into final states with f1�1285� are measured to be B�?�1S� ? f1�1285� � anything� � �46 28�stat� 13�syst�� � 10?4 and B�?�2S� ? f1�1285� � anything� � �22 15�stat� 6.3�syst�� � 10?4. The measured ?b2 ? J=? � anything branching fraction is measured to be �1.50 0.34�stat� 0.22�syst�� � 10?3, and 90% C.L. upper limits for the ?b0;b1 ? J=? � anything branching fractions are found to be 2.3 � 10?3 and 1.1 � 10?3, respectively. For B�?b1 ? ? � anything�, the branching fraction is measured to be �4.9 1.3�stat� 0.6�syst�� � 10?2. All results reported here are the first measurements for these modes. � 2017 American Physical Society.