Using e + e − collision data at 13 center-of-mass energies ranging from 4.600 to 4.951 GeV collected with the BESIII detector, we conduct the first search for the e + e − → process and investigate the resonance structures in the cross section line shape. No significant signal is observed, and the upper limits of the Born cross sections at each center-of-mass energy are presented. The ratio is determined to be 0.15 ± 0.22. This result indicates that if vector states exist in this energy region, their decay into h c is significantly suppressed compared to decays into J / ψ .
Olivier Schneider, Aurelio Bay, Guido Haefeli, Tatsuya Nakada, Frédéric Blanc, Lesya Shchutska, Elena Graverini, Sebastian Schulte, Marie Theres Christin Bachmayer, Serhii Cholak, Ettore Zaffaroni, Aravindhan Venkateswaran, Luis Miguel Garcia Martin, Vitalii Lisovskyi, Federico Ronchetti, Radoslav Marchevski, Anni Matilda Kauniskangas, Dimitrios Kaminaris, Raphaël van Laak, Pierre Paul Louis Mayencourt, Brianna Leililani Thielen, Arnaud Merlin Gauthey, Gianluca Zunica, Abdul-Kerim Guseinov, Esteban Curras Rivera, Roberto Ribatti, Alexandre Brea Rodriguez, Rita De Sousa Ataíde Da Silva, Spencer Edward Collaviti
Olivier Schneider, Aurelio Bay, Guido Haefeli, Tatsuya Nakada, Frédéric Blanc, Lesya Shchutska, Elena Graverini, Sebastian Schulte, Donal Patrick Hill, Marie Theres Christin Bachmayer, Serhii Cholak, Ettore Zaffaroni, Aravindhan Venkateswaran, Luis Miguel Garcia Martin, Vitalii Lisovskyi, Elisabeth Maria Niel, Federico Ronchetti, Radoslav Marchevski, Anni Matilda Kauniskangas, Dimitrios Kaminaris, Raphaël van Laak, Pierre Paul Louis Mayencourt, Brianna Leililani Thielen, Arnaud Merlin Gauthey, Gianluca Zunica, Abdul-Kerim Guseinov, Esteban Curras Rivera, Roberto Ribatti, Alexandre Brea Rodriguez, Rita De Sousa Ataíde Da Silva