• Energy Research

Abstract We report the first measurement of the exclusive cross sections e+e− → $$ B\overline{B} $$ B B ¯ , e+e− → $$ B{\overline{B}}^{\ast } $$ B B ¯ ∗ , and e+e− → $$ {B}^{\ast }{\overline{B}}^{\ast } $$ B ∗ B ¯ ∗ in the energy range from 10.63 GeV to 11.02 GeV. The B mesons are fully reconstructed in a large number of hadronic final states and the three channels are identified using a beam-constrained-mass variable. The shapes of the exclusive cross sections show oscillatory behavior with several maxima and minima. The results are obtained using data collected by the Belle experiment at the KEKB asymmetric-energy e+e− collider.

We report new measurements of the production cross sections of pairs of charged pions and kaonsas a function of their fractional energies using various fractional-energy definitions. Two different fractional-energy definitions were used and compared to the conventional fractional-energy definitionreported previously. The new variables aim at either identifying dihadron cross sections in terms of single-hadron fragmentation functions, or to provide a means of characterizing the transverse momentum created in the fragmentation process. The results were obtained applying the updated initial-state radiation correction used in other recent Belle publications on light-hadron production cross sections. In addition, production cross sections of single charged pions, kaons, and protons were also updated using this initial-state radiation correction. The cross sections are obtained from a 558 fb$^{−1}$ data sample collected at the$Υ(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+e^−$ collider Physical review / D D 101(9), 092004: 1-13 (2020). doi:10.1103/PhysRevD.101.092004 Published by American Physical Society, Melville, NY