Search for B{sup +} --> K{sup +} lepton-plus-lepton-minus and B{sup 0} --> K*{sup 0} lepton-plus-lepton-minus

摘要

Using a sample of 3.7 x 10{sup 6} upsilon(4S) --> B anti-B events collected with the BaBar detector at the PEP-II storage ring, the authors search for the electroweak penguin decays B{sup +} --> K{sup +}e{sup +}e{sup {minus}}, B{sup +} --> K{sup +}mu{sup +}mu{sup {minus}},B{sup 0} --> K*{sup 0} e{sup +}e{sup {minus}}, and B{sup 0} --> K*{sup 0}mu{sup +}mu{sup {minus}}. The authors observe no significant signals for these modes and set preliminary 90% C.L. upper limits of: beta(B{sup +} --> K{sup +}e{sup +}e{sup {minus}}) < 12.5 x 10{sup {minus}6}; beta(B{sup +} --> K{sup +}mu{sup +}mu{sup {minus}}) < 8.3 x 10{sup {minus}6}; beta(B{sup 0} --> K*{sup 0}e{sup +}e{sup {minus}}) < 24.1 x 10{sup {minus}6}; and beta(B{sup 0} --> K*{sup 0}mu{sup +}mu{sup {minus}}) < 24.5 x 10{sup {minus}6}.