Tkaczyk S, Tollefson K, Tollestrup A, Toyoda H, Trischuk W, Tseng J, Turini N, Ukegawa F, Valls J, Vejcik S, Velev G, Vidal R, Vilar R, Volobouev I, Vucinic D, Wagner RG, Wagner RL, Wahl J, Wallace NB, Walsh AM, Wang C, Wang CH, Wang MJ, Watanabe T, Waters D
Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
Phys Rev Lett. 2000 Jun 5;84(23):5273-8. doi: 10.1103/PhysRevLett.84.5273.
We have searched for direct production of scalar top quarks at the Collider Detector at Fermilab in 88 pb(-1) of p&pmacr; collisions at sqrt[s] = 1.8 TeV. We assume the scalar top quark decays into either a bottom quark and a chargino or a bottom quark, a lepton, and a scalar neutrino. The event signature for both decay scenarios is a lepton, missing transverse energy, and at least two b-quark jets. For a chargino mass of 90 GeV/c(2) and scalar neutrino masses of at least 40 GeV/c(2), we find no evidence for scalar top production and present upper limits on the production cross section in both decay scenarios.
我们在费米实验室的对撞机探测器上，利用质心能量√s = 1.8 TeV的88 pb⁻¹ 的质子-反质子碰撞，寻找标量顶夸克的直接产生。我们假设标量顶夸克衰变成一个底夸克和一个 chargino，或者一个底夸克、一个轻子和一个标量中微子。两种衰变情形的事例特征均为一个轻子、横向缺失能量以及至少两个b夸克喷注。对于chargino质量为90 GeV/c² 且标量中微子质量至少为40 GeV/c² 的情况，我们未发现标量顶夸克产生的证据，并给出了两种衰变情形下产生截面的上限。
