Searches for scalar top and scalar bottom quarks at LEP2

• Main Authors: BARATE, R.; et al., THULASIDAS, M.
• Format: text
• Language: English
• Published: Institutional Knowledge at Singapore Management University 1997
• Subjects: Computer Engineering; Databases and Information Systems
• Online Access: https://ink.library.smu.edu.sg/sis_research/5785; https://ink.library.smu.edu.sg/context/sis_research/article/6788/viewcontent/9708013.pdf
• Institution: Singapore Management University

Searches for scalar top and bottom quarks have been performed with data collected by the ALEPH detector at LEP. The data sample consists of 21.7 pb−1 taken at √ s = 161, 170, and 172 GeV and 5.7 pb−1 taken at √ s = 130 and 136 GeV. No evidence for scalar top quarks or scalar bottom quarks was found in the channels ˜t → cχ, ˜t → bℓν˜, and b˜ → bχ. For the channel ˜t → cχ a limit of 67 GeV/c 2 has been set on the scalar top quark mass, independent of the mixing angle between the supersymmetric partners of the left and right-handed states of the top quark. This limit assumes a mass difference between the ˜t and the χ of at least 10 GeV/c 2 . For the channel ˜t → bℓν˜ the mixingangle independent scalar top limit is 70 GeV/c 2 , assuming a mass difference between the ˜t and the ˜ν of at least 10 GeV/c 2 . For the channel b˜ → bχ, a limit of 73 GeV/c 2 has been set on the mass of the supersymmetric partner of the left-handed state of the bottom quark. This limit is valid if the mass difference between the b and the ˜ χ is at least 10 GeV/c 2 .