Related Clues:

• Particles with mass about 200 times that of electrons
• Pericles' T's
• Cross-shaped Greek letters
• Tartarus has two
• Thracian T's
• Letters after sigmas
• Sorority T's
• They follow sigmas
• T's, in the Greek alphabet
• Greek Ts
• Some short-lived particles
• T's, in Thessaloniki
• T's, in sorority names