Tristan (Latin & Brythonic: Drustanus; ), also known as Tristram, is the male hero of the Arthurian Tristan and Iseult story. He was a Cornish knight of the Round Table. He is the son of Blancheflor and Rivalen (in later versions Isabelle and Meliodas), and the nephew of King Mark of Cornwall, sent to fetch Iseult back from Ireland to wed the king. However, he and Iseult accidentally consume a love potion while en route and fall helplessly in love. The pair undergo numerous trials that test their secret affair.

Diego Tristán Herrera (born 5 January 1976) is a Spanish retired professional footballer who played as a striker.

KEKB is the name of a particle accelerator used in the Belle experiment to study CP violation. It is called a B-factory for its copious production of B-mesons which provide a golden mode to study and measure the CP violation due to its property of decaying into other lighter mesons. KEKB is basically an asymmetric electron–positron collider, with electrons having the energy of 8 GeV and positrons having the energy of 3.5 GeV, giving 10.58 GeV centre-of-mass energy, which is equal to the mass of the Upsilon(4S) meson.