down quark

noun Physics.

the quark having electric charge −1/3 times the elementary charge, with strangeness, charm, and other quark quantum numbers equal to 0.

Origin of down quark

First recorded in 1975–80

Also called d quark.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

d quark in Science

[doun]

A quark with a charge of -1/3. Its mass is greater than that of the electron and the up quark, but smaller than that of all the other quarks. See Table at subatomic particle.