The D+ meson is a type of subatomic particle known as a meson, which is made up of a quark and an antiquark. Specifically, the D+ meson consists of a charm quark and an anti-up quark. Mesons are important in the study of particle physics because they help to mediate the strong force that holds atomic nuclei together. D+ mesons are produced in high-energy collisions, such as those occurring in particle accelerators like the Large Hadron Collider. They have a relatively short lifespan, decaying into other particles within a fraction of a second. Studying D+ mesons provides insights into the behavior of quarks and the fundamental forces of nature.