Britain's Peter Higgs and Belgium's Francois Englert won the 2013 Nobel prize for physics for predicting the existence of the Higgs boson - the particle key to explaining why elementary matter has mass - the award-giving body said.
The two scientists will share the 8 million Swedish crown ($1.25 million) prize after their theoretical work was finally justified by experiments at the CERN research centre's gigantic particle collider.
"The awarded theory is a central part of the Standard Model of particle physics that describes how the world is constructed," the Royal Swedish Academy of Sciences said in a statement on Tuesday.
"According to the Standard Model, everything, from flowers and people to stars and planets, consists of just a few building blocks: matter particles."
Physics was the second of this year's crop of the Nobels prizes. The prizes were first awarded in 1901 to honour achievements in science, literature and peace in accordance with the will of dynamite inventor and business tycoon Alfred Nobel.
On Monday, the Americans James Rothman and Randy Schekman and German-born Thomas Sudhof were awarded the Nobel Medicine Prize for their groundbreaking work on how the cell organises its transport system.
The announcements of Nobel laureates will continue this week and next with chemistry, literature and peace. Each prize is worth $1.2m.
Established by the Swedish industrialist Alfred Nobel, the Nobel Prizes have been handed out by award committees in Stockholm and Oslo since 1901.
The winners always receive their awards on December 10, the anniversary of Nobel's death in 1896.