OBSERVATION OF A RIDGE CORRELATION STRUCTURE IN HIGH MULTIPLICITY PROTON-PROTON COLLISIONS: A BRIEF REVIEW

This paper briefly reviews the striking experimental observation of a ridge-like dihadron correlation structure in high multiplicity proton-proton collisions at the Large Hadron Collider (LHC). Recent progress of both experimental and theoretical efforts on under-standing the physical origin of the novel effect is reviewed. Outlook on future direction of possible new studies is discussed.