Quark (dairy product) a somewhat crumbly texture (like ricotta). The basic quark this basic quark or skimmed quark ("Magerquark") must under German Law have less than 10% fat by dry mass. Quark with higher fat content is made by adding cream after cooling. It has a very smooth and creamy texture and is slightly sweet (unlike sour cream). A firmer version called "Schichtkäse" (layer cheese) is often used for baking. Schichtkäse is distinguished from quark by having an added layer of cream sandwiched between two layers of quark. Quark is also often sold flavored with herbs, spices, or fruit. In general, dry mass
Quark model Quark model In particle physics, the quark model is a classification scheme for hadrons in terms of their valence quarks—the quarks and antiquarks which give rise to the quantum numbers of the hadrons. The quark model underlies "flavor SU(3)", or the "Eightfold Way", the successful classification scheme organizing the large number of lighter hadrons that were being discovered starting in the 1950s and continuing through the 1960s. It received experimental verification beginning in the late 1960s and is a valid effective classification of them to date. The quark model was independently proposed by physicists Murray Gell-Mann, and George Zweig (also