Quark (dairy product) considered to be different types of fresh cheese, while in Eastern Europe cottage cheese is usually viewed as a type of quark (e.g. Russian for cottage cheese is "зернёный творог" "zernyony tvorog", literally "grainy quark"). Quark is similar to French fromage blanc, Indian paneer, and the queso fresco/queijo fresco made in the Iberian Peninsula and in some Latin American countries. It is distinct from Italian ricotta because ricotta (Italian "recooked") is made from scalded whey. Quark is somewhat similar to yogurt cheeses such as the South Asian "chak(k)a", the Arabic labneh, and the Central Asian suzma or kashk, but while
Top quark only known way the top quark can decay is through the weak interaction producing a W-boson and a down-type quark (down, strange, or bottom). In particular, it is possible to directly determine the branching ratio Γ(Wb) / Γ(W"q" ("q" = b,s,d)). The best current determination of this ratio is . Since this ratio is equal to according to the Standard Model, this gives another way of determining the CKM element , or in combination with the determination of from single top production provides tests for the assumption that the CKM matrix is unitary. The Standard Model also allows more exotic