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
Quark and top quarks) can change into any down-type quark (down, strange, and bottom quarks) and vice versa. This flavor transformation mechanism causes the radioactive process of beta decay, in which a neutron () "splits" into a proton (), an electron () and an electron antineutrino () (see picture). This occurs when one of the down quarks in the neutron () decays into an up quark by emitting a virtual boson, transforming the neutron into a proton (). The boson then decays into an electron and an electron antineutrino. Both beta decay and the inverse process of "inverse beta decay" are