what are pi mesons??
Answers
In particle physics, a pion is any of three subatomic particles: π⁰ , π⁺ , and π⁻ . Each pion consists of a quark and an antiquark and is therefore a meson. Pions are the lightest mesons and, more generally, the lightest hadrons.
Answer:
Explanation:
Pi mesons (pions) are a type of meson. A meson is made up of a quark and antiquark. There are three different types of pions; π+, π-, and π0. The +/- pions are charged.
π+ are made up of one up quark and one anti-down quark. Whats confusing here is that an anti-down is not the same as an up (though using common knowledge it should be). An up has a charge of +2/3 whereas an anti-down has the opposite charge of a down quark (+1/3) giving a total charge of +1 hence π+.
π- are made up of one down quark and one anti-up quark. The down quark has a charge of -1/3 and anti-up has the opposite charge to up and therefore -2/3, giving a total charge of -1 hence π-.
π0 are made up of one up and anti up quark. The +2/3 and -2/3 charges cancel, leaving an uncharged meson therefore π0.
Pions are the lightest (have the least mass) mesons which is why they are made of up and down quarks, and their anti-quarks. Heavier mesons are made up of a heavier pair (K+ is made up of an up quark and an anti-strange quark).
Note: You may see antiquarks written differently. For example, anti-up quark can be written as up antiquark, but both mean the same thing, and are denoted by the bar on top of the quark.