In particle physics, the hypercharge (represented by Y) is the sum of the baryon number B and the flavor charges: strangeness S, charm C, bottomness and topness T, although the last one can be omitted given the extremely short life of the top quark (it decays to other quarks before strong-interacting with other quarks). CPT-symmetry is a fundamental symmetry of physical laws under transformations that involve the inversions of charge, parity and time simultaneously. ... In the particle physics of quarks, if the physical Hamiltonian is different from the eigenstates of the weak one, a transformation matrix can be defined for these two bases. ... CP-symmetry is a symmetry obtained by a combination of the C-symmetry and the P-symmetry. ... A phenomenon is said to be chiral if it is not identical to its mirror image (see Chirality (mathematics)). The fundamental laws of physics may be chiral, as the weak charge is not invariant under a reflection unless particles are replaced by their antiparticles as well, and kaon decay appears... Particles explode from the collision point of two relativistic velocity (100 GeV) gold ions in the STAR detector of the Relativistic Heavy Ion Collider. ... In particle physics, the baryon number is an approximate conserved quantum number. ... In particle physics, strangeness is the number of anti-strange quarks minus the number of strange quarks in a particle. ... Charm is the number of charm quarks (c) minus the number of charm anti-quarks () that are present in a particle: This makes charm quark to have a charm of +1 and anti-charm quark to have a charm of −1 (the charm sign agreeing with the quark charge sign). ... In Physics, Bottomness (also formerly called Beauty) quantum number is the number of bottom anti-quarks () minus the number of bottom quarks (b) that are present in a particle: Bottom quarks have a bottomness of −1 and bottom anti-quarks of +1, so the bottomness sign agrees with its charge... Topness (formerly also called Truth) quantum number is the number of top quarks (t) minus the number of top anti-quarks () that are present in a particle: Top quarks have a topness of +1 and anti-top quarks have a topness of −1. ...

Originally, hypercharge only included the strangeness flavor in its definition. Do not confuse hypercharge with weak hypercharge: the first one is connected to the strong interaction, while the second appears on the electroweak interaction. Weak hypercharge is twice the difference between the electrical charge and the weak isospin. ... The strong nuclear force or strong interaction (also called color force or colour force) is a fundamental force of nature which affects only quarks and antiquarks, and is mediated by gluons in a similar fashion to how the electromagnetic force is mediated by photons. ... In physics, the electroweak theory presents a unified description of two of the four fundamental forces of nature: electromagnetism and the weak nuclear force. ...

The Gell-Mann/Nishijima Law relates hypercharge with isospin and electric charge: Isospin (isotopic spin, isobaric spin) is a physical quantity which is mathematically analogous to spin. ... Electric charge is a fundamental FATTY STASHEconserved property of some subatomic particles, which determines their electromagnetic interactions. ...

where I_z is the third component of isospin and Q is the particle's charge. This allow us to express the hypercharge in terms of isospin and charge:

Isospin creates multiplets of particles whose average charge is related to the hypercharge by:

.

which is easily derived from (3), since the hypercharge is the same for all members of a multiplet, and the average of the I_z values is 0.

Examples:

• The nucleon group (proton plus neutron) have an average charge of 1 + 0 = +1/2, so they both have hypercharge Y = 1 (barion number B = +1, flavor charges set to 0). From Gell-Mann/Nishima Law we know that proton has isospin +1 - 1/2 = +1/2, while neutron is the 0 − 1/2 = −1/2.
• This also works for quarks: for the up quark, with a charge of +2/3, and an I_z of +1/2, we deduce a hypercharge of 1/3, due to its barion number (since you need 3 quarks to make a barion, a quark has barion number of &plusminus;1/3).
• For a strange quark, with charge −1/3, a barion number of 1/3 and strangeness of −1 we get an hypercharge Y = −1/3, so we deduce an I_z = 0. That means that a strange quark makes a singlet of its own (same happens with charm, bottom and top quarks), while up and down constitute a isospin doublet.

1974 discovery photograph of a possible charmed baryon, now identified as the Σc++ In particle physics, the quarks are subatomic particles thought to be elemental and indivisible. ... In particle physics, strangeness is the number of anti-strange quarks minus the number of strange quarks in a particle. ... 1974 discovery photograph of a possible charmed baryon, now identified as the Σc++ In particle physics, the quarks are subatomic particles thought to be elemental and indivisible. ...

See also

• Flavour (particle physics), baryon number and quark flavor charges: isospin, strangeness, charm, bottomness, topness
• Weak isospin, Weak hypercharge