Passage VI

Quarks constitute 1 of the 3 classes of elementary particles that form all matter in the universe. Three quarks bound together form a type of particle called a baryon. A quark's effective mass (mass when bound to other quarks) is greater than its single-quark mass (mass when unbound). In addition spin-down ().

Table 1 lists the symbol, electric charge, and approximate single-quark mass for each of the 6 quarks.

Table 2 gives the symbol, mass, quark content, and quark spins for several baryons.

Tables adapted from C. Amsler et al., "Review of Particle Physics." ©2008 by Elsevier B.V.

35. For all quarks, the amount of spin is always , where is a constant. A spin-up quark has spin , and a spin-down quark has spin . Given that the spin of a baryon equals the sum of its quark spins, what are the spins of the and baryons listed in Table 2 ?

Answer and Explanation

Your Answer is

Correct Answer is C

Explanation

According to the stem of the question, the spins of a baryon are equal to the sum of its quark spins.

Find Λ0 in table 2, and see that it has two upward quarks and one downward quark, so its spin sum is two (+1/ 2h) and one (-1/2h), the sum is equal to (+1/2h);

Similarly, the spin of Δ0 can be found, see table 2 is three quarks on phase, so it is three (+1/2h) added, equal to (+3/2h)