We study the static three-quark (3Q) potential in detail using SU(3) lattice QCD with $12^3 \times 24$ at $\beta=5.7$ and $16^3 \times 32$ at $\beta=5.8, 6.0$ at the quenched level. For more than 200 patterns of the 3Q systems, we numerically derive 3Q ground-state potential $V_{ 3Q}$ from the 3Q Wilson loop with the smearing technique, which reduces excited-state contaminations. The lattice QCD data of $V_{ 3Q}$ are well reproduced within a few % deviation by a sum of a constant, the two-body Coulomb term and the three-body linear confinement term $\sigma_{ 3Q} L_{ min}$, with $L_{ min}$ the minimal value of total length of color flux tubes linking the three quarks. From the comparison with the Q-$\bar { Q}$ potential, we find a universality of the string tension as $\sigma_{ 3Q} \simeq \sigma_{ \rm Q \bar Q}$ and the one-gluon-exchange result for Coulomb coefficients, $A_{ 3Q} \simeq \frac12 A_{ \rm Q \bar Q}$.
Categories: hep-lat