554
M. B. Wise
Fig. 1 Comparison of the
NLO (hatched) and NNLO
(solid) chiral-continuum fits
for h + versus w
Fig. 2 Comparison of the
NLO (hatched) and NNLO
(solid) chiral-continuum fits
for h − versus w
2.2 T QQ ¯
q ¯
q Tetraquarks
For very heavy quarks Q the lowest lying T QQ ¯
q ¯
q tetraquark states are stable with
respect to the strong and electromagnetic interactions [16, 17]. The reason for this
is quite simple. If m Q Λ QCD , then the heavy QQ diquark in the tetraquark will
be in a color ¯
3 configuration since in the color channel 3 × 3 → ¯
3 the one gluon
color Coulombic potential,
V c (r) = −
2
3
α s
r
(32)
M. B. Wise
Fig. 1 Comparison of the
NLO (hatched) and NNLO
(solid) chiral-continuum fits
for h + versus w
Fig. 2 Comparison of the
NLO (hatched) and NNLO
(solid) chiral-continuum fits
for h − versus w
2.2 T QQ ¯
q ¯
q Tetraquarks
For very heavy quarks Q the lowest lying T QQ ¯
q ¯
q tetraquark states are stable with
respect to the strong and electromagnetic interactions [16, 17]. The reason for this
is quite simple. If m Q Λ QCD , then the heavy QQ diquark in the tetraquark will
be in a color ¯
3 configuration since in the color channel 3 × 3 → ¯
3 the one gluon
color Coulombic potential,
V c (r) = −
2
3
α s
r
(32)