Figure 1: The structure function F2

Figure 1: The structure function F₂ as a function ofxfor various Q² values, exhibiting Bjorken scaling, taken from [Ellis/Stirling/Webber]

Figure 2: Parton distribution function set A from the Martin-Roberts-Stirling group, taken from [Ellis/Stirling/Webber]. Note that this uses the common notation of defining valence quark distri- butions, f^uv ≡f^u−f^u_¯, f^dv ≡f^d−fd¯.

1

0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45

αs(µ) DIS (Bj-SR) DIS (GLS-SR)τ decays QQ− states (lattice)ϒ decays e+ e− (σhad)

pp⁽⁻⁾→bb⁻X, γX

e+ e− (jet & event-shape) e+ e− (σhad) e+ e− (jet & event-shape) e+ e− (Z width) e+ e− (jet & event-shape) N³LO N²LO NLO

0.11 0.12 0.13

1 10 10²

DIS (e/µ; F₂)

[1.9–15.2]

µ scale (GeV) αs(MZ)

Figure 3: Results of a recent compilation of α^S values, see [arXiv:0803.0979 [hep-ph], arXiv:hep- ex/0606035]. The scale dependence shows excellent agreement with the predictions of perturbative QCD over a wide energy range. When translated into measurements of αS(M^z), the separate measurements cluster strongly around the average value,αS(M^z) = 0.1204±0.0009

1 10

F

x=1.3E-05 (x 18) x=2E-05 (x 10) x=3.2E-05 (x 4)

x=5E-05 (x 2) x=8E-05 (x 1)

H1SVX95 H194

H195NVX prel.

H196NVX prel.

E665 NMC BCDMS

H1 QCDFit96 prel

1 10

x=0.00013 (x 10) x=0.0002 (x 5) x=0.00032 (x 3)

x=0.0005 (x 1.8)

x=0.0008 (x 0.8)

x=0.0013 (x 12) x=0.002 (x 8)

x=0.0032 (x 4) x=0.005 (x 2.2)

x=0.008 (x 1.3)

1 10

10^-1 1 10 10² 10³ 10⁴

x=0.013 (x 18) x=0.02

(x 10) x=0.032

(x 6) x=0.05

(x 3.5) x=0.08 (x 2)

10^-1 1 10 10² 10³ 10⁴

Q

[GeV

]

x=0.13 (x 32) x=0.2

(x 16) x=0.32

(x 8) x=0.5

(x 6)

Figure 4: Fit to theF₂data over a wide range ofQ²values, exhibiting violation of Bjorken scaling

2