• Freebound – Asymptotic Freedom (QCD) Physics T-Shirt – white
  • Freebound – Asymptotic Freedom (QCD) Physics T-Shirt – male model, black
  • Freebound – Asymptotic Freedom (QCD) Physics T-Shirt – flat lay, black
1 3

FreeboundAsymptotic Freedom (QCD)

Freebound – Asymptotic Freedom (QCD) Physics T-Shirt

$29.99 USD
$29.99 USD
Sale Sold out
Shipping calculated at checkout. Free US shipping · $10 flat shipping outside the US.
Color
White · Black
Size
S–5XL
Made
To order · shipping times

Why do quarks act freely only when close? In quantum chromodynamics the strong coupling weakens at short distances, so tightly packed quarks interact only weakly. Pull one away and the force does not fade, so quarks stay confined inside hadrons, never seen alone. Gross, Wilczek and Politzer found this in 1973 and shared the 2004 Nobel Prize. Pixel-art unisex tee; equation, symbols and sources in the physics panel below.

Color
Size

Size guideS–5XL · inches

Details

Size & fitS–5XL

Unisex heavy cotton (Gildan 5000), classic fit.

SizeWidthLengthSleeve
S182815.1
M202916.5
L223018
XL243119.5
2XL263221
3XL283322.4
4XL303423.7
5XL323525

Measurements in inches, ±1.5 in tolerance.

ShippingFree US

Free US shipping · $10 flat shipping outside the US. Printed to order for you.

Delivery times & where we ship

Returns & replacements21 days

Every item is printed to order, so we can’t accept returns or exchanges for change of mind, or if you ordered the wrong size or colour.

Print defect, misprint, damage or the wrong item? We’ll send a free replacement, or a refund if you prefer. Report it within 21 days of delivery with a photo; no need to send it back.

Full refund & replacement policy

The physics

Most forces weaken with distance. The strong force between quarks does the opposite.

In 1973 David Gross, Frank Wilczek and David Politzer showed that in quantum chromodynamics the coupling shrinks at short distances and high energies. Packed close, quarks move almost freely; pull them apart and the binding grows until it makes new quarks instead of letting one go.

They shared the 2004 Nobel Prize. Freebound's three quarks know it: closer means freer.

Equations

\[\alpha_s(Q^{2}) = \frac{12\pi}{(33 - 2n_f)\,\ln\!\left(Q^{2}/\Lambda^{2}\right)}\quad\text{(one loop)}\]
SymbolMeaningUnit
\(\alpha_s\) strong coupling \(\mathrm{–}\)
\(Q\) momentum transfer (energy scale) of the probe \(\mathrm{GeV}\)
\(n_f\) number of quark flavours lighter than Q \(\mathrm{–}\)
\(\Lambda\) QCD scale parameter (a few hundred MeV) \(\mathrm{GeV}\)

Sources

  1. Gross & Wilczek (1973) Ultraviolet Behavior of Non-Abelian Gauge Theories, Phys. Rev. Lett. 30, 1343
  2. Politzer (1973) Reliable Perturbative Results for Strong Interactions?, Phys. Rev. Lett. 30, 1346
  3. NobelPrize.org — The Nobel Prize in Physics 2004
View full details

Field notes

View all
1 3
View all