Background magnetic field stabilizes QCD string against breaking

Understand

The confinement of quarks in hadrons occurs due to formation of QCD string.

• At large separation between the quarks the QCD string breaks into pieces due to light quark-antiquark pair creation.
• We argue that there exist a critical background magnetic field e B ~ 16 m_\pi^2, above which the string breaking is impossible in the transverse directions with respect to the axis of the magnetic field.
• Thus, at strong enough magnetic field a new, asymmetrically confining phase may form.