On the $QQ\bar q\bar q$-Quark Potential in String Models
Abstract
We propose a string theory construction for the system of two heavy quarks and two light antiquarks. The potential of the system is a function of separation between the quarks. We define a critical separation distance below which the system can be thought of mainly as a compact tetraquark. The results show the universality of the string tension and factorization at small separations expected from heavy quark-diquark symmetry. Our estimate of the screening length is in the range of lattice QCD. We also make a comparison with the potential of the $QQq$ system. The potentials look very similar at small quark separations but at larger separations they differ. The reason for this is that the flattening of the potentials happens at two well-separated scales as follows from the two different mechanisms: string breaking by light quarks for $QQq$ and string junction annihilation for $QQ\bar q\bar q$. Moreover, a similar construction can also be applied to the $\bar Q\bar Q qq$ system.
- Publication:
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arXiv e-prints
- Pub Date:
- November 2021
- DOI:
- 10.48550/arXiv.2111.14418
- arXiv:
- arXiv:2111.14418
- Bibcode:
- 2021arXiv211114418A
- Keywords:
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- High Energy Physics - Phenomenology;
- High Energy Physics - Lattice;
- High Energy Physics - Theory;
- Nuclear Theory
- E-Print:
- 20 pages, 12 Figures