English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We investigate a doubly-bottomed tetraquark state $T_{bb}$ $(bb\bar{u}\bar{d})$ with quantum number $I(J^P)=0(1^+)$ in $(2+1)$-flavor latticeQCD. Using the Non-Relativistic QCD (NRQCD) quark action for $b$ quarks, wehave extracted the coupled channel potential between $\bar{B}\bar{B}^*$ and$\bar{B}^* \bar{B}^*$ in the HAL QCD method at $a \approx 0.09$ {fm} on$32^3\times 64$ lattices. The potential predicts an existence of a bound$T_{bb}$ below the $\bar{B}\bar{B}^*$ threshold. At the physical pion mass$m_\pi\approx140$ {MeV} extrapolated from $m_\pi\approx 410,\, 570,\, 700${MeV}, a binding energy with its statistical error is given by $E_{\rmbinding}^{\rm (coupled)} = 83(10)$ MeV from a coupled channel analysis whereeffects due to virtual $\bar{B}^* \bar{B}^*$ states are included through thecoupled channel potential, while we obtain $E_{\rm binding}^{\rm (single)} =155(17)$ MeV only from a potential for a single $\bar{B}\bar{B}^*$ channel.This difference indicates that the effect from virtual $\bar{B}^* \bar{B}^*$states is sizable to the binding energy of $T_{bb}$. Adding $\pm 20$ MeV asempirical systematic error caused by the NRQCD approximation for $b$ quarks,our estimate of the $T_{bb}$ binding energy becomes $83(10)(20)$ MeV.

Lattice study on a tetraquark state $T_{bb}$ in the HAL QCD method