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 Plus annual

Presents the access of premium content as premium feature

Premium Content

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 annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We discuss the nature of the $\chi_b(3P)$ and $X(3872)$ mesons: Are the$\chi_b(3P)$'s standard $b \bar b$ mesons or $b \bar b$ states with asignificative continuum component? Is the $X(3872)$ a $c \bar c$ state withcontinuum coupling effects or a meson-meson molecule? To do that, we comparequark model and unquenched quark model results for the mass barycenter andsplittings of the $\chi_b(3P)$ multiplet. Future and more precise experimentalresults will discriminate between the two interpretations. In the case of the$X(3872)$, we interpret it a $c \bar c$ core plus higher Fock components due tothe coupling to the meson-meson continuum, thus we think that it is compatiblewith the meson $\chi_{c1}(2P)$, with $J^{PC} = 1^{++}$. The $J^{PC} = 1^{++}$quantum numbers are in agreement with the experimental results found by theLHCb collaboration. In our view, the $X(3872)$'s mass is lower than the quarkmodel's predictions because of self energy shifts. We also provide anestimation of the open charm/bottom strong decay modes of the $X(3872)$ and$\chi_b(3P)$ mesons, such as $X(3872) \rightarrow D \bar D^*$ and$\chi_{b2}(3P) \rightarrow B \bar B$, and radiative transitions.

Quark structure of the $X(3872)$ and $\chi_b(3P)$ resonances