Search for beautiful tetraquarks in the ϒ (1 S ) μ + μ − invariant-mass spectrum

15 October 2018

Abstract: The ϒ (1 S ) μ + μ − invariant-mass distribution is investigated for a possible exotic meson state composed of two b quarks and two b ¯ $\overline{b}$ quarks, X b b ¯ b b ¯ ${X}_{b\overline{b}b\overline{b}}$ . The analysis is based on a data sample of pp collisions recorded with the LHCb detector at centre-of-mass energies s = 7 $\sqrt{s}=7$ , 8 and 13 TeV, corresponding to an integrated luminosity of 6.3 fb −1 . No significant excess is found, and upper limits are set on the product of the production cross-section and the branching fraction as functions of the mass of the X b b ¯ b b ¯ ${X}_{b\overline{b}b\overline{b}}$ state. The limits are set in the fiducial volume where all muons have pseudorapidity in the range [2 . 0 , 5 . 0], and the X b b ¯ b b ¯ ${X}_{b\overline{b}b\overline{b}}$ state has rapidity in the range [2 . 0 , 4 . 5] and transverse momentum less than 15 GeV/ c .

Published in: JHEP 1810 (2018) 086