Measurement of the Y(1S) pair production cross section and search for resonances decaying to Y(1S)μ+μ- in proton-proton collisions at √{ s } = 13TeV
Abstract
The fiducial cross section for Y (1 S) pair production in proton-proton collisions at a center-of-mass energy of 13 TeV in the region where both Y (1 S) mesons have an absolute rapidity below 2.0 is measured to be 79 ± 11(stat) ± 6(syst) ± 3 (B) pb assuming the mesons are produced unpolarized. The last uncertainty corresponds to the uncertainty in the Y (1 S) meson dimuon branching fraction. The measurement is performed in the final state with four muons using proton-proton collision data collected in 2016 by the CMS experiment at the LHC, corresponding to an integrated luminosity of 35.9fb-1. This process serves as a standard model reference in a search for narrow resonances decaying to Y (1 S)μ+μ- in the same final state. Such a resonance could indicate the existence of a tetraquark that is a bound state of two b quarks and two b bar antiquarks. The tetraquark search is performed for masses in the vicinity of four times the bottom quark mass, between 17.5 and 19.5 GeV, while a generic search for other resonances is performed for masses between 16.5 and 27 GeV. No significant excess of events compatible with a narrow resonance is observed in the data. Limits on the production cross section times branching fraction to four muons via an intermediate Y (1 S) resonance are set as a function of the resonance mass.
- Publication:
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Physics Letters B
- Pub Date:
- September 2020
- DOI:
- 10.1016/j.physletb.2020.135578
- Bibcode:
- 2020PhLB..80835578S
- Keywords:
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- CMS;
- Upsilon