Measurement of the B s 0  → ϕϕ branching fraction and search for the decay B 0 → ϕϕ

Abstract

Using a dataset corresponding to an integrated luminosity of 3.0 fb −1 collected in pp collisions at centre-of-mass energies of 7 and 8 TeV, the B 0 s → φφ branching fraction is measured to bewhere f s /f d represents the ratio of the B 0 s to B 0 production cross-sections, and the B 0 → φK * (892) 0 decay mode is used for normalization. This is the most precise measurement of this branching fraction to date, representing a factor five reduction in the statistical uncertainty compared with the previous best measurement. A search for the decay B 0 → φφ is also made. No signal is observed, and an upper limit on the branching fraction is set as B(B 0 → φφ) < 2.8 × 10at 90% confidence level. This is a factor of seven improvement compared to the previous best limit.

Study of charmonium production in $${b} $$ b -hadron decays and first evidence for the decay $${{{B}} ^0_{{s}}} \!\rightarrow \phi \phi \phi $$ B s 0 → ϕ ϕ ϕ

“…This technique is based on relation of B 0 s production in p p collisions and η c (1S) inclusive production rate in b-hadron decays, and reconstruction of B 0 s and η c (1S) via decays to φφ. The measurement is consistent with the recent LHCb result [22] and the current world average [14], as well as with theoretical calculations [29,30,65].…”

“…As a by-product of the analysis, the branching fraction B(B 0 s → φφ) is determined to be B(B 0 s → φφ) = (2.18±0.17±0.11±0.14 f s ±0.65 B )×10 −5 with a different technique with respect to the previous results [21,22,63,64]. This technique is based on relation of B 0 s production in p p collisions and η c (1S) inclusive production rate in b-hadron decays, and reconstruction of B 0 s and η c (1S) via decays to φφ.…”

“…The measured B 0 s and η c (1S) yields and efficiency ratio, the branching fraction B(B 0 s → φφ) = (1.84 ± 0.05 ± 0.07 ± 0.11 f s / f d ± 0.12 norm ) × 10 −5 [22], the J/ψ production rate in b-hadron decays B(b → J/ψX ) = (1.16 ± 0.10)% [14], the relative production rates of η c (1S) and J/ψ in b-hadron decays…”

“…The B 0 s decay to the φφ final state has been observed by the CDF collaboration [21] and recently precisely measured by the LHCb collaboration [22], where it was also used to search for CP-violating asymmetries [23]. In the Standard Model (SM) the amplitude for the decay B 0 s → φφ is dominated by a loop diagram.…”

“…Here we report first evidence for the B 0 s → φφφ decay and study its resonance structure. The branching fraction of this decay is determined relative to the branching fraction B(B 0 s → φφ) [22]. To cross-check the technique exploited in this paper, the value of B(B 0 s → φφ) is also determined relative to the η c (1S) production rate.…”