Evidence for the decay $ \mathrm{B}_{\mathrm{c}}^{+}\to {{\mathrm{J}} \left/ {{\uppsi\;3{\uppi^{+}}2{\uppi^{-}}}} \right.} $

Abstract

Evidence is presented for the decay B + c → J/ψ 3π + 2π − using proton-proton collision data, corresponding to an integrated luminosity of 3 fb −1 , collected with the LHCb detector. A signal yield of 32 ± 8 decays is found with a significance of 4.5 standard deviations. The ratio of the branching fraction of the B + c → J/ψ 3π + 2π − decay to that of the B + c → J/ψ π + decay is measured to be B (B + c → J/ψ 3π + 2π −) B B + c → J/ψ π + = 1.74 ± 0.44 ± 0.24, where the first uncertainty is statistical and the second is systematic.

Excited ρ mesons in Bc→ψ(′Luchinsky1 2019Phys. Rev. D3030View full textAdd to dashboardCite

“…In a series of papers (see, for example, [6][7][8][9][10][11]) it was shown how the QCD factorization theorem can be used to connect differential branching fraction of light mesons' production in exclusive τ lepton and B c meson decays. Predictions presented in these article are in good agreement with experimental results [12][13][14][15][16]. It could be interesting to try such an approach for B c → J/ψKK S and B c → ψ(2S)KK S decays.…”

S-wave ground state charmonium decays ofBcmesons in the perturbative QCD approach

“…At the current level accuracy, around 5 × 10 10 B c events are expected to be produced each year [6]. Up to now, the LHCb collaboration has measured the B c mass with 6273 AE 1.3ðstatÞ AE 1.6ðsystÞ MeV=c 2 [7] and some new channels, such as B þ c → J=ψπ þ π − π þ [8], B þ c → J=ψK þ [9], B þ c → ψð2SÞπ þ [10], B þ c → J=ψD ðÃÞþ s [11], B þ c → J=ψK þ K − π þ [12], B þ c → B 0 s π þ [13], and B þ c → J=ψ3π þ 2π − [14] for the first time. We can see all of the observed processes involving the J=ψ final state, due to the narrow peak of J=ψ and the high purity of J=ψ → l þ l − , the decay modes containing the signal of J=ψ meson are among the most easily reconstructible B c decay modes.…”

Measurement of the ratio of the production cross sections times branching fractions of B c ± → J/ψπ ± and B± → J/ψK ± and ℬ B c ± → J / ψ π ± π ± π ∓ / ℬ B c ± → J / ψ π ± $$ \mathrm{\mathcal{B}}\left({\mathrm{B}}_{\mathrm{c}}^{\pm}\to \mathrm{J}/\psi {\pi}^{\pm }{\pi}^{\pm }{\pi}^{\mp}\right)/\mathrm{\mathcal{B}}\left({\mathrm{B}}_{\mathrm{c}}^{\pm}\to \mathrm{J}/\psi {\pi}^{\pm}\right) $$ in pp collisions at s = 7 $$ \sqrt{s}=7 $$ TeV

“…The advent of the CERN LHC has opened a new era for B + c investigations; a rich program of measurements involving new decay modes is being carried out by the LHCb Collaboration [5][6][7][8][9][10][11]. The ATLAS experiment has recently observed a new state whose mass is consistent with the predicted mass for the second S-wave state of the B + c meson [12].…”