Observation of e+e−→ηhc at center-of-mass energies from 4.085

Abstract

We observe for the first time the process e þ e − → ηh c with data collected by the BESIII experiment.Significant signals are observed at the center-of-mass energy ffiffi ffi s p ¼ 4.226 GeV, and the Born cross section is measured to be ð9.5 þ2.2 −2.0 AE 2.7Þ pb. Evidence for ηh c is observed at ffiffi ffi s p ¼ 4.358 GeV with a Born cross section of ð10.0 þ3.1 −2.7 AE 2.6Þ pb, and upper limits on the production cross section at other center-of-mass energies between 4.085 and 4.600 GeV are determined.

Possible partner state of the Y(2175)

“…The Yð2175Þ was first observed in 2006 by the BABAR Collaboration in the ϕf 0 ð980Þ invariant mass spectrum [14][15][16][17], and later confirmed in the BESII [18], Belle [19], and BESIII [20,21] experiments. Its mass and width were measured to be M ¼ 2188 AE 10 MeV and Γ ¼ 83 AE 12 MeV, respectively, and its spin-parity quantum number is J PC ¼ 1 −− [1].…”

Modeling charmonium- η decays of JPC=1−− higher charmonia

“…After the revision of this manuscript, BESIII published an evidence of e + e − → ηh c at center-of-mass energy √ s = 4.358 GeV [65]. Along with their earlier measurement [66], this evidence will help to delve into the Y (4360) through its HQSS violating hadronic transitions.…”

Study of e+e−→π+π−Ablikim1, Adlarson2, Biernat3 et al. 2019Phys. Rev. DSelf Cite16060View full textAdd to dashboardCite

“…Charged tracks, photons and K 0 S candidates are reconstructed using the standard criteria of the BESIII experiment [26]. Candidate π 0 and η decays to γγ are reconstructed from pairs of photons with invariant mass in the range ½0.120; 0.145 GeV=c 2 for the π 0 and ½0.50; 0.57 GeV=c 2 for the η.…”

“…The background is described with a second order Chebyshev polynomial (CP). Both the signal and background shapes are channel dependent, but the relative signal yields among all the channels are constrained by branching fractions and efficiencies [26]. The total signal yield of the nine channels is labeled N obs , which is shared for all the channels and required to be positive.…”

“…The methods for estimating the uncertainties due to the vacuum polarization and P i ε i B i are the same as those described in Ref. [26]. Furthermore, the uncertainty due to the e þ e − → π þ π − π 0 η c decay dynamics is obtained by comparing the simulations with and without the Z c resonance.…”