Journal of High Energy Physics > 2017 > 2017 > 1 > 1-43
Measurements of ψ(2S) and X(3872) → J/ψπ+π− production in pp collisions at s = 8 $$ \sqrt{s}=8 $$ TeV with the ATLAS detector
Source
Abstract
Differential cross sections are presented for the prompt and non-prompt production of the hidden-charm states X(3872) and ψ(2S), in the decay mode J/ψπ+π−, measured using 11.4 fb−1 of pp collisions at s = 8 $$ \sqrt{s}=8 $$ TeV by the ATLAS detector at the LHC. The ratio of cross-sections X(3872)/ψ(2S) is also given, separately for prompt and non-prompt components, as well as the non-prompt fractions of X(3872) and ψ(2S). Assuming independent single effective lifetimes for non-prompt X(3872) and ψ(2S) production gives R B = ℬ B → X 3872 + any ℬ X 3872 → J / ψ π + π − ℬ B → ψ 2 S + any ℬ ψ 2 S → J / ψ π + π − = 3.95 ± 0.32 stat ± 0.08 s y s × 10 − 2 $$ {R}_B=\frac{\mathrm{\mathcal{B}}\left(B\to X(3872)+\mathrm{any}\right)\mathrm{\mathcal{B}}\left(X(3872)\to J/\psi {\pi}^{+}{\pi}^{-}\right)}{\mathrm{\mathcal{B}}\left(B\to \psi (2S)+\mathrm{any}\right)\mathrm{\mathcal{B}}\left(\psi (2S)\to J/\psi {\pi}^{+}{\pi}^{-}\right)}=\left(3.95\pm 0.32\left(\mathrm{s}\mathrm{tat}\right)\pm 0.08\left(\mathrm{s}\mathrm{y}\mathrm{s}\right)\right)\times {10}^{-2} $$ separating short- and long-lived contributions, assuming that the short-lived component is due to Bc decays, gives RB = (3.57 ± 0.33(stat) ± 0.11(sys)) × 10−2, with the fraction of non-prompt X(3872) produced via Bc decays for pT(X(3872)) > 10 GeV being (25 ± 13(stat) ± 2(sys) ± 5(spin))%. The distributions of the dipion invariant mass in the X(3872) and ψ(2S) decays are also measured and compared to theoretical predictions.
Identifiers
journal e-ISSN : | 1029-8479 |
DOI | 10.1007/JHEP01(2017)117 |
Authors
The ATLAS collaboration
- Transilvania University of Brasov, Brasov, Romania
- University Politehnica Bucharest, Bucharest, Romania
- Universidade Nova de Lisboa, Dep Fisica and CEFITEC of Faculdade de Ciencias e Tecnologia, Caparica, Portugal
- Centre National de l’Energie des Sciences Techniques Nucleaires, Rabat, Morocco
- CERN, Geneva 23, Switzerland
B. Abbott
- University of Oklahoma, Homer L. Dodge Department of Physics and Astronomy, Norman, United States of America