In:
Journal of High Energy Physics, Springer Science and Business Media LLC, Vol. 2019, No. 10 ( 2019-10)
Abstract:
We report a new measurement of the e + e − → ϒ( nS ) π + π − ( n = 1 , 2 , 3) cross sections at energies from 10 . 52 to 11 . 02 GeV using data collected with the Belle detector at the KEKB asymmetric-energy e + e − collider. We observe a new structure in the energy dependence of the cross sections; if described by a Breit-Wigner function its mass and width are found to be $$ M=\left(10752.7\pm {5.9}_{-1.1}^{+0.7}\right)\mathrm{MeV}/{c}^2 $$ M = 10752.7 ± 5.9 − 1.1 + 0.7 MeV / c 2 and $$ \Gamma =\left({35.5}_{-11.3\kern0.5em -3.3}^{+17.6+3.9}\right) $$ Γ = 35.5 − 11.3 − 3.3 + 17.6 + 3.9 MeV, where the first error is statistical and the second is systematic. The global significance of the new structure including systematic uncertainty is 5.2 standard deviations. We also find evidence for the e + e − → ϒ (1 S ) π + π − process at the energy 10 . 52 GeV, which is below the B $$ \overline{B} $$ B ¯ threshold.
Type of Medium:
Online Resource
ISSN:
1029-8479
DOI:
10.1007/JHEP10(2019)220
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2019
detail.hit.zdb_id:
2027350-2
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