@Article{BABARCollaborationLees_etal2014,
author="BABAR Collaboration (Lees, J. P. et al
and Martinez-Vidal, F.
and Oyanguren, A.
and Villanueva-Perez, P.",
title="Bottomonium spectroscopy and radiative transitions involving the chi(bJ)(1P, 2P) states at BABAR",
journal="Physical Review D",
year="2014",
publisher="Amer Physical Soc",
volume="90",
number="11",
pages="112010--20pp",
abstract="We use (121 +/- 1) million Upsilon(3S) and (98 +/- 1) million Upsilon(2S) mesons recorded by the BABAR detector at the PEP-II e(+)e(-) collider at SLAC to perform a study of radiative transitions involving the chi(bJ)(1P, 2P) states in exclusive decays with mu(+)mu(-)gamma gamma final states. We reconstruct twelve channels in four cascades using two complementary methods. In the first we identify both signal photon candidates in the electromagnetic calorimeter (EMC), employ a calorimeter timing-based technique to reduce backgrounds, and determine branching-ratio products and fine mass splittings. These results include the best observational significance yet for the chi(b0)(2P) -> gamma Upsilon(2S) and chi(b0)(1P) -> gamma Upsilon(1S) transitions. In the second method, we identify one photon candidate in the EMC and one which has converted into an e(+)e(-) pair due to interaction with detector material, and we measure absolute product branching fractions. This method is particularly useful for measuring Upsilon(3S) -> gamma chi(b1,2)(1P) decays. Additionally, we provide the most up-to-date derived branching fractions, matrix elements and mass splittings for chi(b) transitions in the bottomonium system. Using a new technique, we also measure the two lowest-order spin-dependent coefficients in the nonrelativistic QCD Hamiltonian.",
optnote="WOS:000348871500002",
optnote="exported from refbase (https://references.ific.uv.es/refbase/show.php?record=2121), last updated on Fri, 13 Mar 2015 11:24:07 +0000",
issn="1550-7998",
doi="10.1103/PhysRevD.90.112010",
opturl="http://arxiv.org/abs/1410.3902",
opturl="https://doi.org/10.1103/PhysRevD.90.112010",
archivePrefix="arXiv",
eprint="1410.3902",
language="English"
}