Home >

news Help

Publication Information


Title
Japanese:Measurement of the branching ratio $\Gamma(\Lambdab0 \rightarrow \psi(2S)\Lambda0)/\Gamma(\Lambdab0 \rightarrow J/\psi\Lambda0)$ with the ATLAS detector 
English:Measurement of the branching ratio $\Gamma(\Lambdab0 \rightarrow \psi(2S)\Lambda0)/\Gamma(\Lambdab0 \rightarrow J/\psi\Lambda0)$ with the ATLAS detector 
Author
Japanese: 山口洋平.  
English: Youhei Yamaguchi.  
Language English 
Journal/Book name
Japanese: 
English: 
Volume, Number, Page Vol. "B751"        pp. "63-80"
Published date July 2015 
Publisher
Japanese: 
English: 
Conference name
Japanese: 
English: 
Conference site
Japanese: 
English: 
Official URL http://inspirehep.net/record/1385604
 
DOI https://doi.org/10.1016/j.physletb.2015.10.009
Abstract An observation of the $\Lambda_b^0 \rightarrow \psi(2S) \Lambda^0$ decay and a comparison of its branching fraction with that of the $\Lambda_b^0 \rightarrow J/\psi \Lambda^0$ decay has been made with the ATLAS detector in proton--proton collisions at $\sqrt{s}=8\,$TeV at the LHC using an integrated luminosity of $20.6\,$fb$^{-1}$. The $J/\psi$ and $\psi(2S)$ mesons are reconstructed in their decays to a muon pair, while the $\Lambda^0\rightarrow p\pi^-$ decay is exploited for the $\Lambda^0$ baryon reconstruction. The $\Lambda_b^0$ baryons are reconstructed with transverse momentum $p_{\rm T}>10\,$GeV and pseudorapidity $|\eta|<2.1$. The measured branching ratio of the $\Lambda_b^0 \rightarrow \psi(2S) \Lambda^0$ and $\Lambda_b^0 \rightarrow J/\psi \Lambda^0$ decays is $\Gamma(\Lambda_b^0 \rightarrow \psi(2S)\Lambda^0)/\Gamma(\Lambda_b^0 \rightarrow J/\psi\Lambda^0) = 0.501\pm 0.033 ({\rm stat})\pm 0.019({\rm syst})$, lower than the expectation from the covariant quark

©2007 Tokyo Institute of Technology All rights reserved.