新山　雅之
   所属   京都産業大学  理学部 物理科学科
   職種   教授
発行・発表の年月 2022/07
形態種別 その他
標題 Search for a dark leptophilic scalar produced in association with $τ^+τ^-$ pair in $e^+e^-$ annihilation at center-of-mass energies near 10.58 GeV
執筆形態 その他
著者・共著者 Belle Collaboration,D. Biswas,Sw. Banerjee,I. Adachi,H. Aihara,D. M. Asner,T. Aushev,R. Ayad,V. Babu,P. Behera,J. Bennett,M. Bessner,V. Bhardwaj,B. Bhuyan,T. Bilka,D. Bodrov,J. Borah,A. Bozek,M. Bračko,P. Branchini,T. E. Browder,A. Budano,M. Campajola,D. Červenkov,M. -C. Chang,P. Chang,B. G. Cheon,K. Chilikin,H. E. Cho,K. Cho,S. -K. Choi,Y. Choi,S. Choudhury,D. Cinabro,S. Das,G. De Nardo,G. De Pietro,R. Dhamija,F. Di Capua,J. Dingfelder,Z. Doležal,T. V. Dong,S. Dubey,P. Ecker,D. Epifanov,T. Ferb
概要 A dark leptophilic scalar $(\phi_L)$ is a hypothetical particle that couples
only to leptons rather than quarks. We report on a search for $\phi_L$ in the
$e^+e^- \to \tau^+ \tau^- \phi_L, ~\phi_L \to \ell^+ \ell^- ~(\ell = e, \mu)$
process using 626~\invfb of data collected by the Belle experiment near the
\Y4S resonance. We validate the backgrounds with multiple control regions in
data, using a novel multiclass multivariate event classifier. In absence of a
signal, we quote upper limits at the 90\% confidence level on the coupling
between $\phi_L$ and leptons. Our bounds, obtained in a blinded approach, are
19\% more constraining than the previous limits, averaged over the mass range
$0.04 \leq m_{\phi_L} \leq 6.5~\gev$. We exclude the parameter space below
4~\gev favored by measurement of the anomalous magnetic moment of the muon.
DOI 10.1103/PhysRevD.109.032002
PermalinkURL http://arxiv.org/abs/2207.07476v3
researchmap用URL http://arxiv.org/pdf/2207.07476v3