Probing sterile neutrinos in B (D) meson decays at Belle II (BESIII)

C. S. Kim; Youngjoon Kwon; Donghun Lee; Sechul Oh; Dibyakrupa Sahoo

doi:10.1140/epjc/s10052-020-8310-2

EPJ

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2023 Impact factor 4.2

Particles and Fields

Open Access

Eur. Phys. J. C (2020) 80: 730
https://doi.org/10.1140/epjc/s10052-020-8310-2

Regular Article - Theoretical Physics

Probing sterile neutrinos in B (D) meson decays at Belle II (BESIII)

C. S. Kim¹^,2, Youngjoon Kwon¹, Donghun Lee¹, Sechul Oh³ and Dibyakrupa Sahoo¹^*

¹ Department of Physics and IPAP, Yonsei University, Seoul, 03722, South Korea
² Institute of High Energy Physics, Dongshin University, Naju, 58245, South Korea
³ University College, Yonsei University, Incheon, 21983, South Korea

^* e-mail: sahoodibya@yonsei.ac.kr

Received: 24 May 2020
Accepted: 30 July 2020
Published online: 12 August 2020

Abstract

We present, how a systematic study of $B \rightarrow D\ell N$ ( $D \rightarrow K \ell N$ ) decays with $\ell =\mu ,\tau$ , at Belle II (BESIII) can provide unambiguous signature of a heavy neutrino N and/or constrain its mixing with active neutrinos $\nu _\ell$ , which is parameterized by $| U_{\ell N} |^2$ . Our constraint on $\vert U_{\mu N} \vert ^2$ that can be achieved from the full Belle II data is comparable with what can be obtained from the much larger data set of the upgraded LHCb. Additionally, our method offers better constraint on $\vert U_{\mu N} \vert ^2$ for mass of sterile neutrino $$m_N < 2$$ GeV. We can also probe the Dirac and Majorana nature of N by observing the sequential decay of N, including suppression from observation of a displaced vertex as well as helicity flip, for Majorana N.