Decay of ${B}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}{\ensuremath{\tau}}^{\ifmmode\pm\else\textpm\fi{}}+$ missing momentum and direct measurement of the mixing parameter ${U}_{\ensuremath{\tau}N}$

Decay of $B^{\pm} \to τ^{\pm} +$ missing momentum and direct measurement of the mixing parameter $U_{τ N}$

G. Cvetič, C. S. Kim, Y.-J. Kwon, and Y. Yook

Phys. Rev. D 93, 013003 – Published 6 January 2016

Abstract

We derive the decay widths for the leptonic decays of heavy charged pseudoscalars to massive sterile neutrinos, $M^{\pm} \to ℓ^{\pm} + N$ , within the frameworks involving the Standard Model and two-Higgs doublets (type II). We then apply the result to $B^{\pm} \to τ^{\pm} + “ missing momentum ”$ of the Belle/BABAR experimental results, in order to measure directly the relevant parameter space, including the mixing parameter $U_{τ N}$ .

Received 7 October 2015

DOI:https://doi.org/10.1103/PhysRevD.93.013003

Physics Subject Headings (PhySH)

Extensions of Higgs sector Leptonic, semileptonic & radiative decays

Sterile neutrinos

Particles & Fields

Authors & Affiliations

G. Cvetič^*

Department of Physics, Universidad Técnica Federico Santa María, Valparaíso, Chile

C. S. Kim^†, Y.-J. Kwon^‡, and Y. Yook^§

Department of Physics and IPAP, Yonsei University, Seoul 120-749, Korea

^*[email protected]
^†Corresponding author. [email protected]
^‡[email protected]
^§[email protected]

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand

Issue

Vol. 93, Iss. 1 — 1 January 2016

Reuse & Permissions

Access Options

Author publication services for translation and copyediting assistance advertisement

Images

Figure 1
The allowed regions determined from the measurement of $B^{\pm} \to τ^{\pm} ν$ in two cases: (left) the allowed regions in the parameter space of $M_{H^{+}}$ vs $\tan β$ in 2HDM(II) assuming that the missing momenta are only from $ν_{τ}$ of the SM; (right) the allowed regions in the parameter space of $M_{N}$ vs $| U_{τ N} |$ assuming no contributions from charged Higgs but allowing the possible contributions from heavy neutrino $N$ . The dark- and pale-shaded areas (red online) correspond to $\pm 1 σ$ and $\pm 2 σ$ allowed regions, respectively.
Reuse & Permissions
Figure 2
The allowed regions in the parameter space of $M_{N}$ and $| U_{τ N} |$ assuming no contributions from the charged Higgs, where the $\pm 1 σ$ and $\pm 2 σ$ allowed regions are displayed by dark and pale shades (red online), respectively: (left) the central value of $B (B^{\pm} \to τ^{\pm} ν)$ is taken as the current world average Eq. (1), while tenfold reduction of uncertainty is assumed; (right) the central value is taken to be the value predicted by the CKM unitarity constraint, also assuming tenfold reduction of experimental uncertainty. In all cases, the comparison is made to the value determined from the CKM unitarity fitting Eq. (2).
Reuse & Permissions
Figure 3
The allowed regions in the parameter space of $M_{H^{+}}$ vs $\tan β$ in 2HDM (type II), assuming no contributions from heavy neutral particle $N$ , where the $\pm 1 σ$ and $\pm 2 σ$ allowed regions are displayed by dark and pale shades (red online), respectively: (left) the central value of $B (B^{\pm} \to τ^{\pm} ν)$ is taken from the current world average, while tenfold reduction of uncertainty is assumed; (right) the central value is taken to be the value predicted by the CKM unitarity constraint, also assuming tenfold reduction of experimental uncertainty. In both cases, the comparison is made to the value determined from the CKM unitarity constraints Eq. (2).
Reuse & Permissions
Figure 4
The allowed regions under the assumption that both $H^{+}$ and $N$ contribute to the measured value of $B^{\pm} \to τ^{\pm} ν$ , based on the decay rates of Eqs. (5) and (8b). (a) The allowed region in the parameter space of $M_{H^{+}}$ and $\tan β$ when $M_{N} = 1.0 GeV / c^{2}$ and $| U_{τ N} | = 0.6$ . (b) The allowed region when $M_{N} = 1.0 GeV / c^{2}$ and $| U_{τ N} | = 0.5$ . (c) The allowed region in the parameter space of $| U_{τ N} |$ and $M_{N}$ when $M_{H^{+}} = 200 GeV / c^{2}$ and $\tan β = 56.5$ . (d) The allowed region when $M_{H^{+}} = 200 GeV / c^{2}$ and $\tan β = 55$ .
Reuse & Permissions
Figure 5
The decay $M^{+} \to N ℓ^{+}$ via the exchange of (a) $W^{+}$ and (b) $H^{+}$ .
Reuse & Permissions
Figure 6
The inverse canonical decay length ${\bar{L}}_{N}^{- 1} \equiv \bar{Γ} (M_{N}) / γ_{N}$ , in units of $m^{- 1}$ , as a function of the neutrino mass $M_{N}$ , for the choice $γ_{N} [\equiv (1 - β_{N}^{2})^{- 1 / 2}] = 2$ .
Reuse & Permissions

Physical Review D

covering particles, fields, gravitation, and cosmology

Decay of $B^{\pm} \to τ^{\pm} +$ missing momentum and direct measurement of the mixing parameter $U_{τ N}$

G. Cvetič, C. S. Kim, Y.-J. Kwon, and Y. Yook

Phys. Rev. D 93, 013003 – Published 6 January 2016

Abstract

Physics Subject Headings (PhySH)

Authors & Affiliations

Article Text (Subscription Required)

References (Subscription Required)

Issue

Access Options

Physical Review D

covering particles, fields, gravitation, and cosmology

Decay of B±→τ±+ missing momentum and direct measurement of the mixing parameter UτN

G. Cvetič, C. S. Kim, Y.-J. Kwon, and Y. Yook

Phys. Rev. D 93, 013003 – Published 6 January 2016

Abstract

Physics Subject Headings (PhySH)

Authors & Affiliations

Article Text (Subscription Required)

References (Subscription Required)

Issue

Access Options

Authorization Required

Other Options

Download & Share

Images

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Log In

Search

Article Lookup

Paste a citation or DOI

Enter a citation

Decay of $B^{\pm} \to τ^{\pm} +$ missing momentum and direct measurement of the mixing parameter $U_{τ N}$