Favoured $B_c$ Decay modes to search for a Majorana neutrino

Abstract

Recently, the LHCb collaboration reported the observation of the decay mode $B_c^{-}\to {\overline{B}}_s^0{\pi }^{-}$ with the largest exclusive branching fraction amongst the known decay modes of all the $B$ mesons. Here we propose a search for a few lepton-number violating decay modes of $B_c$ which can only be induced by Majorana neutrinos. Distinguishing between Dirac and Majorana nature of neutrinos is an outstanding problem and hence, all possible searches for Majorana neutrinos need to be carried out. Since the lepton number violating modes are expected to be rare, when using meson decay modes for these searches one expects CKM favoured modes to be the preferred ones; $B_c\to B_s$ is one such transition. With a resonance enhancement of the Majorana neutrino mediating the $B_c^{-}\to {\overline{B}}_s^0{\ell }_1-{\ell }_2^{-}{\pi }^{+}$ modes one can hope to observe these rare modes, or, even their non-observation can be used to obtain constraints on the mixing angles of the heavy Majorana singlet with the light flavour neutrinos from upper limits of the branching fractions which are tighter or compatible with results from earlier studies. Also, we find that the relatively suppressed mode $B_c^{-}\to J/\psi {\ell }_1^{-}{\ell }_2^{-}{\pi }^{+}$ can provide even tighter constraints on $\mid V_{eN}{\mid }^2$, $\mid V_{\mu N}{\mid }^2$, $\mid V_{eN}{V}_{\mu N}\mid$, and in a larger range of the heavy neutrino mass. Further, exclusion regions for $\mid V_{eN}{V}_{\tau N}\mid$, $\mid V_{\mu N}{V}_{\tau N}\mid$ can also be obtained for masses larger than those accessible in tau decays. Upper limits on $\mathcal{B}\left(B_c^{-}\to {\pi }^{+}{\ell }_1^{-}{\ell }_2^{-}\right)$ can also result in stringent exclusion curves for all the mixing elements, including that for $\mid V_{\tau N}{\mid }^2$ in a mass range where it is unconstrained thus far.

29 pages, 12 figures; Plots for Bc->Bsllpi mode redone to account for Bs reconstruction, more sections added to include additional Bc decay modes which provide tighter exclusion curves for the mixing angles. References and acknowledgements added. Text modified to widen scope of the paper

References in corpus (17)

• Observation of electron-antineutrino disappearance at Daya Bay
• Effects of new leptons in Electroweak Precision Data
• Signatures for Majorana neutrinos at hadron colliders
• Opening a new window for warm dark matter
• Relic keV sterile neutrinos and reionization
• The Poker Face of the Majoron Dark Matter Model: LUX to keV Line
• Direct Bounds on Electroweak Scale Pseudo-Dirac Neutrinos from $\sqrt{s}=8$ TeV LHC Data
• Probing seesaw at LHC
• Upper Bound on the Mass of the Type III Seesaw Triplet in an SU(5) Model
• Measurement of $B_c^{+}$ production in proton-proton collisions at $\sqrt{s}=8$ TeV
• Neutrino physics at large colliders
• Heavy Neutrinos and the Kinematics of Tau Decays
• Lepton number violating four-body tau lepton decays
• Majorana neutrinos and lepton-number-violating signals in top-quark and W-boson rare decays
• Measurement of the ratio of the production cross sections times branching fractions of Bc+/- to J/psi pi+/- and B+/- to J/psi K+/- and B(Bc+/- to J/psi pi+/- pi+/- pi-/+)/B(Bc+/- to J/psi pi+/-) in pp collisions at sqrt(s) = 7 TeV
• Search for rare and forbidden decays of charm and charmed-strange mesons to final states h^+- e^-+ e^+
• Detecting sterile dark matter in space

Cited by in corpus (26)

• Probing right handed neutrinos at the LHeC and lepton colliders using fat jet signatures
• Effective Majorana mass matrix from tau and pseudoscalar meson lepton number violating decays
• Sensitivity of Lepton Number Violating Meson Decays in Different Experiments
• Rare decays of B mesons via on-shell sterile neutrinos
• Fat Jet Signature of a Heavy Neutrino at Lepton Collider
• Sensitivity limits on heavy-light mixing $|U_{\mu N}{|}^2$ from lepton number violating $B$ meson decays
• Sensitivity bounds on heavy neutrino mixing $|U_{\mu N}{|}^2$ and $|U_{\tau N}{|}^2$ from LHCb upgrade
• Constraining Right Handed Gauge Boson Mass from Lepton Number Violating Meson Decays in a Low Scale Left Right Model
• Lepton Number Violation: Seesaw Models and Their Collider Tests
• Search for lepton-number-violating signals in the charm sector
• Lepton number violation in $B_s$ meson decays induced by an on-shell Majorana neutrino
• Discovering intermediate mass sterile neutrinos through ${\tau }^{-}\to {\pi }^{-}{\mu }^{-}{e}^{+}\nu$ (or $\bar{\nu }$) decay
• Exploring CP-violation, via heavy neutrino oscillations, in rare B meson decays at Belle II
• Exploring GeV-scale Majorana neutrinos in lepton-number-violating ${\Lambda }_b^0$ baryon decays
• Testing electroweak scale seesaw models at $e^{-}\gamma$ and $\gamma \gamma$ colliders
• Constraints on lepton number violating short-range interactions from $|\Delta L|=2$ processes
• Probing sterile neutrino in $B$ ($D$) meson decays at Belle II (BESIII)
• Four-body decays of $B$ meson with lepton number violation
• Interference effect in lepton number violating and conserving meson decays for a left-right symmetric model
• Study Standard Model and Majorana Neutrino Contributions to $B^{+}\to K^{(\ast )\pm }{\mu }^{+}{\mu }^{\mp }$
• CP violation with GeV-scale Majorana neutrino in ${\Lambda }_b\to ({\Lambda }_c^{+},p^{+}){\pi }^{+}{\mu }^{-}{\mu }^{-}$ decays
• $\Delta$L=2 hyperon decays induced by Majorana neutrinos and doubly-charged scalars
• Doubly-charged scalar in rare decays of $B_c$ meson
• Sterile neutrinos in ${\Lambda }_b^0\to ({\Lambda }_c^{+},p^{+}){\ell }_1^{-}{\ell }_2^{-}{\ell }_3^{+}\nu$ decays
• Large $\nu$-$\bar{\nu }$ Oscillations from High-Dimensional Lepton Number Violating Operator
• Dirac-Majorana neutrinos distinction in four-body decays