Searching for New Physics in Rare $B\to \tau$ Decays

Abstract

The rare decays {$B^{-}\to \tau \bar{\nu }$}, \mbox{$B\to {\tau }^{+}{\tau }^{-}$}, {$b\to X\nu \bar{\nu }$} and \mbox{$b\to X{\tau }^{+}{\tau }^{-}$} all contain third generation leptons in the final state, and hence are sensitive to new physics that couples more strongly to the third family. We present model independent expressions for these decays that can be useful to study several types of new physics effects. We concentrate on supersymmetric models without R-parity and without lepton number. We also assume a horizontal U(1) symmetry with fermion horizontal charges chosen to explain the magnitude of fermion masses and quark mixing angles. This allows us to estimate the order of magnitude of the new effects, and to derive numerical predictions for the various decay rates and for the forward-backward asymmetry and the $\tau$ polarization components measurable in \mbox{$b\to X{\tau }^{+}{\tau }^{-}$}. In some cases the branching ratios are enhanced by more than one order of magnitude, rendering foreseeable their detection at upcoming B-factories. We also discuss how a measurement of asymmetries in \mbox{$b\to X{\tau }^{+}{\tau }^{-}$} can be crucial in distinguishing between different sources of new physics.

30 pages, LaTeX, 8 ps-figures (uses epsfig.sty) Equations (2.7) (3.10) (3.14) (3.18) (3.19) (3.20) (4.6) corrected, conclusions unmodified. To be published on Phys. Rev. D

References in corpus (1)

• Re-examination of long distance effects in $b\to s{l}^{+}{l}^{-}$

Cited by in corpus (44)

• More Model-Independent Analysis of b->s Processes
• Analysis of Neutral Higgs-Boson Contributions to the Decays B_s -> l^+l^- and B -> K l^+l^-
• Comprehensive Bayesian Analysis of Rare (Semi)leptonic and Radiative B Decays
• Phenomenological constraints on broken R parity symmetry in supersymmetry models
• Searching for New Physics with $b\to s{\tau }^{+}{\tau }^{-}$ processes
• QCD Corrections to B -> X_{d,s} nu nubar, B_{d,s} -> l^+l^-, K -> pi nu nubar and K_L -> mu^+ mu^- in the MSSM
• A Systematic Analysis of the Lepton Polarization Asymmetries in the Rare B Decay, B -> X_sτ^+τ^-
• Search for $B^{+}\to K^{+}{\tau }^{+}{\tau }^{-}$ at the BaBar experiment
• On new physics in $\Delta {\Gamma }_d$
• Looking for Novel CP-Violating Effects in B->K^*l^+l^-
• General analysis of lepton polarizations in rare B -> K^* l^+ l^- decay beyond the standard model
• Exclusive B -> K^* l^+ l^- decay with polarized K^* and new physics effects
• Charged-Higgs Collider Signals with or without Flavor
• T violation in ${\Lambda }_b\to \Lambda {\ell }^{+}{\ell }^{-}$ decays with polarized $\Lambda$
• Constraints on New Physics from $K\to \pi \nu \bar{\nu }$
• Lepton polarization correlations in $B\to K^{\ast }{\tau }^{-}{\tau }^{+}$
• Polarized lepton pair forward-backward asymmetries in (B -> K^* l^+ l^-) decay beyond the standard model
• New physics effects in (Lambda_b -> Lambda l^+ l^-) decay with lepton polarizations
• τPolarization asymmetry in $B\to X_s{\tau }^{+}{\tau }^{-}$ in SUSY models with large $tan\beta$
• Effects of R-parity Violating Couplings on CP Asymmetries in Neutral B Decays
• Polarization effects in exclusive semileptonic (Lambda_b -> Lambda l^+ l^-) decay
• Flavour-Conserving CP Phases in Supersymmetry and Implications for Exclusive B Decays
• Constraining R-parity violating couplings from B --> PP decays using QCD improved factorization method
• Constraining new physics with B to K* mu+ mu- in the early LHC era
• $b\to ss\bar{d}$ Decay in Two Higgs Doublet Models
• The exclusive $B->(K,K^{\ast }){\ell }^{+}{\ell }^{-}$ decays in a CP softly broken two Higgs doublet model
• Double-lepton polarization asymmetries in the Exclusive (B -> rho l^+ l^-) decay beyond the Standard Model
• Exclusive (B -> rho l^+ l^-) decay and Polarized lepton pair forward--backward asymmetries
• R Parity violating enhancement of Bu -> l nu and Bc -> l nu
• Probing extended Higgs sector through rare b --> s mu+ mu- transitions
• Rate difference between b $\to$ s mu^+ mu^- and b $\to$ s e^+e^- in SUSY with large tan$\beta$
• Lepton polarization asymmetries for $B\to K^{\ast }{\ell }^{+}{\ell }^{-}$: A Model Independent approach
• Longitudinal polarization asymmetry of leptons in the pure leptonic B decays
• General analysis of CP violation in polarized (b -> d l^+ l^-) decay
• Standard Model CP violation in Polarised b->d l^+ l^-
• B_s --> mu+ mu- decay in the R-parity violating minimal supergravity
• The Forward Backward asymmetries of $B\to X_s{\tau }^{+}{\tau }^{-}$ in the MSSM
• General analysis of the rare Bc->D^*_s l^+ l^- decay beyond the standard model
• $B\to \tau \mu (X)$ decays in SUSY models without R-parity
• The fate of $V_1$ vector leptoquarks: the impact of future flavour data
• Impact of Warped Extra Dimensions on the Dipole Coefficients in $\mathbf{b}\to \mathbf{s\gamma }$ Transitions
• Decay rate and asymmetries of ${\Sigma }^{+}\to p{\mu }^{+}{\mu }^{-}$
• Mixing among the neutral Higgs bosons and rare B decays in the CP violating MSSM
• Search for rare B meson decays at the BaBar experiment