D* polarization as a probe to discriminate new physics in B --> D* tau nubar

Abstract

The confirmation of excess in $R_{D^{\ast }}$ at the LHCb is an indication of lepton flavor non-universality. Various different new physics operators and their coupling strengths, which provide a good fit to $R_D$, $R_{D^{\ast }}$ and $q^2$ spectra, were identfied previously. In this work, we try to find angular observables in $\bar{B}\to D^{\ast }\tau \bar{\nu }$ which enable us to distinguish between these new physics operators. We find that the $D^{\ast }$ polarization fraction $f_L(q^2)$ is a good discriminant of scalar and tensor new physics operators. The change in $⟨f_L(q^2)⟩$, induced by scalar and tensor operators, is about three times larger than the expected uncertainty in the upcoming Belle measurement.

8 pages, 2 figures; published in Physical Review D

References in corpus (21)

• Test of lepton universality using $B^{+}\to K^{+}{\ell }^{+}{\ell }^{-}$ decays
• Physics of leptoquarks in precision experiments and at particle colliders
• On the B to D* tau nu Sensitivity to New Physics
• Anomalies in $B$-decays and $U(2)$ flavour symmetry
• Implications of lepton flavor universality violations in B decays
• Simultaneous Explanation of the $R_K$ and $R(D^{(\ast )})$ Puzzles
• The lifetime of the $B_c^{-}$ meson and the anomalies in $B\to D^{(\ast )}\tau \nu$
• New physics in the weak interaction of $\bar{B}\to D^{(\ast )}\tau \bar{\nu }$
• Non-abelian gauge extensions for B-decay anomalies
• Revisiting the one leptoquark solution to the $R(D^{(\ast )})$ anomalies and its phenomenological implications
• Explaining the $R_K$ and $R_{D^{(\ast )}}$ anomalies with vector leptoquarks
• Analyzing new physics in the decays ${\bar{B}}^0\to D^{(\ast )}{\tau }^{-}{\bar{\nu }}_{\tau }$ with form factors obtained from the covariant quark model
• A closer look at the $R_D$ and $R_{D^{\ast }}$ anomalies
• New Physics in the Visible Final States of $B\to D^{(\ast )}\tau \nu$
• The Azimuthal $B\to D^{\ast }{\tau }^{-}\overline{{\nu }_{\tau }}$ Angular Distribution with Tensor Operators
• Probing New Physics with $q^2$ distributions in $\bar{B}\to D^{(\ast )}\tau \bar{\nu }$
• Tau properties in $B\to D\tau \nu$ from visible final-state kinematics
• Consequences of R-Parity violating interactions for anomalies in $\bar{B}\to D^{(\ast )}\tau \bar{\nu }$ and $b\to s{\mu }^{+}{\mu }^{-}$
• Looking for possible new physics in $B\to D^{(\ast )}\tau {\nu }_{\tau }$ in light of recent data
• New physics in the kinematic distributions of $\bar{B}\to D^{(\ast )}{\tau }^{-}(\to {\ell }^{-}{\bar{\nu }}_{\ell }{\nu }_{\tau }){\bar{\nu }}_{\tau }$
• Remarks on the Standard Model predictions for $R(D)$ and $R(D^{\ast })$

Cited by in corpus (56)

• Review of Lepton Universality tests in B decays
• Scalar contributions to $b\to c(u)\tau \nu$ transitions
• New Physics effect on $B_c\to J/\psi \tau \bar{\nu }$ in relation to the $R_{D^{(\ast )}}$ anomaly
• Impact of polarization observables and $B_c\to \tau \nu$ on new physics explanations of the $b\to c\tau \nu$ anomaly
• Addendum to "Impact of polarization observables and $B_c\to \tau \nu$ on new physics explanations of the $b\to c\tau \nu$ anomaly"
• New physics solutions for $R_D$ and $R_{D^{\ast }}$
• $B$ Flavour Anomalies: 2021 Theoretical Status Report
• LHCb anomaly and $B$ physics in flavored Z${}^{\prime }$ models with flavored Higgs doublets
• Addressing $R_{D^{(\ast )}}$, $R_{K^{(\ast )}}$, muon $g-2$ and ANITA anomalies in a minimal $R$-parity violating supersymmetric framework
• $R(D^{(\ast )})$ from $W^{\prime }$ and right-handed neutrinos
• Semitauonic $b$-hadron decays: A lepton flavor universality laboratory
• \large\bf $B_c\to (J/\Psi ,{\eta }_c)\tau \nu$ semileptonic decays within Standard model and beyond
• Right-handed Neutrinos and $R(D^{(\ast )})$
• Asymmetry Observables and the Origin of $R_{D^{(\ast )}}$ Anomalies
• Charged current $b\to c\tau {\bar{\nu }}_{\tau }$ anomalies in a general $W^{\prime }$ boson scenario
• Solutions to $R_D$-$R_{D^{\ast }}$ in light of Belle 2019 data
• Inclusive semileptonic ${\Lambda }_b$ decays in the Standard Model and beyond
• Global fit to $b\to c\tau \nu$ anomalies as of Spring 2024
• Phenomenology of $b\to c\tau \bar{\nu }$ decays in a scalar leptoquark model
• Probing New Physics with $\bar{B}\to \rho (770){\ell }^{-}{\bar{\nu }}_{\ell }$ and $\bar{B}\to a_1(1260){\ell }^{-}{\bar{\nu }}_{\ell }$
• Constraining flavour patterns of scalar leptoquarks in the effective field theory
• Model independent analysis of $b\to (c,u)\tau \nu$ leptonic and semileptonic decays
• R-parity violating solutions to the $R_{D^{(\ast )}}$ anomaly and their GUT-scale unifications
• Resolution of $R_D$/$R_{D^{\ast }}$ puzzle
• Maximizing the Impact of New Physics in $b\to c\tau \nu$ Anomalies
• A comprehensive study on the semileptonic decay of heavy flavor mesons
• CP Violation in ${\bar{B}}^0\to D^{\ast +}{\mu }^{-}{\bar{\nu }}_{\mu }$
• Signature of Lepton flavor universality violation in $B_s\to D_s\tau \nu$ semileptonic decays
• A Measurable Angular Distribution for $\bar{B}\to D^{\ast }{\tau }^{-}{\bar{\nu }}_{\tau }$ Decays
• A Complete Framework for Tau Polarimetry in $B\to D^{(\ast )}\tau \nu$ Decays
• Analysing the charged scalar boson contribution to the charged-current $B$ meson anomalies
• Remarks on the Standard Model predictions for $R(D)$ and $R(D^{\ast })$
• Implication of $R_{D^{(\ast )}}$ anomalies on semileptonic decays of ${\Sigma }_b$ and ${\Omega }_b$ baryons
• ${\tau }^{-}\to {\nu }_{\tau }{M}_1{M}_2$, with $M_1,M_2$ pseudoscalar or vector mesons
• Impact of vector new physics couplings on $B_s\to (K,K^{\ast })\tau \nu$ and $B\to \pi \tau \nu$ decays
• Signatures of complex new physics in $b\to c\tau \bar{\nu }$ transitions
• Implication of $b\to c\tau \nu$ flavor anomalies on $B_s\to D_s^{\ast }\tau \nu$ decay observables
• New physics footprints in the angular distribution of $B_s\to D_s^{\ast }(\to D_s\gamma ,D_s\pi )\tau \nu$ decays
• $D^{\ast }$ Polarization as an Additional Constraint on New Physics in the $b\to c\tau {\bar{\nu }}_{\tau }$ Transition
• Measurement of the $D^{\ast }$ longitudinal polarization in $B^0\to D^{\ast -}{\tau }^{+}{\nu }_{\tau }$ decays
• Detailed Study of the Decay Lambda_b --> Lambda_c tau {\bar ν}_τ
• $b\to c\tau \bar{\nu }$ decays in supersymmetry with $R$-parity violation
• Predictions of $B_c\to (D,D^{\ast })l\nu$ decay observables in the standard model
• Probing New Physics in light of recent developments in $b\to c\ell \nu$ transitions
• Extra gauge bosons and lepton flavor universality violation in ${\rm Y}$ and $B$ meson decays
• A unique discrimination between new physics scenarios in $b\to s{\mu }^{+}{\mu }^{-}$ anomalies
• Investigating the effect of $U_1$ vector leptoquark on $b\to u\tau \bar{\nu }$ mediated $B$ decays
• Analysis of $b\to c\tau {\bar{\nu }}_{\tau }$ anomalies using weak effective Hamiltonian with complex couplings
• Impact of $b\to c$ measurements on ${\Lambda }_b\to p\tau \bar{\nu }$ decay in $U_1$ leptoquark model
• Helicity amplitudes in $B\to D^{\ast }\bar{\nu }l$ decay
• $B$ anomalies in the nonminimal universal extra dimension model
• Resolving $R_D$ and $R_{D^{\ast }}$ anomalies
• New Physics solutions for $b\to c\tau \bar{\nu }$ anomalies after Moriond 2019
• Addressing the $R_{\tau /\mu ,e}\left(D^{(\ast )}\right)$ puzzle through New Physics four-fermion operators and their impact on ${\Lambda }_b\to {\Lambda }_c\tau {\bar{\nu }}_{\tau }$ decay
• The Angular Observables of ${\Lambda }_b\to {\Lambda }_c(\to {\Lambda }^0{\pi }^{+}){\tau }^{-}(\to {\pi }^{-}{\nu }_{\tau }){\bar{\nu }}_{\tau }$ within the Paradigm of FCCC Anomalies
• Helicity amplitudes in the $\bar{B}\to D^{\ast }{\bar{\nu }}_{\tau }\tau$ decay with $V-A$ breaking in the quark sector