Status of B to D(*) &amp;tau; &amp;nu; decays in two-Higgs-doublet models

Celis, Alejandro

doi:10.22323/1.180.0334

Cited by 6 publications

(7 citation statements)

References 15 publications

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“…For the best fit value g S = −0.37 the branching ratio is suppressed by the factor r 2 0.36 with respect to SM, while also large enhancement (r 2 84) is allowed for g S 1.8 ± 0.4 i. The possible large enhancement by the same operator, in the context of Two Higgs Doublet models was also recently reported in [70]. One should note that the production rate of the B c meson at high energy colliders is several orders of magnitude smaller than for other B mesons [71], and the observation prospects for B c leptonic channels are not very promising.…”

Section: Predictionssupporting

confidence: 71%

Minimally flavored colored scalar in $ \overline{B}\to {D^{{\left( * \right)}}}\tau \overline{\nu} $ and the mass matrices constraints

Doršner

Fajfer

Košnik

et al. 2013

J. High Energ. Phys.

148

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The presence of a colored scalar that is a weak doublet with fractional electric charges of |Q| = 2/3 and |Q| = 5/3 with mass below 1 TeV can provide an explanation of the observed branching ratios in B → D ( * ) τν decays. The required combination of scalar and tensor operators in the effective Hamiltonian for b → cτν is generated through the t-channel exchange. We focus on a scenario with a minimal set of Yukawa couplings that can address a semitauonic puzzle and show that its resolution puts a nontrivial bound on the product of the scalar couplings toτ b andcν. We also derive additional constraints posed by Z → bb, muon magnetic moment, lepton flavor violating decays µ → eγ, τ → µγ, τ → eγ, and τ electric dipole moment. The minimal set of Yukawa couplings is not only compatible with the mass generation in an SU (5) unification framework, a natural environment for colored scalars, but specifies all matter mixing parameters except for one angle in the up-type quark sector. We accordingly spell out predictions for the proton decay signatures through gauge boson exchange and show that p → π 0 e + is suppressed with respect to p → K +ν and even p → K 0 e + in some parts of available parameter space. Impact of the colored scalar embedding in 45-dimensional representation of SU (5) on lowenergy phenomenology is also presented. Finally, we make predictions for rare top and charm decays where presence of this scalar can be tested independently.ArXiv ePrint: 1306.6493( 1.2) Both results are consistent with previous measurements performed by Belle [2] but are larger than the SM values of R * ,SM τ / = 0.252(3) and R SM τ / = 0.296(16) with 3.4 σ significance when the two observables are combined (see Ref. [3]). If confirmed these results might point to NP in (semi)tauonic b → c transitions. We accordingly consider a plausible scenario where the presence of one light color triplet, weak doublet, scalar leptoquark (LQ) state addresses the aforementioned discrepancy through a minimal set of couplings to matter. The minimality is motivated by the fact that the presence of this state was shown to be too severely constrained by rare decays of charm and strange mesons and of tau lepton to be able to affect c → s + ν significantly [4,5]. It also renders our analysis more manageable.The colored scalar we consider appears in various studies of possible extensions of the SM [5-10]. In particular, it can be embedded in 45-dimensional scalar representation of SU (5) [11][12][13][14][15] to help provide viable unification of the SM interactions. Inclusion of additional scalar representations can result in two important improvements over the original SU (5) setup [16]. Namely, the mass relations between down-type quarks and charged leptons can be corrected [11] and strong, weak and electromagnetic interactions can unify [12][13][14][15]. We thus investigate whether the minimal set of Yukawa couplings we posit can be made compatible with the mass generation mechanism within a simple SU (5) setup that relies on the use of 45-dimensional...

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Section: Predictionssupporting

confidence: 71%

Minimally flavored colored scalar in $ \overline{B}\to {D^{{\left( * \right)}}}\tau \overline{\nu} $ and the mass matrices constraints

Doršner

Fajfer

Košnik

et al. 2013

J. High Energ. Phys.

148

View full text Add to dashboard Cite

show abstract

“…Those theoretical values are consistent with other predictions calculated using various approaches, such as the heavy quark effective theory (HQET) [14,15], the lattice QCD (LQCD) [16][17][18], the light-cone sum rules (LCSR) [19,20]. Since the theoret-ical predictions are generally smaller than the measured ones, this difference may indicate new physics beyond the SM [21][22][23][24].…”

Section: Introductionsupporting

confidence: 82%

The ratio $\mathcal{R}(D_s)$ for $B_s \to D_s \ellν_\ell$ by using the QCD light-cone sum rules within the framework of heavy quark effective field theory

Zhang,

Zhong,

et al. 2022

Preprint

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“…Experimentally, the BABAR Collaboration measured the semi-leptonic decays B → D ( * ) lν l in 2012 [1][2][3], and these decays were also measured by the Belle [4][5][6] and LHCb Collaborations [7] in 2015. Theoretically, the semi-leptonic decays B → D ( * ) lν l are studied by the heavy quark effective theory (HQET) [8], perturbative QCD (pQCD) factorization approach [9,10], light-cone sum rules (LCSR) [11][12][13][14], and the lattice QCD theory [15,16] within the framework of Standard Model (SM) and the new physics model [17][18][19].…”

Section: Introductionmentioning

confidence: 99%

“…The diagrams whose contributions vanish in the sum rules are not shown.FIG. 2:Feynman diagrams for the second term of Eq (18)…”

mentioning

confidence: 99%

Uncertainties of the $$B\rightarrow D$$ B → D transition form factor from the D-meson leading-twist distribution amplitude

Zhang

Zhong

et al. 2018

Eur. Phys. J. C

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Status of B to D(*) τ ν decays in two-Higgs-doublet models

Cited by 6 publications

References 15 publications

Minimally flavored colored scalar in $ \overline{B}\to {D^{{\left( * \right)}}}\tau \overline{\nu} $ and the mass matrices constraints

Minimally flavored colored scalar in $ \overline{B}\to {D^{{\left( * \right)}}}\tau \overline{\nu} $ and the mass matrices constraints

The ratio $\mathcal{R}(D_s)$ for $B_s \to D_s \ellν_\ell$ by using the QCD light-cone sum rules within the framework of heavy quark effective field theory

Uncertainties of the $$B\rightarrow D$$ B → D transition form factor from the D-meson leading-twist distribution amplitude

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