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Sakaki, Yasuhito; Watanabe, Ryoutaro; Tanaka, Minoru; Tayduganov, A.

doi:10.1103/physrevd.88.094012

Cited by 345 publications

(439 citation statements)

References 34 publications

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“…Measurement of these modes have been reported by the BaBaR [20] and Belle [18,19] collaborations and an average of the experimental results gives [46]:…”

Section: Rare Exclusive B → Sνν Decaysmentioning

confidence: 99%

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Lepton universality violation with lepton flavor conservation in B-meson decays

Alonso

Grinstein

Camalich

2015

J. High Energ. Phys.

369

388

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Anomalies in semileptonic B-meson decays present interesting patterns that might be revealing the shape of the new physics to come. Under the assumption that neutrino and charged lepton mass terms are the only sources of flavor violation and given the hierarchy between the two, we find that charged lepton universality violation without charged lepton flavor violation naturally arises. This can account for a deficit of B + → K + µµ over B + → K + ee decays with new physics coupled predominantly to muons and a new physics scale of a few TeV. A generic prediction of this scenario is a large enhacement of tauonic B decay rates that, in particular, could accommodate an excess in B → D ( * ) τ ν. For the most part, the study is carried out in an effective field theory framework with an underlying SU(2) L × U(1) Y symmetry that emphasizes the model-independent correlations between low-and high-energy observables. As an example, a connection between B-decays and top physics is pointed out. To complement the discussion, all possible (spin 0 and 1) leptoquark models are matched to the low-energy field theory so that the effective analysis can be used to survey these candidates for new physics.

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“…Measurement of these modes have been reported by the BaBaR [20] and Belle [18,19] collaborations and an average of the experimental results gives [46]:…”

Section: Rare Exclusive B → Sνν Decaysmentioning

confidence: 99%

“…The leptoquark particles that couple to SM fermions via operators of dimension d ≤ 4 are either spin-0 or spin-1 bosons and they can be sorted out in terms of their quantum numbers (see [43][44][45][46] and the appendix for details). There is a total of 5 scalars and 5 vector bosons as shown in tables 1 and 2.…”

Section: A Leptoquark Modelmentioning

confidence: 99%

Lepton universality violation with lepton flavor conservation in B-meson decays

Alonso

Grinstein

Camalich

2015

J. High Energ. Phys.

369

388

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“…W gauge bosons [11,14,53,54] 3. Leptoquarks [9,10,12,13,15,16,19,20,42,[55][56][57][58][59][60] Models with charged Higgses lead to (too) large effects in the total B c lifetime [61] and, depending on the coupling structure, can also be disfavored by the q 2 distribution [62][63][64]. Interestingly, if the couplings of the charged Higgs are chosen in such a way that they are compatible with the measured q 2 distribution, these models are ruled out by direct searches [65].…”

Section: Jhep09(2017)040mentioning

confidence: 99%

Simultaneous explanation of R(D (∗)) and b→sμ + μ −: the last scalar leptoquarks standing

Crivellin

Müller

Ota

2017

J. High Energ. Phys.

314

254

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Over the past years, experiments accumulated intriguing hints for new physics (NP) in flavor observables, namely in the anomalous magnetic moment of the muon (a µ ), in R(D ( * ) ) = Br(B → D ( * ) τ ν)/Br(B → D ( * ) ν) and in b → sµ + µ − transitions, which are all at the 3 − 4 σ level. In this article we point out that one can explain the R(D ( * ) ) anomaly using two scalar leptoquarks (LQs) with the same mass and coupling to fermions related via a discrete symmetry: an SU(2) L singlet and an SU(2) L triplet, both with hypercharge Y = −2/3. In this way, potentially dangerous contributions to b → sνν are avoided and non-CKM suppressed effects in R(D ( * ) ) can be generated. This allows for smaller overall couplings to fermions weakening the direct LHC bounds. In our model, R(D ( * ) ) is directly correlated to b → sτ + τ − transitions where an enhancement by orders of magnitude compared to the standard model (SM) is predicted, such that these decay modes are in the reach of LHCb and BELLE II. Furthermore, one can also naturally explain the b → sµ + µ − anomalies (including R(K)) by a C 9 = −C 10 like contribution without spoiling µ − e universality in charged current decays. In this case sizable effects in b → sτ µ transitions are predicted which are again well within the experimental reach. One can even address the longstanding anomaly in a µ , generating a sizable decay rate for τ → µγ. However, we find that out of the three anomalies R(D ( * ) ), b → sµ + µ − and a µ only two (but any two) can be explained simultaneously. We point out that a very similar phenomenology can be achieved using a vector leptoquark SU(2) L singlet with hypercharge 2/3. In this case, no tuning between couplings is necessary, but the model is non-renormalizable.

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“…Scenarios of this type could explain the R D ( * ) anomalies with NP at a scale of Λ ∼ 1 TeV, as discussed in refs. [11,19,20,22,[24][25][26][27].…”

Section: Phenomenologymentioning

confidence: 99%

“…The discrepancy between experiment and the SM is at the level of 4σ, and it can be explained with new physics (NP) [11,[15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33]. These analyses of the data are most fruitful when casted model-independently in an effective field theoretical framework.…”

Section: Introductionmentioning

confidence: 99%

New physics in the kinematic distributions of B¯→D(*)τ−(→

2016

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We investigate the experimentally-accessible kinematic distributions of theB → D ( * ) τ − (→ −ν ντ )ντ decays. Specifically, we study the decay rates as functions of the B → D ( * ) transferred squared momentum, the energy of the final charged lepton and the angle of its 3-momentum with respect to the 3-momentum of the recoiling D ( * ) . The angular distribution allows to introduce new observables, like a forward-backward asymmetry, which are complementary to the total rates. We present analytic formulas for the observable 3-fold 5-body differential decay rates, study the predictions in the Standard Model and investigate the effects in different new-physics scenarios that we characterize using an effective field theory framework.

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Testing leptoquark models inB¯→D(*)τν¯

Cited by 345 publications

References 34 publications

Lepton universality violation with lepton flavor conservation in B-meson decays

Lepton universality violation with lepton flavor conservation in B-meson decays

Simultaneous explanation of R(D (∗)) and b→sμ + μ −: the last scalar leptoquarks standing

New physics in the kinematic distributions of B¯→D(*)τ−(→

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