Implication of family non-universal <i>Z′</i> model to rare exclusive $b \to s(l\bar l,\nu\bar\nu)$ transitions

Maji, P.; Nayek, P.; Sahoo, S.

doi:10.1093/ptep/ptz010

Cited by 12 publications

(11 citation statements)

References 119 publications

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“…(5. 19) Comparing to the SM predictions in table 2 we learn that (pseudo-)scalar contributions in b → d transitions can amount to an O(100%) correction. An improved experimental limit of B(B 0 → ν ν) at the level of ∼ 5 • 10 −7 or smaller would suffice to bring the correction to the SM at the percent-level.…”

Section: Jhep12(2021)061mentioning

confidence: 79%

“…(4.9) and (4.10), while limits on κ bqτ τ L from Drell-Yan data from table 3. Using flavio [49], neglecting effects from scalar and tensor operators, and considering two couplings at a time with κ L ∼ 2 C 9 ∼ 2 C 10 and κ R ∼ 2 C 9 ∼ 2 C 10 , 4 we find the following upper limits for b → s τ + τ − transitions [15,22] 7.8 [15,22] 8.4 [15,19] 7.4 [15,19] 8.1 [15, 18.8]…”

Section: Improved Limits On B → Q τ + τ − Decaysmentioning

confidence: 99%

“…, [15,20] LHCb'15 [78] A [4,6], [15,19] LHCb'20 [79] A [3,4], [4,5], [5,6], [19,22] LHCb'14 [80] [3,4], [4,5], [5,6], [19,22] LHCb'14 [80] 15,20] LHCb'18 [81] † Combination of ATLAS, CMS and LHCb results, where we use the given multivariate numerical distribution of the observables, which is implemented in flavio. In this table we only provide the central value for comparison.…”

Section: Jhep12(2021)061mentioning

confidence: 99%

“…Most of the current phenomenological studies for b → q ν ν decays rely on specific extensions of the SM, see for instance refs. [14][15][16][17][18][19][20][21][22][23][24][25][26][27]. A key goal of this work is to exploit the SU(2) L -link between charged dilepton and dineutrino couplings systematically within the standard model effective field theory (SMEFT) framework [7], and to work out how dineutrino branching ratios contribute to deciphering the present flavor anomalies.…”

Section: Jhep12(2021)061 1 Introductionmentioning

confidence: 99%

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Interplay of dineutrino modes with semileptonic rare B-decays

Bause

Gisbert

Golz

et al. 2021

J. High Energ. Phys.

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We present a systematic global analysis of dineutrino modes b → qν$$ \overline{\nu} $$ ν ¯ , q = d, s, and charged dilepton b → qℓ+ℓ− transitions. We derive improved or even entirely new limits on dineutrino branching ratios including decays B0→ (K0, Xs)ν$$ \overline{\nu} $$ ν ¯ , Bs→ ϕν$$ \overline{\nu} $$ ν ¯ and B0→ (π0, ρ0)ν$$ \overline{\nu} $$ ν ¯ from dineutrino modes which presently are best constrained: B+→ (K+, π+, ρ+)ν$$ \overline{\nu} $$ ν ¯ and B0→ K*0ν$$ \overline{\nu} $$ ν ¯ . Using SMEFT we obtain new flavor constraints from the dineutrino modes, which are stronger than the corresponding ones from charged dilepton rare b-decay or Drell-Yan data, for eτ and ττ final states, as well as for μτ ones in b → s processes. The method also allows to put novel constraints on semileptonic four-fermion operators with top quarks. Implications for ditau modes b → sτ+τ− and b → dτ+τ− are worked out. Even stronger constraints are obtained in simplified BSM frameworks such as leptoquarks and Z′-models. Furthermore, the interplay between dineutrinos and charged dileptons allows for concrete, novel tests of lepton universality in rare B-decays. Performing a global fit to b → sμ+μ−, sγ transitions we find that lepton universality predicts the ratio of the B0→ K*0ν$$ \overline{\nu} $$ ν ¯ to B0→ K0ν$$ \overline{\nu} $$ ν ¯ (B+→ K+ν$$ \overline{\nu} $$ ν ¯ ) branching fractions to be within 1.7 to 2.6 (1.6 to 2.4) at 1σ, a region that includes the standard model, and that can be narrowed with improved charged dilepton data. There is sizable room outside this region where universality is broken and that can be probed with the Belle II experiment. Using results of a fit to B0→ μ+μ−, $$ {B}_s^0 $$ B s 0 →$$ \overline{K} $$ K ¯ *0μ+μ− and B+→ π+μ+μ− data we obtain an analogous relation for |∆b| = |∆d| = 1 transitions: if lepton universality holds the ratio of the B0→ ρ0ν$$ \overline{\nu} $$ ν ¯ to B0→ π0ν$$ \overline{\nu} $$ ν ¯ (B+→ π+ν$$ \overline{\nu} $$ ν ¯ ) branching fractions is within 2.5 to 5.7 (1.2 to 2.6) at 1 σ. Putting upper limits on $$ \mathcal{B} $$ B (Bs→ ν$$ \overline{\nu} $$ ν ¯ ) at the level of 10−5 and $$ \mathcal{B} $$ B (B0→ ν$$ \overline{\nu} $$ ν ¯ ) below 10−6 would allow to control backgrounds from (pseudo-)scalar operators such as those induced by light right-handed neutrinos.

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Section: Jhep12(2021)061mentioning

confidence: 79%

Section: Improved Limits On B → Q τ + τ − Decaysmentioning

confidence: 99%

Section: Jhep12(2021)061mentioning

confidence: 99%

Section: Jhep12(2021)061 1 Introductionmentioning

confidence: 99%

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Interplay of dineutrino modes with semileptonic rare B-decays

Bause

Gisbert

Golz

et al. 2021

J. High Energ. Phys.

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“…There are some models [60][61][62][63] which are in agreement with our result. Furthermore, our model can be used to solve the recently observed anomalies in B meson sector such as (i) , (ii) , (iii) branching ratio and angular distribution of and (iv) angular distribution of and [64][65][66][67].…”

Section: Discussionmentioning

confidence: 99%

A Possible Solution of B → ππ Puzzle in Z’ Model

2019

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The discrepancies among the measurements of branching ratios and CP asymmetries of decays such as large direct CP asymmetry for mode and large branching ratio for mode originate the puzzle. According to diagrammatic approach of this d b  transition the small ratio of color-suppressed amplitude (C) to color-allowed one (T) contradicts between the standard model (SM) approach and the experimental values. To make out the ambiguity we need to scrutinize the decays with different topological amplitudes. In this paper, the decays are studied in the SM by taking different values of ⁄ as constraints. We find that larger ratio of ⁄ is explained successfully in the SM but the lower ratio is not for which new physics (NP) is needed. The NP contribution can be included in decays at tree level by boson. Here, we find that model can explain the puzzle by providing a good solution for lower ratio of ⁄ .

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Global analysis of leptophilic Z′ bosons

Buras

Crivellin

Kirk

et al. 2021

J. High Energ. Phys.

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New neutral heavy gauge bosons (Z′) are predicted within many extensions of the Standard Model. While in case they couple to quarks the LHC bounds are very stringent, leptophilic Z′ bosons (even with sizable couplings) can be much lighter and therefore lead to interesting quantum effects in precision observables (like (g − 2)μ) and generate flavour violating decays of charged leptons. In particular, $$ \mathrm{\ell}\to \mathrm{\ell}^{\prime }v\overline{v} $$ ℓ → ℓ ′ v v ¯ decays, anomalous magnetic moments of charged leptons, ℓ → ℓ′γ and ℓ → 3ℓ′ decays place stringent limits on leptophilic Z′ bosons. Furthermore, in case of mixing Z′ with the SM Z, Z pole observables are affected. In light of these many observables we perform a global fit to leptophilic Z′ models with the main goal of finding the bounds for the Z′ couplings to leptons. To this end we consider a number of scenarios for these couplings. While in generic scenarios correlations are weak, this changes once additional constraints on the couplings are imposed. In particular, if one considers an Lμ− Lτ symmetry broken only by left-handed rotations, or considers the case of τ − μ couplings only. In the latter setup, on can explain the (g − 2)μ anomaly and the hint for lepton flavour universality violation in $$ \tau \to \mu v\overline{v}/\tau \to ev\overline{v} $$ τ → μv v ¯ / τ → ev v ¯ without violating bounds from electroweak precision observables.

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Implication of family non-universal Z′ model to rare exclusive $b \to s(l\bar l,\nu\bar\nu)$ transitions

Cited by 12 publications

References 119 publications

Interplay of dineutrino modes with semileptonic rare B-decays

Interplay of dineutrino modes with semileptonic rare B-decays

A Possible Solution of B → ππ Puzzle in Z’ Model

Global analysis of leptophilic Z′ bosons

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