Top forward-backward asymmetry and the CDF<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>W</mml:mi><mml:mi>j</mml:mi><mml:mi>j</mml:mi></mml:math>excess in leptophobic<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>U</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mn>1</mml:mn><mml:msup><mml:mo stretchy="false">)</mml:mo><mml:mo>′</mml:mo></mml:msup></mml:math>flavor models

Ko, Pyungwon; Omura, Yuji; Yu, Chaehyun

doi:10.1103/physrevd.85.115010

Cited by 37 publications

(97 citation statements)

References 14 publications

(22 reference statements)

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“…[18,19], the present authors proposed flavor models with extra Higgs fields, where gauged U(1) ′ symmetry forbids the potentially problematic FCNCs for B-B and K-K mixings but allows certain amounts of FCNCs which are still consistent with experimental data, by slightly breaking the criteria of ref. [17].…”

Section: Jhep03(2013)151mentioning

confidence: 84%

“…There, neutral CP-even scalars and a CP-odd scalar can have large (t, q) q=u,c,t elements of Yukawa couplings. Their tree-level mediations enhance the top forward-backward asymmetry (A t FB ) at the Tevatron, while accommodating with the newest strong constraints from LHC thanks to the destructive interference among the scalars [18][19][20][21]. In previous works, phenomenology of the charged Higgs boson in our models was not considered carefully because the charge Higgs boson cannot have sizable contribution to the top quark production at hadron colliders.…”

Section: Jhep03(2013)151mentioning

confidence: 99%

“…In section 2, we give a brief review of our models proposed in refs. [18,19]. We assign family dependent U(1) ′ charges to the right-handed (RH) up-type quarks in order to generate flavor changing Z ′ − u R − t R couplings in the mass eigenstates.…”

Section: Jhep03(2013)151mentioning

confidence: 99%

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B → D (*) τν and B → τν in chiral U(1)′ models with flavored multi Higgs doublets

Ko¹,

Omura

2013

J. High Energ. Phys.

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We discuss semileptonic and leptonic B decays, B → D (∗) τν and B → τν, in the chiral U(1)′ models which were proposed by the present authors in the context of the top forward-backward asymmetry $ \left( {A_{\mathrm{FB}}^t} \right) $ observed at the Tevatron. In these models, extra Higgs doublets with nonzero U(1)′ charges are required in order to make the realistic mass matrix for up-type quarks. Then the extra (pseudo)scalars contribute to $ A_{\mathrm{FB}}^t $ with large flavor-changing Yukawa couplings involving top quark. The contribution of the charged Higgs to $ A_{\mathrm{FB}}^t $ is negligible, but it may significantly affect B decays: especially, B → D (*) τν and B → τν. We investigate constraints on the B decays, based on the recent results in BaBar and Belle experiments, and discuss the possibility that the allowed parameter region in the B decays can achieve large $ A_{\mathrm{FB}}^t $ .

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Section: Jhep03(2013)151mentioning

confidence: 84%

Section: Jhep03(2013)151mentioning

confidence: 99%

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B → D (*) τν and B → τν in chiral U(1)′ models with flavored multi Higgs doublets

Ko¹,

Omura

2013

J. High Energ. Phys.

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“…We also consider the presence of two SU (2) (pseudo)scalar doublets, embedded in a 2-Higgs Doublet Model (2HDM) scalar potential, Φ 1 and Φ 2 , with the same hypercharge Y = 1/2 and two different charges z Φ1 and z Φ2 under the extra U (1) ′ . The new Abelian symmetry replaces the discrete Z 2 one usually imposed in 2HDMs to avoid tree-level flavour changing neutral currents [14,15] …”

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confidence: 99%

Explanation of the 17 MeV Atomki anomaly in a U(1)′ -extended two Higgs doublet model

2017

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Motivated by an anomaly observed in the decay of an excited state of Beryllium ( 8 Be) by the Atomki collaboration, we study an extension of the Standard Model with a gauged U (1) ′ symmetry in presence of a 2-Higgs Doublet Model structure of the Higgs sector. We show that this scenario complies with a variety of experimental results and is able to explain the potential presence of a resonant spin-1 gauge boson, Z ′ , with a mass of 17 MeV in the Atomki experimental data, for appropriate choices of U (1) ′ charges and Yukawa interactions.The Atomki pair spectrometer experiment [1] was set up for searching e + e − internal pair creation in the decay of excited 8 Be nuclei (henceforth, 8 Be * ), the latter being produced with the help of a beam of protons directed on a Lithium ( 7 Li) target. The proton beam was tuned in such a way that the different 8 Be excitations could be separated with high accuracy.In the data collection stage, a clear anomaly was observed in the decay of 8 Be * with spin-parity J P = 1 + into the ground state 8 Be with spin-parity 0 + (both with isospin T = 0), where 8 Be * had an excitation energy of 18.15 MeV. Upon analysis of the electron-positron properties, the spectra of both their opening angle θ and invariant mass M presented the characteristics of an excess consistent with an intermediate boson X being produced on-shell in the decay of the 8 Be * state, with the X object subsequently decaying into e + e − pairs. The best fit to the mass M X of X was given as [1] M X = 16.7 ± 0.35 (stat) ± 0.5 (sys) MeV, in correspondence of a ratio of Branching Ratios (BRs) obtained asThis combination yields a statistical significance of the excess of about 6.8 σ [1].An explanation of the X nature was attempted by [2,3], in the form of models featuring a new vector boson Z ′ with a mass M Z ′ of about 17 MeV, with vector-like couplings to quarks and leptons. Constraints on such a new state, notably from searches for π 0 → Z ′ + γ by the NA48/2 experiment [4], require the couplings of the Z ′ to up and down quarks to be 'protophobic', i.e., that the charges eǫ u and eǫ d of up and down quarks -written as multiples of the positron charge e -satisfy the relation 2ǫ u + ǫ d < ∼ 10 −3 [2,3]. Subsequently, further studies of such models have been performed in [5-12] 1 .1 An alternative explanation was given in [13], wherein the X was In the footsteps of this literature, we consider here an extension of the SM described by a generic U (1) ′ group. Due to the presence of two such Abelian symmetries, U (1) Y × U (1) ′ , the most general kinetic Lagrangian of the corresponding fields,B µ andB ′ µ , respectively, allows for a gauge invariant mixing of the two field-strengthswhere κ is the kinetic mixing parameter between U (1) Y and U (1) ′ . A diagonal form for this Lagrangian can be obtained by transformation of the Abelian fields such that the gauge covariant derivative becomeswhere Y and z are the hypercharge and U (1) ′ charge, respectively, andg the gauge coupling mixing between the two Abelian groups. ...

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“…This motivates a systematic study of the realizations of these possibilities, with extra SM charged exotics and/or flavor-dependent Z couplings, along the lines of the explicit solutions found in Refs. [63][64][65][66][67][68][69][70][71][72][73][74][75][76][77].…”

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confidence: 99%

Surprises from complete vector portal theories: New insights into the dark sector and its interplay with Higgs physics

Cui

DʼEramo

2017

Phys. Rev. D

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We study UV complete theories where the Standard Model (SM) gauge group is extended with a new abelian U (1) , and the field content is augmented by an arbitrary number of scalar and fermion SM singlets, potentially including dark matter (DM) candidates. Considerations such as classical and quantum gauge invariance of the full theory and S-matrix unitarity, not applicable within a simplified model approach, are shown to have significant phenomenological consequences. The lack of gauge anomalies leads to compact relations among the U (1) fermion charges, and puts a lower bound on the number of dark fermions. Contrary to naive expectations, the DM annihilation to Zh is found to be p-wave suppressed, as hinted by perturbative unitarity of S-matrix, with dramatic implications for DM thermal relic density and indirect searches. Within this framework, the interplay between dark matter, new vector boson and Higgs physics is rather natural and generic.Introduction. Extra abelian gauge symmetries are among the best motivated extensions to the Standard Model (SM) of particle physics [1]. Spontaneous breaking of such a U (1) symmetry is associated with a massive gauge boson Z that mediates a new type of interaction among SM fields. This Z boson could also provide a portal to the dark matter sector -another robust motivation for physics beyond the SM [2,3]. Extensive studies have pursued this scenario, with simplified models as a commonly employed tool [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. Although this approach is advantageous as it allows to study phenomenology with a handful of masses and couplings, some key issues may be missed unless a UV-complete theory is specified.In this paper, we explore the UV-completeness of vector portal models, in particular the implications of the following important theoretical constraints: 1. Classical level gauge invariance of the theory, including the U (1) invariance of SM Yukawa terms. 2. Quantum level gauge invariance of the theory, namely the absence of gauge anomalies. 3. Perturbative unitarity of the S-matrix. These issues, not apparent in a simplified model approach, have profound phenomenological consequences.We focus on U (1) theories where all the new matter fields are SM gauge singlets, and consider an arbitrary number of them. The gauge invariance of the SM Yukawa interactions implies that the SM Higgs doublet H typically carries U (1) charge, unless SM fermions are vector-like under U (1) [24,25]. This in turn implies a deep connection between DM searches and Higgs physics.The cancellation of gauge anomalies is highly nontrivial in a generic U (1) model. Despite the many constraints, we find very compact relations among the dark

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Top forward-backward asymmetry and the CDFWjjexcess in leptophobicU(1)′flavor models

Cited by 37 publications

References 14 publications

B → D (*) τν and B → τν in chiral U(1)′ models with flavored multi Higgs doublets

B → D (*) τν and B → τν in chiral U(1)′ models with flavored multi Higgs doublets

Explanation of the 17 MeV Atomki anomaly in a U(1)′ -extended two Higgs doublet model

Surprises from complete vector portal theories: New insights into the dark sector and its interplay with Higgs physics

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