scholarly journals Off diagonal charged scalar couplings with the Z boson: Zee-type models as an example

2021 ◽  
Vol 81 (12) ◽  
Author(s):  
Ricardo R. Florentino ◽  
Jorge C. Romão ◽  
João P. Silva
Keyword(s):  
Experimental Data ◽  
Z Boson ◽  
Phenomenological Analysis ◽  
Interesting Property ◽  
Scalar Couplings ◽  
Charged Scalar ◽  
Current Experimental Data ◽  
Scalar Sector

AbstractModels with scalar doublets and charged scalar singlets have the interesting property that they have couplings between one Z boson and two charged scalars of different masses. This property is often ignored in phenomenological analysis, as it is absent from models with only extra scalar doublets. We explore this issue in detail, considering $$h \rightarrow Z \gamma $$ h → Z γ , $$B \rightarrow X_s \gamma $$ B → X s γ , and the decay of a heavy charged scalar into a lighter one and a Z boson. We propose that the latter be actively searched for at the LHC, using the scalar sector of the Zee-type models as a prototype and proposing benchmark points which obey all current experimental data, and could be within reach of the LHC.

scholarly journals Probing new physics in class-I B-meson decays into heavy-light final states

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
Fang-Min Cai ◽  
Wei-Jun Deng ◽  
Xin-Qiang Li ◽  
Ya-Dong Yang
Keyword(s):  
Experimental Data ◽  
Theoretical Calculations ◽  
New Physics ◽  
Class I ◽  
Charged Scalar ◽  
Dirac Structures ◽  
Meson Decays ◽  
Effective Coefficients ◽  
Quark Level ◽  
Current Experimental Data

Abstract With updated experimental data and improved theoretical calculations, several significant deviations are being observed between the Standard Model predictions and the experimental measurements of the branching ratios of $$ {\overline{B}}_{(s)}^0\to {D}_{(s)}^{\left(\ast \right)+}{L}^{-} $$ B ¯ s 0 → D s ∗ + L − decays, where L is a light meson from the set {π, ρ, K(∗)}. Especially for the two channels $$ {\overline{B}}^0\to {D}^{+}{K}^{-} $$ B ¯ 0 → D + K − and $$ {\overline{B}}_s^0\to {D}_s^{+}{\pi}^{-} $$ B ¯ s 0 → D s + π − , both of which are free of the weak annihilation contribution, the deviations observed can even reach 4–5σ. Here we exploit possible new-physics effects in these class-I non-leptonic B-meson decays within the framework of QCD factorization. Firstly, we perform a model-independent analysis of the effects from twenty linearly independent four-quark operators that can contribute, either directly or through operator mixing, to the quark-level b →$$ c\overline{u}d(s) $$ c u ¯ d s transitions. It is found that, under the combined constraints from the current experimental data, the deviations observed could be well explained at the 1σ level by the new-physics four-quark operators with γμ(1 − γ5) ⨂ γμ(1 − γ5) structure, and also at the 2σ level by the operators with (1 + γ5) ⨂ (1 − γ5) and (1 + γ5) ⨂ (1 + γ5) structures. However, the new-physics four-quark operators with other Dirac structures fail to provide a consistent interpretation, even at the 2σ level. Then, as two specific examples of model-dependent considerations, we discuss the case where the new-physics four-quark operators are generated by either a colorless charged gauge boson or a colorless charged scalar, with their masses fixed both at the 1 TeV. Constraints on the effective coefficients describing the couplings of these mediators to the relevant quarks are obtained by fitting to the current experimental data.

CP-VIOLATING PARAMETERS IN A LEFT–RIGHT SYMMETRIC MODEL WITH AN ${\rm SU}(3)^{VL}_H$ HORIZONTAL SYMMETRY

1998 ◽  
Vol 13 (22) ◽  
pp. 3799-3813 ◽  
Author(s):  
DEBASIS BHOWMICK ◽  
ASIM K. RAY ◽  
SREERUP RAYCHAUDHURI
Keyword(s):  
Experimental Data ◽  
Dipole Moment ◽  
Full Range ◽  
Neutral Kaon ◽  
Neutral Meson ◽  
Symmetric Model ◽  
Gauge Model ◽  
Horizontal Symmetry ◽  
Current Experimental Data ◽  
Scalar Sector

CP-violation can occur in the horizontal gauge boson sector of an [Formula: see text] gauge model with natural flavor conservation (NFC) in the scalar sector. We perform explicit calculations in the model of the CP-violating parameters ε and ε′/ε in the neutral kaon sector and of the electric dipole moment of the neutron (dn), along with the usual neutral meson mixings. For the full range of parameter space where the model is consistent with current experimental data on ε, one obtains very small values for the parameters ε′/ε and dn.

scholarly journals MODEL-INDEPENDENT ESTIMATES FOR THE ABELIAN Z′ BOSON AT MODERN HADRON COLLIDERS

2011 ◽  
Vol 26 (23) ◽  
pp. 4083-4100 ◽  
Author(s):  
ALEXEY GULOV ◽  
ANDREY KOZHUSHKO
Keyword(s):  
Experimental Data ◽  
Z Boson ◽  
Hadron Colliders ◽  
Present Experimental Data ◽  
Decay Widths ◽  
Model Independent

The model-independent constraints on the Abelian Z′ couplings from the LEP data are applied to estimate the Z′ production in experiments at the Tevatron and LHC. The Z′ total and partial decay widths are analyzed. The results are compared with model-dependent predictions and present experimental data from the Tevatron. If we assume the 1–2σ hints from the LEP data to be a signal of the Abelian Z′ boson, then the Tevatron data constrain the Z′ mass between 400 GeV and 1.2 TeV.

scholarly journals The role of N*(2120) nucleon resonance in KΛ(1520) photon and hadronic productions

2014 ◽  
Vol 29 ◽  
pp. 1460244
Author(s):  
Ju-Jun Xie ◽  
En Wang ◽  
Bo-Chao Liu ◽  
J. Nieves
Keyword(s):  
Experimental Data ◽  
Invariant Mass ◽  
Cross Sections ◽  
Dalitz Plot ◽  
Total Cross Sections ◽  
Effective Lagrangian ◽  
Hadronic Production ◽  
Current Experimental Data ◽  
Theoretical Results

The associate KΛ(1520) photon and hadronic production in the γp → K+Λ(1520), pp → pK+Λ(1520) and π-p → K0Λ(1520) reactions are investigated within the effective Lagrangian approach and the isobar model. We are interested in the contribution from the N*(2120) (previously called N*(2080)) resonance, which has a significant coupling to the KΛ(1520) channel. The theoretical results show that the current experimental data for the γp → K+Λ(1520) reaction favor the existence of the N*(2120) resonance, and that these measurements can be used to further constrain its properties. We present results, including the N*(2120) contribution, for total cross sections of the γp → K+Λ(1520), π-p → K0Λ(1520), and pp → pK+Λ(1520) reactions. For this latter one, we also calculate invariant mass and Dalitz plot distributions.

NEUTRINO MIXING WITH NEW HEAVY PARTICLES IN THE SU(6)L ⊗ U(1)Y MODEL

1999 ◽  
Vol 14 (26) ◽  
pp. 4143-4152
Author(s):  
R. GAITÁN ◽  
S. RODRIGUEZ-ROMO ◽  
A. HERNÁNDEZ-GALEANA ◽  
J. M. RIVERA-REBOLLEDO
Keyword(s):  
Experimental Data ◽  
Decay Rate ◽  
Z Boson ◽  
Close Agreement ◽  
Neutrino Mixing ◽  
Heavy Particles ◽  
Ckm Matrix ◽  
Mixing Angles ◽  
Invisible Decay ◽  
The Invisible

We analyze the effects arisen from the mixing of heavy neutral fermions with the standard neutrinos in the SU (6)L ⊗ U (1)Y model. We obtain limits on the mixing angles between νe, νμ, ντ and the heavy neutral fermions of the model; these results are consistents with those predicted by using certain experimental constraints. This model also gives values for [Formula: see text], for the first row of the CKM matrix and for the invisible decay rate of the Z boson; its close agreement with the experimental data is shown. This behavior is expected since the standard neutrinos only mix with the exotic neutral leptons of the model which acquire mass in the first stage of SSB.

scholarly journals QUARK AND LEPTON MASS MATRICES WITH A4 FAMILY SYMMETRY

2007 ◽  
Vol 16 (05) ◽  
pp. 1383-1393 ◽  
Author(s):  
HIDEYUKI SAWANAKA
Keyword(s):  
Experimental Data ◽  
Neutrino Mixing ◽  
Family Symmetry ◽  
Mixing Angles ◽  
Quark Masses ◽  
Quark Sector ◽  
Mass Matrices ◽  
Mixing Matrix ◽  
Current Experimental Data

Realistic quark masses and mixing angles are obtained applying the successful A4 family symmetry for leptons, motivated by the quark-lepton assignments of SU (5). The A4 symmetry is suitable to give tri-bimaximal neutrino mixing matrix which is consistent with current experimental data. We study new scenario for the quark sector with the A4 symmetry.

scholarly journals Mean-field approaches for Ξ− hypernuclei and current experimental data

2016 ◽  
Vol 94 (6) ◽  
Author(s):  
T. T. Sun ◽  
E. Hiyama ◽  
H. Sagawa ◽  
H.-J. Schulze ◽  
J. Meng
Keyword(s):  
Experimental Data ◽  
Mean Field ◽  
Current Experimental Data ◽  
Field Approaches

scholarly journals Studying Disturbance Wave Velocity and Wall Shear Stress of Vertical Upward Annular Flow in Narrow Rectangular Channel

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Antai Liu ◽  
Changqi Yan ◽  
Fuqiang Zhu ◽  
Haifeng Gu ◽  
Suijun Gong
Keyword(s):  
Experimental Data ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Wave Velocity ◽  
Annular Flow ◽  
Rectangular Channel ◽  
Disturbance Wave ◽  
New Correlation ◽  
Current Experimental Data ◽  
Wall Shear

As two important parameters, the velocity of disturbance wave and the wall shear stress in annular flow are very important to solve the closed equations of the mechanical model for annular flow. In this study, the disturbance wave velocity and wall shear stress of annular flow in a vertical narrow rectangular channel with a cross section of 70 mm × 2 mm were studied. According to the experimental results, it is found that the wave velocity and wall shear stress of disturbance wave increase with increasing gas phase velocity and liquid phase velocity. Also, existing correlations for predicting the velocity of disturbance wave were summarized and evaluated using the current experimental data. A new correlation for wall shear stress based on the disturbance wave velocity has been proposed. Compared with the existing correlation for predicting wall shear stress, this new correlation can well predict the current experimental data and MAPE is only 7.32%.

scholarly journals Lepton-flavour non-universality of $${\bar{B}}\rightarrow D^*\ell {{\bar{\nu }}}$$ angular distributions in and beyond the Standard Model

2021 ◽  
Vol 81 (11) ◽  
Author(s):  
Christoph Bobeth ◽  
Marzia Bordone ◽  
Nico Gubernari ◽  
Martin Jung ◽  
Danny van Dyk
Keyword(s):  
Experimental Data ◽  
Standard Model ◽  
Effective Theory ◽  
Angular Distributions ◽  
Beyond The Standard Model ◽  
Mass Effects ◽  
Muon Mass ◽  
The Standard Model ◽  
Current Experimental Data ◽  
Lepton Flavour

AbstractWe analyze in detail the angular distributions in $${\bar{B}}\rightarrow D^*\ell {{\bar{\nu }}}$$ B ¯ → D ∗ ℓ ν ¯ decays, with a focus on lepton-flavour non-universality. We investigate the minimal number of angular observables that fully describes current and upcoming datasets, and explore their sensitivity to physics beyond the Standard Model (BSM) in the most general weak effective theory. We apply our findings to the current datasets, extract the non-redundant set of angular observables from the data, and compare to precise SM predictions that include lepton-flavour universality violating mass effects. Our analysis shows that the number of independent angular observables that can be inferred from current experimental data is limited to only four. These are insufficient to extract the full set of relevant BSM parameters. We uncover a $$\sim 4\sigma $$ ∼ 4 σ tension between data and predictions that is hidden in the redundant presentation of the Belle 2018 data on $${\bar{B}}\rightarrow D^*\ell {{\bar{\nu }}}$$ B ¯ → D ∗ ℓ ν ¯ decays. This tension specifically involves observables that probe $$e-\mu $$ e - μ lepton-flavour universality. However, we find inconsistencies in these data, which renders results based on it suspicious. Nevertheless, we discuss which generic BSM scenarios could explain the tension, in the case that the inconsistencies do not affect the data materially. Our findings highlight that $$e-\mu $$ e - μ non-universality in the SM, introduced by the finite muon mass, is already significant in a subset of angular observables with respect to the experimental precision.

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