scholarly journals New physics signatures at a linear collider: model-independent analysis from ‘conventional’ polarized observables

2001 ◽  
Vol 518 (1-2) ◽  
pp. 128-136 ◽  
Author(s):  
A.A. Babich ◽  
P. Osland ◽  
A.A. Pankov ◽  
N. Paver
Keyword(s):  
Linear Collider ◽  
New Physics ◽  
Independent Analysis ◽  
Model Independent

scholarly journals Constraints on new physics in MFV models: A model-independent analysis of ΔF=1 processes

2009 ◽  
Vol 808 (1-2) ◽  
pp. 326-346 ◽  
Author(s):  
Tobias Hurth ◽  
Gino Isidori ◽  
Jernej F. Kamenik ◽  
Federico Mescia
Keyword(s):  
New Physics ◽  
Independent Analysis ◽  
Model Independent

scholarly journals Tau $$g{-}2$$ at $$e^-e^+$$ colliders with momentum-dependent form factor

2021 ◽  
Vol 81 (2) ◽  
Author(s):  
Hieu Minh Tran ◽  
Yoshimasa Kurihara
Keyword(s):  
Form Factor ◽  
Linear Collider ◽  
International Linear Collider ◽  
Large Mass ◽  
New Physics ◽  
Magnetic Form Factor ◽  
Beam Polarization ◽  
Electron Positron ◽  
Dependent Form ◽  
Model Independent

AbstractThe deviation between the prediction based on the standard model and the measurement of the muon $$g{-}2$$ g - 2 is currently at $$3{-}4 \sigma $$ 3 - 4 σ . If this discrepancy is attributable to new physics, it is expected that the new contributions to the tau $$g{-}2$$ g - 2 even larger than those of muon due to its large mass. However, it is much more difficult to directly measure the tau $$g{-}2$$ g - 2 because of its short lifetime. In this report, we consider the effect of the tau $$g{-}2$$ g - 2 at $$e^-e^+$$ e - e + colliders using a model independent approach. Using the tau pair production channel at the Large Electron Position Collider (LEP), we have determined the allowed range for the new physics contribution of the tau $$g{-}2$$ g - 2 assuming a q-square-dependence ansatz for the magnetic form factor. We also investigated the prospect at future $$e^+e^-$$ e + e - colliders, such as International Linear Collider, the Compact Linear Collider, the Future Circular $$e^+e^-$$ e + e - Collider, and Circular Electron Positron Collider, and determined the expected allowed range for the new physics contribution to the tau anomalous magnetic moment. The best limits are about $$4{-}5$$ 4 - 5 times more severe than the LEP one due to the beam polarization and the high luminosities at future colliders.

scholarly journals Search for single production of vector-like B quark decaying to bZ at future linear colliders

2021 ◽  
Vol 81 (5) ◽  
Author(s):  
Lin Han ◽  
Jie-Fen Shen
Keyword(s):  
Linear Collider ◽  
Decay Channel ◽  
High Energy ◽  
New Physics ◽  
Beyond The Standard Model ◽  
The Standard Model ◽  
Linear Colliders ◽  
Single Production ◽  
Model Independent ◽  
B Quark

AbstractNew vector-like quarks are predicted in many new physics scenarios beyond the Standard Model (SM). Based on a model-independent framework, we investigate the prospect of discovering the SU(2) singlet vector-like bottom quark (VLQ-B) in $$e^{+}e^{-}$$ e + e - collisions at 3 TeV Compact Linear Collider. We study the single VLQ-B production process $$e^{-}e^{+}\rightarrow B{\bar{b}}\rightarrow Zb{\bar{b}}$$ e - e + → B b ¯ → Z b b ¯ with two types of decay channel: $$Z\rightarrow \ell ^{+}\ell ^{-}$$ Z → ℓ + ℓ - , and $$Z\rightarrow \nu {\bar{\nu }}$$ Z → ν ν ¯ . By carrying out a full simulation for the signals and the relevant SM backgrounds, the $$2\sigma $$ 2 σ exclusion limit and $$5\sigma $$ 5 σ discovery prospects are, respectively, obtained on the B quark mass and the coupling strength $$g^{*}$$ g ∗ with the integrated luminosity of 5 $$\hbox {ab}^{-1}$$ ab - 1 . Our numerical results show that the possible signals of the singlet VLQ-B might be detected at the future high-energy $$e^{+}e^{-}$$ e + e - linear colliders.

scholarly journals Is there evidence for a hotter Universe?

2020 ◽  
Vol 80 (10) ◽  
Author(s):  
Carlos A. P. Bengaly ◽  
Javier E. Gonzalez ◽  
Jailson S. Alcaniz
Keyword(s):  
Hubble Constant ◽  
Far Infrared ◽  
New Physics ◽  
Wilkinson Microwave Anisotropy Probe ◽  
Microwave Background ◽  
Independent Analysis ◽  
Independent Observations ◽  
Model Independent ◽  
Good Agreement ◽  
Made In

AbstractThe measurement of present-day temperature of the Cosmic Microwave Background (CMB), $$T_0 = 2.72548 \pm 0.00057$$ T 0 = 2.72548 ± 0.00057  K (1$$\sigma $$ σ ), made by the Far-InfraRed Absolute Spectrophotometer (FIRAS) as recalibrated by the Wilkinson Microwave Anisotropy Probe (WMAP), is one of the most precise measurements ever made in Cosmology. On the other hand, estimates of the Hubble Constant, $$H_0$$ H 0 , obtained from measurements of the CMB temperature fluctuations assuming the standard $$\varLambda $$ Λ CDM model exhibit a large ($$4.1\sigma $$ 4.1 σ ) tension when compared with low-redshift, model-independent observations. Recently, some authors argued that a slightly change in $$T_0$$ T 0 could alleviate or solve the $$H_0$$ H 0 -tension problem. Here, we investigate evidence for a hotter or colder universe by performing an independent analysis from currently available temperature-redshift T(z) measurements. Our analysis (parametric and non-parametric) shows a good agreement with the FIRAS measurement and a discrepancy of $$\ge 1.9\sigma $$ ≥ 1.9 σ from the $$T_0$$ T 0 values required to solve the $$H_0$$ H 0 tension. This result reinforces the idea that a solution of the $$H_0$$ H 0 -tension problem in fact requires either a better understanding of the systematic errors on the $$H_0$$ H 0 measurements or new physics.

scholarly journals New physics in b → se+e−: A model independent analysis

2021 ◽  
pp. 115419
Author(s):  
Ashutosh Kumar Alok ◽  
Suman Kumbhakar ◽  
Jyoti Saini ◽  
S. Uma Sankar
Keyword(s):  
New Physics ◽  
Independent Analysis ◽  
Model Independent

scholarly journals Diphoton resonances at the LHC

2017 ◽  
Vol 32 (27) ◽  
pp. 1730024 ◽  
Author(s):  
Emiliano Molinaro ◽  
Natascia Vignaroli
Keyword(s):  
Effective Field Theory ◽  
New Physics ◽  
Effective Field ◽  
Current Status ◽  
Beyond The Standard Model ◽  
Theory Approach ◽  
Independent Analysis ◽  
The Standard Model ◽  
Model Independent ◽  
Production Mechanisms

We review the current status of searches for new physics beyond the Standard Model in the diphoton channel at the LHC and estimate the reach with future collected data. We perform a model independent analysis based on an effective field theory approach and different production mechanisms. As an illustrative example, we apply our results to a scenario of minimal composite dynamics.

scholarly journals Disentangling QCD and new physics in D → πℓ+ℓ−

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Aoife Bharucha ◽  
Diogo Boito ◽  
Cédric Méaux
Keyword(s):  
Standard Model ◽  
Branching Ratio ◽  
Branching Ratios ◽  
New Physics ◽  
Operator Product ◽  
Beyond The Standard Model ◽  
Spectral Functions ◽  
The Standard Model ◽  
Model Independent ◽  
Weak Annihilation

Abstract In this paper we consider the decay D+ → π+ℓ+ℓ−, addressing in particular the resonance contributions as well as the relatively large contributions from the weak annihilation diagrams. For the weak annihilation diagrams we include known results from QCD factorisation at low q2 and at high q2, adapting the existing calculation for B decays in the Operator Product Expansion. The hadronic resonance contributions are obtained through a dispersion relation, modelling the spectral functions as towers of Regge-like resonances in each channel, as suggested by Shifman, imposing the partonic behaviour in the deep Euclidean. The parameters of the model are extracted using e+e− → (hadrons) and τ → (hadrons) + ντ data as well as the branching ratios for the resonant decays D+ → π+R(R → ℓ+ℓ−), with R = ρ, ω, and ϕ. We perform a thorough error analysis, and present our results for the Standard Model differential branching ratio as a function of q2. Focusing then on the observables FH and AFB, we consider the sensitivity of this channel to effects of physics beyond the Standard Model, both in a model independent way and for the case of leptoquarks.

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