LARGE CONTRIBUTIONS TO THE ANOMALOUS MAGNETIC MOMENT OF THE MUON IN SUPERSYMMETRIC THEORIES

2001 ◽  
Vol 16 (12) ◽  
pp. 795-802 ◽  
Author(s):  
M. FRANK
Keyword(s):  
Standard Model ◽  
Supersymmetric Standard Model ◽  
Minimal Supersymmetric Standard Model ◽  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
Loop Level ◽  
Supersymmetric Theories

We show that, in supersymmetric theories beyond the Minimal Supersymmetric Standard Model, the anomalous magnetic moment of the muon can receive large contributions at one-loop level, of [Formula: see text], rather than [Formula: see text]. We evaluate all such contributions and show that, for low supersymmetric masses, they already exceed the value measured by the Brookhaven E821 experiment. These contributions put more stringent mass constraints on the parameters of the model and can distinguish it from the same process in the MSSM.

scholarly journals Improved (g − 2)μ measurement and singlino dark matter in μ-term extended ℤ3-NMSSM

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Junjie Cao ◽  
Jingwei Lian ◽  
Yusi Pan ◽  
Di Zhang ◽  
Pengxuan Zhu
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Supersymmetric Standard Model ◽  
Minimal Supersymmetric Standard Model ◽  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
Hadron Collider ◽  
Higgs Bosons ◽  
Mass Hierarchy ◽  
Relic Abundance

Abstract Very recently, a Fermilab report of muon g− 2 showed a 4.2σ discrepancy between it and the standard model (SM) prediction. Motivated by this inspiring result and the increasing tension in supersymmetric interpretation of the anomalous magnetic moment, it is argued that in the general next-to-minimal supersymmetric standard model (GNMSSM), a singlino-dominated neutralino can act as a feasible dark matter (DM) candidate in explaining the discrepancy naturally. In this case, the singlino-dominated DM and singlet-dominated Higgs bosons can form a secluded DM sector with $$ {\overset{\sim }{\chi}}_1^0{\overset{\sim }{\chi}}_1^0 $$ χ ~ 1 0 χ ~ 1 0 → hsAs responsible for the measured DM relic abundance when $$ {m}_{{\overset{\sim }{\chi}}_1^0} $$ m χ ~ 1 0 ≳ 150 GeV and the Yukawa coupling κ is around 0.2. This sector communicates with the SM sector by weak singlet-doublet Higgs mixing, so the scatterings of the singlino-dominated DM with nucleons are suppressed. Furthermore, due to the singlet nature of the DM and the complex mass hierarchy, sparticle decay chains in the GNMSSM are lengthened in comparison with the prediction of the minimal supersymmetric standard model. These characteristics lead to sparticle detection at the Large Hadron Collider (LHC) being rather tricky. This study surveys a specific scenario of the GNMSSM, which extends the ℤ3-NMSSM by adding an explicit μ-term, to reveal the features. It indicates that the theory can readily explain the discrepancy of the muon anomalous magnetic moment without conflicting with the experimental results in DM and Higgs physics, and the LHC searches for sparticles.

scholarly journals ONE-LOOP ELECTROWEAK EFFECTS ON STOP-CHARGINO PRODUCTION AT LHC

2009 ◽  
Vol 24 (30) ◽  
pp. 5539-5559 ◽  
Author(s):  
M. BECCARIA ◽  
G. MACORINI ◽  
E. MIRABELLA ◽  
L. PANIZZI ◽  
F. M. RENARD ◽  
...  
Keyword(s):  
Standard Model ◽  
Symmetry Breaking ◽  
Supersymmetric Standard Model ◽  
Invariant Mass ◽  
Minimal Supersymmetric Standard Model ◽  
Basic Formula ◽  
Mass Distributions ◽  
Theoretical Scheme ◽  
Loop Level

The process of stop-chargino production at LHC has been calculated in the Minimal Supersymmetric Standard Model at the complete electroweak one-loop level, assuming a mSUGRA symmetry breaking scheme. Several properties of the angular and invariant mass distributions of the basic [Formula: see text] amplitudes have been derived. For a meaningful collection of different benchmark points the overall electroweak one-loop effects are at most of the order of a few percent. At the realistically expected LHC accuracy, the main supersymmetric electroweak features of the process can be therefore essentially derived in this theoretical scheme from the simple Born level expressions.

INFLUENCE OF CHARGINOS AND NEUTRALINOS ON THE ANOMALOUS MAGNETIC MOMENT OF THE MUON WITH AND WITHOUT R-PARITY BREAKING

1992 ◽  
Vol 07 (04) ◽  
pp. 279-292 ◽  
Author(s):  
HEINZ KÖNIG
Keyword(s):  
Standard Model ◽  
Supersymmetric Standard Model ◽  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Detailed Calculation ◽  
Expectation Value ◽  
Tau Neutrino ◽  
Parity Breaking

We present a detailed calculation of the contribution ∆aμ to the anomalous magnetic moment of the muon, when charginos and neutralinos are taken into account inside the relevant penguin diagrams. We consider the minimal supersymmetric standard model and include spontaneous R-parity breaking through the vacuum expectation value ντ of the scalar tau neutrino [Formula: see text]. We show that R-parity breaking leads to a result for Δaμ, which is less than a factor 10 below the experimental value.

scholarly journals BEYOND THE MINIMAL SUPERSYMMETRIC STANDARD MODEL: FROM THEORY TO PHENOMENOLOGY

2012 ◽  
Vol 27 (07) ◽  
pp. 1230007 ◽  
Author(s):  
BENJAMIN FUKS
Keyword(s):  
Monte Carlo ◽  
Standard Model ◽  
Supersymmetric Standard Model ◽  
Minimal Supersymmetric Standard Model ◽  
Top Quark ◽  
Monte Carlo Event ◽  
Beyond The Standard Model ◽  
Color Structure ◽  
Phenomenological Studies ◽  
Supersymmetric Theories

Thanks to the latest development in the field of Monte Carlo event generators and satellite programs allowing for a straightforward implementation of any beyond the Standard Model theory in those tools, studying the property of any softly-broken supersymmetric theory is become an easy task. We illustrate this statement in the context of two nonminimal supersymmetric theories, namely the Minimal Supersymmetric Standard Model with R-parity violation and the Minimal R-symmetric Supersymmetric Standard Model and choose to probe interaction vertices involving a nonstandard color structure and the sector of the top quark. We show how to efficiently implement these theories in the MATHEMATICA package FEYNRULES and use its interfaces to Monte Carlo tools for phenomenological studies. For the latter, we employ the latest version of the MADGRAPH program.

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