IMPLICATIONS OF A LIGHT RADION ON β(λ) AND β(gt) AND A LOWER BOUND ON RADION VEV

2004 ◽  
Vol 19 (24) ◽  
pp. 1855-1861 ◽  
Author(s):  
PRASANTA KUMAR DAS ◽  
UMA MAHANTA
Keyword(s):  
Lower Bound ◽  
Yukawa Coupling ◽  
Higgs Mass ◽  
Boundary Values ◽  
Loop Order

In this paper we determine how the beta funtions of Higgs self-coupling λ and top Yukawa coupling gt to one-loop order are modified by a light stabilized radion in the Randall–Sundrum model. We then use these beta functions to evolve λ from the cutoff <ϕ> down to μ0=115 GeV starting from different boundary values λ(<ϕ>). We find that although for large <ϕ> the value of λ(μ0) does depend on λ(<ϕ>), for small enough <ϕ> the curves merge together. We then determine a lower bound on <ϕ> by demanding that [Formula: see text] in order to be consistent with the LEPII lower bound on the Higgs mass. The lower bound on <ϕ> obtained by us is insensitive to the value of λ(<ϕ>).

scholarly journals A CALCULATION OF HIGGS MASS IN THE STANDARD MODEL

2000 ◽  
Vol 15 (26) ◽  
pp. 1605-1610 ◽  
Author(s):  
J. PASUPATHY
Keyword(s):  
Standard Model ◽  
Yukawa Coupling ◽  
Higgs Mass ◽  
Renormalization Scale ◽  
The Standard Model ◽  
Gauge Couplings ◽  
Top Mass

The assumption that the ratio of the Higgs self-coupling to the square of its Yukawa coupling to the top is (almost) independent of the renormalization scale fixes the Higgs mass within narrow limits at m H =160 GeV using only the values of gauge couplings and top mass.

scholarly journals Two-loop $$ \mathcal{O} $$((αt + αλ + ακ)2) corrections to the Higgs boson masses in the CP-violating NMSSM

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Thi Nhung Dao ◽  
Martin Gabelmann ◽  
Margarete Mühlleitner ◽  
Heidi Rzehak
Keyword(s):  
Higgs Boson ◽  
Higgs Mass ◽  
Goldstone Boson ◽  
Higgs Sector ◽  
Momentum Dependence ◽  
Loop Order ◽  
Fortran Code ◽  
Higher Order Corrections ◽  
Infrared Divergences ◽  
The Impact

Abstract We present our computation of the $$ \mathcal{O} $$ O ((αt + αλ + ακ)2) two-loop corrections to the Higgs boson masses of the CP-violating Next-to-Minimal Supersymmetric Standard Model (NMSSM) using the Feynman-diagrammatic approach in the gaugeless limit at vanishing external momentum. We choose a mixed $$ \overline{\mathrm{DR}} $$ DR ¯ -on-shell (OS) renormalisation scheme for the Higgs sector and apply both $$ \overline{\mathrm{DR}} $$ DR ¯ and OS renormalisation in the top/stop sector. For the treatment of the infrared divergences we apply and compare three different regularisation methods: the introduction of a regulator mass, the application of a small momentum expansion, and the inclusion of the full momentum dependence. Our new corrections have been implemented in the Fortran code NMSSMCALC that computes the Higgs mass spectrum of the CP-conserving and CP-violating NMSSM as well as the Higgs boson decays including the state-of-the-art higher-order corrections. Our numerical analysis shows that the newly computed corrections increase with rising λ and κ, remaining overall below about 3% compared to our previously computed $$ \mathcal{O} $$ O (αt(αt + αs)) corrections, in the region compatible with perturbativity below the GUT scale. The renormalisation scheme and scale dependence is of typical two-loop order. The impact of the CP-violating phases in the new corrections is small. We furthermore show that the Goldstone Boson Catastrophe due to the infrared divergences can be treated in a numerically efficient way by introducing a regulator mass that approximates the momentum-dependent results best for squared mass values in the permille range of the squared renormalisation scale. Our results mark another step forward in the program of increasing the precision in the NMSSM Higgs boson observables.

scholarly journals The Higgs mass in the MSSM at two-loop order beyond minimal flavour violation

2016 ◽  
Vol 758 ◽  
pp. 18-25 ◽  
Author(s):  
Mark D. Goodsell ◽  
Kilian Nickel ◽  
Florian Staub
Keyword(s):  
Higgs Mass ◽  
Loop Order ◽  
Minimal Flavour Violation ◽  
Flavour Violation

scholarly journals Exact one-loop running couplings in the standard model

2008 ◽  
Vol 86 (9) ◽  
pp. 1067-1070 ◽  
Author(s):  
F A Chishtie ◽  
M D Lepage ◽  
D GC McKeon ◽  
T G Steele ◽  
I Zakout
Keyword(s):  
Standard Model ◽  
Yukawa Coupling ◽  
Top Quark ◽  
Higgs Mass ◽  
Gauge Coupling ◽  
New Physics ◽  
Energy Scale ◽  
Scalar Coupling ◽  
Upper And Lower Bounds ◽  
The Standard Model

Taking the dominant couplings in the standard model to be the quartic scalar coupling, the Yukawa coupling of the top quark, and the SU(3) gauge coupling, we consider their associated running couplings to one-loop order. Despite the nonlinear nature of the differential equations governing these functions, we show that they can be solved exactly. The nature of these solutions is discussed and their singularity structure is examined. It is shown that for a sufficiently small Higgs mass, the quartic scalar coupling decreases with increasing energy scale and becomes negative, indicative of vacuum instability. This behavior changes for a Higgs mass greater than 168 GeV, beyond which this couplant increases with increasing energy scales and becomes singular prior to the ultraviolet pole of the Yukawa coupling. Upper and lower bounds on the Higgs mass corresponding to new physics at the TeV scale are obtained and compare favourably with the numerical results of the one-loop and two-loop analyses with inclusion of electroweak couplings.PACS Nos.: 11.10.Hi, 14.80.Bn

scholarly journals MUON ANOMALY AND A LOWER BOUND ON HIGGS MASS DUE TO A LIGHT STABILIZED RADION IN THE RANDALL–SUNDRUM MODEL

2006 ◽  
Vol 21 (26) ◽  
pp. 5205-5220 ◽  
Author(s):  
PRASANTA KUMAR DAS
Keyword(s):  
Lower Bound ◽  
Extra Dimension ◽  
Higgs Mass ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Quartic Coupling ◽  
Muon Anomalous Magnetic Moment ◽  
Expectation Value ◽  
The Standard Model ◽  
Standard Model Result

We investigate the Randall–Sundrum model with a light stabilized radion (required to fix the size of the extra dimension) in the light of muon anomalous magnetic moment [Formula: see text]. Using the recent data (obtained from the E821 experiment of the BNL Collaboration) which differs by 2.6σ from the Standard Model result, we obtain constraints on radion mass mϕ and radion vacuum expectation value 〈ϕ〉. In the presence of a radion the beta functions β(λ) and β(gt) of Higgs quartic coupling (λ) and top-Yukawa coupling (gt) gets modified. We find these modified beta functions. Using these beta functions together with the anomaly constrained mϕ and 〈ϕ〉, we obtain lower bound on Higgs mass mh. We compare our result with the present LEP2 bound on mh.

scholarly journals Probing loop effects in wrong-sign Yukawa coupling region of Type-II 2HDM

2021 ◽  
Vol 81 (5) ◽  
Author(s):  
Wei Su
Keyword(s):  
Parameter Space ◽  
Yukawa Coupling ◽  
Higgs Mass ◽  
Precision Measurements ◽  
Tree Level ◽  
Type Ii ◽  
Coupling Region ◽  
Loop Level ◽  
Wrong Sign

AbstractIn the framework of 2HDM, we explore the wrong-sign Yukawa region with direct and indirect searches up to one-loop level. The direct searches include the latest $$H/A \rightarrow f{\bar{f}}, VV, Vh, hh$$ H / A → f f ¯ , V V , V h , h h reports at current LHC, and the study of indirect Higgs precision measurements works with current LHC, future HL-LHC and CEPC. At tree level of Type-II 2HDM, for degenerate heavy Higgs mass $$m_A=m_H=m_{H^\pm }<800$$ m A = m H = m H ± < 800 GeV, the wrong-sign Yukawa regions are excluded largely except for the tiny allowed region around $$\cos (\beta -\alpha )\in (0.2,0.3)$$ cos ( β - α ) ∈ ( 0.2 , 0.3 ) under the combined Higgs constraints. The excluded region is also nearly independent of parameter $$m_{12}$$ m 12 or $$\lambda v^2=m_A^2-m_{12}^2/(\sin \beta \cos \beta )$$ λ v 2 = m A 2 - m 12 2 / ( sin β cos β ) . The situation changes a lot after including loop corrections to the indirect searches, for example $$m_A=1500 \text {~GeV}$$ m A = 1500 GeV , the region with $$\lambda v^2<0$$ λ v 2 < 0 will be stronger constrained to be totally excluded. Whilst parameter space with $$\lambda v^2>0$$ λ v 2 > 0 would get larger survived wrong-sign region for $$m_A=800 ~\text {~GeV}$$ m A = 800 GeV compared to it at tree level. We also conclude Higgs direct searches works better on constraining $$\lambda v^2 \approx 0$$ λ v 2 ≈ 0 GeV range than theoretical constraints. We also find that the loop-level wrong-sign Yukawa limit only occurs at mass decoupling scale.

HIGGS PROPAGATOR IN THE PRESENCE OF STRONG DYNAMICS IN THE ELECTROWEAK SECTOR

2000 ◽  
Vol 15 (24) ◽  
pp. 1483-1490
Author(s):  
BIPIN R. DESAI ◽  
ALEXANDER R. VAUCHER
Keyword(s):  
Yukawa Coupling ◽  
Higgs Mass ◽  
Scattering Amplitude ◽  
Precision Measurements ◽  
The Standard Model ◽  
200 Gev ◽  
Low Mass ◽  
Electroweak Sector ◽  
Top Mass ◽  
Compositeness Scale

The Higgs propagator, in the presence of strong top-Yukawa coupling, is expressed in the form of dispersion integrals so that unitarity in top–antitop scattering amplitude is maintained. It is found that a large top-Yukawa coupling lowers the Higgs mass from the condensate-model value of twice the top mass (≈350 GeV) to 100–200 GeV consistent with the Z0 width precision measurements. The coupling is found to be ≈3.7 at the top-mass, much larger than the Standard Model value ≈1. It corresponds to a compositeness scale ≈1.4 TeV, which is consistent with top-color models. A second scalar state around 1 TeV also emerges as a solution in combination with the low mass Higgs.

scholarly journals Induced top-Yukawa coupling and suppressed Higgs mass parameters

2005 ◽  
Vol 71 (11) ◽  
Author(s):  
Tatsuo Kobayashi ◽  
Hiroaki Nakano ◽  
Haruhiko Terao
Keyword(s):  
Yukawa Coupling ◽  
Higgs Mass

HIGGS SECTOR CORRECTIONS TO THE ρ-PARAMETER IN THE TREE BREAKING SUPERGRAVITY MODELS

1988 ◽  
Vol 03 (10) ◽  
pp. 965-973
Author(s):  
C.C. CHEN ◽  
Y. KIKUCHI
Keyword(s):  
Supergravity Models ◽  
Yukawa Coupling ◽  
Higgs Mass ◽  
Higgs Sector

One-loop corrections to the ρ-parameter in supergravity models with large Yukawa coupling (i.e. in the limit of large Higgs mass) is calculated. It is found that the contributions from the Higgs sector cancel, hence no new constraints are obtained on the Higgs masses.

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