QUASI SUPERSYMMETRY WITHIN THE STANDARD MODEL AND HIGGS MASS

1999 ◽  
Vol 14 (35) ◽  
pp. 2447-2452
Author(s):  
B. B. DEO ◽  
L. P. SINGH
Keyword(s):  
Standard Model ◽  
Top Quark ◽  
Degrees Of Freedom ◽  
Higgs Mass ◽  
Higgs Bosons ◽  
Tree Level ◽  
Mass Relation ◽  
The Standard Model ◽  
A Charge ◽  
Higgs Fields

The 12 bosonic degrees of freedom of the standard model (SM) are exactly matched by fermionic degrees of freedom of a single colored quark, e.g. top. Indeed, we construct a charge involving top-quark, gauge and Higgs fields which satisfy usual supersymmetry algebra. The colored quark states behave like the superpartners of gauge and Higgs bosons and vice versa. When this SUSY is broken, a mass relation must be satisfied at the tree level from which the mass of the Higgs is predicted to be 300.5±11 GeV.

scholarly journals Quantum stabilization of cosmic strings

2015 ◽  
Vol 30 (27) ◽  
pp. 1530022 ◽  
Author(s):  
H. Weigel ◽  
M. Quandt ◽  
N. Graham
Keyword(s):  
Standard Model ◽  
Top Quark ◽  
Cosmic String ◽  
Bound States ◽  
Degrees Of Freedom ◽  
Energy Levels ◽  
Binding Energies ◽  
Fermion Mass ◽  
The Standard Model ◽  
A Charge

In the standard model, stabilization of a classically unstable cosmic string may occur through the quantum fluctuations of a heavy fermion doublet. We review numerical results from a semiclassical expansion in a reduced version of the standard model. In this expansion, the leading quantum corrections emerge at one loop level for many internal degrees of freedom. The resulting vacuum polarization energy and the binding energies of occupied fermion energy levels are of the same order, and must therefore be treated on equal footing. Populating these bound states lowers the total energy compared to the same number of free fermions and assigns a charge to the string. Charged strings are already stabilized for a fermion mass only somewhat larger than the top quark mass. Though obtained in a reduced version, these results suggest that neither extraordinarily large fermion masses nor unrealistic couplings are required to bind a cosmic string in the standard model. Furthermore, we also review results for a quantum stabilization mechanism that prevents closed Nielsen–Olesen-type strings from collapsing.

scholarly journals Mass Reconstruction of MSSM Higgs Boson

2019 ◽  
Vol 64 (8) ◽  
pp. 714
Author(s):  
T. V. Obikhod ◽  
I. A. Petrenko
Keyword(s):  
Experimental Data ◽  
Higgs Boson ◽  
Standard Model ◽  
Top Quark ◽  
Computer Programs ◽  
Higgs Bosons ◽  
Associated Production ◽  
The Standard Model ◽  
The Masses ◽  
Mass Reconstruction

The problems of the Standard Model, as well as questions related to Higgs boson properties led to the need to model the ttH associated production and the Higgs boson decay to a top quark pair within the MSSM model. With the help of computer programs MadGraph, Pythia, and Delphes and using the latest kinematic cuts taken from experimental data obtained at the LHC, we have predicted the masses of MSSM Higgs bosons, A and H.

SEARCH FOR CHARGED HIGGS BOSONS IN DECAYS OF PAIR-PRODUCED TOP QUARKS AT DØ

2001 ◽  
Vol 16 (supp01a) ◽  
pp. 395-398
Author(s):  
◽  
PHILLIP GUTIERREZ
Keyword(s):  
Standard Model ◽  
Top Quark ◽  
Top Quarks ◽  
Higgs Bosons ◽  
Full Data ◽  
The Standard Model ◽  
Charged Higgs ◽  
Charged Higgs Bosons

We present a search for t → bH+ in [Formula: see text] candidate events at DØ based on two methods. The first seeks a deficit in signal relative to expectations from the standard model (SM). Such a deficit would imply the presence of a non-SM decay of the top quark. This search involves the full data sample of ≈ 110 pb -1 of [Formula: see text] collisions at [Formula: see text], collected with the DØ detector. The second method looks for charged Higgs decays to τ leptons (and associated neutrinos), and is based on a 62 pb -1 subset of the aforementioned data sample.

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 CONSTRAINTS ON A GENERAL HIGGS SECTOR FROM $K^0 - \tilde K^0$, $B_d - \bar B_d$ MIXING AND THE ε PARAMETER

1996 ◽  
Vol 11 (08) ◽  
pp. 675-686 ◽  
Author(s):  
DEBRUPA CHAKRAVERTY ◽  
ANIRBAN KUNDU
Keyword(s):  
Standard Model ◽  
Higgs Mass ◽  
Higgs Sector ◽  
Tree Level ◽  
Text Data ◽  
Mixing Angle ◽  
Stringent Constraint ◽  
The Standard Model ◽  
Charged Higgs ◽  
Scalar Sector

The scalar sector of the standard model is extended to include an arbitrary assortment of scalars. In the case where this assignment does not preserve p=1 at the tree-level, the departure from unity itself puts the most stringent constraint on the scalar sector, and where ptree=1 is maintained, useful bounds on the parameter space of the charged Higgs mass and the doublet-nondoublet mixing angle can arise from data on [Formula: see text], [Formula: see text] mixing and the ε parameter. These constraints turn out to be comparable (and in some cases, better) to those obtained from [Formula: see text] data.

scholarly journals Towards a Higgs mass determination in asymptotically safe gravity with a dark portal

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
Astrid Eichhorn ◽  
Martin Pauly ◽  
Shouryya Ray
Keyword(s):  
Standard Model ◽  
Top Quark ◽  
Quark Mass ◽  
Higgs Mass ◽  
Beyond The Standard Model ◽  
Top Quark Mass ◽  
Dark Sector ◽  
Central Value ◽  
The Standard Model ◽  
Higgs Portal

Abstract There are indications that an asymptotically safe UV completion of the Standard Model with gravity could constrain the Higgs self-coupling, resulting in a prediction of the Higgs mass close to the vacuum stability bound in the Standard Model. The predicted value depends on the top quark mass and comes out somewhat higher than the experimental value if the current central value for the top quark mass is assumed. Beyond the Standard Model, the predicted value also depends on dark fields coupled through a Higgs portal. Here we study the Higgs self-coupling in a toy model of the Standard Model with quantum gravity that we extend by a dark scalar and fermion. Within the approximations used in [1], there is a single free parameter in the asymptotically safe dark sector, as a function of which the predicted (toy model) Higgs mass can be lowered due to mixing effects if the dark sector undergoes spontaneous symmetry breaking.

scholarly journals High $$P_T$$ Higgs excess as a signal of non-local QFT at the LHC

2021 ◽  
Vol 81 (9) ◽  
Author(s):  
Xing-Fu Su ◽  
You-Ying Li ◽  
Rosy Nicolaidou ◽  
Min Chen ◽  
Hsin-Yeh Wu ◽  
...  
Keyword(s):  
Standard Model ◽  
Cross Sections ◽  
Higgs Mass ◽  
Vector Boson ◽  
Higgs Bosons ◽  
Enhanced Production ◽  
The Standard Model ◽  
Non Local ◽  
Infinite Derivative ◽  
Non Locality

AbstractNon-local extensions of the Standard Model with a non-locality scale $$\varLambda _{NL}$$ Λ NL have the effect of smearing the pointlike vertices of the Standard Model. At energies significantly lower than $$\varLambda _{NL}$$ Λ NL vertices appear pointlike, while beyond this scale all beta functions vanish and all couplings approach a fixed point leading to scale invariance. Non-local SM extensions are ghost free, with the non-locality scale serving as an effective cutoff to radiative corrections of the Higgs mass. We argue that the data expected to be collected at the LHC phase 2 will have a sensitivity to non-local effects originating from a non-locality scale of a few TeV. Using an infinite derivative prescription, we study modifications to heavy vector-boson cross sections that can lead to an enhanced production of boosted Higgs bosons in a region of the kinematic phase space where the SM background is very small.

scholarly journals SEARCHES FOR NEW PARTICLES

2002 ◽  
Vol 17 (23) ◽  
pp. 3336-3351 ◽  
Author(s):  
GAIL G. HANSON
Keyword(s):  
Standard Model ◽  
Top Quark ◽  
New Physics ◽  
Higgs Bosons ◽  
Standard Model Higgs Boson ◽  
The Past ◽  
Flavor Changing ◽  
The Standard Model ◽  
The Status ◽  
New Particles

The status of searches for new particles and new physics during the past year at the Fermilab Tevatron, at HERA and at LEP is summarized. A discussion of the hints for the Standard Model Higgs boson from LEP2 data is presented. Searches for non-Standard Model Higgs bosons are also described. Many searches have been carried out for the particles predicted by supersymmetry theories, and a sampling of these is given. There have also been searches for flavor changing neutral currents in the interactions of the top quark. In addition, searches for excited leptons, leptoquarks and technicolor are summarized.

scholarly journals HIGGS MASS IN THE STANDARD MODEL FROM COUPLING CONSTANT REDUCTION

2002 ◽  
Vol 17 (03) ◽  
pp. 335-346 ◽  
Author(s):  
B. ANANTHANARAYAN ◽  
J. PASUPATHY
Keyword(s):  
Renormalization Group ◽  
Standard Model ◽  
Top Quark ◽  
Higgs Mass ◽  
Gauge Coupling ◽  
Renormalization Scale ◽  
Coupling Constant ◽  
Top Quark Mass ◽  
The Standard Model ◽  
The One

Plausible interrelations between parameters of the standard model are studied. The empirical value of the top quark mass, when used in the renormalization group equations, suggests that the ratio of the color SU(3) gauge coupling g3, and the top coupling gt is independent of the renormalization scale. On the other hand, the variety of top-condensate models suggests that the Higgs self-coupling λ is proportional to [Formula: see text]. Invoking the requirement that the ratio [Formula: see text] is independent of the renormalization scale t, fixes the Higgs mass. The pole mass of the Higgs (which differs from the renormalization group mass by a few percent) is found to be ~ 154 GeV for the one-loop equations and ~ 148 GeV for the two-loop equations.

scholarly journals Extending low energy effective field theory with a complete set of dimension-7 operators

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
Yi Liao ◽  
Xiao-Dong Ma ◽  
Quan-Yu Wang
Keyword(s):  
Field Theory ◽  
Standard Model ◽  
Cross Sections ◽  
Effective Field Theory ◽  
Degrees Of Freedom ◽  
Independent Set ◽  
Effective Field ◽  
Low Energy ◽  
Tree Level ◽  
The Standard Model

Abstract We present a complete and independent set of dimension-7 operators in the low energy effective field theory (LEFT) where the dynamical degrees of freedom are the standard model five quarks and all of the neutral and charged leptons. All operators are non-Hermitian and are classified according to their baryon (∆B) and lepton (∆L) numbers violated. Including Hermitian-conjugated operators, there are in total 3168, 750, 588, 712 operators with (∆B, ∆L) = (0, 0), (0, ±2), (±1, ∓1), (±1, ±1) respectively. We perform the tree-level matching with the standard model effective field theory (SMEFT) up to dimension-7 (dim-7) operators in both LEFT and SMEFT. As a phenomenological application we study the effective neutrino-photon interactions due to dim-7 lepton number violating operators that are induced and much enhanced at one loop from dim-6 operators that in turn are matched from dim-7 SMEFT operators. We compare various neutrino-photon scattering cross sections with their counterparts in the standard model and highlight the new features. Finally, we illustrate how these effective interactions could arise from ultraviolet completion.

Sign in / Sign up

Export Citation Format

Share Document