scholarly journals Current Issues in the Phenomenology of Particle Physics

1997 ◽  
Vol 12 (31) ◽  
pp. 5531-5554 ◽  
Author(s):  
John Ellis
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Present Status ◽  
Particle Physics ◽  
Neutrino Oscillations ◽  
Experimental Tests ◽  
Grand Unification ◽  
The Standard Model

The present status of the Standard Model and its experimental tests are reviewed, including indications on the likely mass of the Higgs boson. Also discussed are the motivations for supersymmetry and grand unification, searches for sparticles at LEP, neutrino oscillations, and the prospects for physics at the LHC.

scholarly journals The Standard Model

2012 ◽  
Vol 370 (1961) ◽  
pp. 805-817 ◽  
Author(s):  
Tara Shears
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Particle Physics ◽  
Experimental Tests ◽  
Fundamental Particles ◽  
The Standard Model ◽  
Fundamental Forces ◽  
Physics Experiments

The Standard Model is the theory used to describe the interactions between fundamental particles and fundamental forces. It is remarkably successful at predicting the outcome of particle physics experiments. However, the theory has not yet been completely verified. In particular, one of the most vital constituents, the Higgs boson, has not yet been observed. This paper describes the Standard Model, the experimental tests of the theory that have led to its acceptance and its shortcomings.

scholarly journals The gravitational condensate of the higgs field

2019 ◽  
Author(s):  
Vitaly Kuyukov
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Higgs Field ◽  
Higgs Bosons ◽  
Grand Unification ◽  
Gravitational Potential Energy ◽  
Mass Hierarchy ◽  
The Standard Model ◽  
Cell Condensation ◽  
The Difference

This paper analyses a method of producing the Higgs mass via the gravitational field. This approach has become very popular in recent years, as the consideration of other forces do not help in solving the problem of mass hierarchy. Not understand the difference between scales of the standard model and Grand unification theory. Here, we present a heuristic mechanism which eliminated this difference. The idea is that the density of the condensate of the Higgs is increased so that it is necessary to take into account self gravitational potential energy of the Higgs boson. The result is as follows. The mass of the Higgs is directly proportional to the cell density of the Higgs bosons. Or else the mass of the Higgs is inversely proportional to the cell volume, which is the Higgs boson in the condensate. The most interesting dimension of this cell condensation is equal to the scale of Grand unification. This formula naturally combines the scale of the standard model and Grand unification through gravitational condensation.

scholarly journals An approach to Grand Unification

2021 ◽  
Vol 2081 (1) ◽  
pp. 012010
Author(s):  
Peter Rowlands
Keyword(s):  
Standard Model ◽  
Particle Physics ◽  
Grand Unification ◽  
Planck Mass ◽  
The Standard Model

Abstract Around the time of the completion of the Standard Model of particle physics in the 1970s, schemes were put forward for unifying the three gauge interactions (electric, strong and weak) using the renormalization equations at an energy approaching the Planck mass. Though these looked promising, the exact unification never materialised, and doubts have been raised about whether this Grand Unification can be achieved. It may be possible, however, to create Grand Unification at the Planck mass if we start with a radical examination of the nature of the colour model of quarks.

scholarly journals Synthesis on Heavy Higgs from the Standard Model to 2HDM and Beyond

2020 ◽  
Vol 18 ◽  
pp. 110-142
Author(s):  
Abdeljalil Habjia
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Cross Sections ◽  
Particle Physics ◽  
Hadron Collider ◽  
Signal Strength ◽  
Beyond The Standard Model ◽  
Decay Channels ◽  
Higgs Decay ◽  
The Standard Model

In the context of particle physics, within the ATLAS and CMS experiments at large hadron collider (LHC), this work presents the discussion of the discovery of a particle compatible with the Higgs boson by the combination of several decay channels, with a mass of the order of 125.5 GeV. With increased statistics, that is the full set of data collected by the ATLAS and CMS experiments at LHC ( s1/2 = 7GeV and s1/2 = 8GeV ), the particle is also discovered individually in the channel h-->γγ with an observed significance of 5.2σ and 4.7σ, respectively. The analysis dedicated to the measurement of the mass mh and signal strength μ which is defined as the ratio of σ(pp --> h) X Br(h-->X) normalized to its Standard Model where X = WW*; ZZ*; γγ ; gg; ff. The combined results in h-->γγ channel gave the measurements: mh = 125:36 ± 0:37Gev, (μ = 1:17 ± 0:3) and the constraint on the width Γ(h) of the Higgs decay of 4.07 MeV at 95%CL. The spin study rejects the hypothesis of spin 2 at 99 %CL. The odd parity (spin parity 0- state) is excluded at more than 98%CL. Within the theoretical and experimental uncertainties accessible at the time of the analysis, all results: channels showing the excess with respect to the background-only hypothesis, measured mass and signal strength, couplings, quantum numbers (JPC), production modes, total and differential cross-sections, are compatible with the Standard Model Higgs boson at 95%CL. Although the Standard Model is one of the theories that have experienced the greatest number of successes to date, it is imperfect. The inability of this model to describe certain phenomena seems to suggest that it is only an approximation of a more general theory. Models beyond the Standard Model, such as 2HDM, MSSM or NMSSM, can compensate some of its limitations and postulate the existence of additional Higgs bosons.

The Discovery of a Higgs Particle at the Large Hadron Collider

2015 ◽  
Vol 23 (1) ◽  
pp. 57-70
Author(s):  
Aleandro Nisati
Keyword(s):  
Higgs Boson ◽  
Large Hadron Collider ◽  
Standard Model ◽  
Particle Physics ◽  
Hadron Collider ◽  
Scientific Programme ◽  
Fundamental Particle ◽  
The Standard Model ◽  
8 Tev ◽  
The Masses

The Large Hadron Collider (LHC) at CERN is the highest energy machine for particle physics research ever built. In the years 2010–2012 this accelerator has collided protons to a centre-mass-energy up to 8 TeV (note that 1 TeV corresponds to the energy of about 1000 protons at rest; the mass of one proton is about 1.67×10–24 g). The events delivered by the LHC have been collected and analysed by four apparatuses placed alongside this machine. The search for the Higgs boson predicted by the Standard Model and the search for new particles and fields beyond this theory represent the most important points of the scientific programme of the LHC. In July 2012, the international collaborations ATLAS and CMS, consisting of more than 3000 physicists, announced the discovery of a new neutral particle with a mass of about 125 GeV, whose physics properties are compatible, within present experimental and theoretical uncertainties, to the Higgs boson predicted by the Standard Model. This discovery represents a major milestone for particle physics, since it indicates that the hypothesized Higgs mechanism seems to be responsible for the masses of elementary particles, in particular W± and Z0 bosons, as well as fermions (leptons and quarks). The 2013 Physics Nobel Prize has been assigned to F. Englert and P. Higgs, ‘for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles, and which recently was confirmed through the discovery of the predicted fundamental particle, by the ATLAS and CMS experiments at CERN's Large Hadron Collider’.

scholarly journals The pre-LHC Higgs hunt

2015 ◽  
Vol 373 (2032) ◽  
pp. 20140039 ◽  
Author(s):  
G. Dissertori
Keyword(s):  
Higgs Boson ◽  
Large Hadron Collider ◽  
Standard Model ◽  
Particle Physics ◽  
Hadron Collider ◽  
Precise Data ◽  
Electron Positron ◽  
The Standard Model ◽  
The World ◽  
Large Electron Positron

Enormous efforts at accelerators and experiments all around the world have gone into the search for the long-sought Higgs boson, postulated almost five decades ago. This search has culminated in the discovery of a Higgs-like particle by the ATLAS and CMS experiments at CERN's Large Hadron Collider in 2012. Instead of describing this widely celebrated discovery, in this article I will rather focus on earlier attempts to discover the Higgs boson, or to constrain the range of possible masses by interpreting precise data in the context of the Standard Model of particle physics. In particular, I will focus on the experimental efforts carried out during the last two decades, at the Large Electron Positron collider, CERN, Geneva, Switzerland, and the Tevatron collider, Fermilab, near Chicago, IL, USA.

scholarly journals A BRIEF REVIEW OF THE SEARCH FOR ISOLATABLE FRACTIONAL CHARGE ELEMENTARY PARTICLES

2004 ◽  
Vol 19 (35) ◽  
pp. 2595-2610 ◽  
Author(s):  
MARTIN L. PERL ◽  
ERIC R. LEE ◽  
DINESH LOOMBA
Keyword(s):  
Standard Model ◽  
Present Status ◽  
Particle Physics ◽  
Elementary Particles ◽  
Electron Charge ◽  
Search Methods ◽  
Fractional Charge ◽  
The Standard Model ◽  
Production Mechanisms

Since the initial measurements of the electron charge a century ago, experimenters have faced the persistent question as to whether elementary particles exist that have charges that are fractional multiples of the electron charge. In the standard model of particle physics the quarks are such particles, but it is assumed that quarks cannot be individually isolated, the quarks always being confined inside hadrons. This paper is a brief review of the present status of searches for isolatable fractional charge particles such as a lepton-like particle with fractional charge or an unconfined quark. There have been a very large number of searches but there is no confirmed evidence for existence of isolatable fractional charge particles. It may be that they do not exist, but it is also possible that they are very massive or that their production mechanisms are very small so that they have been missed by existing searches. Therefore the aim of this review is to urge (a) the invention of ways to substantially increase the range of known search methods and (b) to urge the invention of new search methods for isolatable fractional charge particles.

SEARCH FOR THE STANDARD MODEL HIGGS BOSON WITH THE ATLAS DETECTOR

2013 ◽  
Vol 22 (07) ◽  
pp. 1330015
Author(s):  
◽  
DOMIZIA ORESTANO
Keyword(s):  
Higgs Boson ◽  
Large Hadron Collider ◽  
Standard Model ◽  
Particle Physics ◽  
Hadron Collider ◽  
Atlas Detector ◽  
Standard Model Higgs Boson ◽  
Cern Large Hadron Collider ◽  
Atlas Experiment ◽  
The Standard Model

This document presents a brief overview of some of the experimental techniques employed by the ATLAS experiment at the CERN Large Hadron Collider (LHC) in the search for the Higgs boson predicted by the standard model (SM) of particle physics. The data and the statistical analyses that allowed in July 2012, only few days before this presentation at the Marcel Grossman Meeting, to firmly establish the observation of a new particle are described. The additional studies needed to check the consistency between the newly discovered particle and the Higgs boson are also discussed.

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