scholarly journals Phenomenological study of theories beyond the standard model of particle physics in large hadron collider

2013 ◽  
Author(s):  
Kristaq Suxho
Keyword(s):  
Large Hadron Collider ◽  
Standard Model ◽  
Particle Physics ◽  
Phenomenological Study ◽  
Hadron Collider ◽  
Beyond The Standard Model ◽  
The Standard Model

scholarly journals Outstanding questions: physics beyond the Standard Model

2012 ◽  
Vol 370 (1961) ◽  
pp. 818-830 ◽  
Author(s):  
John Ellis
Keyword(s):  
Dark Matter ◽  
Higgs Boson ◽  
Large Hadron Collider ◽  
Standard Model ◽  
Particle Physics ◽  
Hadron Collider ◽  
Beyond The Standard Model ◽  
The Standard Model ◽  
The Difference ◽  
The Universe

The Standard Model of particle physics agrees very well with experiment, but many important questions remain unanswered, among them are the following. What is the origin of particle masses and are they due to a Higgs boson? How does one understand the number of species of matter particles and how do they mix? What is the origin of the difference between matter and antimatter, and is it related to the origin of the matter in the Universe? What is the nature of the astrophysical dark matter? How does one unify the fundamental interactions? How does one quantize gravity? In this article, I introduce these questions and discuss how they may be addressed by experiments at the Large Hadron Collider, with particular attention to the search for the Higgs boson and supersymmetry.

scholarly journals Unleashing the full power of LHCb to probe Stealth New Physics

2021 ◽  
Author(s):  
Martino Borsato ◽  
Xabier Cid-Vidal ◽  
Yuhsin Tsai ◽  
Carlos Vázquez Sierra ◽  
Jose Francisco Zurita ◽  
...  
Keyword(s):  
Large Hadron Collider ◽  
Standard Model ◽  
Hadron Collider ◽  
Theoretical Models ◽  
New Physics ◽  
Precision Measurements ◽  
Beyond The Standard Model ◽  
Lhcb Experiment ◽  
The Standard Model ◽  
Full Power

Abstract In this paper, we describe the potential of the LHCb experiment to detect Stealth physics. This refers to dynamics beyond the Standard Model that would elude searches that focus on energetic objects or precision measurements of known processes. Stealth signatures include long-lived particles and light resonances that are produced very rarely or together with overwhelming backgrounds. We will discuss why LHCb is equipped to discover this kind of physics at the Large Hadron Collider and provide examples of well-motivated theoretical models that can be probed with great detail at the experiment.

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.

Why Antimatter Matters

2015 ◽  
Vol 23 (1) ◽  
pp. 45-56 ◽  
Author(s):  
Alban Kellerbauer
Keyword(s):  
Large Hadron Collider ◽  
Discrete Symmetries ◽  
Particle Physics ◽  
Hadron Collider ◽  
Beyond The Standard Model ◽  
Parity Symmetry ◽  
The Standard Model ◽  
Charge Parity ◽  
First Time ◽  
The Universe

Almost ten years after the first production of cold antimatter at CERN, the confinement of antihydrogen has recently been achieved for the first time. Several experiments installed at the Antiproton Decelerator intend to test the symmetry between matter and antimatter by means of trapped anti-atoms. In addition, in the coming years it is planned to study the effect of gravity on antiparticles for the first time. Meanwhile, evidence from the Large Hadron Collider hinting at a violation of charge–parity symmetry beyond the Standard Model of particle physics has yet to be confirmed. A violation of the discrete symmetries that describe the relation between matter and antimatter could explain the excess of ordinary matter in the Universe.

scholarly journals EFFECTS OF UNIVERSAL EXTRA DIMENSIONS ON HIGGS SIGNALS AT LHC

2008 ◽  
Vol 23 (06) ◽  
pp. 823-834 ◽  
Author(s):  
SANTOSH KUMAR RAI
Keyword(s):  
Higgs Boson ◽  
Large Hadron Collider ◽  
Standard Model ◽  
Extra Dimension ◽  
Extra Dimensions ◽  
Hadron Collider ◽  
Beyond The Standard Model ◽  
Universal Extra Dimension ◽  
Major Focus ◽  
The Standard Model

A major focus at the Large Hadron Collider (LHC) will be on Higgs boson studies and it would be an interesting prospect to simultaneously probe for physics beyond the Standard Model in the Higgs signals. In this work we show as to what extent, the effects of universal extra dimension (UED) can be isolated at the LHC through the Higgs signals. By doing a detailed study of the different uncertainties involved in the measurement of the rates for the process pp →h →γγ, we estimate the extent to which these uncertainties can mask the effects of the contributions coming from UED.

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.

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