RECENT RESULTS FROM LEP

1993 ◽  
Vol 08 (08) ◽  
pp. 675-695 ◽  
Author(s):  
GÜNTER QUAST
Keyword(s):  
Standard Model ◽  
Center Of Mass ◽  
Electroweak Interaction ◽  
Electron Positron ◽  
Main Emphasis ◽  
The Standard Model ◽  
Large Electron Positron ◽  
Integrated Luminosity

Recent results from the four experiments ALEPH, DELPHI, L3 and OPAL at the large electron-positron collider, LEP, at CERN are reviewed. Analyzes from an integrated luminosity of about 20 pb −1 per experiment, taken at different center-of-mass energies within ±3 GeV around the Z0 resonance, are available now. Here, the main emphasis is put on the relevance of these measurements for precision tests of the Standard Model of the electroweak interaction.

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 RECENT τ LEPTON RESULTS FROM BABAR

2014 ◽  
Vol 35 ◽  
pp. 1460440
Author(s):  
ALBERTO LUSIANI
Keyword(s):  
Standard Model ◽  
Branching Fractions ◽  
Charged Particles ◽  
Babar Collaboration ◽  
Final States ◽  
Final State ◽  
Experimental Knowledge ◽  
Electron Positron ◽  
The Standard Model ◽  
Positron Collisions

We report recent measurements on τ leptons obtained by the BABAR collaboration using the entire recorded sample of electron-positron collisions at and around the Υ(4S) (about 470fb-1). The events were recorded at the PEP-II asymmetric collider at the SLAC National Accelerator Laboratory. The measurements include high multiplicity τ decay branching fractions with 3 or 5 charged particles in the final state, a search for the second class current the τ decay τ → πη′ν, τ branching fractions into final states containing two KS mesons, [Formula: see text], with h = π, K, and preliminary measurements of hadronic spectra of τ decays with three hadrons (τ- → h-h+h-ντ decays, where h = π, K). The results improve the experimental knowledge of the τ lepton properties and can be used to improve the precision tests of the Standard Model.

High(est) energy lepton colliders

2021 ◽  
pp. 2142016
Author(s):  
Roberto Franceschini
Keyword(s):  
Standard Model ◽  
Center Of Mass ◽  
High Energy ◽  
New Physics ◽  
Mass Energy ◽  
Center Of Mass Energy ◽  
Lepton Colliders ◽  
The Standard Model

We discuss the physics opportunities and challenges presented by high energy lepton colliders in the range of center-of-mass energy between few and several tens of TeV. The focus is on the progress attainable on the study of weak and Higgs interactions in connection with new physics scenarios motivated by the shortcomings of the Standard Model.

scholarly journals Search for an LSP Gluino from Stop Decay

2001 ◽  
Vol 16 (supp01b) ◽  
pp. 804-806
Author(s):  
PATRICE VERDIER
Keyword(s):  
Standard Model ◽  
Centre Of Mass ◽  
Mass Energy ◽  
Delphi Detector ◽  
The Standard Model ◽  
Model Predictions ◽  
Supersymmetric Models ◽  
Integrated Luminosity

In some supersymmetric models, the gluino [Formula: see text] could be light and stable, and would hadronize to form R-hadrons. Data collected by the DELPHI detector at centre-of-mass energy from 189 to 202 GeV corresponding to an integrated luminosity of 384 pb -1 have been used to search for R-hadrons from stop decay. The observed number of events is in agreement with the Standard Model predictions. Results are presented in terms of excluded regions in the plane [Formula: see text]

scholarly journals AFTER THE STANDARD MODEL: NEW RESONANCES AT THE LHC

2009 ◽  
Vol 24 (01) ◽  
pp. 1-15 ◽  
Author(s):  
GUSTAAF BROOIJMANS
Keyword(s):  
Large Hadron Collider ◽  
Standard Model ◽  
Hadron Collider ◽  
Center Of Mass ◽  
New Physics ◽  
Mass Energy ◽  
High Expectations ◽  
Center Of Mass Energy ◽  
Energy Regime ◽  
The Standard Model

Experiments will soon start taking data at CERN's Large Hadron Collider (LHC) with high expectations for discovery of new physics phenomena. Indeed, the LHC's unprecedented center-of-mass energy will allow the experiments to probe an energy regime where the standard model is known to break down. Here, the experiments' capability to observe new resonances in various channels is reviewed.

scholarly journals Search for single production of vectorlike top partners through th channel at the HE-LHC and FCC-hh

2021 ◽  
Vol 81 (7) ◽  
Author(s):  
Xi-Yan Tian ◽  
Liu-Feng Du ◽  
Yao-Bei Liu
Keyword(s):  
Standard Model ◽  
Production Cross ◽  
Branching Fraction ◽  
Hadron Collider ◽  
High Energy ◽  
New Physics ◽  
Beyond The Standard Model ◽  
The Standard Model ◽  
Single Production ◽  
Integrated Luminosity

AbstractThe vectorlike top partners are potential signature of some new physics beyond the Standard Model at the TeV scale. In this paper, we propose to search for the vectorlike T quark with charge 2/3 in the framework of a simplified model where the top partners only couples with the third generation of Standard Model quarks. We investigate the observability for electroweak production of a vectorlike T quark in association with a standard model bottom quark through the process $$pp \rightarrow T\bar{b}j$$ p p → T b ¯ j with the subsequent decay mode of $$T\rightarrow t(\rightarrow b W^+\rightarrow b \ell ^{+} \nu _{\ell })h( \rightarrow \gamma \gamma )$$ T → t ( → b W + → b ℓ + ν ℓ ) h ( → γ γ ) , at the proposed High Energy Large Hadron Collider (HE-LHC) and Future Circular Collider in hadron-hadron mode (FCC-hh) including the realistic detector effects. The 95% confidence level excluded regions and the $$5\sigma $$ 5 σ discovery reach in the parameter plane of $$\kappa _{T}-m_T$$ κ T - m T , are respectively obtained at the HE-LHC with the integrated luminosity of 15 ab$$^{-1}$$ - 1 and the FCC-hh with the integrated luminosity of 30 ab$$^{-1}$$ - 1 . We also analyze the projected sensitivity in terms of the production cross section times branching fraction at the HE-LHC and FCC-hh.

scholarly journals Possible bilepton resonances in like-sign pairs

2019 ◽  
Vol 34 (10) ◽  
pp. 1950076 ◽  
Author(s):  
Claudio Corianò ◽  
Paul H. Frampton
Keyword(s):  
Standard Model ◽  
Pair Production ◽  
Model Prediction ◽  
Standard Model Prediction ◽  
Mass Range ◽  
Entire Mass Range ◽  
Large Ratio ◽  
The Standard Model ◽  
Integrated Luminosity

We consider pair production of bileptons Y[Formula: see text]Y[Formula: see text] at the LHC for the presently accumulated integrated luminosity of 150/fb. It is shown that the entire mass range 800 GeV [Formula: see text]M(Y) [Formula: see text] 2000 GeV can be successfully searched. A bilepton resonance will have an exceptionally large ratio of signal to background because the Standard Model prediction is so infinitesimal. A 5[Formula: see text] discovery is quite feasible.

Search for physics beyond the Standard Model using jet observables

2015 ◽  
Vol 30 (31) ◽  
pp. 1546009 ◽  
Author(s):  
Konstantinos Kousouris
Keyword(s):  
Standard Model ◽  
Center Of Mass ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Final States ◽  
Proton Proton ◽  
Center Of Mass Energy ◽  
The Standard Model ◽  
8 Tev ◽  
Jet Observables

Jet observables have been exploited extensively during the LHC Run 1 to search for physics beyond the Standard Model. In this article, the most recent results from the ATLAS and CMS collaborations are summarized. Data from proton–proton collisions at 7 and 8 TeV center-of-mass energy have been analyzed to study monojet, dijet, and multijet final states, searching for a variety of new physics signals that include colored resonances, contact interactions, extra dimensions, and supersymmetric particles. The exhaustive searches with jets in Run 1 did not reveal any signal, and the results were used to put stringent exclusion limits on the new physics models.

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