SEARCHES FOR NEW PHYSICS WITH JETS-PLUS-$E\hspace{-6.2pt}/_T$ SIGNATURES USING DATA-DRIVEN BACKGROUND ESTIMATES

2010 ◽  
Vol 25 (17) ◽  
pp. 1383-1401 ◽  
Author(s):  
PIERRE-HUGUES BEAUCHEMIN ◽  
PIERRE SAVARD
Keyword(s):  
Standard Model ◽  
Transverse Energy ◽  
Wide Spectrum ◽  
High Energy ◽  
New Physics ◽  
Early Data ◽  
Data Driven ◽  
Missing Transverse Energy ◽  
Model Independent ◽  
Using Data

Events featuring high energy jets and a large amount of missing transverse energy constitute a key signature for a wide spectrum of new physics models. In this review, the results of two searches with such signatures are presented. The benefits of performing these searches in a model-independent way are discussed and data-driven techniques used to estimate Standard Model backgrounds are described in detail. These data-driven techniques will be an important part of searches for new physics at the LHC, especially in the early data-taking period.

MONOJET EVENTS: FROM DARK MATTER TO EXTRA DIMENSIONS, A SEARCH FOR THE EXOTICS USING THE STANDARD MODEL

2013 ◽  
Vol 28 (08) ◽  
pp. 1330012
Author(s):  
PIERRE-HUGUES BEAUCHEMIN ◽  
REYHANEH REZVANI
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Extra Dimensions ◽  
Transverse Energy ◽  
Large Extra Dimensions ◽  
High Energy ◽  
New Physics ◽  
High Transverse Momentum ◽  
Final State ◽  
The Standard Model

Monojet events consist in event topologies with a high transverse momentum jet and a large amount of missing transverse energy. They constitute a promising final state that could lead to phenomena beyond the Standard Model. The theoretical models giving rise to such a signature include the pair production of Weakly Interacting Massive Particles, as dark matter candidates, and models of large extra dimensions. Monojet events can even be used to measure the Standard Model properties of Z boson decays, provided that the precision of the analysis is high enough. Such precision can be achieved by using data-driven determinations of the Standard Model contributions to monojet events. Exotics searches for new physics in such a final state have been performed at all high energy hadronic collider experiments since SPS. The ATLAS and CMS analyses with 7 TeV LHC data provide the latest and most useful information obtained from monojet studies. Their results are presented and discussed in this review paper.

SEARCH FOR SUSY WITH $/\kern-7.2pt E_T$ AND JETS AT CDF

2001 ◽  
Vol 16 (supp01b) ◽  
pp. 793-796
Author(s):  
◽  
RICHARD HAAS
Keyword(s):  
Standard Model ◽  
Transverse Energy ◽  
New Physics ◽  
Spontaneous Breaking ◽  
Beyond The Standard Model ◽  
Heavy Flavor ◽  
Missing Transverse Energy ◽  
Breaking Parameter ◽  
Scalar Top ◽  
Search Modes

Events with signatures involving large missing transverse energy [Formula: see text] are among the quintessential search modes for R-parity conserving supersymmetry. CDF has conducted two recent analyses for supersymmetry which use [Formula: see text] and jets. The [Formula: see text] and monojet signature is employed to determine process independent limits for the production of new physics beyond the Standard Model and then applied to models of spontaneous breaking of supersymmetry to determine limits on the supersymmetry breaking parameter and the gravitino mass. Direct searches for scalar top and scalar bottom quarks within the framework of supersymmetric models are performed using a signature of [Formula: see text] and two heavy flavor jets. Since the data is found to be consistent with Standard Model expectations, limits are determined in the mass planes [Formula: see text] and [Formula: see text].

scholarly journals Disentangling QCD and new physics in D → πℓ+ℓ−

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Aoife Bharucha ◽  
Diogo Boito ◽  
Cédric Méaux
Keyword(s):  
Standard Model ◽  
Branching Ratio ◽  
Branching Ratios ◽  
New Physics ◽  
Operator Product ◽  
Beyond The Standard Model ◽  
Spectral Functions ◽  
The Standard Model ◽  
Model Independent ◽  
Weak Annihilation

Abstract In this paper we consider the decay D+ → π+ℓ+ℓ−, addressing in particular the resonance contributions as well as the relatively large contributions from the weak annihilation diagrams. For the weak annihilation diagrams we include known results from QCD factorisation at low q2 and at high q2, adapting the existing calculation for B decays in the Operator Product Expansion. The hadronic resonance contributions are obtained through a dispersion relation, modelling the spectral functions as towers of Regge-like resonances in each channel, as suggested by Shifman, imposing the partonic behaviour in the deep Euclidean. The parameters of the model are extracted using e+e− → (hadrons) and τ → (hadrons) + ντ data as well as the branching ratios for the resonant decays D+ → π+R(R → ℓ+ℓ−), with R = ρ, ω, and ϕ. We perform a thorough error analysis, and present our results for the Standard Model differential branching ratio as a function of q2. Focusing then on the observables FH and AFB, we consider the sensitivity of this channel to effects of physics beyond the Standard Model, both in a model independent way and for the case of leptoquarks.

SEARCH FOR NEW PHYSICS IN eμX DATA AT THE TEVATRON USING SLEUTH: A QUASI-MODEL-INDEPENDENT SEARCH STRATEGY FOR NEW PHYSICS

2001 ◽  
Vol 16 (supp01b) ◽  
pp. 888-890
Author(s):  
◽  
BRUCE KNUTESON
Keyword(s):  
Standard Model ◽  
Search Strategy ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Final States ◽  
Final State ◽  
The Standard Model ◽  
Model Independent

We present a quasi-model-independent search for physics beyond the standard model. We define final states to be studied, and construct a rule that identifies a set of variables appropriate for any particular final state. A new algorithm ("Sleuth") searches for regions of excess in the space of those variables and quantifies the significance of any detected excess. After demonstrating the sensititvity of the method, we apply it to the semi-inclusive channel eμX collected in ≈108 pb -1 of [Formula: see text] collisions at [Formula: see text] at the DØ experiment at the Fermilab Tevatron. We find no evidence of new high pT physics in this sample.

scholarly journals W-boson production in the high energy electron-photon collisions

2019 ◽  
pp. 41-50
Author(s):  
Ivan A. Shershan ◽  
Tatiana V. Shishkina
Keyword(s):  
Standard Model ◽  
Cross Sections ◽  
W Boson ◽  
High Energy ◽  
New Physics ◽  
Coupling Constants ◽  
Boson Production ◽  
The Standard Model ◽  
Electron Photon ◽  
W Boson Production

In this paper the analysis of W-boson production process in high-energy electron-photon collisions as a tool to search for deviations from the Standard Model is considered. In particular, a set of extended gauge models, including anomalous multi-boson interactions, are discussed as a promising way for «new physics» study. A numerical analysis of the total cross sections of the processes was carried out. The lowest order radiative corrections in the soft-photon approximation within the Standard Model are taken into account. Calculations beyond the Standard Model was performed, the kinematic features of the cross sections were identified. The restrictions on the anomalous triple gauge boson coupling constants were analyzed and the kinematic areas to the search for their manifestations were obtained during the experiments at the International Linear Collider. The paper shows that the search for «new physics» effects based on electron-photon collisions around the W-boson production peak is the maximal promising. It was also shown that future experiments at high luminosity linear colliders will significantly clarify the constraints on anomalous gauge coupling constants.

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.

SEARCHES FOR NEW PHYSICS AT HIGH ENERGY COLLIDERS

2005 ◽  
Vol 20 (22) ◽  
pp. 5164-5173 ◽  
Author(s):  
BEATE HEINEMANN
Keyword(s):  
Standard Model ◽  
Extra Dimensions ◽  
High Energy ◽  
New Physics ◽  
Standard Model Background ◽  
Beyond The Standard Model ◽  
Gauge Bosons ◽  
Model Background ◽  
The Standard Model

Recent searches for physics beyond the Standard Model at high energy colliders are presented. The main focus is on searches for supersymmetry, extra dimensions and new gauge bosons. In all search analyses the data are found to agree well with the Standard Model background expectation and no evidence for contributions from physics beyond the Standard Model is found. The data are thus used to place limits on new physics scenarios.

Implementation of the ATLAS-SUSY-2018-32 analysis (sleptons and eletroweakinos with two leptons and missing transverse energy; 139 fb−1)

2020 ◽  
pp. 2141005
Author(s):  
Jack Y. Araz ◽  
Benjamin Fuks
Keyword(s):  
Pair Production ◽  
Transverse Energy ◽  
Center Of Mass ◽  
New Physics ◽  
Missing Transverse Energy ◽  
Missing Energy ◽  
Final State ◽  
Proton Proton ◽  
Weak Boson ◽  
Center Of Mass Energy

We present the implementation in MadAnalysis 5 of the ATLAS-SUSY-2018-32 search for new physics and document the validation of this re-implementation. This analysis targets, with 139 fb[Formula: see text] of proton–proton collisions at a center-of-mass energy of 13 TeV recorded by the ATLAS detector, the electroweak pair production of supersymmetric charginos and sleptons when they further decay into a final state comprising a pair of leptons and missing energy. The validation of our work is based on three [Formula: see text]-parity conserving supersymmetric benchmark setups that feature, respectively, chargino pair-production followed by decays into leptons via an intermediate weak boson, chargino pair-production followed by chargino cascade decays into leptons through a slepton mediator, and slepton pair-production followed by slepton direct decays into leptons.

scholarly journals Physics Beyond The Standard Model: Experimental

2001 ◽  
Vol 16 (supp01a) ◽  
pp. 92-103 ◽  
Author(s):  
R. L. Culbertson
Keyword(s):  
Standard Model ◽  
Extra Dimensions ◽  
Large Extra Dimensions ◽  
High Energy ◽  
Higgs Bosons ◽  
Beyond The Standard Model ◽  
The Standard Model ◽  
Model Independent

The search for physics beyond the Standard Model includes Technicolor particles, Higgs Bosons, compositeness, many variations of Supersymmetry, large extra dimensions, model-independent searches for anomalies, and other topics. This article reports a subset of these ongoing searches at the high-energy colliders, Tevatron, HERA and LEP.

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