scholarly journals Hunting New Physics with ATLAS

2018 ◽  
Vol 182 ◽  
pp. 02089
Author(s):  
Vasiliki A. Mitsou ◽  

Highlights from recent new physics searches with the ATLAS detector at the CERN LHC are presented in this paper. They include searches for extra-dimension models, compositeness, new gauge bosons, supersymmetry, among others. Results are based on analyses of pp collision data recorded at a centre-of-mass energy of 13 TeV.

2018 ◽  
Vol 182 ◽  
pp. 02096
Author(s):  
James Pinfold

MoEDAL is a pioneering experiment designed to search for highly ionizing messengers of new physics such as magnetic monopoles or massive (pseudo-)stable charged particles, that are predicted to exist in a plethora of models beyond the Standard Model. It started data taking at the LHC at a centre-of-mass energy of 13 TeV, in 2015. MoEDAL’s ground breaking physics program defines a number of scenarios that yield potentially revolutionary insights into such foundational questions as: are there extra dimensions or new symmetries; what is the mechanism for the generation of mass; does magnetic charge exist; and what is the nature of dark matter. MoEDAL’s purpose is to meet such far-reaching challenges at the frontier of the field. We will present an overview of the MoEDAL detector, including the planned MAPP subdetector, as well as MoEDAL’s physics program. The concluding section highlights our first physics results on Magnetic Monopole production, that are the world’s best for Monopoles with multiple magnetic charge.


2018 ◽  
Vol 182 ◽  
pp. 02012
Author(s):  
L. Bellagamba

This report presents an overview of some of the most recent results obtained by the ATLAS Collaboration using pp and heavy-ion collisions at the LHC. The review is not intended to be comprehensive and includes recent updates on the Higgs boson properties, precision Standard Model measurements, as well as searches for new physics. Most of the results exploit the data collected in the last LHC run, providing pp collisions at a centre of mass energy of 13 TeV.


2020 ◽  
Vol 18 ◽  
pp. 66-77
Author(s):  
Abdeljali Habjial

The Standard Model production of four top quarks in the process pp --> tttt at a center-of-mass energy s1/2=13 Tev. The data collected by the ATLAS detector represents an impressive study potential, with an integrated luminosity of around 139 fb-1. In this manuscript, we present the production process of four top quarks at the LHC as well as some new physics models associated with this process. These models are studied in analysis carried. Some preliminary results are presented, in particular those of a new method for estimating background noise due to false leptons developed.


2018 ◽  
Vol 182 ◽  
pp. 02065
Author(s):  
Nicolas Köhler

Naturalness arguments for weak-scale supersymmetry favour supersymmetric partners of the third generation quarks with masses not too far from those of their Standard Model counterparts. Top or bottom squarks with masses less than or around one TeV can also give rise to direct pair production rates at the Large Hadron Collider (LHC) that can be observed in the data sample recorded by the ATLAS detector. This document presents recent ATLAS results from searches for direct top and bottom squark pair production considering both R-parity conserving and R-parity violating scenarios, using the data collected during the LHC Run 2 at a centre-of-mass energy of √s = 13 TeV.


2019 ◽  
Author(s):  
Wing Sheung Chan

Lepton flavour violation in the charged lepton sector is an unambiguous signal of physics beyond the Standard Model. Searches for lepton flavour violation in decays of the ZZ boson with the ATLAS detector is reported, focusing on decays into an electron or muon and a hadronically decaying \tauτ-lepton, using pppp collisions data with a centre-of-mass energy of 13 TeV. Upper limits on the branching ratios of lepton-flavor-violating decays are set at the 95% confidence level: \mathcal{B}(Z\to e\tau) < 5.8\times10^{-5}ℬ(Z→eτ)<5.8×10−5 and \mathcal{B}(Z\to \mu\tau) < 2.4\times10^{-5}ℬ(Z→μτ)<2.4×10−5. When combined with a previous ATLAS result based on pppp collisions data with a centre-of-mass energy of 8 TeV, an upper limit of \mathcal{B}(Z\to \mu\tau) < 1.3\times10^{-5}ℬ(Z→μτ)<1.3×10−5 is obtained.


2019 ◽  
Vol 79 (12) ◽  
Author(s):  
G. Aad ◽  
◽  
B. Abbott ◽  
D. C. Abbott ◽  
O. Abdinov ◽  
...  

AbstractMeasurements of $$K_S^0$$KS0 and $$\Lambda ^0$$Λ0 production in $$t\bar{t}$$tt¯ final states have been performed. They are based on a data sample with integrated luminosity of 4.6 $$\mathrm {fb}^{-1}$$fb-1 from proton–proton collisions at a centre-of-mass energy of 7 TeV, collected in 2011 with the ATLAS detector at the Large Hadron Collider. Neutral strange particles are separated into three classes, depending on whether they are contained in a jet, with or without a b-tag, or not associated with a selected jet. The aim is to look for differences in their main kinematic distributions. A comparison of data with several Monte Carlo simulations using different hadronisation and fragmentation schemes, colour reconnection models and different tunes for the underlying event has been made. The production of neutral strange particles in $$t\bar{t}$$tt¯ dileptonic events is found to be well described by current Monte Carlo models for $$K_S^0$$KS0 and $$\Lambda ^0$$Λ0 production within jets, but not for those produced outside jets.


Sign in / Sign up

Export Citation Format

Share Document