Conveners
Monday afternoon: Monday afternoon
- Riccardo Catena (Chalmers University of Technology)
- Erin O'Sullivan (Uppsala University)
ALICE has observed that strangeness production increases with multiplicity in
small collision systems (proton-proton and proton-lead collisions) at LHC energies.
This means that proton-proton collisions cannot be seen as
incoherent sums of parton-parton collisions, an idea that has been central in
most proton-proton generators, for example PYTHIA. To accommodate the new ALICE results,...
The constituents of dark matter are still unknown, and the viable possibilities span a very large mass range. Specific scenarios for the origin of dark matter sharpen the focus on a narrower range of masses: the natural scenario where dark matter originates from thermal contact with familiar matter in the early Universe requires the DM mass to lie within about an MeV to 100 TeV. Considerable...
The presentation will summarize the scope and status of the SHIFT project, which is a collaboration between experimental and theoretical particle physicists at Chalmers, Stockholm and Uppsala. The focus is to search for top partners that can protect the mass of the Higgs boson from large quantum corrections. We study possible signatures of such top partners and search for them using data from...
Conventional dark matter (DM) searches are looking for scattering events between DM particles of the galactic halo and nuclei in a detector target. For kinematic reasons, they lose sensitivity to masses below typically a few GeV. The most prominent strategy to probe sub-GeV masses is to search for DM-electron scatterings.
In modelling these interactions, the literature has been dominated by...
We study the consequences of the hadron-quark phase transition in failing core-collapse supernovae, which lead to the stellar-mass black-hole formation. For progenitor models with a range of compactness, the supernova core collapses and bounces for a second time due to the appearance of quarks. However, this second bounce cannot overcome the ram pressure of the envelope and result in the...
In the years following the initial discovery of a new scalar boson, data-analyses related to the Higgs sector in and beyond the Standard Model continue to be a central part of the ATLAS physics program. A number of new results have recently become available, following the exploitation of the full Run 2 proton-proton collision dataset recorded by the ATLAS experiment at the LHC. This talk...
While the LHC completed its second run in 2018, analyses of the 140 fb⁻¹ data recorded by the ATLAS experiment during that period are in full swing. In order to provide the best possible sensitivity to Standard Model and new physics, the collaboration is reprocessing the full Run-2 dataset with improved calibrations as well as simulations in all relevant areas.
The four ATLAS-Sweden groups...
Electromagnetic form factors serve to explore the intrinsic structure of nucleons and their strangeness partners. With electron scattering at low energies the electromagnetic moments and radii of nucleons can be deduced. The corresponding experiments for hyperons are limited because of their unstable nature. Only for one process this turns to an advantage: the decay of the neutral Sigma...
In recent papers we proposed the Chirality-flow method, a novel method that allows a one-line journey from a Standard-Model Feynman diagram to a complex number, which can then be easily squared. In this talk I will describe this method and show its power in some representative examples.
The European Consortium for Astroparticle Theory (EuCAPT) was founded in 2019 with the aim of supporting and bringing together the European community of theoretical astroparticle physicists and cosmologists. This short talk will explain the organisational structure, scope and plans of EuCAPT.
Gamma ray bursts (GRBs) have long been considered as a possible source of ultra high energy cosmic rays, which makes them a promising neutrino source candidate. Previous IceCube searches for neutrino correlations with GRBs focused on the prompt phase of the GRB and found no significant correlation between neutrino events and the observed GRBs. This motivates us to extend our search beyond the...
Abstract
A new type of short beam separation scans (“Emittance Scans”) was initiated at the ATLAS Experiment, at the CERN LHC, in 2018. Emittance scans are beam separation scans in which the beams are scanned across each other in the x and y planes. At every separation point we estimate the average interactions, also called the luminosity of the accelerator. These studies involved searching...
Starting in 2027, the HL-LHC will begin operation and deliver unprecedented luminosities allowing higher-precision measurements and searches for new physics processes. One central problem that arises in the ATLAS detector when reconstructing event information is to separate the interesting hard scatter (HS) vertex from uninteresting pileup (PU) vertices in a spatially compact environment. This...
The current ATLAS inner detector provided tracking and vertex reconstruction with high precision and efficiency during Run 1 and Run 2, and will continue to provide similar performance for Run 3 of the Large Hadron Collider (LHC). However, with the increased radiation damage and bandwidth requirements from the future High Luminosity LHC (HL-LHC), the ATLAS inner detector needs to be upgraded....
The High-Luminosity LHC (HL-LHC) is expected to provide a data set of 4000 fb-1 allowing precision Higgs physics and search for deviations from the Standard Model. The HL-LHC poses new challenges in terms of radiation hardness and requires an unprecedented ability to select interesting collisions (trigger) at the collision frequency with a fully digital trigger.
The ATLAS Hadronic Tile...
We calculate fixed-order electroweak corrections to the angular coefficients parameterizing the Drell-Yan process in the Z-boson mass range. We examine how the electroweak corrections affect the Lam-Tung relation, which was measured at the LHC to deviate from the SM predictions. For the calculations, we introduce a technical single lepton cut in order to avoid a double-soft/collinear...
