ALTO is a future very-high-energy (VHE) gamma-ray observatory, which is currently in the prototyping phase. The proposed design of the array consists of more than a thousand Water Cherenkov Detectors (WCDs) each coupled with a liquid scintillator. The observatory will be installed at an altitude of 4 to 5 km above the sea level in the Southern Hemisphere. WCDs sample the secondary particles in...
We present methods to find anomaly-free gauged U(1) Froggatt-Nielsen type models using results from real algebraic geometry. These methods should be of general interest for model building beyond the Standard Model when rational charges are required. We consider models with a gauged U(1) flavour symmetry with one flavon and provide several model examples based on different physical assumptions....
At high densities and temperatures the standard quantum field theoretical approach to particle physics should be modified. Temperature enters explicitly in observables, for instance in decay rates, and under certain conditions expected results deviate significantly from the case of zero-temperature. I have put together a collection of thermal decay rates covering scalars, pseudo scalars and...
It is well-known that the spinor-helicity method can significantly simplify the calculations of both Feynman diagrams and scattering amplitudes. In this work, we attempt to further simplify the Feynman-diagram calculation by converting the spinor-helicity method into a flow method, analogous to allowing a one-line journey from Feynman diagram to inner products. The cases of massless QED and...
The sources and accelerating mechanisms of cosmic rays, with energies as high as 10^{20} eV, are not completely understood. Gamma ray bursts (GRBs) have long been considered as promising source candidates, yet so far don't show evidence for a correlated neutrino signal to prove this hypothesis. Previous analyses by IceCube have searched for neutrino in coincidence with the prompt phase of the...
An important part of the ATLAS dark matter (DM) search programme is comprised of searches for new resonances (dark matter mediators) decaying to hadronic final states. This talk will give an overview of one such analysis: the recently-published search for low-mass dark-matter mediators decaying to jets, with an associated high-pT photon. This search triggers on an associated photon in order to...
Current estimates put Dark Matter to 26.8% of the energy-matter content of the universe, but very little is known about it other than its gravitational interactions. Efforts to learn more about Dark Matter include searching for it at high energy particle colliders. The lack of information about the nature of Dark Matter makes this a complicated task, and many searches are performed in...
Recently, searches for pair production of Higgs bosons in several final states have been carried out by the ATLAS exeperiment at the Large Hadron Collider (LHC). This study focuses on the search for non-resonant di-Higgs production decaying to a final state with two $b$-jets and two $\tau$-leptons using 36.1 fb$^{-1}$ of data recorded by the ATLAS detector. The analysis for this process has...
With strong constraints on the mass of vector-like quarks (VLQ) from the top partner (T) decay T->SM, it is necessary to consider non-standard decays of such partners. This talk considers models where the VLQ decays to a BSM (pseudo)scalar (S) and a top-quark. The scalar is assumed to be fermiophobic, and dominantly decays into two SM bosons. With dedicated analyses, we realistically quantify...
Experimental observations and advanced computer simulations in High Energy Physics (HEP) paved way for the recent discoveries at the Large Hadron Collider (LHC) at CERN. Currently, Monte Carlo simulations account for a very significant amount of computational resources of the Worldwide LHC Computing Grid (WLCG).
In looking at the recent trends in modern computer architectures we see a...
One overarching objective of science is to further our understanding of the universe, from its early stages to its current state and future evolution. This depends on gaining insight on the universe’s most macroscopic components, for example galaxies and stars, as well as describing its smallest components, namely elementary particles and nuclei and their interactions. It is clear that this...
A key observable for new physics at the Large Hadron Collider is the displaced vertex signature. Heavy and hitherto unseen particles can be produced and travel a short distance prior to decaying into Standard Model particles. A search for a such signature associated with a muon and charged particles from the ATLAS collaboration is shown in this poster. The search is based on a data sample of...
The possibility of dark matter being a composite particle, such as a hadron under a gauge group, is becoming increasingly appealing as the non-excluded part of parameter space for the WIMP paradigm is shrinking. In this talk I will present a ongoing search for a resonance originating from a QCD-like dark sector, that decays to two dark partons which then hadronise to form ”dark jets”. The...
