Exploring New Physics with the ATLAS Experiment at LHC

1. Experimental Particle Physics at UiOActivities and Master Thesis Subjectswww.uio.no/~farido/HEPP-Hovedfagwithin theHigh Energy Particle Physics Projectfor more information contact us

2. Join the High Energy Particle Physics Project, Work with the ATLAS experiment at LHC, Discover New Physics ... ... and maybe take part in a Revolution. Particle physics or “High Energy Physics” is the activity which seeks to discover and understand the basic constituents of matter and the interactions among them. The present state of our knowledge is contained in the Standard Model (SM). The SM is however incomplete.  The Large Hadron Collider LHC at the CERN laboratory in Geneva will be the first particle accelerator to explore directly a new energy frontier, the TeV scale. By colliding beams of protons at 14 TeV, the LHC will probe deeper into matter than ever before, reproducing conditions in the first picoseconds in the life of the Universe. Starting in 2007, four  experiments, among them ATLAS, will collect data that might reveal new physics phenomena.  Among the open questions,  LHC may reveal the origin of particle masses, explain dark matter, investigate extra space dimensions, and help understand the origin of matter in the Universe.  Several aspects of LHC physics touch on the interface between particle physics and cosmology. In a sense, particle physics is the science of matter, energy, space and time. Links:HEPPBigBang MachineEPF

3. Towards higher symmetries ... a Particle physicist’s tool High Symmetry “Chaos” Astronomy Chemistry Biology... Elementary Particle Physics or High Energy Physics A simple theory of everything Various theories describing Various aspects of Nature Physics beyond SM Experiment not accessible LHC contributions SM describes Nature up to ~200 GeV

4. What is the origin of mass? • Are masses due to the Higgs Field? • Does the Higgs particle exist? • How many Higgs particles? • Does Supersymmetry exist? • Any Relation to Cosmology? • Universe’s Inflation? • Dark Energy? t u c b s d e “Search for Higgs at LHC with ATLAS - Study of production of Higgs at LHC through the decays: H gg or H ZZ l+l-l+l- - Take into account a detailed simulation of the ATLAS detector - Study signal and background and optimise your analysis code - Make use of the Grid infrastructure - Produce large samples of simulated events - Perform distributed analysis of data stored all over the world. H-> gg H-> ZZ* ->l+l-l+l-

5. Wake-up SUSY wake-up! Supersymmetry unifies matter and force particles – “matter-force duality”, relates Fermions and Bosons. And helps Grand Unification (GUT). • Any relation to Superstrings or Cosmological Dark Matter? SPIN ½ FERMIONS electrons SPIN 0 BOSONS LSP Squarks Quarks LSP Sleptons SUSY SUSY Leptons Generations of Smatter Generations of Matter Photino Fermions Gluino Gravitino “Search for SUSY at LHC with ATLAS” - Study of production of Supersymmetric particles at LHC through some characteristic decay chains involving Lightest Supersymmetric Particles (LSP) - Take into account detailed simulation of the ATLAS detector - Study signal and background and optimise your analysis code - Make use of the Grid infrastructure - Produce large samples of simulated events - Perform distributed analysis of data stored all over the world. Bosons

6. Why is gravity much weaker than electromagnetism? - Do Extra Dimensions (ED) exist? Can we observe themat the TeV already scale, far from the Planck scale? - Superstrings leave in 11 dimensions Search for ED using missing Energy (ADD) - Proton-proton collisions at high energies can produce a graviton - the mediator of gravity - along with jets of familiar elementary particles. - The graviton flies out of the brane (into the extra dimensions) carrying away E/P. Search for ED using missing Energy (RS) - Look for Narrow Graviton resonances: G e+e- , m+m- , ZZ , W+W- , jet-jet - Study signal and background and optimise your analysis code - Take into account a detailed simulation of the ATLAS detector - Make use of the Grid infrastructure - Produce large samples of simulated events - Perform distributed analysis of data stored all over the world EM Strength gravity r M(e+e-)

7. Black hole in ATLAS? - A BH would decay equally to all SM particles - Look for events involving high particle multiplicities and no missing E/P - Improve and study current BH generators - Study signal and background and optimise your analysis code - Make use of the Grid infrastructure - Produce large samples of simulated events - Perform distributed analysis of data stored all over the world

8. Study Standard Model processes sensitive to new physics, such as - B0 (Ks) m+m- - SM predictions lead to very small branching ratios (BR). - These BR can be drastically enhanced by the presence of supersymmetric or other exotic particles. Search for CP violation in Bottom meson decays - Matter-antimatter asymmetry in the Universe? - B0 J/psi Ks ; J m+m- , Ks p+p- - B0 F Ks ; F  K+K- , Ks p+p– Study of SM processes and measure of corresponding parameters (mass, width, BR, …) - Zo production and decay into l+l- and jet-jet - W production and decay into l nl or and jet-jet - Top quark production - Take into account a detailed simulation of the ATLAS detector - Study signal and background and optimise your analysis code - Make use of the Grid infrastructure - Produce large samples of simulated events - Perform distributed analysis of data stored all over the world.

9. If you are more interested in some experimental work, take part in the Cosmic run next autumn. This involves data taking with most of the ATLAS detector. Of particular interest is the analysis of the muon events in order to measure the resolution of SiliCon Tracker partly built in Oslo. Other studies involve tracking through the whole detector, alignment and efficiency determinations. ~24m First ATLAS Cosmic Muon recorded in the Hadronic Calorimeter

10. If you are interested in physics related computing you can contribute to develop methods to track particles through the ATLAS detector and reconstruct them efficiently. This involves both simulation and analysis of beam-test data as well as Cosmic muon data that ATLAS will record during fall 2006. The latter gives you the possibility to take part in a first data taking before LHC will be swithed on in 2007. Computer programs reconstruct the particle trajectories and energies in each collision (each “event”)

11. Another LHC Challenge: Data Volume and Distribution! - Participation in development of Grid middleware within NorduGrid - Participation in ATLAS Data Challenges - Data Management issues - Distribution production of simulated events - Access and Distributed Analysis of Physics Data GRID: next Revolution after the World Wide Web?