1 / 18

Introduction to B Physics in ATLAS Detector at LHC

Introduction to B Physics in ATLAS Detector at LHC. Ahmet BİNGÜL Department of Engineering Physics University of Gaziantep. Feb 2010. Outline. Introduction Physics in ATLAS Experiment ATLAS B-Physics Programme Trigger Simulation of the Events Example Reconstruction. Introduction.

hadassah-haynes
Télécharger la présentation

Introduction to B Physics in ATLAS Detector at LHC

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Introduction to B Physics in ATLAS Detector at LHC Ahmet BİNGÜL Department of Engineering Physics • University of Gaziantep Feb 2010

  2. Outline • Introduction • Physics in ATLAS Experiment • ATLAS B-Physics Programme • Trigger • Simulation of the Events • Example Reconstruction

  3. Introduction • This is a short introduction to some current topics in B-Physics in ATLAS Detector at LHC. • Wewilllook at briefly • the LHC • the ATLAS detector

  4. LHC: Large Hadron Collider • PHYSICS • Higgs Boson(s) • Supersymmetric particles • furher quarks and/or hadrons • Big-Bang and mini-black holes • Circumference 27 km • ~100 m underground • Protons ve Pb nuclei will collide • Cost: 3 billions € EP328 – Particle Physics

  5. LHC About p-p collisions • Max proton energy: E = 7 TeV • Velocity: v = 0.999999991 c ~ 300,000 km/s • 2808 x 2808 bunches of protons • # of p / bunch = 1011 • Bunch diameter = 16 μm (hair 50 μm) • Max Luminosity: L = 1034 cm‒2s‒1 • Collision frequency f = 1/25 ns = 40,000,000 Hz = 40 MHz Debris of a collision E = mc2

  6. LHC Detectors CMS

  7. ATLAS Detector (http://atlas.ch) 22 m 44 m YFD

  8. Physics Groups in ATLAS https://twiki.cern.ch/twiki/bin/view/Atlas/AtlasResults • Standard Model (SM) • QCD • W/Z and jets • Electroweak measurements • Higgs • Discovery of SM Higgs Boson (for several decay channels) • Charged Higgs Boson searces

  9. Physics in ATLAS • B-Physics • Heavy quarkonium physics with early ATLAS data • Production cross-sections measurements • Study of B-hadrons • Rare B-dacays • Top Physics • t-tbar pair cross-section • Top mass, charge, spin measurements • Rare top decays

  10. Physics in ATLAS • SUSY • Discovery of SUSY particles • Test of SUSY models • Exotics • Black hole Production • New quarks and leptons • Heavy Ion • Results of Pb-Pb collisions • Heavy quark production • Jet studies • Quarkonia Reconstruction

  11. ATLAS B-Physics Programme B-Physicsprogrammecoversmanyaspects of beautyflavourphysics. • bymeasuringproductioncross-sectionsof beautyandcharmhadronsandof heavy-flavourquarkonia (J/ψand Y (upsilon)),ATLAS willprovidesensitivetests of QCD predictions. • ATLAS willstudytheproperties of entirefamily of B-mesons (B+, Bd, Bs, Bc) andB-baryons (Y, Λb ) • Precisemeasurements of weakB-hadronsdecays • Raredecays of B-hadrons

  12. The rate of B-hadron production at the LHC is enormous thanks to the large hadronic cross-sectionfor b-quark production and the high luminosity of the machine (L = 1033 / s.cm2) • About one collision in every hundred will produce a b-quark pair. (better S:N ratio wrt Tevatron) • At the LHC, ATLAS and CMS will face stiff competition fromLHCb, which is a dedicated B-physics experiment.ATLAS and CMS will improve the combined precision of B-physicsmeasurements from the LHC.

  13. In ATLAS, B-Physicspotentialbeginsduringearly data taking at lowluminosity (L = 1031/ s.cm2) • MainB-Physicsmeasurementswill be made at theluminosity of L = 1033/ s.cm2. • Withtheintegrateluminosity of Lint = 10 pb-1ATLAS will be abletoregisterabout1.3x105eventscontaining • eitherdirectlyproducedfrom p-p collisions • orindirectlyfromdecays of B-hadrons.

  14. During the period of Lint = 10 – 100 pb-1 • B-physics and heavy quarkiona signatures will helpunderstand the detector performance and muon trigger • promt J/ψ and Y events andB-hadron decays to muon pairs via J/ψ will be analysed • followind exclusive decays will be stuied • During the period of Lint = 200 pb-1 – 1 fb-1 • Statistics will be simalar to Tevatron • SM rare decays will be studied (e.g. ) • During the period of Lint = 10 – 30 fb-1 (around 3 years) • Luminosity will mostly be L = 1033/ s.cm2 • Measuremnts of Λb and osciallation pghenomena of Bs – Bs_bar

  15. Trigger • All B-Physics studies include trigger reconstruction • ATLAS have three levels of trigger • L1 – Hardware trigger • L2 - L3 – Software trigger • B-Physics events is initiated • by a L1 di-muon trigger • by a L1 single-muon trigger • L2 is used to combine ID tracks with L1 muon • each muon has to have pT > 4 GeV (later rising to 6-8 GeV) • After getting L1 muon(s), cuts on invariant mass and secondary vertex reconstruction of B decay products are used.

  16. Simulation of Events • Some 1 million B-hadron events, along with 4x105 prompt J/ψ and Y as well as c-cbar events were produced using PYHTIA 6.4. • The events were passed trough detector simulation based on GEANT4.

  17. Example Reconstruction

More Related