Presentation is loading. Please wait.

Presentation is loading. Please wait.

H1 EventsJoachim Meyer DESY 20051 HERA e-p scattering events observed in the H1Detector.

Published byJoana Bottom Modified over 10 years ago

Similar presentations

Presentation on theme: "H1 EventsJoachim Meyer DESY 20051 HERA e-p scattering events observed in the H1Detector."— Presentation transcript:

1 H1 EventsJoachim Meyer DESY 20051 HERA e-p scattering events observed in the H1Detector

2 H1 EventsJoachim Meyer DESY 20052 The idea The realisation The eventsThe Physics

3 H1 EventsJoachim Meyer DESY 20053 What we think what happens, when we scatter electrons on protons at HERA Hadrons or neutrino Proton W

4 H1 EventsJoachim Meyer DESY 20054 e p The H1 detector at the e-p storage ring HERA Tracking chambers Calorimeters Instrumented iron system Forward muon detector

5 H1 EventsJoachim Meyer DESY 20055 Calorimeter

6 H1 EventsJoachim Meyer DESY 20056 Principle of particle identification

7 H1 EventsJoachim Meyer DESY 20057 Principle of particle identification

8 H1 EventsJoachim Meyer DESY 20058 An event display : What do we see ? Energy depositions in calorimeter Hits and reconstructed tracks in tracker R-Z view : e-p interaction point e p Hadronic calorimeter Electromagnetic calorimeter e Hadrons Scattered Electron

9 H1 EventsJoachim Meyer DESY 20059 Same event in radial view : Energydepositions in calorimeter Hits and reconstructed tracks in tracker Hadronic calorimeter e X

10 H1 EventsJoachim Meyer DESY 200510 The hits (fired wires) in the tracking chambers Gas volumen with sense wires at HV Hits = Signals recorded on sense wires

11 H1 EventsJoachim Meyer DESY 200511..and the result of the pattern recognition program trying to combine the hits to tracks (red lines) : Tracks bend in magnetic field : momentum determination Electron Hadrons Central tracking chambers

12 H1 EventsJoachim Meyer DESY 200512.. and the same procedure in R-Z view : Electron Hadrons Central tracking chambers

13 H1 EventsJoachim Meyer DESY 200513 another event : Here you see the CJC hits including the ‘mirror hits’ (ambiguity not resolved) Curling tracks track Mirror tracks

14 H1 EventsJoachim Meyer DESY 200514 and here the tracks found by the pattern regognition program successfully fitted to the event vertex Note : The curling tracks seen on the last picture are not vertex-fitted

15 H1 EventsJoachim Meyer DESY 200515 Side view (R-z) Transverse view (R-Phi) Calorimeter energies Event : Combined view (R-z, R-Phi, calorimeter energies) Electron and hadronic system X balanced in transverse momentum e e X X

16 H1 EventsJoachim Meyer DESY 200516 Electron Photon Proton leaves unseen down the beam pipe A very simple event :

17 H1 EventsJoachim Meyer DESY 200517 Here an electron and two photons are recorded Electrons ‘easily’ radiate photons

18 H1 EventsJoachim Meyer DESY 200518 Photons tend to convert to e+ e- pairs in material Photon Chamber material e+ e- Pair e Photon X e

19 H1 EventsJoachim Meyer DESY 200519 This looks like a di-electron, but is not. A photon converted to a small angle e+ e- pair within the beam pipe e e Conversion point

20 H1 EventsJoachim Meyer DESY 200520 Another ‘simple’ event : A elastic dimuon production Muons penetrate thick materials ! MUON IRON

21 H1 EventsJoachim Meyer DESY 200521 An inelastic dimuon production without visible scattered electron X X

22 H1 EventsJoachim Meyer DESY 200522 Another inelastic dimuon production without visible scattered electron X X The muons are low energetic and don’t read the iron,they are ‘mips’ in calorimeter

23 H1 EventsJoachim Meyer DESY 200523 Another inelastic dimuon production without visible scattered electron X X One muon identified in calorimeter, the other in the iron system

24 H1 EventsJoachim Meyer DESY 200524 In the ‘forward direction’ muons are measured by the ‘Forward Toroid Muon Detector’ Forward Toroid Muon Detector

25 H1 EventsJoachim Meyer DESY 200525 Here it is very visible how electron, muon and photon are distinguished e e

26 H1 EventsJoachim Meyer DESY 200526 No detector is perfect : Here the scattered electron enters a nonsensitive region (Phi-crack) of the electromagnetic calorimeter Electron penetrates into hadronic part of calorimeter e e Such an effect has to be recognized in the physics analysis ! Phi-crack in em. calorimeter

27 H1 EventsJoachim Meyer DESY 200527 Converted photon e e z-crack Phi-crack Here a photon converts and the e+ e- pair enters an insensitive region of the em. calorimeter (z- and Phi-cracks)

28 H1 EventsJoachim Meyer DESY 200528 Muons also come from the sky …… This is BACKGROUND, which we do not like !

29 H1 EventsJoachim Meyer DESY 200529 Interaction of cosmic primaries create showers in the atmosphere, and multimuons reach us here

30 H1 EventsJoachim Meyer DESY 200530 Cosmic dimuon seen in calorimeter and central track detector

31 H1 EventsJoachim Meyer DESY 200531 Another cosmic dimuon … wires in iron system pads in iron system Muon radiates

32 H1 EventsJoachim Meyer DESY 200532 …and it can be even more fierce ….

33 H1 EventsJoachim Meyer DESY 200533 Muons interact rarely, but they do Hit pattern in the central track detector (transverse view)

34 H1 EventsJoachim Meyer DESY 200534 Here a cosmic muon radiates a photon which gets absorbed in the calorimeter. The muon then exits the detector. The radiated energy deposition

35 H1 EventsJoachim Meyer DESY 200535 A HERA ep event overlayed with a cosmic muon Cosmic muon ep event Such an effect has to be recognized in the physics analysis !

36 H1 EventsJoachim Meyer DESY 200536 There is not only background from cosmics but also from the Proton beam interacting with the restgas Event vertex is here e-p event vertex should be here P - beam

37 H1 EventsJoachim Meyer DESY 200537 Scattering of the HERA-proton on a nucleus of the restgas. The nucleus dissociates into lots of protons (positive tracks) and neutrons

38 H1 EventsJoachim Meyer DESY 200538 Another kind of beam-related background : Protons lost in the ring create showers and muons from decaying pions accompany the beam and may be visible in the detector Beamhalo muons

39 H1 EventsJoachim Meyer DESY 200539 Here a NC event is overlayed by a beam halo muon Such an effect has to be recognized in the physics analysis !

40 H1 EventsJoachim Meyer DESY 200540 Back to HERA -e-p scattering events : A very forward Dimuon event Muons bent in the magnetic field of the forward toroid magnet These muons are decay products of the famous J/Psi particle

41 H1 EventsJoachim Meyer DESY 200541 Another event where the J/Psi particle decays into two muons (this time ‘backward’) Iron Muon

42 H1 EventsJoachim Meyer DESY 200542 e e Backward calorimeter Central Tracker particle has a sister the The

43 H1 EventsJoachim Meyer DESY 200543 Most events are much more complicated : Very high track multiplicity Small visible energy in calorimeter

44 H1 EventsJoachim Meyer DESY 200544 The Central Silicon Detector (CST) measures hits very precisely (10 micrometer). search for secondary vertices of heavy quark (charm,bottom) decays : Zoom in …. H1 Central Tracker CST CST Reconstruction Secondary Vertex

45 H1 EventsJoachim Meyer DESY 200545 Another event with detailed track measurement in the CST CST : R-z viewCST : R-Phi view

46 H1 EventsJoachim Meyer DESY 200546 Tracks seen in the Forward Silicon Track Detector (FST) FST CJC 1 CJC 2 CST Forward Direction The FST allows to cover very small forward angles

47 H1 EventsJoachim Meyer DESY 200547 Often there is activity in forward direction around the beam pipe : that are the ‘left overs’ of the ‘broken’ proton Electron scattered under small angle into backward calorimeter

48 H1 EventsJoachim Meyer DESY 200548 But in 10% of all cases there is no forward activity : the proton stays intact, and disappears down the beam pipe pe e-tagger

49 H1 EventsJoachim Meyer DESY 200549 Back to the Deep-Inelastic-Electron-Proton-Scattering (DIS) Incident e Scattered e The electron is scattered back by 160 degree and got an energy of 300 GeV. Very virulent scattering ! e e X X 27 GeV

50 H1 EventsJoachim Meyer DESY 200550.and here its even more virulent. The squared momentum transfer is, this corresponds to a space resolution of Notice : The hadronic system X is a well collimated bundle of particles. This is called JET Jet e e Jets are the ‘footprints’ of the quarks and gluons

51 H1 EventsJoachim Meyer DESY 200551 A NC-DIS event with two jets e e Jet1 Jet2 e J1 J2

52 H1 EventsJoachim Meyer DESY 200552 Here the ‘forward scattered’ electron radiates a very energetic photon electron photon

53 H1 EventsJoachim Meyer DESY 200553 In general the photon is ‘near’ to the electron. Here both created a single electromagnetic shower in the calorimeter, but can be resolved in the tracker electron-track converted photon tracks combined electromagnetic shower in calorimeter

54 H1 EventsJoachim Meyer DESY 200554 Another event, but here the scatted electron and photon are far apart It is likely that here the photon is of hadronic origin (prompt photon) e X

55 H1 EventsJoachim Meyer DESY 200555 There is also a chance that two photons are radiated : e e

56 H1 EventsJoachim Meyer DESY 200556 In this NC event a muon is produced within the hadronic final state X e e X X

57 H1 EventsJoachim Meyer DESY 200557 Hadrons X A new event class : In this event the hadrons X are NOT balanced by an electron ! The Neutrino does not leave a trace in the detector This is a different type of DIS event It is pure weak interaction. It is a Charged Current (CC) event X X

58 H1 EventsJoachim Meyer DESY 200558 The CC event with the highest recorded transverse momentum The quark on which the electron scattered had nearly all of the proton momentum

59 H1 EventsJoachim Meyer DESY 200559 This is a CC event with a pronounced two-jet structure j1 j2 j1

60 H1 EventsJoachim Meyer DESY 200560 CC event with three jets J1 J2 J3

61 H1 EventsJoachim Meyer DESY 200561 Also CC events exhibit multijet structures

62 H1 EventsJoachim Meyer DESY 200562 In this CC event the ‘Jet’ is very broad

63 H1 EventsJoachim Meyer DESY 200563 A CC event with a photon radiated from the incident electron

64 H1 EventsJoachim Meyer DESY 200564 This CC event shows a muon separated from the jet This could be a muon produced in the semileptonic decay of a charm quark

65 H1 EventsJoachim Meyer DESY 200565 Another event class : ‘Photoproduction’ Here two jets are visible, but the scattered electron is not recorded, it leaves the detector under very small scattering angle Jet 1 Jet 2 Needles of energy e

66 H1 EventsJoachim Meyer DESY 200566 A dijet event with very high dijet-mass

67 H1 EventsJoachim Meyer DESY 200567 Here a THREE-JET-EVENT J1 J2 J3 J1 J2 J3

68 H1 EventsJoachim Meyer DESY 200568 A very high three-jet mass

69 H1 EventsJoachim Meyer DESY 200569 Here 5 jets are visible, there is no limit in the number. J1 J2 J3 J4 J5 Quarks radiate gluons, which in turn may radiate gluons or produce quark- antiquark pairs. All turn (if energetic enough) to visible jet structures

70 H1 EventsJoachim Meyer DESY 200570 The jets can be so energetic that they are not absorbed in the main calorimeter but leak out into the instrumented iron yoke. Leakage Energy

71 H1 EventsJoachim Meyer DESY 200571 It happens that a jet is associated to only a single charged particle Explanation : -statistical fluctuation ? -physics reason Tau –Lepton ?

72 H1 EventsJoachim Meyer DESY 200572 We also record events with an unbalanced jet associated to a single particle. Are these events with isolated tau-mesons and missing transverse momentum ?

73 H1 EventsJoachim Meyer DESY 200573 Sometimes strange features show up : Muonic Electromagnetic Neutral behavior Explanation ??

74 H1 EventsJoachim Meyer DESY 200574 The most exciting issue : Are there new phenomema, we don’t expect ? We have seen DIS - events But this looks like Fluctuating background or sign of new physics ? X X Muon (As such forbidden in HEP Standard Model)

75 H1 EventsJoachim Meyer DESY 200575 A similar event, but here muon and hadronic jet are not back-to-back : clear evidence for unobserved particle (neutrino ?) ?

76 H1 EventsJoachim Meyer DESY 200576 Similar event, but here also the scattered electron is visible. This allows to reconstruct the invariant mass of the muon-neutrino-system. It turns out to be 82 GeV. That’s close to the W mass. H1 sees more events than expected from this reaction. New physics ? e e

77 H1 EventsJoachim Meyer DESY 200577 Here only an unbalanced electron is visible. This topology is predominantly expected for e e

78 H1 EventsJoachim Meyer DESY 200578 The W decays also into quark-antiquark producing two jets. The jet-jet-mass is 80 GeV, just the known W-mass. Jet1 Jet2 Jet1 Jet2

79 H1 EventsJoachim Meyer DESY 200579 The W particle has a sister, the Z, of 90 GeV mass, decaying into lepton pairs

80 H1 EventsJoachim Meyer DESY 200580 In this event an even more massive e+ e- pair ….. : What physics is that ?

81 H1 EventsJoachim Meyer DESY 200581 A collinear electron pair Such events we were used to see at the electron-positron collider PETRA

82 H1 EventsJoachim Meyer DESY 200582 Here a positron and 2 electrons are recorded. Presumably the scattered electron and a pair created in the interaction Note : All ‘electrons’ are well confined in the electromagnetic part (green) of the calorimeter

83 H1 EventsJoachim Meyer DESY 200583 There are also dilepton events with different lepton types : Electron and muon e e muon

84 H1 EventsJoachim Meyer DESY 200584 Here it is evident that a pair of muons is produced e e Muon2 identified as minimum ionizing particle in calorimeter

85 H1 EventsJoachim Meyer DESY 200585 A pair of tau-mesons with the scattered electron e

86 H1 EventsJoachim Meyer DESY 200586 Summary

87 H1 EventsJoachim Meyer DESY 200587 The Method: Nobel prize 2004 Cartoon The Data e p scattering

88 H1 EventsJoachim Meyer DESY 200588 Physics Results Protonstructure : Quarks and GluonsElectroweak Unification examples :..and many more …..

89 H1 EventsJoachim Meyer DESY 200589 All this became possible thanks to the work of the H1 members…… Some members of the H1 Collaboration Work at the innermost parts of the H1 detector

90 H1 EventsJoachim Meyer DESY 200590 …and thanks to HERA…... the worlds most powerful microscope H1

Download ppt "H1 EventsJoachim Meyer DESY 20051 HERA e-p scattering events observed in the H1Detector."

Similar presentations

Masterclass 20081 Introduction to hands-on Exercise Aim of the exercise Find out what happens in proton-proton collisions at the LHC as seen by the ATLAS.

Masterclass Introduction to hands-on Exercise Aim of the exercise Find out what happens in proton-proton collisions at the LHC as seen by the ATLAS.
Experimental Particle Physics

Experimental Particle Physics
Masterclass 20081 Introduction to hands-on Exercise Aim of the exercise Identify electrons, muons, neutrinos in the ATLAS detector Types of Events (particles.

Masterclass Introduction to hands-on Exercise Aim of the exercise Identify electrons, muons, neutrinos in the ATLAS detector Types of Events (particles.
B. List, ETH Zürich Page 1 Report from H1: PRC Open Session, 30.10.2002 H1: Status and Prospects Benno List Institute for Particle Physics, ETH Zürich.

B. List, ETH Zürich Page 1 Report from H1: PRC Open Session, H1: Status and Prospects Benno List Institute for Particle Physics, ETH Zürich.
HEP Experiments Detectors and their Technologies Sascha Marc Schmeling CERN.

HEP Experiments Detectors and their Technologies Sascha Marc Schmeling CERN.
Detectors & Measurements: How we do physics without seeing… Prof. Robin D. Erbacher University of California, Davis References: R. Fernow, Introduction.

Detectors & Measurements: How we do physics without seeing… Prof. Robin D. Erbacher University of California, Davis References: R. Fernow, Introduction.
PHENIX Decadal Plan o Midterm upgrades until 2015 o Long term evolution after 2015 Dynamical origins of spin- dependent interactions New probes of longitudinal.

PHENIX Decadal Plan o Midterm upgrades until 2015 o Long term evolution after 2015 Dynamical origins of spin- dependent interactions New probes of longitudinal.
An accelerator beam of muon neutrinos is manufactured at the Fermi Laboratory in Illinois, USA. The neutrino beam spectrum is sampled by two detectors:

An accelerator beam of muon neutrinos is manufactured at the Fermi Laboratory in Illinois, USA. The neutrino beam spectrum is sampled by two detectors:
Introduction to Hadronic Final State Reconstruction in Collider Experiments Introduction to Hadronic Final State Reconstruction in Collider Experiments.

Introduction to Hadronic Final State Reconstruction in Collider Experiments Introduction to Hadronic Final State Reconstruction in Collider Experiments.
Basic Measurements: What do we want to measure? Prof. Robin D. Erbacher University of California, Davis References: R. Fernow, Introduction to Experimental.

Basic Measurements: What do we want to measure? Prof. Robin D. Erbacher University of California, Davis References: R. Fernow, Introduction to Experimental.
Particle Detection and Identification

Particle Detection and Identification
1 BaBar Collaboration Randall Sobie Institute for Particle Physics University of Victoria.

1 BaBar Collaboration Randall Sobie Institute for Particle Physics University of Victoria.
Detecting Particles Martin Gallacher – University of Birmingham.

Detecting Particles Martin Gallacher – University of Birmingham.
The Physics Potential of the PHENIX VTX and FVTX Detectors Eric J. Mannel WWND 13-Apr-2012.

The Physics Potential of the PHENIX VTX and FVTX Detectors Eric J. Mannel WWND 13-Apr-2012.
Sourav Tarafdar Banaras Hindu University For the PHENIX Collaboration Hard Probes 2012 Measurement of electrons from Heavy Quarks at PHENIX.

Sourav Tarafdar Banaras Hindu University For the PHENIX Collaboration Hard Probes 2012 Measurement of electrons from Heavy Quarks at PHENIX.
Anatomy of a collider detector Silicon vertex detectors- small but important.

Anatomy of a collider detector Silicon vertex detectors- small but important.
CMS Masterclass 2015. It’s a time of exciting new discoveries in particle physics! At CERN, the LHC and its experiments are underway. ATLAS and CMS, the.

CMS Masterclass It’s a time of exciting new discoveries in particle physics! At CERN, the LHC and its experiments are underway. ATLAS and CMS, the.
Calibration of the ZEUS calorimeter for electrons Alex Tapper Imperial College, London for the ZEUS Collaboration Workshop on Energy Calibration of the.

Calibration of the ZEUS calorimeter for electrons Alex Tapper Imperial College, London for the ZEUS Collaboration Workshop on Energy Calibration of the.
“Experimental Observation of Isolated Large Transverse Energy Electrons with Associated Missing Energy at = 540 GeV” Okamura Yusuke Shibata lab. G. Arnison.

“Experimental Observation of Isolated Large Transverse Energy Electrons with Associated Missing Energy at = 540 GeV” Okamura Yusuke Shibata lab. G. Arnison.
LHC Detectors 101 Vivek Sharma (with slides stolen from talks of several people ) 1 Good review article: ARNPS 2006, “General purpose detectors for large.

LHC Detectors 101 Vivek Sharma (with slides stolen from talks of several people ) 1 Good review article: ARNPS 2006, “General purpose detectors for large.

Similar presentations

Ads by Google