Presentation is loading. Please wait.

Presentation is loading. Please wait.

26/07/2002C.Diaconu High Pt Multileptons at HERA 1 Cristinel Diaconu CPP Marseille On behalf of H1 and ZEUS collaboration Lepton pair production in ep.

Published byMabel Merritt Modified over 8 years ago

Similar presentations

Presentation on theme: "26/07/2002C.Diaconu High Pt Multileptons at HERA 1 Cristinel Diaconu CPP Marseille On behalf of H1 and ZEUS collaboration Lepton pair production in ep."— Presentation transcript:

1 26/07/2002C.Diaconu High Pt Multileptons at HERA 1 Cristinel Diaconu CPP Marseille On behalf of H1 and ZEUS collaboration Lepton pair production in ep collisions at HERA

2 26/07/2002C.Diaconu High Pt Multileptons at HERA 2 Introduction HERA e ± p collider  s=300-318 GeV HERA I : H1/ZEUS ~120 pb-1 HERA II 1fb -1 Di-lepton production in e-p collisions possible mainly trough  collisions Spectacular topology Precise SM prediction Interesting phase space for BSM signals (e+p  e - H ++  e-l+l+ see J.Dingfelder talk in BSM) l+ l- E(27.5 GeV) p(920 GeV)

3 26/07/2002C.Diaconu High Pt Multileptons at HERA 3 Standard Model Processes NC-DIS ep  eX fake 2 nd electron from radiation or mis-id Compton: e  (p)  e+photon(->fake 2 nd e)  elastic  inelastic ee  l + l - (Cabibbo-Parisi) qq  l + l - (Drell-Yan) (small @HERA) Fake muons from hadrons (negligible ) +Resonant/HQ production (low PT< 5 GeV) GRAPE (T.Abe et al.) : full diagram a+b+c (EW)+proton structure quasi-elastic (small @HERA)  */Z  l + l -

4 26/07/2002C.Diaconu High Pt Multileptons at HERA 4 LAr,44000 cells em:  (E)=12%/  E Uranium,6500 cells, precise timing, em:  (E)=18%/  E H1 and ZEUS : electron identification Electron identified in calorimeters 5 o <  <175 o (isolated) Central region: –H1 : 20 o <  <150 o –ZEUS: 17 o <  <164 o –calo-tracker redundancy exploited for background rejection: Good quality isolated track required 17 o 164 o 150 o 20 o Electrons ordered in PT: e1,e2,e3  PT1>PT2>PT3

5 26/07/2002C.Diaconu High Pt Multileptons at HERA 5 Multi-electron selection Two central high PT electrons –H1 : P T (1)>10 GeV P T (2)>5 GeV 20 o <  <150 o –ZEUS: P T (1)>10 GeV E(2)>10 GeV 17 o <  <164 o + any other electron(3 rd ) identified in the calo 5 o <  <175 o H1 115 pb -1 DataSMGrapeNC+Compton 2e105118.2±12.893.3±11.525.0±5.5 3e 16 21.6±3.021.5±3.00.1±0.0 ZEUS 130 pb -1 DataSMGrapeNC+Compton 2e191213.9±3.9182.2±1.231.7±3.7 3e 26 34.7±0.5 - Statistical errors Statistical and systematical errors

6 26/07/2002C.Diaconu High Pt Multileptons at HERA 6 Longitudinal momentum as expected for 2e and 3e –(E-Pz=2*Ee=55 GeV when all particles detected) No high P t miss Inelasticity spectrum well described Inclusive Distribution (H1) z

7 26/07/2002C.Diaconu High Pt Multileptons at HERA 7 Electron transverse momenta (H1) Steep spectra Good overall description Three 2e events @PT>50 GeV

8 26/07/2002C.Diaconu High Pt Multileptons at HERA 8 Electron PT and polar angles (ZEUS) Good overall description PT1>30 GeV 8(Data)/7.1(SM) Two events with PTe1,2>50 GeV

9 26/07/2002C.Diaconu High Pt Multileptons at HERA 9 Mass distribution M 12 Mass of two highest PT electrons in the event H1 Good overall agreement Several events at high mass M 12 >100 GeV

10 26/07/2002C.Diaconu High Pt Multileptons at HERA 10 Multi-electron events at high mass M 12 >100 GeV H1 115 pb -1 DataSMGrapeNC+Compton 2e 30.25±0.050.21±0.040.04±0.03 3e 30.23±0.04 0.0±0.0 ZEUS 130 pb -1 DataSMGrapeNC+Compton 2e 2 0.77±0.080.47±0.050.30±0.07 3e 0 0.37±0.04 - Statistical errors Statistical and systematical errors Reminder: H1/ZEUS different polar angle domains

11 26/07/2002C.Diaconu High Pt Multileptons at HERA 11 Example 2e event (ZEUS) M 12 =134 GeV PT=56 GeV PT=53 GeV

12 26/07/2002C.Diaconu High Pt Multileptons at HERA 12 Example 2e event (H1) M 12 =130GeV

13 26/07/2002C.Diaconu High Pt Multileptons at HERA 13 Example 3e event (H1) M 12 =118 GeV High mass from forward-backward topology

14 26/07/2002C.Diaconu High Pt Multileptons at HERA 14 H1: Cross section measurement ep  ee + e - X 2e Sample E-Pz<45 GeV, opposite charges Good agreementInelastic process well described P e T (1,2)>10,5 20 o <  <150 o y<0.82 Q 2 <1 GeV 2 Data/MC: 41/48.3±6.1 (1.9BG) + -Q2Q2 z

15 26/07/2002C.Diaconu High Pt Multileptons at HERA 15 Multi-muon Events PT(  1,2 )>2GeV 20 o <   <160 o L=70pb -1 PT(  1,2 )>5GeV 20 o <   <160 o L=105pb -1 No events at high M12>100 H1: ~1ev expected from e-channel Muons identified in central tracker, mips in Calo and external muon chambers signals

16 26/07/2002C.Diaconu High Pt Multileptons at HERA 16 M  =80 GeV Example of di-muon event (H1)

17 26/07/2002C.Diaconu High Pt Multileptons at HERA 17 H1 Di-muon Cross Section Measurement Good agreement with SM Good description of inelasticity spectrum Total Cross-section 46.5±1.3±4.7 pbSM:46.2 Inelastic Cross-Section 20.8±0.9±3.3 pbSM:21.5 PT(  1,2 )>2GeV 20 o <   <160 o

18 26/07/2002C.Diaconu High Pt Multileptons at HERA 18 Summary Multi-electron and multi-muon production has been measured in ep collision for –PT’s up to 50 GeV –M(ll) up to 100 GeV Good overall agreement is found with the SM calculation. Multi-electron events with M12> 100 GeV observed : –2e : 3/0.25 (H1) 2/0.77 (ZEUS) –3e : 3/0.23 (H1) 0/0.37 (ZEUS) Promising for future investigationPromising for future investigation with 1fb-1 at HERA II with 1fb-1 at HERA II

19 26/07/2002C.Diaconu High Pt Multileptons at HERA 19 Events at High Mass (H1) The 3 high mass pairs have also high PT The 3 high mass pairs have a bwd-fwd topology

20 26/07/2002C.Diaconu High Pt Multileptons at HERA 20 Isolated leptons event Not the same topology As high mass di-electrons High PT jet in the events

21 26/07/2002C.Diaconu High Pt Multileptons at HERA 21 Mass combinations for 3e events No other events with high mass combination

22 26/07/2002C.Diaconu High Pt Multileptons at HERA 22 High Mass Event (H1) M

23 26/07/2002C.Diaconu High Pt Multileptons at HERA 23 High Mass Event (H1)

24 26/07/2002C.Diaconu High Pt Multileptons at HERA 24 High Mass Event (H1)

25 26/07/2002C.Diaconu High Pt Multileptons at HERA 25 High Mass Event (H1)

26 26/07/2002C.Diaconu High Pt Multileptons at HERA 26 High Mass Event (H1)

27 26/07/2002C.Diaconu High Pt Multileptons at HERA 27 High Mass Event (H1)

28 26/07/2002C.Diaconu High Pt Multileptons at HERA 28 Control Analysis: photon conversions Photon conversions studied with a clean Compton sample: two e.m. clusters and nothing else H1 innner detector tomography with high PT photons Good Description by the simulation, conversion @high PT under control

29 26/07/2002C.Diaconu High Pt Multileptons at HERA 29 Fake electrons : control analysis Second e.m. cluster studied in a sample where a good isolated electron already identified Good description of fake electrons: under control Asking for a track greatly reduce the Compton component

30 26/07/2002C.Diaconu High Pt Multileptons at HERA 30 Tracking efficiency control Track requirement efficiency has been calculated from an inclusive NC-DIS sample

31 26/07/2002C.Diaconu High Pt Multileptons at HERA 31 High Mass Events (ZEUS) M12=122 GeV

32 26/07/2002C.Diaconu High Pt Multileptons at HERA 32 High Mass Event (ZEUS) M12=94 GeV

33 26/07/2002C.Diaconu High Pt Multileptons at HERA 33 GRAPE/LPAIR comparison Grape: full EW diagrams Lpair: only  Increase of ~20% Z  ee and  ee contributions LPAIR: Vermaseren calculation based on peripheral diagrams only Grape(“lpair”)/LPAIR Grape/LPAIR

34 26/07/2002C.Diaconu High Pt Multileptons at HERA 34 H1 multi-e events 2e 3e 2/3 “2e” events have a third electron

Download ppt "26/07/2002C.Diaconu High Pt Multileptons at HERA 1 Cristinel Diaconu CPP Marseille On behalf of H1 and ZEUS collaboration Lepton pair production in ep."

Similar presentations

Peter Schleper, Hamburg University SUSY07 Non-SUSY Searches at HERA 1 Non-SUSY Searches at HERA Peter Schleper Hamburg University SUSY07 July 27, 2007.

Peter Schleper, Hamburg University SUSY07 Non-SUSY Searches at HERA 1 Non-SUSY Searches at HERA Peter Schleper Hamburg University SUSY07 July 27, 2007.
Search for Large Extra Dimensions at the Tevatron Bob Olivier, LPNHE Paris XXXVI ème Rencontre de Moriond 17 - 24 Mars 2001 1 Search for Large Extra Dimensions.

Search for Large Extra Dimensions at the Tevatron Bob Olivier, LPNHE Paris XXXVI ème Rencontre de Moriond Mars Search for Large Extra Dimensions.
Tau dilepton channel The data sample used in this analysis comprises high-p T inclusive lepton events that contain an electron with E T >20 GeV or a muon.

Tau dilepton channel The data sample used in this analysis comprises high-p T inclusive lepton events that contain an electron with E T >20 GeV or a muon.
14 Sept 2004 D.Dedovich Tau041 Measurement of Tau hadronic branching ratios in DELPHI experiment at LEP Dima Dedovich (Dubna) DELPHI Collaboration E.Phys.J.

14 Sept 2004 D.Dedovich Tau041 Measurement of Tau hadronic branching ratios in DELPHI experiment at LEP Dima Dedovich (Dubna) DELPHI Collaboration E.Phys.J.
Searches and EW physics at HERA 5 th Rencontres du VietNam 2004 New Views in Particle Physics Sascha Caron (NIKHEF) (former Aachen) P(920 GeV)e(27.5 GeV)

Searches and EW physics at HERA 5 th Rencontres du VietNam 2004 New Views in Particle Physics Sascha Caron (NIKHEF) (former Aachen) P(920 GeV)e(27.5 GeV)
1 Rutherford Appleton Laboratory The 13th Annual International Conference on Supersymmetry and Unification of the Fundamental Interactions Durham, 2005.

1 Rutherford Appleton Laboratory The 13th Annual International Conference on Supersymmetry and Unification of the Fundamental Interactions Durham, 2005.
Recent Electroweak Results from the Tevatron Weak Interactions and Neutrinos Workshop Delphi, Greece, 6-11 June, 2005 Dhiman Chakraborty Northern Illinois.

Recent Electroweak Results from the Tevatron Weak Interactions and Neutrinos Workshop Delphi, Greece, 6-11 June, 2005 Dhiman Chakraborty Northern Illinois.
DPF-2006 1 Victor Pavlunin on behalf of the CLEO Collaboration DPF-2006 Results from four CLEO Y (5S) analyses:  Exclusive B s and B Reconstruction at.

DPF Victor Pavlunin on behalf of the CLEO Collaboration DPF-2006 Results from four CLEO Y (5S) analyses:  Exclusive B s and B Reconstruction at.
July 22 nd, 2005 A.Canepa, SUSY 2005, Durham 1 Search for chargino and neutralino in trilepton final states Anadi Canepa (Purdue University IN, USA) for.

July 22 nd, 2005 A.Canepa, SUSY 2005, Durham 1 Search for chargino and neutralino in trilepton final states Anadi Canepa (Purdue University IN, USA) for.
WW  e ν 14 April 2007 APS April Meeting WW/WZ production in electron-neutrino plus dijet final state at CDFAPS April Meeting 14-17 April 2007 Jacksonville,

WW  e ν 14 April 2007 APS April Meeting WW/WZ production in electron-neutrino plus dijet final state at CDFAPS April Meeting April 2007 Jacksonville,
1 BaBar Collaboration Randall Sobie Institute for Particle Physics University of Victoria.

1 BaBar Collaboration Randall Sobie Institute for Particle Physics University of Victoria.
HEP2008-OlympiaTh. D. Papadopoulou1 Neda, the unique river with a feminine name ! Theodora D. Papadopoulou ( coming from the highland of Olympia…) NTU.

HEP2008-OlympiaTh. D. Papadopoulou1 Neda, the unique river with a feminine name ! Theodora D. Papadopoulou ( coming from the highland of Olympia…) NTU.
Heavy charged gauge boson, W’, search at Hadron Colliders YuChul Yang (Kyungpook National University) (PPP9, NCU, Taiwan, June 04, 2011) June04, 2011,

Heavy charged gauge boson, W’, search at Hadron Colliders YuChul Yang (Kyungpook National University) (PPP9, NCU, Taiwan, June 04, 2011) June04, 2011,
W properties AT CDF J. E. Garcia INFN Pisa. Outline Corfu Summer Institute Corfu Summer Institute September 10 th 2 1.CDF detector 2.W cross section measurements.

W properties AT CDF J. E. Garcia INFN Pisa. Outline Corfu Summer Institute Corfu Summer Institute September 10 th 2 1.CDF detector 2.W cross section measurements.
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.
1 Inclusive Photoproduction of ρº, K*º and φ Mesons at HERA Andrei Rostovtsev (ITEP) ‏ on behalf of H1 Collaboration Published in H1 Collab., Phys. Lett.

1 Inclusive Photoproduction of ρº, K*º and φ Mesons at HERA Andrei Rostovtsev (ITEP) ‏ on behalf of H1 Collaboration Published in H1 Collab., Phys. Lett.
L. Bellagamba, Excited fermions and other searches at HERA 1 International Conference on High Energy Physics Amsterdam 24-31 July 2002 Excited fermions.

L. Bellagamba, Excited fermions and other searches at HERA 1 International Conference on High Energy Physics Amsterdam July 2002 Excited fermions.
A few slides to summarise what Alessandro and I were up to for March 24th video meeting Taking for granted that W+/- are good measurements to make- are.

A few slides to summarise what Alessandro and I were up to for March 24th video meeting Taking for granted that W+/- are good measurements to make- are.
C. K. MackayEPS 2003 Electroweak Physics and the Top Quark Mass at the LHC Kate Mackay University of Bristol On behalf of the Atlas & CMS Collaborations.

C. K. MackayEPS 2003 Electroweak Physics and the Top Quark Mass at the LHC Kate Mackay University of Bristol On behalf of the Atlas & CMS Collaborations.
LHC France 2013, 3 rd April 2013 1 ATLAS results on inclusive top quark pair production cross section in dilepton channel Frédéric Derue, LPNHE Paris Rencontres.

LHC France 2013, 3 rd April ATLAS results on inclusive top quark pair production cross section in dilepton channel Frédéric Derue, LPNHE Paris Rencontres.

Similar presentations

Ads by Google