Published and Preliminary results from ZEUS EXO group

Note: There is a new top layer of ZEUS EXO public results page.

• 1994-2000 data:
  • DESY 03-218: Search for contact interaction, large extra dimensions and finite quark radius in ep collisions at HERA.
  • DESY 03-182: Isolated tau leptons in events with large missing transverse momentum at HERA.
  • DESY 03-041: A search for resonance decays to lepton+jet at HERA and limits on leptoquarks .
    • Figures (color): Fig2, Fig3, Fig4, Fig5, Fig6, Fig7, Fig8, Fig9, Fig10, Fig11, Fig12
  • DESY 03-012: Searches for single-top production in ep collisions at HERA.
  1994-1997 and 1998-1999 data:
  • DESY 01-132: Searches for excited fermions in ep collisions at HERA.
    • Figures (color):
  1994-1997 data:
  • DESY 01-222: Search for lepton-flavor Violation in e⁺p collisions at HERA.
    • Figures (color): Fig1, Fig2, Fig3, Fig4
    • Figures (bw): Fig5, Fig6, Fig7
    • Tables (color): Tab1, Tab2, Tab3, Tab4
    • Lambda x Br limits in text format (mu channel): S12L, S12R, tS12L, V0L, V0R, tV0R, V1L
    • Lambda limits in text format (mu channel): tS12L, V0R
  • DESY 00-133: A Search for Resonance Decays to nu(bar)-jet in e⁺p Scattering at HERA.
    • Figures (color): 11b
  • DESY 00-023: Search for Resonances Decaying to e⁺-jet in e⁺p Interactions at HERA.
    • Figures (color): 4, 5, 8, 11a, 11b
  • DESY 99-054: W production and high-Pt leptons in large-missing-Pt events.
  • DESY 99-058: Search for Contact Interactions.
    • Figures (b/w): 1, 2, 3, 4, 5, 6, 7, Table2.
    • Figures (color): 2, 3, 4, overlay to 4, 5, 6, 7, Table2.
  • DESY 98-069: Search for MSSM e~ q~ production.

• 1994-1996 data:
  • DESY 97-025: Comparison of high-Q² NC DIS to SM predictions.

• 1994-1995 data:
  • DESY 97-112: A search for Excited Fermions in e+p Collisions at HERA.
    • Figures (b/w): 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
    • Figures (color): 2, 3, 4, 5, 6, 7, 8, 9, 10, 11

• 1993-1994 data:
  • DESY 96-161: Search for lepton flavour violation.
  • DESY 96-104: Charged Current paper.

• 1993 data:
  • DESY 95-053: NC and CC paper.
  • DESY 94-175: excited fermion paper.

• 1992 data:
  • DESY 93-075: Excited electron paper.
  • DESY 93-017: Leptoquark paper.

  ---

• Proceedings of the Monte Carlo Generators for HERA Physics workshop 1998/1999
  • The Exotics working group.

• Proceedings of the Future Physics at HERA workshop 1995/1996 (many contributions written by ZEUS members)
  • The electroweak working group proceedings (including e.g. W production).
  • The beyond the Standard Model working group proceedings.

The plots are ordered by analysis topics. Within each topic, more recent plots come first and are in red . Plots which appear in or are superseded by published papers or later public presentations might be removed from this section. Please contact one of the ZEUS Exotics and Rare Phenomena coordinators before you present these results in public.

• New Results for EPS 2001 (Budapest)
  • paper #602
  • bar chart of limits for all CI models
    
  • Q² spectra for e^-p and e⁺p data with limit curves for VV, AA, and VA contact interaction models
    
  • Q² spectra for e^-p and e⁺p data with limit curves for S^L_1/2 and S₁ or V^L_1/2 and V₁ models
    
  • Table of all CI Limits
    
  • Table of all LQ Limits
    

• Preliminary results using the full 1994-2000 data set (combining e⁺ and e^- data)
  • Sum of e⁺ and e^- Q² spectra normalized to SM with curve representing 95% CL limit on the quark radius.
  • e⁺ and e^- Q² spectra normalized to SM with curves representing 95% CL LED mass scale limits.
  • e⁺ and e^- Q² spectra normalized to SM with curves representing 95% CL limits on LED mass scales and the quark radius.

• The (94-97) contact interaction analysis is published ( DESY-99-058). No updated plots are available.

• The 1994-2000 data are published ( DESY 03-041)
  NEW PLOTS for S0L , S1/2L~ and S1/2L, H1(prel)/Zeus(published)/L3 (prelim ICHEP02)

• The following results are older and superseded
  • Preliminary Results for ICHEP02 (Amsterdam)
    Search for leptoquarks in ep collisions at HERA (Paper 907)
    Figures: fig1ab, fig1cd, fig2ab, fig2cd, fig3 , fig4a, fig4b, fig4c, fig4d,
    (In color: fig3, fig4a, fig4b, fig4c, fig4d)
    
    NEW PLOTS for S0L , S1/2L , H1(DIS02)/Zeus(DIS02)/new L3 (ICHEP02)

  • New Preliminary Results for DIS02 (Cracow)
    • the results are based on all 94-00 statistics and on the neutral current and charged current channels combined
    • Mass spectrum for NC e⁺p 94-97 99-00 data
    • Mass spectrum for NC e^-p 98-99 data
    • Mass spectrum for CC e⁺p 94-97 99-00 data
    • Mass spectrum for CC e^-p 98-99 data
    • CC,NC and combined compared to Tevatron and LEP for V0L , S0L , S1/2L
    • NC and CC limits (colour) combined for F=0 scalars , F=2 scalars , F=0 vectors , F=2 vectors
    • NC and CC limits (black and white) combined for F=0 scalars , F=2 scalars , F=0 vectors , F=2 vectors
    • Limits for S0L, S1/2L prepared by H1

  • Preliminary Results for EPS 2001 (Budapest)
    • paper #600
    • neutrino-jet invariant mass spectrum(98-99 e^-p data)
      
    • e-jet invariant mass spectrum(94-00 e⁺p data)
      
    • Cross section limits for scalar and vector F=2 leptoquarks
      
    • Scalar and vector LQ(e^-u) limits in BR(LQ->e jet) vs. M_LQ plane for lambda=0.05, 0.10, 0.31
      
    • Scalar and Vector LQ(e^-u and e^-d) limits in BR(LQ->e jet) vs. M_LQ plane for lambda=0.05, 0.10, 0.31
      
    • Limit on lambda vs. M_LQ for F=2 scalar leptoquarks
      
    • Limit on lambda vs. M_LQ (up to 400 GeV) for F=0 scalar and vector leptoquarks
      
    • ZEUS and H1 limits for F=0 and F=2 scalar leptoquarks.

  • Results for spring 2001 conferences.
    • Electron-jet invariant mass distribution of 1999-2000 e+p NC data.
      ( Corresponding spectrum for e-p, from Tampere paper 552.)
      (This version you can compare with the corresponding spectrum in the 94-97 paper DESY 00-023.)
    • Constrained mass distribution of combined 1994-2000 e+p data, before and after the cos(theta*) cuts optimized for scalar LQ. (For the definition of constrained mass and cos(theta*), please refer to DESY 00-023.)
    • Coupling limits for scalar F=0 LQ and vector F=0 LQ from 1994-2000 e+p data.
    • New version of H1-ZEUS plot for ~S(1/2)L LQ (F=0) in which ZEUS limit is updated with the new result.

  • Results presented for ICHEP 2000 conference
    • Osaka paper #1038 presents comparison of high-x, high-Q2 NC events with SM expectation for 1994-97 e+p data, 1998-99 e-p data and newest 1999-2000(up to April) e+p datasets.
    • Osaka paper #1043 reports 1994-97 nu(bar)-jet resonance search, and also combined resonance limits from e-jet and nu-jet channels. --> This paper was superseded by the published paper DESY 00-133

  • H1-ZEUS common plots prepared for summer 2000 conferences
    • Limits on ~S(1/2)L LQ (F=0) coupling versus mass from e+p published results
    • Limits on S0L LQ (F=2) coupling versus mass from e-p preliminary results

  • A quick look on 99 e+p data at high Q2 and high y, for spring 2000 conferences.
    • Scatter plot (xDA, yDA) of events at Q2(DA) > 5000 GeV^2 from 18pb-1 99 e+p data.
    • Q^2 distribution in histogram and table.
    • x(DA) distribution with y(DA) > 0.25 cut in histogram and table.

  • Resonance search from 98-99 e-p data for summer 1999 conferences.
    • See Tampere paper 552.

  • A first look at the 98-99 e-p data (for the spring conferences 1999)
    • See the DIS99 talks by Raphael Galea and Radek Pawlak for a first look at the high-Q² distributions of the new e-p NC and CC data.

  • neutrino-jet resonance search in CC events from 95-97 e+p data
    • Tampere paper 546 was superseded by Osaka paper #1043 (see above).

  • e-jet resonance search from 94-97 e+p data is published (DESY 00-023). No updated plots are available.

• New Preliminary Results for EPS03 (Aachen) on the tau channel
  Search for lepton-flavor violation in tau production in ep collisions at HERA (Paper 498)
  Figures:
  Fig. 1 (diagram) ,
  Fig. 2 (tau-jet variables) , Fig. 2a , Fig. 2b , Fig. 2c , Fig. 2d , Fig. 2e , Fig. 2f ,
  Fig. 3 (tau discriminant) ,
  Fig. 4 (LFV tau limits) , Fig. 4a , Fig. 4b , Fig. 4c , Fig. 4d ,
  Tables:
  Tab. 1 , Tab. 2 , Tab. 3 , Tab. 4

  
  

• New Preliminary Results for ICHEP02 (Amsterdam) on the muon channel
  Search for lepton-flavor violations in e⁺p collisions at a center-of-mass energy of 318 GeV at HERA (Paper 906)
  Figures: Fig. 1 Fig. 2 Fig. 3 Fig. 4

• Preliminary Results for DIS02 (Cracow)
  • based on the analysis of the e⁺p 99-00, combined with the e⁺ 94-97 data for the low mass and with all 94-00 data for the high mass limits
  • Control plots 1 and 2
  • Low mass limits for scalar LQs and compared to low energy experiments
  • Low mass limits for vector LQs and compared to low energy experiments
  • High mass limits: tables in preparation

• Results for EPS 2001 (Budapest)
  • based on 98-99 e^-p data, muon channel only
  • paper #605
  • Limit on lambda vs. M_LQ for scalar and vector leptoquarks.
  • Limit on lambda BR^1/2 vs. M_LQ for scalar and vector leptoquarks.

• The 1994-1997 data are published DESY 01-222.

• The following results are old and superseded
  • Results sent to ICHEP 2000
    • The DIS2000 results in the following two bullets were written up as Osaka paper #1039.
      Please read this together with Tampere paper #551 (which contains low-mass LQ limit plots in muon channel).

  • (94-97) Search for e p -> tau X events and limits on LFV leptoquarks
    • All tau decay channels considered, no event candidate found. For details on the event selection see Robert Kerger's talk at DIS2000.
    • Limits curves on lambda x sqrt(Br) as a function of M_LQ for scalar and vector leptoquarks. By assuming electroweak couplings at both the LQ production and decay vertex, upper limits on LQ masses are:

      tS1/2L: 259 GeV S1/2L: 276 GeV S1/2R: 277 GeV

      tV0R: 279 GeV V0L: 260 GeV V0R: 265 GeV V1L: 283 GeV

    • Limit tables on (lambda₁*lambda₂)/M²_LQ (10^-4 GeV^-2) for high mass F=0 and F=2 LQs (in red are ZEUS limits, in green H1 published results, in blue are the most stringent indirect constraints taken from the H1 publication; a frame indicates where HERA results improve the existing limits).

  • (94-97) Search for e p -> mu X events and limits on LFV leptoquarks
    • Event selection, search results and lambda x sqrt(Br) limits can be found in the Tampere paper 551.
    • Limit tables on (lambda₁*lambda₂)/M²_LQ (10^-4 GeV^-2) for high mass F=0 and F=2 LQs; in red are the ZEUS limits, in green the H1 published results, in blue are the most stringent indirect constraints taken from the H1 publication; a frame indicates where HERA results improve the existing limits.

  • The (93-94) LFV analysis is published ( DESY-96-161).

• Update of 1994-2000 results presented at EPS03 (Aachen) on FCNC single-top limits
  Search for single-top production in ep-collisions at HERA (Paper 495)
  Figures: Fig. 1 (diagram) , Fig. 2 (updated limit)
  Same Fig. 2 with preliminary limit from H1 (ICHEP02 result)
  
  NEW PLOT ZEUS prel.EPS03/H1 prel. ICHEP02/LEP combined prel./CDF publ./HeraII/TevatronII (courtesy of Dominik Dannheim)

  
  

• The 1994-2000 data for single-top production (isolated muons and electrons) are published:
  • paper (DESY 03-012).
  • FCNC limit plot for Zeus published, H1 preliminary (ICHEP02), CDF and L3 published.

• New Results for ICHEP02 (Amsterdam), tau channel
  Search for events with isolated tau leptons and large missing transverse momentum in ep collisions at HERA (paper 909)
  
  • Fig.1 , Fig.2 , Fig.3 , Fig.4 , Fig.5
    Event1 (b/w), Event1 (color), Event2 (b/w), Event2 (color)

• The following results are old and superseded

  • Results for EPS 2001 (Budapest), electron and muon channel
    • paper #650 on a search for single top production
    • Signal MC distributions of M^JJ and M^3J for 3 jet events.
    • Data distributions of E_T and eta for the first, second, and third highest E_T jets.
    • Data distributions of M¹²,M²³,M¹³.
    • Datadistributions of M^JJ and M^3J
    • Data distributions of M^JJ for the jet-pair with mass closest to M_W and M^3J for events with 63 GeV < M^JJ < 91 GeV
    • Data distributions of M^JJ for the jet-pair with mass closest to M_W and M^3J for events in the final sample.
    • Limits on anomalous couplings from Aleph, CDF, and ZEUS
    • Limits on anomalous couplings from CDF, H1, LEP, and ZEUS

  • Updated results for spring 2001 conferences (2000 data added)
    • Dtrk-Djet plot from whole 94-00 data, 10 electrons and 7 muons.
    • Table of number of events compared to MC, also separately for e+p and e-p periods.
    • Acoplanarity, PtX, missing Pt, Mt distribution of electron events.
    • Acoplanarity, PtX, missing Pt, Mt distribution of muon events.
      Note: One event has a stiff muon track with a poor momentum measurement and lies outside of the Pt and Mt histograms. Its values are consistent with rather low Pt ( > 0.9 GeV) and low Mt ( > 1.4 GeV) within 2-sigma.
    • Table of number of events compared to MC, after further cuts to enhance W component of SM (see Osaka paper linked below) and with cuts on PtX. This table should be compared to H1 numbers with the same PtX cuts.
    • Event display of the new muon event which passes PtX > 25 GeV cut. (also without caption and caption only available)
    • New H1-ZEUS common plot of FCNC coupling limits, compared with ALEPH (curve taken from CERN-EP-2000-102) and CDF. The convention of k_tugamma is different by factor 3/2 from the plot on kappa used for Osaka conference (below).

  • Results presented to ICHEP 2000
    • The DIS 2000 results in the bullet below were written up as Osaka paper #1041
      (including results after new cuts for comparison with H1).
      It also includes results on the search for single-top production and limits on FCNC t-u-gamma coupling.
      H1-ZEUS common plot of FCNC t-u-gamma coupling limits, compared with LEP and TeVatron limits (which have limits on t-q-gamma vs. t-q-Z coulings, q=u,c).

  • Result from 99 e+p data on isolated-track search (for spring 2000 conferences)
    
    • Dtrk-Djet plot from 18pb-1 99 e+p data, 2 electrons and 4 muons.
    • Acoplanarity and P_T^X distribution of the muon events.
      (P_T^X is the transverse momentum of the event excluding the muon track)
      (note: two plots updated for DIS2000 to have MC expectation from 1994-99, not only from 1999)
    • Table summarizing all the ZEUS data from 94-99.
    • Example event display of a muon event.

    • (released for DIS2000) Acoplanarity, P_T^X, missing P_T, transverse mass distribution of 1994-99 electron/positron events (7 events). The red arrow shows the H1 electron event in 1994-97 paper.
      For P_T^X > 25 GeV cut, ZEUS has 2 e and 2 mu, while SM expectations are 1.0+-0.1 and 2.4+-0.4 events.

  • Result from 98-99 e-p data on isolated-track search
    
    • Tampere LFV paper (# 551) has a section on this result.

  • The (94-97) W and isolated-lepton paper is published ( DESY-99-054). No updated plots are available.

• New result for EPS03 (Aachen):
• Search for W production using the hadronic decay channel in ep collisions at HERA (Paper 499, submitted)
  Figures: Fig. 1 , Fig. 2 , Fig. 3 ( Fig. 3a , Fig. 3b , Fig. 3c )
  Tables: Tab. 1 , Tab. 2