1 / 46

Electroweak Physics and Top Production (three+ talks)

Summary of WG B contributions at DIS03 ElectroWeak and Physics Beyond the SM Convenor: Wilfried Buchmüller (DESY), Stefan Schlenstedt (DESY Zeuthen). Electroweak Physics and Top Production (three+ talks) Physics Beyond the Standard Model (18+ talks)

cullen-head
Download Presentation

Electroweak Physics and Top Production (three+ talks)

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. Summary of WG B contributions at DIS03ElectroWeak and Physics Beyond the SMConvenor: Wilfried Buchmüller (DESY), Stefan Schlenstedt (DESY Zeuthen) Electroweak Physics and Top Production(three+ talks) Physics Beyond the Standard Model (18+ talks) SUSY, LeptoQuarks, Contact Interactions, Extra Dimensions Search for Excited Fermions Excess of isolated leptons and search for unusual events Limits on Single Top production

  2. ElectroWeak Physics over 1000 measurements can be presented as ~20 pseudo-observables (talks by A Mehta, G Altarelli and recent reviews) • on the Z pole: line shape, asymmetries, charm- and beauty-production • and: W mass and width, top-production, N-cross section (translated into sin2W or MW ), Atomic parity-violation … collected at LEP I/II , Tevatron and , HERA (see WG A) DIS03 - WG B summary - S Schlenstedt

  3. ElectroWeak physics at LEP II Many precise measurements up to √s=209 GeV • Branching ratio’s and cross sections • new measurements of the W-mass at threshold and at high energies • and the W-width • the triple charged and neutral gauge couplings (ZWW, ZZZ, ZZ …) Talk by J Wilson DIS03 - WG B summary - S Schlenstedt

  4. ElectroWeak physics at LEP II cont’d Measure directly the triple-boson vertex threshold measurement Talk by J Wilson DIS03 - WG B summary - S Schlenstedt

  5. ElectroWeak physics at LEP II … and lepton universality and  the global SM fit Talk by J Wilson DIS03 - WG B summary - S Schlenstedt

  6. ElectroWeak results from Tevatron Run I W (2)Theory Z Talk by A Stone Top cross section (pb) (based on 100 evts)

  7. Tevatron Run II • Higher beam energy • new detectors and trigger • CDF and D0 took ~100 pb-1, presented analyses of 30…90 pb-1 • detector commissioning and physics analysis hand in hand • in 0304 less integrated luminosity but improved detector acceptances Talks by A Stone and T Nelson

  8. Run II ElectroWeak Results from CDF combined e, ,  sW  B(W l)= 2640 ± 12 ± 93 ± 158lum pb sZ B(Z ll)= 251.5 ± 4.3 ± 10.6 ±15.1lum pb tt (pb) measured W  B(W  e,), Z Talk by T Nelson DIS03 - WG B summary - S Schlenstedt

  9. D0 EW Results • Four new W & Z cross section measurements: • Combining the observation of the top decay channels an excess of 3s is observed, compatible with a signal expectation at the 35% CL 0 40 tt (pb)  Talk by A Stone

  10. ElectroWeak summary Higgs mass constraints Because of two 3 sigma anomalies, the Standard Model (SM) fit of the precision electroweak data has a poor confidence level, CL= 0.02. […] The data then favor new physics whether the anomalous measurements are excluded from the fit or not…and the Higgs boson mass cannot be predicted until the new physics is understood. M Chanowitz, hep 0304199 • AFB(b) and NuTeV ~3  effects: • Just a regular statistical pattern? • QCD effects (s, c, isospin…)?

  11. NNLO for EW, Higgs and SUSY processes • Calculation of cross sections in pQCD: factorization of calculable “hard” short-distance and “soft” long-distance physics, the latter with virtual corrections • A unified approach and a master formula to calculate in NNLO the soft and virtual functions for processes like hadron-hadron- (Drell-Yan),lepton-hadron-scattering, total xsec’s, SM and charged Higgs production, FCNC single top production, SUSY … • Example FCNC single top production at HERA: eu  et at √s = 300 Talk by N Kidonakis DIS03 - WG B summary - S Schlenstedt

  12. Phenomenology of a SU(2) Triplet Higgs • Extension of the SM Higgs sector: add a real triplet to the complex doublet (unlike the MSSM with a second doublet) • investigate if the then “SM” Higgs can be heavy and what the relation to the new Higgs masses is 500 checked if the Quantum- corrections are changing the picture (  no) 100 Talk by A Sabio-Vera 100 500 DIS03 - WG B summary - S Schlenstedt

  13. OPAL: mH>98.5 GeV/c2 Double charged Higgs at LEP Predicted by LR super symmetric model (Higgs triplet): Decay in two charged leptons, mainly in tau’s. Yukawa coupling to lepton is free parameter. h>10-7 : look for 4 ’s close to interaction point h<10-7 : search for kick of charged tracks h<10-8 : search for anomalous ionisation Talk by A Tilquin DIS03 - WG B summary - S Schlenstedt

  14. Doubly Charged Higgs at CDF • Same sign dielectron data analyzed • Selection: High ET inclusive electron trigger • Search in mass windows of 10% MH (3) Signal: 0 observed Control Region Zmass 0 observed (0.6+0.5-0.1 predicted) “Any model with Higgs triplets predicts double charged Higgs.” Reach sensitivity up to 125 GeV/ c 2 by Summer (see also H++ from H1 later) Talk by A Munar DIS03 - WG B summary - S Schlenstedt

  15. e+ ,Z* e+ e- e- Slepton searches at LEP 2 acoplanar leptons + missing energy Main background from WWll Talk by A Tilquin DIS03 - WG B summary - S Schlenstedt

  16. Search for Neutralino at LEP Chargino, neutralino slepton and Higgs results are combined. LSP mass limit obtained at high tan() Talk by A Tilquin DIS03 - WG B summary - S Schlenstedt

  17. e+ u ~ u Lj ’1j1 q d 01 e+, e- , e+ e+ q ’1j1 ’1j1 d d ~ q* ~ u Lj Search for resonant squarks in H1 [ 94-97 data: H1, EPJC20 (2001) 639. ] Here: 99-00 e+ p data, L = 63 pb-1 Look for the signal in ~ all possible decay modes: ~ 1.Rp-violating decay : q  e q (mainly at large ’ ) • High ET e + jet (similar to scalar LeptoQuark ) i.e. look for signal in high ET/ Q2 NC DIS ~ ~ 2. “Gauge” decays : q  q i0 or q i+ or q g followed by cascade decay of gaugino L = 2 All decays involving at most 2 gauginos are considered • e+ + multi-jets ………………… NC DIS • e- + multi-jets …………………  bckgd free •  + multi-jets …………………… CC DIS • e () + l + multi-jets…………… small SM bckgd (Majorana) Large number of final states ! BRs depend on model parameters Talk by E Perez

  18. ’ 1j1 Masses of gauginos & couplings to f-f  branchings 10 -1 ~ 10 -2 100 200 M squark(GeV) ~ ~ c L (APV ) u L ( 0 ) Constraints in the MSSM sector from H1 example for j=1,2 Consider first an “unconstrained model” : sfermion & gaugino sectors are not related, i.e. M f are free parameters ~ 0.3 Scanof the SUSY parameter space: M2, , tan • Limits on ’ 1j1do not depend strongly • on the MSSM parameters • For ’ = 0.3 ( ’2 / 4 =  em) : • squarks can be ruled out up to  280 GeV • HERA’s sensitivity extends beyond the indirect limits from low energy experiments for cL (also for tL) ~ ~ weakest strongest Talk by E Perez DIS03 - WG B summary - S Schlenstedt

  19. larger BR (01   qq) L3 D0 (Run I) ~ ~ D0 (Run I) (pair prod q & g) Constraints on mSUGRA model : ’111,121 from H1 • Sfermion & gaugino masses related via RGE • m0 (m1/2) = common mass param for scalar (gauginos) at GUT scale • Assume Radiative Electroweak Symmetry Breaking 5 parameters : m0, m1/2, tan, sgn(), A0 tan  = 2 tan  = 6 ’ 1j1 = 0.3 m1/2 (GeV) m1/2 (GeV) (pair prod, sfermion & ) 100 100 ’ 1j1 = 0.3 0 0 0 150 0 150 m0 (GeV) m0 (GeV) For medium tan : H1’s sensitivity extends beyond the domain excluded by D0  Complementarity. However H1 bounds depend on ’, D0’s do not. Talk by H Dreiner In such constrained models : LEPII has highest sensitivity Talk by E Perez

  20. ~ light  … Constraints on mSUGRA : ’131 from H1 the stop ’131 would allow resonant stop production at HERA. Interesting since the stop might be the lightest squark ! tan  = 10 Larger part of the parameter space is covered (compared to the case ’1j1, j  3) m1/2 (GeV) ’131 = 0.3 For intermediate m0, excluded domain not ruled out by LEPII ~ 100 Sensitivity to M(t1,L) up to  270 GeV 01 < 30 GeV, i.e. “loose” t  b +1  b01XX sensitivity via RpV decay only NB: Tevatron RunI : different frameworks, but typical sensitivities  130 GeV. RunII:  200-250 GeV +1 < 30 GeV, “loose” t  b +1 0 Discovery potential for RpV stop at HERA with larger L ! 0 100 200 m0 (GeV) Talk by E Perez DIS03 - WG B summary - S Schlenstedt

  21. Resonance search in the CDF-dijet Spectrum Event Selection: Inclusive Jet Sample (75 pb-1), two Highest ET jets Fit the Mass Spectrum with a smooth background No evidence of resonances Limits on Axigluons,Excited Quarks, Octet Technirhos , E6 Diquarks, W’ • already improved with respect run I Talk by A Munar DIS03 - WG B summary - S Schlenstedt

  22. 1st Gen. b Scalar (GeV/c) Vector Minimal Coupling (GeV/c) Vector Yang-Mills Coupling (GeV/c) DZero 1 0.5 0 225(242) 204 98 292 282 238 345 337 298 CDF 1 0.5 220(242) 202 280 265 330 310 LeptoQuarks at Tevatron LQ LQ’s appear in extended gauge sectors and composite models, scalar and vector particles, coupling  to u or d decay and search strategy: LQ  e ()q, q with  Branching Ratio (LQ  l q) LQ and qq LQ LQ already strong limits from run I for all three generations DIS03 - WG B summary - S Schlenstedt

  23. LeptoQuarks at D0 1st Gen LQ : 2 e + 2 jets 2nd Gen 2  + 2 jets MLQ > 179 GeV Theoretical NLO  (for Q = 1, 0.5, 2  MLQ) MLQ > 157 GeV L = 43.0 pb-1 L = 30.0 pb-1  limit at 95% CL MLQ > 225 GeV (L = 115 pb-1) Run I MLQ > 200 GeV (L = 120 pb-1) Talks by O Kouznetsov DIS03 - WG B summary - S Schlenstedt

  24. LeptoQuarks at CDF (1rst Gen) 2 high ET electrons and 2 jets Missing Energy and 2 jets M(LQ) > 230 GeV/c2 @ 95% CL (Run I 220 GeV/c2 ) M(LQ) < 60 GeV/c2 or M(LQ) > 107 GeV/c2 @ 95% CL • Limit already better than Run I • 25% increase in the cross section • ~factor 1/3 less luminosity • acceptances slightly higher ( not searched in Run I by CDF) • Limit from D0 (Run I, similar luminosity) M(LQ) > 98 GeV/c2 @ 95 % CL Talk by A Munar DIS03 - WG B summary - S Schlenstedt

  25. LeptoQuarks at H1 direct search of resonant LQ production in NC mass spectrum : no excess  limits e- sensitive to F=3B+L=2 99-00 data above √s=318 u- and s-channel contribution Talk by J Scheins

  26. LeptoQuarks at ZEUS Combine channels with eq and q when possible Constant  for scalar LQ as function of branching ratios  into eq and q Talk by G Barbagli DIS03 - WG B summary - S Schlenstedt

  27. e+ ,Z LQ LQ e- I3 OPAL Preliminary OPAL e+ LQ e- LeptoQuarks at LEP New color triplets bosonic fields mediating interaction between quark and leptons Talk by A Tilquin DIS03 - WG B summary - S Schlenstedt

  28. Contact Interaction at HERA parametrize the deviation from SM through four-fermion contact interaction with an effective coupling g2/2 for different chiral combinations Limits for effectice mass scale eeqq 1.7 … 7.0 TeV All models are consistent with the SM Talks by J Scheins and G Barbagli

  29. Number of ED Planck mass Planck mass in ED Radius of extra dimensions Extra dimensions at LEP • Trying to solve the hierarchy problem: • Weakness of Gravity at electroweak scale • Our word confined to four dimensions • Gravity propagates in extra dimensions (ADD) By choosingMDEWNo hierarchy problem Small but large number of states (GKK) 1/MPl d=1 R=1013 m Excluded d=2 R=1 mm d=3 R=1 nm …. d=7 R=1 fm Max in M-theory f,V G f,V Talk by A Tilquin DIS03 - WG B summary - S Schlenstedt

  30. For n=2 MD>1.36 TeV Extra dimensions at LEP (cont) Direct search: missing energy LEP average: MS>1.2 TeV (=+1) MS>1.09TeV (=-1) Indirect: look for deviation from (d/d)SM Talk by A Tilquin DIS03 - WG B summary - S Schlenstedt

  31. where Search for Extra Dimensions at D0 Fit the distributions in the Mll - cos* plane to determine the value of hGdi-e: hG = 0.0±0.27 TeV-4, di-: hG = 0.02±1.35 TeV-4 ( hG = 0 in SM) Extract 95% CL upper limits on hGtranslate to 95% CL lower limits on Planck scale MS Di-e limit close to Run I, Di-  (new) Talk by O Kouznetsov DIS03 - WG B summary - S Schlenstedt

  32. Search for Extra Dimensions at HERA Search again for deviations in the Q2 distribution Talks by J Scheins and G Barbagli DIS03 - WG B summary - S Schlenstedt

  33. Excited Fermions: Composite models to explain the number of families Talk by M Schneider DIS03 - WG B summary - S Schlenstedt

  34. Excited Fermions at HERA Neutrino Electron Quarks > HERA superior at high s (LEP) > more sensitive at small fs (FNAL) Talk by M Schneider DIS03 - WG B summary - S Schlenstedt

  35. f/ ,Z,W,g  e+ e* e-  Excited fermions at LEP In composite models, fermion & boson are composite with and associated energy scale . gauge group weights factor Lot of decay channel at LEP: From differential x-section Talk by A Tilquin DIS03 - WG B summary - S Schlenstedt

  36. Excited Fermions at CDF Search 0 events observed Limits on Me and BR(e*e ) • Me = , Me < 785 GeV/c2 compare to current Limit ( H1 ) Me =  Me < 223 GeV/c2 Talk by A Munar DIS03 - WG B summary - S Schlenstedt

  37. Inclusive Searches in DiPhoton Signature at CDF Search for Diphoton + extra leptons: 0 events found (in agreement w SM)  Limits on Gauge Mediated Supersymmetry Observed: 2 Expected Events: 2  2 MC > 113 GeV/c2 @ 95% C.L. Talk by A Munar DIS03 - WG B summary - S Schlenstedt

  38. Unusual events at HERA DIS03 - WG B summary - S Schlenstedt

  39. Isolated e and  at HERA with large missing pT Talk by G Frising Confirmation of excess H1 in e+ data no excess in H1 e– and ZEUS e± “Backgrounds” well understood largest SM contribution W production (hadronic channel checked as well) W production calculated in NLO (two independent calculations) correction ± 10-15% w reduced scale uncertainty - not the source of the H1 excess Talk by C Schwanenberger Excess at large pT and MT where the SM contribution is small

  40. Unusual events at HERA DIS03 - WG B summary - S Schlenstedt

  41. Isolated  at ZEUS with large missing pT Talk by D Lelas DIS03 - WG B summary - S Schlenstedt

  42. Multileptons at HERA • di- cross section (H1) and events (ZEUS): OK • di-e cross section (H1) and events (ZEUS): OK • H1 observesexcess at high masses M12>100: 3/3 • (for 2/3 e) and expects .25/.23 • ZEUS observes 2/0 (for 2/3 e) and expects 1.2/0.4 at high pT mainly  Understand this SM process, e.g. as BG to isolated leptons and for the exclusion plot on coupling hee Search for Higgs++ (coupling to di-lepton) as source for excess  too small  set limits Talk by A Parenti DIS03 - WG B summary - S Schlenstedt

  43. Single Top production at HERA e e • physics explanation of the lepton excess could be anomalous top production in FCNC (see Fritsch and Holtmann 1999)- the SM cross section is small ~1 pb • Search for isolated electron or muon with a high missing pT (from the ) • Search for 3 jets (two from W) • reconstruct the “top” mass • main Background is SM W production • no excess found: set 95% CL limit on (epetX) and the tu magnetic coupling limit  W  t u,c b p  W  lep or had Talks by A Schöning and D Dannheim (status of ICHEP02) DIS03 - WG B summary - S Schlenstedt

  44. Talk by D Dannheim DIS03 - WG B summary - S Schlenstedt

  45. l,q W ,q e+ t b e- Anomalous t-coupling and SUSY at LEP R-parity violation Talk by A Tilquin DIS03 - WG B summary - S Schlenstedt

  46. Summary • LEP1/2 and Tevatron run I and HERA I data sets analyzed • Tevatron run II preliminary results, HERA II will start • Electroweak Standard Model sector well measured and understood: we need more top and of course the Higgs • One expects PhysicsBeyond the SM at (1/GF) ≈ 300 GeV • A wide search program showed no signal yet • A few interesting event classes need confirmation at high luminosities at FNAL and DESY Many thanks to the speakers and the local help DIS03 - WG B summary - S Schlenstedt

More Related