Thirteenth International Conference on Supersymmetry and Unification of

Thirteenth International Conference on Supersymmetry and Unification of Fundamental Interactions Searches for New Phenomena : non-SUSY scenarios Emmanuelle PEREZ DESY & CEA-Saclay, DSM / DAPNIA / Spp • Searches in well-known final states : • indirect effects • resonances • Searches in rare SM final states • Funny experimental signatures… SUSY ’ 05, Durham 23 July 2005

Searches for New Physics : why & where Mechanism of the EW symmetry breaking ? Higgs (i. e. fundamental scalar) ? Find it… structure of the Higgs sector ? solution of the hierarchy problem ? SUSY MPl ? “Little Higgs” 10 Te. V ? extra dimensions no hierarchy ? no Higgs ? Dynamical breaking ? ( H ~ condensate ) extra-dim physics ? ( H ~ Gauge Field|4 d ) In most scenarios, new physics is expected at the Te. V scale. Also hoped for, that NP might answer some of the questions unexplained by the SM or by SM+SUSY (e. g. quantization of EM charge, particle masses etc) Various strategies to track new physics, e. g. : - high precision measurements ( need good theoretical control ) - rare decays (K & B) , LFV processes - searches at high energy colliders LEP, Tevatron, HERA Some complementarities between these different approaches and between measurements at the three high energy colliders. E. Perez SUSY’ 05, 23 / 07 / 05

Good performances of our facilities ! _ Tevatron pp, s = 1. 96 Te. V CDF & D 0 Run I (92 -96) : 110 pb-1 / exp Run II (since 01) 1 fb-1 delivered HERA e p, s = 320 Ge. V H 1 & ZEUS until summer 2000 : 120 pb-1 / exp (mainly e+ p) 1000 ! 2005 2003 -04 Analyses presented here 200 -450 pb-1 of Run II data (2002 - 2004) HERA-II sample > HERA-I HERA I+II analyses : up to 200 pb-1 + LEP data ! Very relevant constraints on NP ! some final combinations are still to come + B-factories : Ba. Bar and Belle collected 350 millions of BB pairs ! E. Perez SUSY’ 05, 23 / 07 / 05

Some news from the Standard Model… • sin 2 W at Nu. Tev ? Differs by 3 from global SM analysis Not clear… theoretical uncertainty ? e. g. asymmetry in s-s, violaton of isospin in parton distributions due to QED effects ? ? • (g-2) ? Very precise measurement at BNL (0. 5 ppm !) Above the SM value (2. 7 ) if low energy e+e- data are used for a HAD - e+e- 4 at Ba. Bar using ISR photons : somehow in-between e+e- & - (e+e- ) by KLOE at DA NE ( s 1 Ge. V) : confirms the other e+e- meas. … KLOE, hep-ex/0407048 Burkhardt & Pietrzyk, hep-ph/0506323 • New value of Vus : New measurements from KTe. V and KLOE unitarity restored ! • sin(2 ) from b s penguins : WA. from charmonium modes went down (LP’ 05) Discrepancies seem to get smaller … E. Perez • Still discrepancies in polarisation data in B decays into vector meson when penguins are involved… could be explained by final state interactions ? Belle, PRL 94 (2005) 221804 4 SUSY’ 05, 23 / 07 / 05

Our backgrounds for NP searches at colliders NC(Q 2>400 Ge. V 2) ~ 1000 pb CC(Q 2>400 Ge. V 2) ~ 25 pb Blue = not yet observed NC Tevatron HERA Single top tt CC Wbb Q 2 (Ge. V 2) WZ l ll LEP In this talk : From well-known processes to rare & very rare processes WZ+ZZ l , llll, ll E. Perez 5 SUSY’ 05, 23 / 07 / 05

d / (d )SM A lot to learn from “bread & butter” @ colliders First simple example : Rq < 10 -18 m E. g. DIS as the golden process to study the structure of matter : (at HERA, Q 2 max 105 Ge. V 2) assign a finite size to the EW charge distributions. 2 r < > 2 f(Q ) = 1 Q 6 2 2 nd “generic” example : assume Q 2 (Ge. V 2) that the scale of NP is large, parameterize the effects of NP as a four-fermion interaction : _ _ ( ei )( qj ) Typical bounds > 5 – 20 Te. V Next slides : examples of model-dependent constraints E. Perez 6 SUSY’ 05, 23 / 07 / 05

Dileptons, , DIS & Extra Dim. Scenarios Interference of KK exchange with SM processes (ee, , , DIS) • Large extra-dim (AADD) : tower of gravitons G(k) q q , Z l G(k) l - ee & at LEP : MS > 1. 34 Te. V - DIS at HERA : MS > 0. 82 Te. V DY, QCD “fake” DY D 0 Run II + Run I, ee & : MS > 1. 43 Te. V D 0 Run II Prelim, 200 pb-1 SM SM + signal, Mc = 500 Ge. V E. Perez ee Most stringent collider bound: Tevatron 2 fb-1 : MS up to 2 Te. V QCD bckgd At high mass : e. g. ll, at Tevatron : Effective coupling : A / MS 4 (not a direct probe of MD) D 0, hep-ex/0506063 Negative interference • Gauge bosons in “internal” extra-dim : MC = 1/R// ~ mass of V(1) qq , Z, (1), Z(1) ee LEP & low energy Mc > a few Te. V Mc > 1. 12 Te. V First dedicated search at a collider SUSY’ 05, 23 / 07 / 05

Examples of dilepton resonances • New heavy gauge boson Z ’, e. g. models with L-R symmetry or E 6 GUT inspired • (Color-singlet) technirho in Technicolor models • Kaluza-Klein gravitons in some extra-dim. models q _ q cotan • ZH - Intrinsic width of new particles usually small compared to the detector resolution - At high mass acceptances do not depend too much on the spin (typically ~ 50% for ee) “Little Higgs” CDF II Prelim, 200 pb-1 D 0/CDF, X BR(e) < ~ 30 fb from ee from Mll and X BR( ) < ~ 40 -80 fb from ~ 200 pb-1 X BR( ) < ~ 1 pb from Z’H ee First constraints (direct) on “Little Higgs” models ! (although “minimal” models predict heavier ZH, 2 -6 Te. V) E. Perez above 600 Ge. V Still good agreement with SM in 450 pb-1 ~ 100 evts above 200 Ge. V SUSY’ 05, 23 / 07 / 05

Recent Z’ searches Limits & sensitivities on Z ’ bosons often expressed in : • SSM : Z ’ couples to fermions like the SM Z CDF Prelim, 450 pb-1, e+e • E 6 inspired models : Z ’ = Z sin 6 + Z cos 6 • Recent Tevatron searches for Z’ use both Mee and cos( *) (cf LEP sensitivity via AFB) E 6 Z’ models Adding cos( *) to 25% more L ! M(Z’SSM) > 845 Ge. V (LEP : 1. 8 Te. V) X BR(e ) < 30 fb @ 800 Ge. V APV E 6 models : direct bounds from Tevatron better than the indirect LEP bounds Indirect bounds from LEP much more model dependent • New models tested, beyond E 6 M. Carena et al, PRD 70 (2004) 093009 - Relax GUT relations for g. Z’ - Classify models according to the U(1)’ charges of fermions : E. Perez 9 SUSY’ 05, 23 / 07 / 05

Dilepton & diboson resonances : RS gravitons “Localized gravity” on a “brane” at d 0 from our brane; propagation of gravity in the extra dim is exponentially damped due to the (tuned) space-time metric PRL 83 (1999) 3370; Randall & Sundrum models; “usual” version : n=1, Rc Planck length Graviton propagate in extra dim Kaluza-Klein modes In localized gravity : Spin 2 resonance First direct constraints on Randall-Sundrum models ! G(k) heavy, G(1) Te. V Coupling of G(k) to SM fields Te. V Coupling k/MPl (determined by some model param, k/MPl 0. 1) brings a large sensitivity to RS gravitons since large branching D 0 ( , ee, ) : for M > 500 Ge. V, X BR( ) < 18 fb E. Perez PRL 83 (1999) 4690 Main bckgs in : D 0, hep-ex/0505018 0 - jets - genuine , dominates at high masses 10 785 Ge. V -1 S tivi ensi fb or 2 ty f (1) mass 05, 23 /(Ge. V) 07 / 05 GSUSY’

Z from a long-lived particle ? Look at the Z resonance itself… but in events where the Z decay vertex is displaced, e. g. in Z Use of the silicon devices to measure the transverse dca of tracks; apply tight track quality criteria. Could come from a 4 th generation b’ : If m(b’) < m(top) : b’ b. Z via loop decay Acceptance depends mainly on c (b’) Complements earlier searches : - b’ b. Z, negligible lifetime, b-tag - low mass b’ via FCNC (b’ b , bg) Analysis not optimised for the b’ hypothesis i. e. constraints are quite model-independent. E. Perez 11 SUSY’ 05, 23 / 07 / 05

W l , DIS and new W’ bosons q _ q WR e, e R q WR R q’ s-channel W production at Tevatron and t-channel exchange in DIS at HERA : very clean experimental signatures Look for new W’ boson, e. g. WR Same signature as W exchanged provided that R is light and stable • Tevatron : ET and ET thresholds ~ 25 Ge. V, ~ 45% Likelihood fit of the MT distribution : *BR(W’ e ) < 50 – 100 fb for M > 500 Ge. V For g. L = g. R : M(W’) > 788 Ge. V e- e+ E. Perez • HERA : polarised e. L, R beam since 2003 CC(e , SM) ~ (1 Pe) Extrapolations to Pe = 1 consistent with no WR (not competitive with Tevatron bounds, but nice “textbook” plot !) 12 SUSY’ 05, 23 / 07 / 05

DIS, Zjj, Wjj: Leptoquarks Apparent symmetry between the lepton & quark sectors ? Exact cancellation of QED triangular anomaly ? • LQs appear in many extensions of SM • Scalar or Vector color triplet bosons • Carry both L and B, frac. em. charge ee LQ decays into (lq) or ( q) : HERA (unknown) Yukawa coupling l-q-LQ TEVATRON eq q llqq l qq NC DIS CC DIS Z/DY + jj QCD W + jj W/Z + jj QCD ZEUS, PRD 68 (2003) 052004 NC DIS E. Perez 13 • HERA : resonant peak, ang. distr. • Tevatron : highest ET events PRD 71, 071104 (2005) Z/DY+jets 05, 23(Ge. V) / 07 / 05 ST = ETe 1 + ETe 2+ SUSY’ ETjets

Existing Bounds on 1 st Generation LQs = BR( LQ eq ) e 1 1 0. 5 0 Run II bounds D 0 241 CDF 235 D 0 (e jj) 208 CDF (e jj) 176 CDF 117 For l = 4 p a em 0. 3 : HERA rules out LQ masses < 290 Ge. V @ 95 % CL = BR (LQ eq) D 0 Run II + D 0 Run I : M > 256 Ge. V for =1 H 1, hep-ex/0506044 D 0, PRD 71, 071104 (2005) CDF, hep-ex/0506074 • Tevatron probes large masses for large (LQ eq) independently of • HERA better probes LQs with small provided that not too small Complementarity of both facilities NB : at HERA, e+ / e- + polarisation could help in disentangling the LQ quantum nbs E. Perez MLQ (Ge. V) 14 SUSY’ 05, 23 / 07 / 05

Second and Third Generation Leptoquarks So far, LQ 2, 3 with M > 100 Ge. V can be probed exclusively at the Tevatron ! • Search for LQ 2 in Run II data : + at least 2 jets : bckgd = only DY+jets ~ no bckgd at the end while ~ 20% • Search for LQ 3 b : one e or , the other had. Same analysis as RPV stop b Total acceptance ~ a few % D 0 Prelim. , 300 pb-1 SM bckgd DY + jets M > 129 Ge. V … New physics might couple mainly to 3 rd gene fermions Combined with MLQ > 251 Ge. V for = 1 D 0 Run I : E. Perez 15 More sensitivity expected by using b-tagging techniques SUSY’ 05, 23 / 07 / 05

Searches in radiative processes • + E at LEP sets strong constraints on large extra-dim (ADD) : (also branons) Coupling of G(k) to SM fields 1 / MPl G(k) stable ! May be copiously produced n=2 : MD > 1. 5 Te. V n=4 : MD > 0. 9 Te. V 1 / MPl compensated by huge multiplicity of states CDF, PRL 94 (2005) 101802 • Searches for singly produced excited fermions, e. g. e* e , search for a (e ) resonance - Z/DY + at Tevatron q , Z e - radiative Bhabha at LEP - radiative DIS, QED Compton q e* at HERA For f/ = 1/M(e*) : E. Perez M(e*) > 250 Ge. V 16 LEP & HERA : all decay modes considered SUSY’ 05, 23 / 07 / 05

Multilepton events at HERA Events with 2 leptons in final state. Mainly produced via Cross-section when both leptons are central, PT 1 > 10 Ge. V, PT 2 > 5 Ge. V : ~ 0. 6 pb H 1 data 94 -00 : excess of 2 e+3 e events at high M 12 = mass of two highest PT e No such excess seen in ZEUS HERA-I data The H 1 evts are not consistent with e H++ (e) ee(e) 209 pb-1 (H 1 prelim. ) H 1 Prelim. , HERA I+II obs. / exp. H 1 94 -00 data expt selection H 1 ( 115 pb-1) 2 e, M 12 > 100 Ge. V 3 / 0. 30 0. 04 3 e, M 12 > 100 Ge. V 3 / 0. 23 0. 04 H 1, EPJ C 31 (2003) 17 H 1 analysis extended to include 03 -05 data Extended to other 2 l & 3 l topologies : Now ee, , eee, e are considered • no new 2 e / 3 e evt at M 12 > 100 Ge. V (but one high mass 3 e event …) • one e evt at M > 100 Ge. V, one at Me > 100 Ge. V 2 l + 3 l E. Perez Altogether, at PT > 100 Ge. V : Nobs = 4, Nexp = 0. 81 0. 14 SUSY’ 05, 23 / 07 / 05

W Production at HERA Main SM contribution for single W production at HERA : HERA I : excess (H 1) of observed evts at high PTX w. r. t. SM expectation PTX H 1, PLB 561 (2003) 241 (W prod) 1 pb e p l + jet + PT, miss H 1 prelim 94 -05, e p, 211 pb-1 H 1 ep data, 118 pb-1 Combined e & PTX > 25 Ge. V 11 / 3. 4 0. 6 Such evts are still observed in HERA II H 1 data… PTX > 25 Ge. V e channel Combined e & H 1 94 -05 211 pb-1 11 / 3. 2 0. 6 6 / 3. 2 0. 6 17 / 6. 4 1. 1 ZEUS 99 -05 106 pb-1 1 / 1. 5 0. 18 But still do not show up in ZEUS data… • no new evt in H 1 HERA II data • new ZEUS analysis : close to H 1 cuts • ZEUS & H 1 expectations agree… • no significant excess in H 1 e-p data (53 pb-1) E. Perez 18 SUSY’ 05, 23 / 07 / 05

HERA events with isolated lepton + PT, miss H 1 Preliminary, 211 pb-1 obs. / exp. PTX > 25 Ge. V e channel Combined e & Electrons, 98 -05 53 pb-1 2 / 0. 9 0. 2 0 / 0. 9 0. 2 2 / 1. 8 0. 3 Positrons, 94 -04 158 pb-1 9 / 2. 3 0. 4 6 / 2. 3 0. 4 15 / 4. 6 0. 8 A “leptoquark-like” interaction, e. g. Rp. V SUSY e+ d stop ? (was not supported by HERA-I data alone) Wait for more e- data… • Non SM W production in e ? Most likely smthg should have been seen at LEP… • New physics in q ? D 0, hep-ex/0503048 But NP might not be W seen in W if q’ is a b, NP e. g. FCNC coupling to the top quark ? q q’ u q q’ E. Perez NP W t ET (Ge. V) W production at Tevatron agrees with SM… 19 _ b tu W+ SUSY’ 05, 23 / 07 / 05

FCNC couplings to the top quark ? FCNC couplings tq , tq. Z (tqg) where q = u, c can be searched for in single top prod. at LEP & HERA, in t q. V decays in tt pairs at Tevatron. Possible explanation of “the H 1 events” ? H 1 @ HERA-I : 5 (3 e + 2 ) of the “isolated lepton evts” appear top-like ! exp. = 1. 31 0. 22 H 1, EPJ. C 33 (2004) 9 ZEUS, PLB 559 (2003) 153. To explain the “H 1 events” as FCNC top production : need ~ 0. 4 pb ( tu ~ 0. 2 in the fig. ) Not excluded by CDF & LEP. Not inconsistent with ZEUS HERA-I modulo little + (-) fluct. in H 1 (ZEUS) tu ~ 0. 2 would lead to (single top, FCNC) of ~ O(1 pb) at Tevatron NB : getting close to observe SM single top at Tevatron ! Future HERA & Tevatron sensitivities D 0, hep-ex/0505063 E. Perez 20 SUSY’ 05, 23 / 07 / 05

Other searches for NP in the top sector Pair-production of top at Tevatron Run II: ~ 7 pb _ • Searches for t t resonances • Tests of the (V-A) nature of the tb. W vertex : t l b W from t decays are mainly longitudinal (f 0 = 70%). Rest has =-1 (f-1 = 30%). Fit to cos( *) yields : f+1 < 0. 25 @ 95% CL | R | < 1. 05 Yields to (my interpretation) : if the tb. W vertex is : t [ (1 + R) – (1 - R) 5 ] b W (more stringent bounds from b s but model dependent) • Constraints on R = (t b W) / (q. W) • Flavor anomaly in dilepton tt ? By comparing the number of tt candidates with 0, 1 or 2 b-tags. Excess in e , not stat. significant (yet…) E. Perez 21 SUSY’ 05, 23 / 07 / 05

Wbb production at Tevatron • Enhanced Wbb production ? may occur from - WH followed by H bb - technicolor resonances ( T TW, T bb) 1 b-tagged jet, sample of ~ 100 events Search for a mass peak in M(jj) & M(Wjj) Sensitivity getting close to theo. predictions. • Run I CDF data : excess of W + 2, 3 jets where both a secondary vertex and a soft lepton are found in one jet (“superjets”) Similar analysis carried out on Run II data, W e or D 0, PRL 94 (2005) 152002 Dominant SM contributions from Wbb ( ~ 3 pb), tt & single top, mistags No excess observed in the “doubly-tagged” jet sample in Run II data. E. Perez 22 SUSY’ 05, 23 / 07 / 05

Very rare processes : B decays Probe very rare processes : better have a huge lumi… e. g. B-factories. Tevatron also probes very rare decays, e. g. Bs, d Branchings as low as a few 10 -8 can be observed. Known that b s (~ 3 X 10 -4) is a sensitive probe to NP. Eg SUSY, top couplings, … Recent observation of b d (5 ) ! Belle, hep-ex/0506079 Large bckgd (continuum & b s ) Look in exclusive modes B+ + , B 0 0 , B 0 . Simultaneous fit assuming isospin relations BR(B / + ) = + 0. 14 1. 34 +- 0. 34 31 - 0 10 0. X 10 -6 . Consistent w/ CKM … Constraints on FCNC top coupling t-u- ? E. Perez 23 t Vtb tu • u V* SUSY’ 05, 23 /td 07 / 05

Lepton Flavor Violation • New results (Ba. Bar) on and e : BR( ) < 6. 8 x 10 -8 BR( e ) < 1. 1 x 10 -7 (hep-ex/0502032) (prelim. ) BR ~ 10 -40 in SM but could be much enhanced beyond SM NB : 200 M of ee evts ! e. g. constrains a particle coupling both to ( l) and to ( l), l=e, , Example for a doubly-charged Higgs: h l < 0. 18 (MH/1 Te. V)2 (my interpretation) Similar constraints from e and e (latter : BR < 1. 2 x 10 -11, MEGA Coll. ) -7 Belle, PRD 68 • Searches for LFV B-decays : eg Bd e : BR(Bd e) < 1. 7 10 (2003) 111101 _ 23 b Bounds on ed b / M 2 LQ LQ e. g. case of Pati-Salam LQs where = (M ) : M > 46 Te. V d 11 S e Such exchanges are also probed in DIS : Several examples where DIS constraints are competitive with those from rare B decays ZEUS, hep-ex/0501070 E. Perez 24 LQ ZEUS bounds on eq q / MLQ 2 in units of Te. V-2, for LQ types ed b eb s SUSY’ 05, 23 / 07 / 05

Exotic experimental signatures Rich detector capabilities ! search for particles which behave in an exotic way : Ø Charged quasi-stable particles : will look like anomalous . Large mass implies : • a fraction of them will have low =v/c D 0 Run II Preliminary i. e. reach our muon detector “late” 390 pb-1 Use timing information from det. to reco e. g. allows to set a limit on stable charginos : M( , “stable”, gaugino-like) > 174 Ge. V MC signal CDF, hep-ex/0503004, 292 pb-1 0 HL HR 133 Ge. V 4 10 (1 - )/ • Large energy loss by ionisation exploit the d. Edx measurement e. g. with cuts for a doubly-charged Higgs, no candidate while ~ 40% m ~ 34 n 2 >> e eg = nhc/4 Ø Magnetic monopoles M : - exploit the large energy loss (CDF Prelim. ) H 1, DESY 04 -240 - Eloss could be so large that M may stop in the beam-pipe ! EPJC xxx (2005) E. Perez Upper bounds on pp & ep (MM) as a function of M mass. SUSY’ 05, 23 / 07 / 05 25

Conclusions The search for new physics is a very active field. Tevatron & HERA are working very well, the experiments might “see” something in the near future ! Constraints set on many models, often the most stringent up to date. e. g. Z’ and W’ above ~ 750 Ge. V Leptoquarks > ~ 250 Ge. V (Tevatron) > ~ 290 Ge. V (HERA, coupling of EM strength) Randall-Sundrum gravitons > 780 Ge. V (coupling 0. 1) Complementarity between the experiments. “Puzzling” events observed at HERA by H 1. Clarification (or discovery ? ) should come soon with the increasing HERA-II luminosity. E. Perez 26 SUSY’ 05, 23 / 07 / 05