ELW. AN D ALT ERN AT IVES WG SU MMARY REPORT

Transcription

1 ELW. AN D ALT ERN AT IVES WG SU MMARY REPORT Michael Spira (PSI) other convenors: A. Denner, K. Mönig, T. Ohl, G. Pasztor

2 Signatures of new ρ-resonances from strong EWSB in e + e ν νt t Strong electroweak symmetry breaking from ee V V νν Ivan Melo Predrag Krstonosic (presented by K. Mönig) Triple gauge couplings in γγ collisions Jadranka Sekaric Four-fermion production at future photon colliders Precision measurements of beam polarization at the LC (The case of single-w production) Two-loop Sudakov logarithms in electroweak processes Electroweak precision observables in the MSSM with non minimal flavor violation Axel Bredenstein Filip Franco-Sollova Bernd Feucht Sven Heinemeyer

3 ' - + * ) ) 3 = 0 =? 0 3 = < %$ # "! ( & #, -, / 0 > 7 = <3 ; 9. : > =2= 0 B = / 9A > =2= 0 B = / 9A E

4 W L W L t ρ t W L W S L ρ S W L W L g π g π g v e ν e ν t t W L W L W L W L W L W L ν ν e e

5 "M ρ =0.7 T ev " vs. "n o resonance" s 1/2 = 0.8 T ev L = 200 fb -1 b g'' "M ρ =0.7 T ev " vs. "n o resonance". b s 1/2 = 1.0 T ev L = 200 fb g''

6 !" # $ &% ' ' ' ( *) + $,' -. *0/ 1 2 ' 3 # 4 *5/ *6 *87 )9 #: ;. ) / * 2 ' 3 # 4 *0/ <) *=7 * 9 > #: - & ' -, ' ACB ' -B 1 $ CD,' B - $ E ACD ' A - - : & AA ' A,- - '& ' $ F F HG

7 StrongElectroweakSymmetryBreaking from e e ν ν V K. Mönig, P. Krstonosic DESY - Zeuthen 1

8 Introduction In absence of light H iggs interaction am ong gauge bosons becom es strong at high energy E ffective Lagrangian contains five C P conserving operators that can be directly probed in w eak boson α4 µ ν α 5 µ ν scattering( L4 = tr Vµ Vν ) tr ( V V ) L5 = tr ( Vµ V ) tr ( Vν V ) L 6 16 π 2 µ ν ( V V ) tr ( TV ) tr ( TV ) α6 = tr 2 µ ν 16 π = α7 µ ν α10 tr ( Vµ V ) tr ( TV ν ) tr ( TV ) L ( ) ( ) 10 = tr TV 2 µ tr TV ν 16 π 16 π L π 2 ( ) 2 SU conserving SU breaking (2) C (2) C α i v C ouplings are related to the scale of new physics 2 = 16 π by Λ, * i 2 and it s necessary to do the m ultidim ensional analysis in order to obtain the inform ation on scale and dynam ics of 2

9 B inned M axim um Likelihood fit to the expected distributions for a L = N log( N ) S M sam ple (all quartic couplings equal zero) MC i jkl i jkl C oefficients obtained by recalculating m atrix elem ents in 5 points in? 4? 5 space for each event and solving R equations: DATA i jkl MC i jkl R is the ratio of the m atrix elem ent to the S M one. + i jkl N MC i jkl N = 1 + A α4 + B α4 + C α5 + D α5 + E α4 α5 i BIN 2 Fit 2 system of A α4 i + B α4i + C α5i + D α5i + E α4i α5i = = i 1,5 A fter separate analysis for signal processes double counted events w ere assigned to one or another sam ple according to the distance form M (V )+M (V ) m ass (V =W or Z ) 12

10 W - W - result e e ν eν ~ ew W 350 fb -1 sam ple C onfidence level contour full line 68% C L dotted 90% C L 14

11 W + W - result C onfidence level contours F ull line 68% C L dotted 90% C L In red present analy sis in black * Stro ng E lectro w eak Sy m m etry B reaking Signals in W W Scattering at T E SL A R o berto C hierici, Stefano R o sati and 15

12 ZZresult C onfidence level contours F ull line 68% C L dotted 90% C L In red present analy sis in black * Stro ng E lectro w eak Sy m m etry B reaking Signals in W W Scattering at T E SL A R o berto C hierici, Stefano α 6 α 7 R o sati and M ichael K o bel set to zero 16

13 e+e- & e-e- processes combined In red analysis results, in black com bined fit for W +W - and Z Z only from * C onfidence level contours, full line 68% C L dotted 90% α 6 α 7 set to zero 19

14 Future improvement in Z Z analysis still possible results in easy to use and combine form W Z analysis in progress combined limits on full parameter set at 800GeV to be obtained soon going for 1TeV 24

15 W-TGCsata?? colliderattesla K.Mönig, J.Sekaric DESY-Zeuthen ECFA, Sept. 04, UK Sekaric Jadranka DESY-Zeuthen 1

16 Introduction? W + W qqqq S = 40GeV Dominating diagram for?? W + W - T G C T w o co u p lin g s,?? in d im -4 an d?? in d im -6 o p erato rs Deviations from SM TGC values test of EW theory, probe of some possible extensions new physics beyond the SM Ambiguities : (cos? 1,2,? 1,2 )? (-cos? 1,2,? 1,2 +?) W BACKWARD z ϕ 2 θ 2 q Sekaric Jadranka ECFA, Sept. 04, UK DESY-Zeuthen x y γ θ x ϕ 1 γ y θ 1 z W FORWARD q 2

17 2ParameterFitResults J Z =0 J Z =0 3D/5D E CM = 400 GeV, L = 110 fb -1, FBE L ikelih o o d (n o rm alized ) (?=0-2?) L D E1% T E C T O R L E0.1% V E L M W 1,2 =(60 accu rate 100) κ γ 10-4 / / /5.4 G ev 3.8/2.6 λ γ 10-4 / / / /3.0 κ γ p ileu p λ γ p ileu p D 5D decreases the error in κ γ ; in λ γ significantly! Pile-up distorts the?-distribution increase of error in λ γ for ~20% Sekaric Jadranka 13 κ γ dependences on normalization ECFA, Sept. 04, UK DESY-Zeuthen

18 2ParameterFitResults J Z =2 J Z =2 3D/5D E CM = 400 GeV, L = 110 fb -1, FBE L ikelih o o d (n o rm alized ) (?=0-2?) L D E1% T E C T O R L E0.1% V E L M W 1,2 =(60 accu rate 100) κ γ 10-4 / / /6.2 G ev 3.9/3.8 λ γ 10-4 / / / /1.5 κ γ p ileu p λ γ p ileu p D 5D no influences in the error estimations Pile-up distorts the?-distribution increase of error in λ γ for ~25% Sekaric Jadranka κ γ dependences on normalization ECFA, Sept. 04, UK DESY-Zeuthen 14

19 Conclusions J Z =0,2 are sensitive to the anomalous couplings to the possible scenarios of EWSB? distribution important for J Z =0 Pile-up influences on?? measurement (~25%) Promising channel for?? -?? measurements???,??? ~ 10-4 FUTURE to include the possible backgrounds, variable beam energy rejection of bad tracks from pileup Sekaric Jadranka ECFA, Sept. 04, UK DESY-Zeuthen 15

20 Four-fermion production at the γγ Collider Axel Bredenstein in collaboration with Stefan Dittmaier und Markus Roth Max-Planck-Institut für Physik, Munich September 1,2004 based on Eur. Phys. J. C 36 (2004) 341 [arxiv:hep-ph/ ] Four-fermion production at the γγ Collider 1/16

21 Contents Calculation of γγ 4f und γγ 4fγ in lowest order Construction of a Monte Carlo generator Motivation Calculation of helicity amplitudes Phase space and photon spectrum integration Anomalous couplings Effective Higgs coupling Finite gauge-boson width Double-pole approximation Four-fermion production at the γγ Collider 2/16

22 . )( ' 4 0! 50 "! " ; 0 : : / 4 0 / 0 / Anomalous triple couplings γγ 4f all semi-leptonic final states photon spectrum included s ee = 500 GeV Ldt = 100 fb 1 χ 2 = 1 χ 2 (N(a i) N SM ) 2 N SM (* & & /! % # < ; 9 "$# % ; 7 9! ; 7 69 ; : 9 ; ; 9 8$ ,$- Baillargeon et al. 97; Bozovic-Jelisavcic et al. 02 ) large interference with SM amplitude expected limits comparable to e + e -mode (see also full study requires consideration of distributions Four-fermion production at the γγ Collider 9/16

23 Summary Relevance of γγ WW due to its high cross section Calculation of Born amplitudes for γγ 4f and γγ 4fγ Monte Carlo generator with multi-channel Monte Carlo integration Inclusion of a realistic photon spectrum Anomalous couplings, Higgs resonance Double-pole approximation is a promising approach for radiative corrections (cf. RacoonWW), work in progress Four-fermion production at the γγ Collider 16/16

24 Filip Franco-Sollova 2 nd ECFA Workshop Durham, 1-4 September

25 !"# Filip Franco-Sollova 2 nd ECFA Workshop Durham, 1-4 September

26 $' ## /4"20 $:' ;""2 /#0 4 )%-6 σ -6. σ 6- /$+**)50-6-#:- -6 # : ;7 Filip Franco-Sollova 2 nd ECFA Workshop Durham, 1-4 September

27 0? : " ( 0? # : : #' σ " σ- σ: " ( $ # "σ σ3 # () Filip Franco-Sollova 2nd ECFA Workshop Durham, 1-4 September

28 "#D :".* GH,/"θ e+ 8* C*0 (:"#' ".=+,3.G+, /#"0 " 9:/µµB0 :'?"; "436/B0 " Filip Franco-Sollova 2 nd ECFA Workshop Durham, 1-4 September

29 2nd workshop of the ECFA Physics and Detectors for a Linear Collider study series Durham, 1 4 September 2004 Electroweak Sudakov logarithms The form factor in a massive U(1) model and in a U(1) U(1) model with mass gap Bernd Feucht Institut für Theoretische Teilchenphysik, Universität Karlsruhe In collaboration with Johann H. Kühn, Alexander A. Penin and Vladimir A. Smirnov I II III IV V Why logarithmic 2-loop results in EW theory? Massive U(1) form factor: evolution equation & 2-loop results U(1) U(1) model with mass gap: factorization of IR singularities Applications: how to treat the EW mass gaps Z W photon Summary & outlook

30 Bernd Feucht, Sudakov logarithms 2/15 I Why logarithmic 2-loop results in EW theory? Electroweak (EW) precision physics experimentally measured by now at energy scales up to M W,Z future generation of accelerators (LHC, LC) TeV region Electroweak radiative corrections Kühn et al. 00, 01; Fadin et al. 00; Denner et al. 01, 03; B.F. et al. 03; at high energies s TeV M W,Z Pozzorini 04;... large negative corrections in exclusive cross sections EW corrections dominated by Sudakov logarithms α n ln 2n (s/m 2 W,Z ) 1-loop corrections 10% 2-loop corrections 1%, need to be under control for LC

31 Bernd Feucht, Sudakov logarithms 6/15 Massive U(1) form factor in 2-loop approximation Known from resummation & full calculation of n f contribution: (n f = # fermions) ( α ) 2 α 2 F 2 = [+ 1 ( ) ( ) ( ) Q 2 4 Q 4π 2 ln4 M 2 9 n f + 3 ln 3 2 M 2 ( n f + 2 ) ( ) Q 3 π2 + 8 ln 2 2 M 2 ( ) ( ) ( 34 Q n f +... ln M π ) ] n f growing coefficients with alternating sign: 0.4 n f ln n f ln n f ln n f ln 4 3 ln ln 2... ln +... Q 1 TeV +ln 4 ln 3 +ln 2 large cancellations between logarithmic terms Kühn, Moch, Penin, Smirnov 01 B.F., Kühn, Moch 03 Complete 2-loop corrections in logarithmic approximation necessary.

32 Bernd Feucht, Sudakov logarithms 8/15 Massive U(1) form factor in 2-loop approximation: result (n f = 0) ( α ) [ 2 α 2 F 2 = 4π + 1 ( ) Q 2 agreement 2 ln4 M ( 2 ) Q 3 ln 3 2 M ( 2 ) ( ) 2 Q + 3 π2 + 8 ln 2 2 M 2 ( ) ( ) Q 24ζ 3 + 4π ln M ( ) Li LL (ln 4 ) NLL (ln 3 included) NNLL (ln 2 included) N 3 LL (ln 1 included) complete ln π2 ln π4 + 80ζ π B.F., Kühn, Penin, Smirnov, hep-ph/ M = 80 GeV, α/(4π) = 0.003, n f = Q [GeV] ] new! size of coefficients: +0.5 ln 4 3 ln ln ln at Q = 1 TeV: alternating signs! small constant (N 4 LL) contribution

33 Bernd Feucht, Sudakov logarithms 15/15 V Summary & outlook Massive U(1) form factor complete 2-loop result in logarithmic approximation precise control of radiative corrections U(1) U(1) model with mass gap factorization of IR singularities shown explicitly Applications calculation with mass gap reduced to the 1-mass case M W = M Z = M photon M Z M W taken into account by expanding around the equal mass approximation Outlook extend to non-abelian models: SU(2), SU(N), SU(2) U(1) consider Higgs contributions 4-fermion scattering amplitude predictions for EW corrections to f f f f cross sections

34 Electroweak precision observables in the MSSM with NMFV Sven Heinemeyer, CERN Durham, 09/2004 based on collaboration with W. Hollik, F. Merz and S. Peñaranda 1. Introduction 2. Results for M W and sin 2 θ eff 3. Results for m h 4. Conclusions S. Heinemeyer, LCWS Durham,

35 NMFV in the MSSM NMFV: Non Minimal Flavor Violation Mixing of scalar quark families (beyond CKM) Mixing of stop/scharme ( ) T 0 ( t L, t R, c L, c R ) 0 C t L t R c L and of sbottom/sstrange: ) ( b ( b ) L B 0 L, b R, s L, s R b R 0 S s L ( t L, t R, c L, c R ) ( T 0 0 C c R t ) L t R c L add NMFV ) ( b ( B 0 L, b R, s L, s R 0 S s R b ) L b R s L c R s R S. Heinemeyer, LCWS Durham,

36 0 : experimentally only partially restricted can e.g. be induced by RGE running in msugra changes Higgs-squark couplings changes Gauge boson-squark couplings Analytical result: evaluation with arbitrary NMFV couplings Numerical result: t/ c : λ T C LL LL b/ s : λ B S LL LL SU(2): T LL B LL, C LL S LL suggested by RGE analysis no relevant experimental bounds on λ S. Heinemeyer, LCWS Durham,

37 ρ as a function of λ: m max h, M SUSY = 1 TeV no-mixing, M SUSY = 1 TeV m max h, M SUSY = 2 TeV no-mixing, M SUSY = 2 TeV increasing λ increasing mixing increasing ρ ρ increasing M SUSY increasing mixing increasing ρ ρ < can be saturated λ S. Heinemeyer, LCWS Durham,

38 δm W as a function of λ: δmw [GeV] m max h, M SUSY = 1 TeV no-mixing, M SUSY = 1 TeV m max h, M SUSY = 2 TeV no-mixing, M SUSY = 2 TeV follows the behavior of ρ δm exp,today W δm exp,future W = 34 MeV = 7 MeV extreme parameter regions already ruled out λ S. Heinemeyer, LCWS Durham,

39 δ sin 2 θ eff as a function of λ: δ sin 2 θeff m max h, M SUSY = 1 TeV no-mixing, M SUSY = 1 TeV m max h, M SUSY = 2 TeV no-mixing, M SUSY = 2 TeV λ follows the behavior of ρ δ sin 2 θ exp,today eff δ sin 2 θ exp,future eff = = extreme parameter regions already ruled out highly sensitive test in the future S. Heinemeyer, LCWS Durham,

40 Effects in benchmark scenarios: m h [GeV] tanβ = 5, M A = 500 GeV m h max max m (Xt h / M SUSY = -2) no-mixing gluophobic Higgs m h [GeV] tanβ = 20, M A = 500 GeV m h max max m (Xt h / M SUSY = -2) no-mixing gluophobic Higgs small α eff λ small effects for small/moderate λ small α eff λ δm h = O (5 GeV) only for very large λ mostly decreasing m h, but also increase possible (e.g. in small α eff scenario) S. Heinemeyer, LCWS Durham,

41 4. Conclusinos Precision observables can give valuable information about the true Lagrangian constrain MSSM parameter space already today MSSM with NMFV: mixing in the t/ c and in the b/ s sector Evaluation of M W, sin 2 θ eff, m h in NMFV MSSM Analytical results: for arbitrary mixing Numerical results: only for LL mixing, parametrized with λ corresponds to (δ LL ) 23 large effects possible for M W, sin 2 θ eff : λ < 0.2 δm W < 20 MeV λ < 0.2 δ sin 2 θ eff < 10 4 moderate effects possible for m h only for large λ S. Heinemeyer, LCWS Durham,