Heavy Vector Searches at the LHC

Transcription

1 BLV, 15 Ma 17 Heav Vector Searches at the LHC Andrea Thamm JGU Mainz in collaboration with D. Pappadopulo, R. Torre and A. Wulzer based on arxiv:1.31 and work in progress

2 Heav Vector Resonances heav vectors among the most motivated direct searches since the appear in man NP models Weakl coupled SPIN 1 Strongl coupled Z models, sequential W, Composite Higgs models various colourless vectors SU(3) C SU() L U(1) Y B µ 1 1 Bµ L µ 1 3/ W µ 1 3 Wµ singlets (work in progress) no coupling to quarks studied here! no coupling to fermions [del Aguila, de Blas, Perez-Victoria, arxiv: ] simplified model approach

3 Bridge explicit models Simplified Lagrangian can be matched to explicit models Theor c( p) Ls L( c) Data limit on BR Simplified Lagrangian parameters c fixed in terms of explicit model parameters p translate limits into bounds on simplified model parameters

4 Bridge bounds are extremel general can be easil used in everone s favorit model explicit models Simplified Lagrangian can be matched to explicit models Theor c( p) Ls L( c) Data limit on BR Simplified Lagrangian parameters c fixed in terms of explicit model parameters p translate limits into bounds on simplified model parameters

5 Phenomenological Lagrangian L V = 1 D [µv a ] D[µ V ] a + m V V a µ V µa + ig V c H Vµ a H a D $ µ H + g c F Vµ a J µa F g V + g V c VVV abc V a µ V b D [µ V ] c + g V c VVHH V a µ V µa H H V = V +,V,V g c VVW abc W µ a V b µ V c Coupling to SM Vectors Coupling to SM fermions J µa F = X f f L µ a f L W L,Z L,h f g V c H V µ W L,Z L,h V µ f g g V c F c F V J F! c l V J l + c q V J q + c 3 V J 3

6 Phenomenological Lagrangian L V = 1 D [µv a ] D[µ V ] a + m V V a µ V µa + ig V c H Vµ a H a D $ µ H + g c F Vµ a J µa F g V + g V c VVV abc V a µ V b D [µ V ] c + g V c VVHH V a µ V µa H H V = V +,V,V g c VVW abc W µ a V b µ V c Couplings among vectors do not contribute to V decas do not contribute to single production onl effects through (usuall small) VW mixing irrelevant for phenomenolog onl need (c H,c F )

7 Phenomenological Lagrangian L V = 1 D [µv a ] D[µ V ] a + m V V a µ V µa + ig V c H Vµ a H a D $ µ H + g c F Vµ a J µa F g V + g V c VVV abc V a µ V b D [µ V ] c + g V c VVHH V a µ V µa H H V = V +,V,V g c VVW abc W µ a V b µ V c Weakl coupled model Strongl coupled model g V tpical strength of V interactions g V g 1 c H g /g V and c F 1 1 <g V apple dimensionless coefficients c i ch cf 1

8 Production rates DY and VBF production DY = X i,j p V! ij M V 3 dl ij dŝ ŝ=m V VBF = X i,j p can compute production rates analticall easil rescale to different points in parameter space V! W Li W Lj M V model dependent 8 dl W LiW Lj dŝ ŝ=m V model independent quark initial state vector boson initial state TeV u i d j HV + L u i u j HV L d i d j HV L d i u j HV - L CTEQ6L1 Hm = s`l TeV W L + Z L HV + L W L + W L - HV L W L - Z L HV - L CTEQ6L1 Hm = M W L s` = M s` = M

9 V ±!ff ' V!ff ' N c[f] V!W + L W L Deca widths relevant deca channels: di-lepton, di-quark, di-boson ' V ±!W ± L Z L g c F g V MV 96, ' g V c H M V 19 V!Z L h ' V ±!W ± L h ' g V c H M V 19 1+O( ) 1+O( ) Weakl coupled model Strongl coupled model g V c H ' g c F /g V ' g /g V g V c H ' g V, g c F /g V ' g /g V BRHV Æ XL Model A W + W - Zh uu dd g V = 1 ll è nn bb tt è BRHV Æ XL Model B W + W - Zh uu dd ll è nn bb tt è. 1-3 g V =

10 LHC bounds Weakl coupled model Strongl coupled model 1 1 shpp Æ theoreticall excluded M excluded for masses < 3 TeV di-lepton most stringent di-boson searches < 1- TeV CMS A gv =1 σ(pp V) [pb] theoreticall excluded V Æ tt V ± Æ tb V Æ ll V ± Æ l ± n V ± Æ W ± Z Æ 3l ± n V ± Æ W ± Z Æ jj V Æ WW Æ jj V Æ WW Æ lnqq _ ' V Æ tt pp Æ V pp Æ V M V [GeV] CMS B gv =3 similar bounds for ATLAS excluded for masses < 1.5 TeV unconstrained for larger g V di-boson most stringent in excluded region G F, m Z not reproduced

11 Heav Vector Resonances man searches at 8 and 13 TeV

12 Limits on parameter space experimental limits converted into (c H,c F ) plane ellow: CMS l + analsis dark blue: CMS light blue: CMS WZ! jj black: bounds from EWPT WZ! 3l c F - * B gv =1 A gv =1 c F - * B gv =3 A gv =3 c F - * B gv =6 A gv = M V = TeV g V =1-6 M V = TeV g V =3-6 M V = TeV g V = c H c H c H l dominates EWPT not competitive onl 1. c F. 1 allowed EWPT become comparable di-bosons more and more relevant strongl coupled model evades bounds from direct searches [Pappadopulo, Thamm, Torre, Wulzer, arxiv:1.31 ]

13 Limits on parameter space ATLAS: W to WZ ellow: CMS l + analsis dark blue: CMS light blue: CMS WZ! jj black: bounds from EWPT WZ! 3l [ATLAS, arxiv:16.56 ] [Pappadopulo, Thamm, Torre, Wulzer, arxiv:1.31 ] ATLAS: V to HV to (bb)(lep lep) [ATLAS, arxiv: ] CMS: Z to HZ to (tau tau)(qq) [CMS, arxiv:15.99 ]

14 Combination of searches simplified model makes combination of searches eas arxiv:1.31 to appear Triplet of SU()L Singlet of SU()L Singlet of SU()L

15 Limit setting

16 Limit setting SM s SM Hpp Æ l + l - L Signal onl shpp Æ V Æ l + l - L Signal BW shpp Æ V L â BRHV Æ l + l - L SM + Signal Hwêo interferencel shpp Æ V Æ l + l - L + s SM Hpp Æ l + l - L SM + BW Hwêo interferencel shpp Æ V L â BRHV Æ l + l - L + s SM Hpp Æ l + l - L Effect of interference -1 < < 1 want limits on BR since model-independent can be easil reinterpreted but depends on details of analsis (assumed total width of resonance) discuss two (well known, but often forgotten) effects example: di-lepton invariant mass distribution TeV resonance 3.5 TeV resonance dsêdml + l pbêgevd 8 6 M V = TeV G êm V = 1 % dsêdml + l pbêgevd M V = 3.5 TeV G êm V = 11 %

17 Limit setting 1. Interference with SM background SM s SM Hpp Æ l + l - L Signal onl shpp Æ V Æ l + l - L Signal BW shpp Æ V L â BRHV Æ l + l - L SM + Signal Hwêo interferencel shpp Æ V Æ l + l - L + s SM Hpp Æ l + l - L SM + BW Hwêo interferencel shpp Æ V L â BRHV Æ l + l - L + s SM Hpp Æ l + l - L Effect of interference -1 < < 1 dsêdml + l pbêgevd 8 6 M V = TeV G êm V = 1 % constructive dsêdml + l pbêgevd M V = 3.5 TeV G êm V = 11 % destructive (pp! V ) BR (V! ll) depends on S/B ratio dashed green: signal + background with no interference green shaded region: constructive and destructive interference can be large effect interference vanishes exactl at, is odd around this point [M V,M V + ] less sensitive ŝ = M V background ˆI(ŝ) / (ŝ M V ) (ŝ M V ) + M V [Accomando, Becciolini, Balaev, Moretti, Shepherd, arxiv:13.67 ] [Accomando, Becciolini, de Curtis, Dominici, Fedeli, Shepherd, arxiv: ]

18 Limit setting 1. Interference with SM background SM s SM Hpp Æ l + l - L Signal onl shpp Æ V Æ l + l - L Signal BW shpp Æ V L â BRHV Æ l + l - L SM + Signal Hwêo interferencel shpp Æ V Æ l + l - L + s SM Hpp Æ l + l - L SM + BW Hwêo interferencel shpp Æ V L â BRHV Æ l + l - L + s SM Hpp Æ l + l - L Effect of interference -1 < < 1 dsêdml + l pbêgevd 8 6 M V = TeV G êm V = 1 % constructive dsêdml + l pbêgevd M V = 3.5 TeV G êm V = 11 % destructive parameterize interference as inset plot: (pp! V ) BR (V! ll), 1 Full() BW background within mass window, deviation is < 1% d Full dm l + l () = d B dm l + l + d S dm l + l + d I dm l + l [Accomando, Becciolini, Balaev, Moretti, Shepherd, arxiv:13.67 ] [Accomando, Becciolini, de Curtis, Dominici, Fedeli, Shepherd, arxiv: ]

19 dsêdml + l pbêgevd. Distortion from BW 8 6 M V = TeV G êm V = 1 % Limit setting dsêdml + l pbêgevd SM s SM Hpp Æ l + l - L Signal onl shpp Æ V Æ l + l - L Signal BW shpp Æ V L â BRHV Æ l + l - L SM + Signal Hwêo interferencel shpp Æ V Æ l + l - L + s SM Hpp Æ l + l - L SM + BW Hwêo interferencel shpp Æ V L â BRHV Æ l + l - L + s SM Hpp Æ l + l - L Effect of interference -1 < < 1 [Accomando, Becciolini, Balaev, Moretti, Shepherd, arxiv:13.67 ] [Accomando, Becciolini, de Curtis, Dominici, Fedeli, Shepherd, arxiv: ] ! due to steep fall of parton luminosities at large energies total BW cross section d S dm l + l = X i,j 3 in peak region onl M l + l M V V!q i q j M V = 3.5 TeV G êm V = 11 % V!l + l (M l + l M V ) + M V M l + l M V BW dl ij dŝ ŝ=m l + l ' dl ij dŝ ŝ=m V d S dm l + l = BR V!l+ l BW(M l + l ; M V, )

20 dsêdml + l pbêgevd. Distortion from BW 8 6 M V = TeV G êm V = 1 % Limit setting dsêdml + l pbêgevd SM s SM Hpp Æ l + l - L Signal onl shpp Æ V Æ l + l - L Signal BW shpp Æ V L â BRHV Æ l + l - L SM + Signal Hwêo interferencel shpp Æ V Æ l + l - L + s SM Hpp Æ l + l - L SM + BW Hwêo interferencel shpp Æ V L â BRHV Æ l + l - L + s SM Hpp Æ l + l - L Effect of interference -1 < < 1 [Accomando, Becciolini, Balaev, Moretti, Shepherd, arxiv:13.67 ] [Accomando, Becciolini, de Curtis, Dominici, Fedeli, Shepherd, arxiv: ] ! assumption depends on variation of parton luminosities M V = 3.5 TeV G êm V = 11 % BW M l + l M V dl ij dŝ ŝ=m l + l agreement better for small width parton luminosities decrease faster at larger masses however, in peak region deviation < 1% ' dl ij dŝ ŝ=m V

21 dsêdml + l pbêgevd Conclusion 8 6 M V = TeV G êm V = 1 % Limit setting dsêdml + l pbêgevd SM s SM Hpp Æ l + l - L Signal onl shpp Æ V Æ l + l - L Signal BW shpp Æ V L â BRHV Æ l + l - L SM + Signal Hwêo interferencel shpp Æ V Æ l + l - L + s SM Hpp Æ l + l - L SM + BW Hwêo interferencel shpp Æ V L â BRHV Æ l + l - L + s SM Hpp Æ l + l - L Effect of interference -1 < < 1 [Accomando, Becciolini, Balaev, Moretti, Shepherd, arxiv:13.67 ] [Accomando, Becciolini, de Curtis, Dominici, Fedeli, Shepherd, arxiv: ] ! M V = 3.5 TeV G êm V = 11 % BW onl limits set on peak region give model independent bounds (give bounds on BR for each mass and width) searches sensitive to the tail onl valid in the assumed model, not reusable

22 Conclusions model independent strateg to stud heav spin-1 triplets extremel useful to present results in terms of simplified model parameters allows eas reinterpretation limits should be set on BR b focussing on the on-shell region