Are there hidden scalars in the LHC Higgs results? BURI2014 - - PowerPoint PPT Presentation

Are there hidden scalars in the LHC Higgs results? BURI2014 - University of Toyama 13 February 2014 Rui Santos ISEL & CFTC (Lisbon) with A. Arhrib and P. Ferreira

LHC The Higgs Multi-”Higgs”? One Higgs?

What is this talk about? Gluon fusion Direct h H → hh Chain (the two most relevant) ; A A → hZ A. Arhrib, P. Ferreira, RS 1311.1520 - to appear in JHEP The SM-like Higgs decays are just the same (with different widths though) h → γγ ; h → W + W − ; h → ZZ ; h → τ + τ − ; h → bb

In which model? ⎧ SM + singlet ⎨ SM +doublet ⎩ Z 2 symmetric CP-conserving 2HDM (softly broken) ⎛ 0 ⎞ ⎛ 0 ⎞ φ 1 = 1 ; φ 2 = 1 ⎜ ⎟ ⎜ ⎟ v 1 v 2 2 2 ⎝ ⎠ ⎝ ⎠ 7 free parameters + M W : tan β = v 2 ratio of vacuum expectation values v 1 rotation angle neutral CP-even sector

2HDM Lagrangian  scalars-gauge bosons couplings cos( β − α ) hVV sin( β − α ) for the lightest for the heavier CP- g SM CP-even Higgs even Higgs  Yukawa couplings sin α tan β III = I’ = Y = Flipped=… IV = II’ = X = Lepton Specific= … no FCNC at tree- level

The decoupling limit of the 2HDM J. Gunion, H. Haber, PRD67 (2003) 075019. S. Kanemura, Y. Okada, E. Senaha, C.-P. Yuan PRD70 (2004) 115002. I. Ginzburg, M. Krawczyk, PRD72 (2005) 115013.

Experimental and theoretical constraints • Perturbative unitarity • Potential is bounded from below • Electroweak precision • Constraints on the masses from LEP • Constraints on the plane (m H +, tan β ) from Tevatron and LHC and B-physics • LHC exclusion bounds on the heavy scalars BR ( H − → τν ) Corrected for m H + = 90 GeV I II Y X tan β 4.3 6.4 3.2 5.2 ATLAS-CONF-2013-090

Vacuum structure of 2HDMs A. Barroso, P. Ferreira, RS Local minimum – PLB603(2004), PLB632(2006), PLB652(2007) NORMAL (V N ) M. Maniatis, A. von Manteuffel, O. Nachtmann and F. Nagel EPJC48(2006)805 I. Ivanov Global minimum – CHARGE BREAKING (V CB ) PRD75(2007)035001, PRD77(2008)15017 The tree-level global picture 1. 1. 2HDM have at most two minima 2. 2. Minima of different nature never coexist 3. Unlike Normal, CB and CP minima are uniquely determined 4. If a 2HDM has only one normal minimum then this is the absolute minimum – all other SP if they exist are saddle points 5. If a 2HDM has a CP breaking minimum then this is the absolute minimum – all other SP if they exist are saddle points

Two normal minima - potential with the soft breaking term m W = 80.4 GeV V G − V L = − 4.2 × 10 8 GeV m W =107.5 GeV IF D < 0 PANIC Let The vacuum is the global minimum of the potential if and only if D > 0. A. Barroso, P.M. Ferreira, I.P. Ivanov, RS, JHEP06 (2013) 045. A. Barroso, P.M. Ferreira, I.P. Ivanov, RS, J.P. Silva, Eur. Phys. J. C73 (2013) 2537 .

Consequences of finding a ~125 GeV Higgs for 2HDMs

Scan • Set m h = 125 GeV. • Generate random values for potential’s parameters such that • Impose all experimental and theoretical constraints previously described. • Calculate all branching ratios and production rates at the LHC. • Impose ATLAS and CMS results.

Green – ATLAS 1 σ Green – CMS 1 σ Blue – ATLAS 2 σ Blue – CMS 2 σ SM-like limit sin( β - α ) = 1 • The function sin 2 ( β – α ) is very sensitive to deviations from 1 – large dispersion. • For ATLAS R ZZ is above 1 – 1 σ (green) excluded; 2 σ (blue) allowed. • For CMS R ZZ is below 1 – 1 σ (green) away from SM limit but allowed; 2 σ (blue) allowed and with a large dispersion. • Large positive values of sin α already excluded at 2 σ .

Green – ATLAS 1 σ Green – CMS 1 σ Blue – ATLAS 2 σ Blue – CMS 2 σ SM-like limit sin( β - α ) = 1 sin( β + α ) = 1 • This function is not sensitive to deviations from 1 – small dispersion. • In both cases we have 1 σ (green) and 2 σ (blue) allowed regions. • For CMS they are mostly above the red lines (R’s below 1) and for ATLAS they are mostly below the red lines (R’s above 1). • Large positive values of sin α (and the ones close to -1) already excluded at 2 σ .

Green – ATLAS 1 σ Green – CMS 1 σ Blue – ATLAS 2 σ Blue – CMS 2 σ D E D U L C X E SM-like limit sin( β + α ) = 1 sin( β - α ) = 1 D E D U L C X E • sin( β – α ) < 0.5 excluded at 2 σ – deviations of the light Higgs couplings to gauge bosons relative to the SM’s. • For sin( β – α ) < 0.8, tan β < 4 – large tan β only close to sin( β – α ) = 1. This is a major difference relative to type I models.

What is this talk about? Gluon fusion Direct h H → hh Chain (the two most relevant) ; A A → hZ A. Arhrib, P. Ferreira, RS 1311.1520 - to appear in JHEP The SM-like Higgs decays are just the same (with different widths though) h → γγ ; h → W + W − ; h → ZZ ; h → τ + τ − ; h → bb

Consequences of not finding other scalars for 2HDMs. ) [pb] Observed bb � CLs 2 10 Expected bb � ! ! Observed gg CLs � � / � Expected gg � � � � 1 bb � � � � # � � 10 � 2 bb # � � BR( " 1 � � 95% CL limit on � � ! ! -1 10 ATLAS s = 7 TeV � -1 Ldt = 4.7 - 4.8 fb -2 10 100 150 200 250 300 350 400 450 500 m [GeV] � ATLAS, JHEP02(2013)095 These are the searches for taus in the final state. All other available searches were considered.

Comparison between 2HDM predictions and the LHC results. (a) predicted values for pp -> H -> ττ in type I; (b) predicted values for pp -> A -> ττ in type II. Green points include all constraints except the light Higgs ones. The black line is the ATLAS exclusion line. Excludes large tan beta in type II. Very important because couplings do not depend on alpha. Direct constraints on the (m A , tan β ) plane.

R WW in type II with all R WW in type II with all constraints constraints. except for light Higgs measurements. Type II � after imposing LHC h results (b) 0 10 WW R H � 1 10 � 2 10 150 200 250 300 350 400 450 500 550 600 m H All this is telling us is that H cannot There are still points in couple very strongly to gauge bosons… parameter space that are … and that is to be expected: if h excluded with this couples strongly to ZZ and WW, H must particular bound. couple weakly:

Comparison between 2HDM predictions and the LHC results. Cross section for A production R γγ (for A production) in type II times BR(A-> γγ ) in type II Increases until the opening of the A -> tt channel. It could improve our understanding of the models when combined with the A -> ττ results.

What if some of the h’s we are observing at the LHC are coming from the decays of the other heavy scalar states? There are new contributions to the lightest Higgs rates This is the “usual” rate, which includes only “direct” production There are however “indirect” contributions as well: An H, an A or a H + is produced first, and THEN decays to a light h – CHAIN HIGGS PRODUCTION.

All production processes considered Vector boson fusion Gluon fusion ⎧ H → hh ⎪ H → H + H − → hhW + W − ⎨ ⎪ H → AA → hhZZ ⎩ ; A ⎧ H → AZ → hZ ⎨ H → H + W − → hW + W − ⎩ ⎧ A → hZ ⎨ A → H + W − → hW + W − ⎩ Associated production with Higgs-strahlung t t ; A ; A The SM-like Higgs decays are just the same (with different widths though) h → γγ ; h → W + W − ; h → ZZ ; h → τ + τ − ; h → bb

For instance, for H the new contribution would be given by With being the “expectation value of h’s produced in H decays”.

Does it make any difference…? Manage to get larger values of R ZZ , which couldn’t occur for Type I… Also for R γγ . Plenty of Green points in the middle of blue ones DIRECT + CHAIN PRODUCTION CAN YIELD PERFECTLY REASONABLE VALUES OF THE R’S! SM-like points can already come from chain decays.

HOW IMPORTANT CAN CHAIN PRODUCTION BE? • Take all R’s of h within 20% of their SM values. • Consider the ratio between the CHAIN cross sections and the TOTAL. • CHAIN PRODUCTION CAN BE UP TO ~25% OF THE TOTAL PRODUCTION OF HIGGSES AT THE LHC. GREEN – before 20 %. BLUE – AFTER 20%.

WHERE ARE THESE POINTS IN PARAMETER SPACE? Type II Plots clearly shows that in both model types the enhancement reaches a maximum very close to sin ( β - α ) ≈ 1. GREEN – before 20 %. BLUE – AFTER 20%.

WHERE ARE THESE POINTS IN PARAMETER SPACE? Type II Preferred values of tan β are small - close to 1. Again this is valid for both model types. GREEN – before 20 %. BLUE – AFTER 20%.

WHICH PROCESSES CONTRIBUTE THE MOST? Type II H → hh A → hZ All constraints taken into account, including the 20 % one. Here we also show the sum of all contribution of the charged Higgs to chain decays which is clearly negligible (in BLUE).

Conclusions We could already be seeing heavy scalars hidden in chain decays. Chain decays give also a larger range of variation for R XX . Searches for A -> hZ and H -> hh can improve our knowledge on extensions of the scalar sector of the SM. Now, dedicated analysis are needed. Wait, don’t go away. I still have two announcements: one short, and the other very short.