Hidden Higgs boson in extended supersymmetric scenarios at the LHC

Transcription

1 Hidden Higgs boson in extended supersymmetric scenarios at the LHC Priyotosh Bandyopadhyay INFN Lecce & University of Salento, Lecce arxiv: , arxiv: , JHEP 1512 (2015) 127, JHEP 1509 (2015) 045 PB, Claudio Coriano, Antonio Costantini, Katri Huitu, Aslı, Saurabh Niyogi High1-2016, KIAS-NCTS Joint Workshop, High1, South Korea February 3, 2016

2 Outline 1 Plan Experimental constraints 2 TNSSM 3 Collider Phenoenology 4 Charged Higgs Phenomenology Triplet charged Higgs boson Charged Higgs boson in NMSSM

3 Plan 1 Standard Model Higgs boson 2 MSSM and its status 3 Triplet and Singlet extended Supersymmetric SM 4 Possibility of Hidden Higgs boson 5 Collider searches 6 Triplet like charged Higgs

4 Higgs The direct mass bound on SM Higgs is m H > GeV Very low reduced couplings of Z Z h and h f f can bring down the lower bound.

5 Status of Higgs at the LHC s CMS and ATLAS combined the results in H ZZ 4l and H γγ The combined measured mass of the Higgs boson is m H = ± 0.21(stat) (sys) GeV

6 Supersymmetry Standard Model Higgs mass is not protected by any symmetry! Supersymmetry protects the Higgs mass by giving possible cancellation. h ψ < Price: In the minimal extension, for each particle there is a super partner differing by spin 1/2.

7 Higgs sector in MSSM Minimal supersymmetric extension (MSSM) has five Higgs bosons, h, H the CP-even neutral Higgs bosons A the CP-odd neutral Higgs bosons H ± charged Higgs bosons Including R-parity, P R = ( 1) 3(B L)+2s conservation leads to the lightest supersymmetric particle as Dark matter candidate. Lightest Higgs in MSSM While in the SM the Higgs mass is essentially a free parameter the lightest CP even Higgs particle in the MSSM is bounded from above. At tree level the lightest CP-even Higgs (h) mass, m h M Z For desired Higgs mass around 125 GeV, one has to look for quantum correction.

8 Higgs sector in MSSM Lightest Higgs in MSSM Depending on the SUSY parameters that enter the radiative corrections, it is restricted to values M max h M Z cos 2β + radiative corrections < GeV SUSY particles mass and other parameters enter in the radiative correction to the Higgs sector. Observed M h 125 GeV at the LHC, would place very strong constraints on the MSSM parameters through their contributions to the radiative corrections to the Higgs sector. more

9 Lightest CP-even Higgs boson in MSSM more In MSSM, the main loop contributions come from the third generation strong sectors, push the mass scale > 1 TeV to up to 10 TeV depending on the models. In most constrained SUSY scenarios viz msugra, the required SUSY mass scale is > few TeV. In pmssm, < TeV SUSY scale still a possibility but with large mixing in the stop mass matrix. Fine tuning is necessary for MSSM to have lightest Higgs boson mass around 125 GeV. 125 GeV Higgs very large SUSY mass scale or/and large mixings fine tuning.

10 Solution! Extended Higgs sector! New scalars give additional contributions to the lightest Higgs mass so no large mixing and/or heavy sfermions needed Extended theory may solve the µ problem Possibility of spontaneous CP-violation. Options? Triplet and/or singlet extensions.

11 Outline 1 Plan Experimental constraints 2 TNSSM 3 Collider Phenoenology 4 Charged Higgs Phenomenology Triplet charged Higgs boson Charged Higgs boson in NMSSM

12 Triplet-Singlet extended Supersymmetric scenarios The µ D term in the superpotenial can be generated spontaneously by the introduction of a gauge singlet superfield S. The scale invariant superpotential with the Y = 0 triplet T and singlet S is given by, W S = λ T H d.th u + λ S SH d H u + λ TS STr[T 2 ] + κ 3 S 3. The complete Lagrangian with the soft SUSY breaking terms has an accidental Z 3 symmetry; φ i e 2πi/3 φ i more When the neutral parts get vev, < H 0 u,d >= v u,d 2, < S >= v S 2 < T 0 >= v T 2 generate the the doublet mixing term µ D = λ S 2 v S + λ T 2 v T with v T < 5 GeV from ρ parameter.

13 Triplet-Singlet extended Supersymmetric scenarios Enhanced Higgs particle spectrum CP even CP odd charged h 1, h 2, h 3, h 4 a 1, a 2, a 3 h ± 1, h± 2, h± 3. The extra interaction terms also enhances the Higgs mass contribution at the tree-level thus reduces required SUSY the fine-tuning further. m 2 h 1 m 2 Z (cos2 2β + λ 2 T g 2 L + g 2 Y sin 2 2β + 2λ 2 S g 2 L + g 2 Y sin 2 2β), tan β = v u v d

14 TNMSSM: Radiative corrections We follow Coleman-Weinberg effective potential approach for one-loop Higgs mass spectrum. Parameter space scan λ T,S,TS 1, κ 3, v s 1 TeV, 1 tan β 10, A T,S,TS,U,D 500, A κ 1500, m 2 Q 3,ū 3, d , 65 M 1,2 1000, The presence of more scalar enhances the Higgs self correction drastically.

15 Plan TNSSM Collider Phenoenology Charged Higgs Phenomenology TNMSSM: axion like pseudo-scalar In the limit of a continuous symmetry In the limit when the Ai parameters go to zero, the discrete Z3 symmetry of the Lagrangian is promoted to a continuos U(1) symmetry (H u, H d, T, S ) e iφ m h1 200 (H u, H d, T, S ) 150 If this symmetry is softly broken by very small parameters Ai of O(1) GeV, we get a very light pseudoscalar as pseudo-nambu-goldstone boson of the symmetry m a1 mh1 Axion like psedo-scalar For ma1 < 2me, the pseudo-scalar decays to diphotons only. If the decay life-time τa is greater than the age of the universe, it cloud be potential dark matter candidate τa = 64π 2 gaγγ ma3 Triplet and singlet part do not couple to fermions helps to evade the bounds from flavour physics and others ma

16 TNMSSM: Hidden Higgs bosons m h1 125 GeV ZZ, WW m h2 125 GeV ZZ, WW m h1 125 GeV VV, ΓΓ m h2 125 GeV VV, ΓΓ ma m h ma m h1 We consider the discovered Higgs decay modes WW, ZZ and γγ along with LEP data. Possibilities of light pseudo-scalar and very light m a1 < 2m e are still there. Possibilities of two hidden Higgs are still alive. PB, Claudio Coriano and Antonio Costantini, JHEP 1509 (2015) 045

17 TNMSSM: Higgs mass hierarchy : Doublet, : Triplet and : Singlet

18 Outline 1 Plan Experimental constraints 2 TNSSM 3 Collider Phenoenology 4 Charged Higgs Phenomenology Triplet charged Higgs boson Charged Higgs boson in NMSSM

19 Hidden Higgs phenomenology We consider a light pseudo-scalar GeV, which is mostly singlet/triplet. These points are consistent with 125 Higgs data in the discovered modes of γγ, ZZ and WW. The uncertainties of 2σ B(h 125 a 1 a 1 ) 20%. Being mostly singlet/triplet they cannot be produced directly at the LHC Production via the decays of doublet scalar states is a possibility

20 Hidden Higgs phenomenology g τ jet, b jet t, b a 1 τ jet, b jet t, b t, b h 125 a 1 τ jet, b jet g τ jet, b jet The light pseudo-scalars mostly decay to b and τ pairs.

21 Hidden Higgs phenomenology We analysed the scenario in 2b + 2τ, 3τ, 2b + 2µ and 2τ + 2µ final state topology. A PYTHIA based simulation has been conducted with taking into account the SM backgrounds. Earlier hints can be found around 25 fb 1 of integrated luminosity of the LHC at 14 TeV. This mode can be very handy in measuring the Higgs cubic coupling. PB, Claudio Coriano and Antonio Costantini, JHEP 1512 (2015) 127

22 Outline 1 Plan Experimental constraints 2 TNSSM 3 Collider Phenoenology 4 Charged Higgs Phenomenology Triplet charged Higgs boson Charged Higgs boson in NMSSM

23 Triplet charged Higgs boson Charged Higgs in TNSSM There are three charged Higgs bosons: h ± 1, h± 2, h± 3 Two of them are triplet like. The triplet component does not couples to fermions. Non-standard decay of charged Higgs Non-zero triplet vev gives rise to non-zero tree-level Z h ± W coupling. more i which is absent in MSSM or 2HDM. h ± i ZW ± Charged Higgs searches at the LHC Charged Higgs was searched in H ± τν τ mode. Main production mode searched is t bh ± Upper bounds given on expected cross-sections. Triplet charged Higgs No coupling to fermions a triplet like light charged Higgs can evade the recent bounds The light charged Higgs cloud be still allowed and unseen. this decay mode can give us smoking gun signal of triplet nature of the model.

24 Production and decay modes of charged Higgs 1 tanβ=5 ZW ± t b 0.8 τ ν τ tanβ=30 ZW ± q i Br(h 1 ± > 2x) t b τ ν τ q j h ± i 0.2 % 1D, % 99T m h ±1 (GeV) q q W ± h ± i Z Among those charged Higgs production in vector boson fusion is unique to Triplet one which is absent in MSSM and 2HDM. Tri-leptonic signature can probe the scenario with 72 fb 1 data at the LHC. q q Z h ± i W PB, Claudio Coriano, Antonio Costantini, arxiv: P.B, Katri Huitu, Asli Sabanci, JHEP05(2015)026

25 Charged Higgs boson in NMSSM g t W + b g t W + b NMSSM charged Higgs boson NMSSM with Z 3 symmetry only extra has extra singlet along with the two Higgs doublets of MSSM. We can have a light pseudo-scalar with mass < 100 GeV Singlet does not contribute to charged Higgs There is only one charged Higgs boson which is doublet type. Non-standard decay Possibility of very light pseudo-scalar opens up h ± a 1 W ± For healthy branching in this mode we need P.B, Katri Huitu, Saurabh Niyogi, arxiv: some doublet mixing in the light pseudo-scalar. b h a1 Searches at the LHC W Final states with 1b + 2τ + 2l, 3b + 2l can probe such possibility A PYTHIA based simulation show with early data 10 fb 1 can probe some of the parameter space. b h a1 W

26 Distinguishing TNSSM, NMSSM, TESSM and MSSM p W h j Z NMSSM and MSSM charged Higgs boson MSSM and NMSSM have one doublet like charged Higgs boson. In case of MSSM pseudo-scalar and charged Higgs boson are nearly degenerate h ± aw ± is not kinematically allowed. NMSSM can have a light pseudo-scalar so h ± a 1 W ± is open. p Searches at the LHC h ± i ak W ± TESSM and TNMSSM TESSM and TNSSM have two additional triplet type charged Higgs bosons. The triplet charged Higgs does not couple to fermion but can decay to ZW ±. In TESSM possibility of light pseudo-scalar is not so natural and h ± 1 a 1 W ± is not kinematically open. In TNSSM we have a light pseudo-scalar so both h ± 1 ZW ± and h ± 1 a 1 W ± can be open. pp h ± 1 h 1 a 1 W ± ZW 2τ(2b) + 2j + 3l+ E T 2τ(2b) + 4l+ E T. Extracting both a 1 and ZW ± can be proof of existence of both triplet and singlet. P.B, Claudio Coriano, Antonio Costaniti (work in

27 Conclusions So far we have discovered a CP-even Higgs boson around 125 GeV. All possible Standard Model modes are yet to be discovered. Possibility of hidden Higgs bosons still exists. Observation of Charged Higgs would be a direct proof of extended Higgs sector. In the extended Higgs SUSY scenarios, lighter SUSY mass scale is still a possibility. h 1 ± ZW ± could be a smoking gun signature for the triplet scenario. A very light pseudo-scalar is still a possibility with extended Higgs sector. We expect that LHC at 14 TeV will unveil few more and surprise more.

28 Thank you

29 MSSM Higgs sector In the large m A limit, the lightest CP-even neutral Higgs mass at tree-level is m 2 h m2 Z cos2 2β m h cannot be greater than m Z. With the radiative correction at one-loop the lightest Higgs mass becomes, m 2h < m2 Z cos2 2β + 3 m 4 [ t 4π 2 v 2 ln M2 S mt 2 + X t 2 MS 2 (1 X t 2 ] 12MS 2 ) where M S = m t 1 m t 2, the stop mixing parameter is X t = A t µ cot β and for maximal mixing scenario: X max t = 6M S. back

30 MSSM Higgs sector back After 125 GeV Higgs boson discovery, the parameter spaces of MSSM like theories are stringently constrained. Let s consider two well known theories: msugra/cmssm, pmssm. msugra/cmssm Soft SUSY breaking parameters are unified at the high scale (GUT). Parameter space of the theory contains only sign(µ), tan β, A 0, m 0, m 1/2. Phenomenological MSSM: CP conservation, flavor diagonal mass and coupling matrices, universality of the 1st and 2nd generations are imposed. Parameter space of the model (22 parameters) : tan β, µ, M A, gaugino Masses: M 1,M 2,M 3 A f (3 for the 3rd generation+3 for 1st and 2nd generations) m f L and m fr (5 5)

31 125 GeV Higgs in MSSM M max h in pmssm, Djouadi et al. PLB708 (2012) Only the scenarios with large X t /M S values and, in particular, those close to the maximal mixing scenario A t /M S 6 survive. The no mixing scenario is ruled out for M S < 3 TeV. The typical mixing scenario needs large M S and moderate to large tan β values. Mh max =136, 123 and 126 GeV have been obtained in, the maximal, zero and typical mixing scenarios. M max h in pmssm, Carena et al. JHEP 1203 (2012) 014 With the significant splitting of the stop soft masses, the mass of the heaviest stop is of the order of the largest soft stop mass, and the lightest stop mass can be as low as 100 GeV 125 GeV Higgs does not imply a hard lower bound on the squark masses. A t larger than 2 TeV are required to achieve 125 GeV Higgs. In the case of no splitting between the two stop soft masses, values of A t above 1.5 TeV are needed to achieve Higgs masses in the region of interest. In this case the mass of the lightest stop is naturally above a few hundred GeV. mu3 GeV At 1.5 TeV, Tan Β m h GeV m t GeV mq3 GeV

32 msugra with 125 GeV Higgs Baer et al. With 125 GeV Higgs For A 0 = 0, m 0 versus m 1/2 planes are excluded ( only possible 125 GeV solutions with m 1/2 m 0 10 TeV; corresponding squark/gaugino masses 20 TeV). For A 0 = ±2m 0 and m TeV: Possible to get desired Higgs mass. Result: heavy scalars but light gauginos are still possible. A 0 < 1.8m 0 is excluded for m 0 < 5 TeV A 0 < 0.3m 0 is excluded for m 0 up to 20 TeV Conclusion: High m 0 and A 0 are required!. PRD85(2012) back m t1 (TeV) m h (GeV) msugra: m 0 =4TeV, m 1/2 =0.5TeV, µ >0, m t =173.3 GeV tan β =10 tan β =45 tan β =30 tan β = A 0 (TeV) msugra: m 0 =4TeV, m 1/2 =0.5TeV, µ >0, m t =173.3 GeV tan β =10 tan β =30 tan β =45 tan β = A 0 (TeV)

33 125 GeV Higgs boson in the TESSM Μ D GeV tanβ 10 tanβ 15 tanβ 30 tanβ 50 Μ D GeV tanβ 5 tanβ 10 tanβ 15 tanβ 30 tanβ (a) Λ (b) Λ back

34 Constraints from B X s γ B X s γ in TESSM TESSM has two more charged Higgses and one more chargino than in the MSSM. The difference compared to the MSSM is that the triplet part of the charged Higgses and charginos does not couple to quarks Percentage of Mixing λ=0.9 tanβ=5 H u H d T 1 T 2 W = λh d.σh u + µ D H d.h u + µ T Tr(Σ 2 ), For this purpose we check the doublet content in Both the lightest Charged Higgs and lightest chargino µ D back

35 TNMSSM potential V soft = mh 2 u H u 2 + mh 2 d H d 2 + ms 2 S 2 + mt 2 T 2 + mq 2 Q 2 + mu 2 U 2 + md 2 D 2 +(A S SH d.h u + A κ S 3 + A T H d.t.h u + A TS STr(T 2 ) + A U UH U.Q + A D DH D.Q + h.c), while the D-terms are given by V D = 1 gk 2 2 (φ i ta ijφ j ) 2. k back

36 TNMSSM perturbativityl Λ Λ Λ S Λ T Κ Λ TS ln Μ Μ0 back

37 Plan TNSSM Collider Phenoenology Charged Higgs Phenomenology TNMSSM Fine-tuning Fine-tuning m = µsoft µeff µeff = 1 vs λs vt λt, 2 2 = mh tan2 β mh d tan2 β 1 u F = 1 µ2soft µ2eff 2 - Μ eff : Λ S, T > 1 2 M Z vs vs m It is also convenient to introduce the additional parameter µ2soft 2 Μ soft : Λ S, T > Μ eff : Λ S, T < MZ µsoft 2 Μ soft : Λ S, T < , back characterizing the ratio between MZ2 and µ2soft, which can be considered a measure of the fine-tuning

38 h ± 1 W Z Non-standard decay of charged Higgs For Y = 0, ±2 triplet extended models, h ± ZW i coupling is not zero at tree-level for non vanishing triplet VEV. g ± h W i Z = 1 2 ig 2 ( ) g 1 sin θ w (v ur (i+1)1 v d R (i+1)2 ) 1 ( ) 2 ig 2 2g2 v T cos θ W (R (i+1)3 + R (i+1)4 ). where θ W is the Weinberg angle R ij is the rotation matrix, h i = R ij H j. The h ± W Z coupling goes to zero for v i T = 0 to preserve U(1) em gauge symmetry. Similarly when the charged Higgs is completely doublet like i.e., R (i+1)3,4 = 0, h ± W Z again zero giving rise i to MSSM like scenario. g h1 ± ZW v T back back

39 Decay Modes of charged Higgs Decay modes of charged Higgs h ± i tb ZW ± τν h j W ± Triplet nature Br(h 1 ± > 2x) tanβ=5 ZW ± t b τ ν τ tanβ=30 ZW ± t b τ ν τ D, % % 0 90T m h ± (GeV) 1 The triplet part does not couple to fermions, so normal decays to tb or τν is suppressed. The triplet can decay to ZW ± which is absent in MSSM or 2HDM. this decay mode can give us smoking gun signal of triplet nature of the model. If kinematically allowed, ZW ± mode gets tough competition from tb. Br(h 1 ± > 2x) tanβ=5 ZW ± t b τ ν τ tanβ=30 ZW ± t b τ ν τ back 0.2 1D, % % 0 99T m h ±1 (GeV)

40 Production of charged Higgs Production modes of charged Higgs As the triplet part does not couple to fermions the dominant mode pp t t for light charged Higgs is no longer the most important one for m ± < m t. h i For m t > m ±, gg h ± h 1 tb and bg h± 1 t i are also suppressed. q i q j h ± i Due to non-zero h Z W ± coupling i there are now few more additional production processes. Among those charged Higgs production in vector boson fusion is unique to Triplet one which is absent in MSSM and 2HDM. q q W ± h ± i Z Final state studies We mainly focus on the multi-leptonic final states coming from charged Higgs decays to ZW ± Additional modes like τν and tb enrich the final states with more jets: b or τ We found that the charged Higgs production in association with neutral Higgses, i.e. h i /A i h ± is quite interesting. j q q Z h ± i W

41 Benchmark point for collider study at the LHC To select to few benchmark points with a light charged Higgs to see the prospect at the LHC. Given points have a SM like Higgs bosons around 125 GeV The other heavy and charged Higgs constraints have also been checked. Benchmark Points We can see the light charged Higgs is quite non-standard due to its decay to ZW ±. It is this non-standard decay that evade the recent bounds from LHC on the light charged Higgs. It also decays to tb and τν This prompts us to look for different final states constitute of lepton, tau, jets and b-jets. tan β m h2 m A1 m ± H 1 (GeV) (GeV) (GeV) BP BP BP BP back Branching fractions Branching fractions ZW ± h 1 W ± t b τν τ BP BP O(10 2 ) BP BP O(10 2 )

42 Searches for charged Higgs in TESSM at the LHC Production modes of charged Higgs h ± h i 1, h± 1 W and h ± 1 φ give the dominant contributions for the light charged Higgs production in TESSM at the LHC. Considering different leptonic decays we focus on multi-leptonic final states: 3l, 4l and 5l final states. Due to other decay modes we also looked for 3l + 2j+ p T, 3l + 2b+ p T, 3l + 1τ+ p T final states Basic Cuts the calorimeter coverage is η < 4.5 As we are looking for leptonic final state we demanded hard jets, p jet = 20 GeV and T,min jets are ordered in p T leptons (l = e, µ) are selected with p T 10 GeV and η 2.5 R lj 0.4 and R ll 0.2 Collider Set up We analyse the signals and SM backgrounds via Pythia+Fastjet simulation at the LHC with 14 TeV. t t, t tz, t tw ± and VV (V : Z, W ± ) have been considered as dominant SM backgrounds.

43 Tri-lepton final states at the LHC 3l + 2j final state 3l + 2b final state When the charged Higgs decays to ZW ± 3l other associated particles decay hadronically. For the final state we choose: 3l ( M ll M Z 5 GeV) + 2j+ p T 30 GeV For BP1 5σ signal significance reaches in around 70 fb 1 of integrated luminosity at the LHC with 14 TeV. At 1000 fb 1 of luminosity, rest of the benchmark points reach around 10σ. more back This h ± 1 φ process can have additional b-jets from φ To find out we choose 3l ( M ll M Z 5GeV) + 2b jets+ p T 30 GeV as our final state. For BP1 and BP2 h ± h 2 contributes due low masses of h 2. For BP3 and BP4, h ± A 1 contributes. The highest reach is for BP1, reaches 5σ in 100 fb 1 of integrated luminosity at the LHC with 14 TeV. whereas BP2 has the lowest reach takes 1000 fb 1 to reach 5σ due to triplet nature of h 2, Br(h 2 b b is very small. more back 3l + 1 τ h ± can also decay to τν, so also search 3l ( M i ll M Z 5GeV)+ 1τ jet+ p T 30 GeV final state. The extra τ-jet reduces the backgrounds substantially. Highest reach is again for BP1, reaches 5σ in around 146 fb 1 of integrated luminosity. more back

44 4l and 5l final states at the LHC 4l final state When the associate particle to the light charged Higgs also contribute leptonically we can have 4l final state. We look for 4l+ p T 30 GeV final state. t t and VV are still dominant backgrounds. For BP1 & BP2 5σ signal significance reaches in around 200 fb 1 of integrated luminosity at the LHC with 14 TeV. At 1000 fb 1 of luminosity, rest of the benchmark points reach around 5σ. more back 5l final state In h ± 1 h 1 if both the charged Higgs decay to ZW ± then we can have 5l and 6l final states. We look for 5l+ p T 30 GeV final state. In BP2 h ± 1 φ also contributes as Br(h 2 ZZ 44%). The highest reach is for BP2, 10σ at 1000 fb 1 of integrated luminosity at the LHC with 14 TeV. more back 5l + 2 jet, 6l Mainly charged Higgs pair-production contributes. 5l + 2 jet and 6l final states are almost background free. These are important at higher luminosities. PB, K. Huitu, A. S. Keçeli

45 Mass reconstruction of the charged Higgs at LHC h ± 1 mass reconstruction BP1 BP4 When one of the h ± 1 decays to full visible particle via h ± i Z, W ± llqq Number of events It is possible to reconstruct M lljj invariant mass distribution M lljj in GeV Probing triplet decay mode This is one of the direct way to probe the triplet nature of the charged Higgs. Reconstruction of the peak can lead to a discovery of the light charged Higgs in TESSM. The edge at the end part of the distribution also carries information about the higher Higgs masses contributing to the production processes. Requirements of multiple leptons ( 3) and b-jets ( 2) make this almost background free H + W- H + H H + H PB, K. Huitu, A. S. Keçeli back