X. Higgs Bosonen in Supersymmetrie

Standard Modell: 1 komplexes Higgs Duplett (4 Komponenten)

1 Vakuumerwartungswert 174 GeV

3 massive Eichbosonen (W+, W-, Z0)Eine mögliche Anregung übrig:

1 neutrales Higgs Boson h

Supersymmetrie2 komplexe Higgs Dupletts (8 Komponenten)3 massive Eichbosonen (W+, W-, Z0)

5 mögliche Anregungen übrig:3 neutrale Higgs Bosonen: h, H, A2 geladene Higgs Bosonen: H+, H-

In niedr. Ordnung 2 Parameter : tan = und mA

In mehr Detail (Martin, 7.1.)

2 komplexe Isospindupletts 8 reelle skalare Felder3 Goldstone Felder (G+, G0, G-) verschwinden in massiven W+, Z0, W-

Verbleiben 3 neutrale (h0, H0, A0) und 2 geladene (H+, H-) Higgs Bosonen

X.1. Higgs Phänomenologie in Supersymmetrie

Minimal Supersymmetry: 3 neutral Higgs Bosons: h, H, A 2 charged Higgs Bosons: H+, H-

at tree level, 2 parameters : tan = v2/v1 and mA

Stephen Martin, hep-ph/97-09356

gMSSM = gSM

MSSM on tree level

t b/ W/Z

h cos/sin -sin/cos sin()

H sin/sin cos/cos cos()

A cot tan -----

MSSM at 2-loop level

Loop level (constrained MSSM):SUSY breaking parameters, assumed to be unified at some scale :

gluino mass and Higgs mass parameter Mğ and  

SU(2) gaugino mass term unified at MGUT M2 at MEW

sfermion mass terms : common at MEW Msusy at MEW

sfermion trilinear couplings : common at MEW A at MEW

mixing parameter in the stop sector : Xt = At - cot

Total: 8 parametersmt=171.4 GeV measured

M2, Msusy, Mğ, and Xt chosen to define a “benchmark scenario” tan and mA free to vary

(tan[1, 50] and mA[50, 1000]GeV)

Higgs MassesA ~ degenerate in mass with

h at low massesH and H± high masses

h mass < 130 GeV (all scenarios)

S.Heinemeyer in J.Ellis et al CERN-PH-TH/2007-012

Benchmark scenarios

Examples: Description: http://arxiv.org/abs/hep-ph/0202167

M. Carena, S. Heinemeyer, C.E.M. Wagner, G. Weiglein

Features ofLarge mA and mH:

h is SM-like w/ maximal mass

gMSSM = gSM

H/A/H± produced via Fermion-couplings!Large enhancement of SUSY-Higgs ~(tan)2 possible

Large tan: b- associated production

Small tan: t- associated production

Easy pattern for large mA

t b/ W/Z

h 1 1 -1

H -cot tan 0

A cot tan 0

Example: Widths and Branching Ratios to From Ph.D. thesis, Jana Schaarschmidt, TU Dresden, 2010Widths

H,A:enhanced by tanh:

above m ~ 200 GeVSM-like (narrow)

Branching ratiosSM: negligible above 160 GeVSUSY: always sizableincreasing w/ tanA and H

Cross Sections

Can we see the additional Higgses?

good news:at least one Higgs boson observable for all parameters in all four MSSM benchmark scenarios

bad news: significant area where only lightest Higgs boson h is observablee.g. Higgs discovery, ATLAS prel., 300 fb-1

(M. Schumacher, hep-ph/0410112, ATL-com-phys-2004-070)

X. 2. Search for Neutral Higgs Bosons

How to discover?

Basic 2 2 diagram Corresponding to b-pdf in ProtonDetails much more complex

Add 23, 22, and 21 w/o double counting

Solution: SHERPA MC generator w/ CKKW matchingbetween Matrix Element and Parton Shower contributionsJet fractions agree with analytic calculation (Harlander+Kilgore)

Example: full (down-type) leptonic modesb h/H/A b µ+µ-

b h/H/A b b ℓ+νν ℓ-νν

Main backgrounds (several 100 pb)tt (b)b µ+ν µ-ν tt (b)b ℓ+ν ℓ-ν

qZ ‘‘b‘‘µ+µ- qZ ‘‘b‘‘

Associate A/H production with b-quarks

Mass Resolutions

µ+µ-: exzellente Massenauflösung ~ 3 GeVh/A/H trotzdem nicht getrennt, aber Breite messbar

gröbere Massenauflösung 30 - 40 GeVbenutzt kolineare Näherung des Tau Zerfalls

tan mA=132 GeV

tan mA=150 GeV

M.Warsinsky, DoktorarbeitDresden, 200814 TeV, 30 fb-1

~ 2014 / 2015

J.Schaarschmidt, DiplomarbeitDresden, 2007 14 TeV, 30 fb-1

~ 2014 / 2015

Collinear Approximation

Performance (Ph.D. Thesis, Jana Schaarschmidt, 2010)

Lepton + Hadrons (ATLAS)Typical signal and background distributions at 14 TeV

without b-Jet with b-Jet

Extraction of Z background m shape from data

Use Z and Zee and reweight the lepton signalsJust needs reweighting of track momentaeeNeeds also reweighting of *longitudinal* shower shape

Very successful results

(Jana Schaarschmidt, 2007) Zee (Kathrin Leonhardt, 2008, Patrick Czodrowski, 2009)

Expected sensitivities

X.3. Charged H±

Mass and Couplings:mH±

2 = mA2 + mW

2 in MSSM w/ negligible radiative corrections

No coupling to W, ZTwo fermionic couplings dominant:

Minimum tb coupling at tan √(mt / mb ) ≈ 7

LEP Limits

Direct LEP limits for e+e- H+H- stop at ~mW due to W+W- backgr.

MSSM: BR(H±) dominant for mH± < mt mH± >~ 85 – 89 GeV

LEP direct H± limits:Relevant in non-SUSY 2-Higgs Doublet Models (2HDM)Marginal in MSSM, since mH±

2 = mA2 + mW

2 anyway

Search for Charged Higgs Bosons

New input from b-physics!

Newly developping constraints from b-decays

Gino Isidori, 3rd Workshop: Flavour in the Era of the LHC, 2006

Well defined pattern for exp. observables Starting to give useful constraintsMost limits in literature for 2HDM !No systematic studies for MSSM yet (too many param.!)

Leading-order H± contribution!

2HDM (W.S.Hou, PRD 48 (1993) 2342)

rBBR(2HDM)/BR(SM) =

MSSM (G.Isidori, P.Paradisi, hep-ph/0605012)

Gluino-induced corrections ((mg,mq)to down-type Yukawa couplings considerable for large tan

rBBR(MSSM)/BR(SM) =

B New Physics

222

2

)tan1(

H

B

m

m

2

0

2

2

2

)tan1

tan1(

H

B

m

m

Amplitude M(H±) has opposite sign!suppression

|M (H±)| < |M (W±)|

(near-)cancellation

|M (H±)| ~ |M (W±)|

(near-)compensation

|M (H±)| ~ 2|M (W±)|

enhancement

|M (H±)| > 2|M (W±)|

rB

tan

± ±

~ ~

B Experimental Signature

B First Observations

2.6

C.Bozzi, HCP2007

MSSM interpretation of B- and other constraints

G. Isidori, F. Mescia, P. Paradisi, D. Temes: hep-ph/07030351.01 < Rbs < 1.24 (1 sigma): blue lines

0.8 < R‘B < 0.9 (future guess!): black lines

current 1-sigma would be 0.7 < R‘B < 1.3

NB: 2nd solution for mH < 200GeV not shown!

B → μ+μ− < 8.0 × 10−8: allowed below green linemBs

= 17.35 ± 0.25 ps−1 : allowed below gray line

(g-2)μ: 2 < aμ(exp− SM)/10−9 < 4 : purple lines

Dark Matter (~Bino) density: light blue forbidden

M˜q = 1.5 TeV AU = −1 TeVμ = 1.0 TeVM˜ℓ = 0.4

TeV

M˜q = 1.5 TeV AU = −1 TeVμ = 0.5 TeVM˜ℓ = 0.3

TeV

Two main production processes

for mH± < mt

gg t t bW bH±

for mH± > mt

bg tH± bW H±

Two main decay modesH± dominant for “small“ mH±

below 200 GeV (large tan 10)below 150 GeV (small tan )

H± tb,approaches for “large“ tan BR(tb)/BR() = (mb/m)2 ~ 6

H± at LHC

H±

±

95 130 170 215 310 mH±(GeV)

H±(f

b)

M. Schumacher, ATL-com-phys-2004-070

H±

t

z.B. für mH± > mt : tH± bW

Transversale Massenverteilung nach 30 fb-1

Entdeckungs und Ausschlusspotenzial (Alle Kanäle kombiniert)

H± Discovery reach (ATLAS, TDR 2008)

~