Probing Two Higgs Doublet Models with LHC and EDMs

Transcription

1 Probing Two Higgs Doublet Models with LHC and EDMs Satoru Inoue, w/ M. Ramsey-Musolf and Y. Zhang (Caltech) ACFI LHC Lunch, March 13, 2014

2 Outline 1 Motivation for 2HDM w/ CPV 2 Introduction to 2HDM 3 LHC bounds 4 EDM bounds 5 Conclusions

3 Motivations for 2HDM We now know that there is a scalar sector Are there more scalars? Can the scalar sector really be minimal? 2 Higgs doublets appear in SUSY extension of and some Peccei-Quinn models 2HDM is the EFT when other particles are very heavy Baryogenesis Richer scalar potential can violate CP, allow 1st order EW phase transition

4 Basics of 2HDM 2HDM = + one more Higgs doublet i! H + i 1 p 2 v i + H 0 i + ia 0 i!, i =1, 2, with v = q v v 2 2 = 246 GeV 8 degrees of freedom! 3 Goldstones + 5 physical: H 0 1, H0 2, A0, H ± Pseudoscalar A 0 important for CPV

5 Flavor-changing neutral current 2HDM Yukawa interaction gives fermion mass matrix (y 1,ij i j 1 + y 2,ij i j 2 ) M ij = y 1,ij v 1 p 2 + y 2,ij v 2 p 2 In general, M cannot be diagonalized simultaneously with y s.! tree level FC Yukawa interaction, e.g. ds term (bad!)

6 Z 2 symmetry (type II 2HDM) Introduce symmetry: 1! 1, d R! d R Each type of fermions couples to only one doublet L Y = Y U Q L (i 2 ) 2u R Y D Q L 1 d R Y L L 1 e R + h.c. Mass matrix and Yukawa can both be diagonalized. Same structure as SUSY. Other schemes exist (type I, aligned, etc.), but ignore for this talk

7 Higgs potential V = h i 5( 1 2) 2 + h.c. 2 1 n h m m12( i 2)+h.c. + m o Quartic terms respect Z 2, and we break it softly with m 2 12 term. Red parameters are complex Only one CPV invariant - Im( 5 m 4 12 )

8 Mass eigenbasis After EWSB, there is a 3 3 mass matrix for the neutral Higgs. Diagonalization involves rotation in 3D h 1 H 0 1 h 2 A = H 0 A 2 h 3 A 0 With CPV in the scalar potential, all 3 states mix to form mass eigenstates, e.g. h 1 = s c b H c c b H s b A 0 (1) Roughly - gives how much of each doublet is in h 1 b gives how much pseudoscalar is in h 1 Another angle c a ects heavy Higgs

9 Higgs interactions in mass basis Finally, we can write the lightest Higgs interactions to fermions and gauge bosons: L h1 = m f 2m 2 v h 1 c f ff + c f fi 5f +ah W 1 W µ W µ + m2 Z v v Z µz µ c f and a are CP-even, 1 in, mostly a ected by angle c f is CP-odd, 0 in, mostly a ected by angle b

10 Recap Type-II 2HDM w/ softly broken Z 2 : There are 3 neutral Higgs, h 1,2,3, and a charged Higgs, H + FCNC is suppressed by symmetry Potential can have 1 new CPV phase CP even mixing angle shifts scalar Yukawa and gauge-higgs couplings for h 1 CP odd b introduces scalar-pseudoscalar mixing, and pseudoscalar Yukawa coupling for h 1

11 Higgs production and decay There are heavy/charged Higgs searches (for another LHC lunch?) but (lightest) Higgs phenomenology can already probe 2HDM. gg!h 1 gg!h 1 = h 1! h! VV!h 1 VV!h h 1!b b h!b b h 1!gg h!gg (1.03c t 0.06c b ) 2 +(1.57 c t 0.06 c b ) 2 ( ) 2 (0.23c t 1.04a) 2 +(0.35 c t ) 2 ( ) 2 = = V!Vh 1 V!Vh h 1! + h! + = h 1!WW h!ww c b 2 + c b 2 = h 1!ZZ h!zz a 2

12 Fit to LHC Higgs data Fit to Higgs decay signal strengths ( 25 fb 1 ) WW ZZ Vbb ATLAS 1.6 ± ± ± ± ± 0.7 CMS 0.8 ± ± ± ± ± Combined, tan b= Combined, tan b= Combined, tan b= ab a a a mostly constrained near value ( b not well constrained /2)

13 EDMs - very short review B CPV sources induce d = 6 CPV operators Main ones generated by 2HDM: EDMs - f m 2 f e f µ 5fF µ chromo-edms - q 2 m q g s q µ 5 T a qg aµ Weinberg operator - C G 2 2 g s f abc µ G a µ G b G c f, q, C G are dimensionless Wilson coe cients These operators need to be run down to QCD and matched to EDMs by evaluating matrix elements

14 2-loop diagrams In 2HDM, 1-loop EDM/CEDM for e, u, d are tiny (Yukawas) g g t t t,h + W +,G + g hi g g hi f f f,z hi f f f 2-loop diagrams dominate

15 EDM experimental summary 90% C.L. limits: eedm: d e < e cm ACME experiment on ThO molecule, nedm: d n < e cm Grenoble, Many groups aiming for order of magnitude or more improvement. HgEDM: d Hg < e cm Seattle, Taking more data. Plans for Ra and Xe - more sensitive due to nuclear enhancement

16 EDM current bounds Exclusion plots on tan sin b plane: electron, neutron, Hg (magenta - theoretically inaccessible) eedm places strongest constraints: sin b..01 nedm and HgEDM have large theory uncertainties

17 EDM future bounds electron, neutron, Hg, Ra Left - current Center - 10x improvement for neutron and Hg Right - 100x improvement for neutron Ra limit taken to be order of magnitude short of target

18 Conclusions 2HDM is a theoretically motivated model to probe a richer scalar sector LHC Higgs data is constraining CP-even e ects of 2HDM EDM constrains CPV e ects - complementarity Current CPV bounds come from eedm, but other experiments can become competitive Hadronic/nuclear uncertainties are problematic

19 Backup slides

20 Higgs mass matrix The Higgs mass matrix in (H 0 1, H0 2, A0 )basisis 0 M 2 = v 1 c 2 + s 2 1 ( 345 )c s 2 Im 1 5 s ( 345 )c s 2s 2 + c Im 5 c A, 1 2 Im 1 5 s 2 Im 5 c Re Re 5, Re 5 csc sec /2v 2 Scalar-pseudoscalar mixing from Im 5,asexpected.

21 Rotation matrix parameterization Neutral Higgs mass matrix is diagonalized with a rotation in 3D h 1 H 0 1 h 2 A = H 0 A 2 h 3 A 0 R =R 23 ( c )R 13 ( b )R 12 ( + /2) 0 1 s c b c c b s b s s b s c c c c s c c c s b s c c b s c A s s b c c + c s c s s c c s b c c c b c c + /2 = makes Yukawa and vev proportional ( limit) b = 0 is the CP-conserving limit

22 Charged Higgs and Goldstones The charged sector divides up into the physical charged Higgs H + and charged Goldstone G + : H + = sin H cos H+ 2, G + = cos H + 1 +sin H+ 2 Charged Higgs mass is m 2 H + = 1 2 (2 4 Re 5 ) v 2 There are also neutral Goldstones, from CP-odd sector: A 0 = sin A cos A 0 2, G 0 = cos A 0 1 +sin A 0 2 Physical pseudoscalar A 0 can mix with scalar Higgs H 0 1,2

23 Yukawa expressions Yukawa couplings for i-th mass eigenstate of the Higgs are functions of and the mass diagonalization matrix R: c t,i c b,i c t,i c b,i Type I R i2 / sin R i2 / sin R i3 cot R i3 cot Type II R i2 / sin R i1 / cos R i3 cot R i3 tan The gauge coupling is shifted by an overall factor a: a = R i2 sin + R i1 cos

24 Type-I 2HDM In type-i 2HDM, only the 2nd doublet couples to fermions L Y = Y U Q L (i 2 ) 2u R Y D Q L 2 d R Y L L 2 e R + h.c. The expressions for the Yukawa coupling are di erent from type II c t,i c b,i c t,i c b,i Type I R i2 / sin R i2 / sin R i3 cot R i3 cot Type II R i2 / sin R i1 / cos R i3 cot R i3 tan

25 Fit to LHC Higgs data (type-i) Fit to Higgs decay signal strengths ( 25 fb 1 ) WW ZZ Vbb ATLAS 1.6 ± ± ± ± ± 0.7 CMS 0.8 ± ± ± ± ± Combined, tan b= Combined, tan b=1 1.0 Combined, tan b= ab a a a mostly constrained near value ( b not well constrained /2)

26 EDM current bounds (type-i) Exclusion plots on tan sin b plane: electron, neutron, Hg (magenta - theoretically inaccessible) eedm places strongest constraints: sin b..01 for small tan nedm does not constrain this model

27 EDM future bounds (type-i) electron, neutron, Hg, Ra Left - current Center - 10x improvement for neutron and Hg Right - 100x improvement for neutron eedm is the most sensitive channel for type-i