Flavor and Scalar Signals of an Extended Color Sector. R. Sekhar Chivukula Michigan State University

Transcription

1 Flavor and Scalar Signals of an Extended Color Sector R. Sekhar Chivukula Michigan State University Extended Color Dynamics A Top-Coloron Model Flavor Symmetries and Constraints Scalars: Same Sign Top Signature Flavor Independent Constraints - Conclusions KMI, Nagoya University March 5-7, 2014

2 Extended Color Dynamics New colored gauge bosons Classic Axigluon: P.H. Frampton and S.L. Glashow, Phys. Lett. B 190, 157 (1987). Topgluon: C.T. Hill, Phys. Lett. B 266, 419 (1991). Flavor-universal Coloron: R.S. Chivukula, A.G. Cohen, & E.H. Simmons, Phys. Lett. B 380, 92 (1996). Chiral Color with gl gr: M.V. Martynov and A.D. Smirnov, Mod. Phys. Lett. A 24, 1897 (2009). New Axigluon: P.H. Frampton, J. Shu, and K. Wang, Phys. Lett. B 683, 294 (2010). Other color-octet states: (cf. partial compositeness ) KK gluon: H. Davoudiasl, J.L. Hewett, and T.G. Rizzo, Phys. Rev. D63, (2001) B. Lillie, L. Randall, and L.-T. Wang, JHEP 0709, 074 (2007). Techni-rho: E. Farhi and L. Susskind, Physics Reports 74, 277 (1981). Recent catalog of colored states: Color sextets, colored scalars, low-scale scale string resonances... T. Han, I. Lewis, Z. Liu, JHEP 1012, 085 (2010).

3 Gauge Sector

4 Coloron Models: Gauge Sector u SU(3) 1 SU(3) 2 h 1 h 2 SU(3)1 x SU(3)2 color sector with M 2 = u2 4 h 2 1 h 1 h 2 h 1 h 2 h 2 2 unbroken subgroup: SU(3)1+2 = SU(3)QCD gluon state: G A µ = cos A A 1µ +sin A A 2µ h 1 = g s cos h 2 = g s sin couples to: g S J µ G g S(J µ 1 + J µ 2 ) coloron state: Cµ A = sin A A 1µ + cos A A M 2µ C = p u qh h2 2 couples to: g S J µ C g S( J µ 1 tan + J µ 2 cot ) low-energy current-current interaction: L 2 FF = g 2 S 2M 2 C J µ C J Cµ

5 Fermions

6 Coloron Models: Quark Charges u SU(3) 1 SU(3) 2 h 1 h 2 g S J µ G g S(J µ 1 + J µ 2 ) g S J µ C g S( J µ 1 tan + J µ 2 cot ) low-energy current-current interaction: L 2 FF = g 2 S 2M 2 C J µ C J Cµ Depending on how quarks transform under SU(3)1 x SU(3)2 the presence of colorons may impact LHC dijet mass distribution (or angular distribution) kinematic distributions of tt or bb final states asymmetry in top-quark production: A t FB FCNC processes: K K,D D, B B mixing, b! s precision EW observables: delta-rho, Rb

7 Patterns of Quark Charges SU(3)1 SU(3)2 model pheno. (t,b)l ql tr,br qr coloron dijet qr (t,b)l ql tr,br tr,br (t,b)l ql qr ql (t,b)l tr,br qr ql tr,br (t,b)l qr new axigluon dijet, A t FB, FCNC ql qr (t,b)l tr,br topgluon dijet, tt, bb, FCNC, Rb... tr,br qr (t,b)l ql classic axigluon dijet, A t FB ql tr,br qr (t,b)l (No spectators required) q = u,d,c,s

8 A Flavorful Top-Coloron Model R.S.C., Elizabeth Simmons, N. Vignaroli PRD 87 (2013)

9 Flavorful Top-Coloron Model particles SU(3)1 SU(3)2 SU(2)W 3rd generation (t,b)l quarks tr,br light quarks (u,d)l (c,s)l ur,dr cr,sr vector quarks QL,QR light scalar φ heavy scalar Φ 3 3* 1 Next to minimal flavor symmetry:

10 Generational Mixing SU(3)1 x SU(3)2 x SU(2)W (1,1,2) (3, 3 *,1) <φ> <Φ> X tr, br QL QR (u,d)l (c,s)l (3,1,1) (3,1,2) (3,1,2) (1,3,2) Mixing to third generation occurs indirectly, through mixing with vector quarks.

11 Generational Mixing Light Generations { { { { { { Third Generation Vector Quarks Weak Mixing Cabbibo Matrix, C, and d = O(1) 1 = O( 3 ) 2 = O( 2 )

12 Constraints from Flavor Physics R.S.C., Elizabeth Simmons, N. Vignaroli PRD 87 (2013)

13 FCNC in Top-Coloron Model Mixing among ordinary and heavy vector quarks also leads to flavor-changing b-quark decays: b! s Coloron exchange yields KK, DD, and BB mixing quark charges under strong gauge groups are non-universal the top and bottom mass eigenstate quarks are admixtures of ordinary and heavy vector gauge eigenstate quarks

14 Constraints: b sυ D Re@l b ' Mixing with righthanded electroweak doublets enhances contributions to b sγ Re@l t ' D

15 Constraints: B-Bbar Mixing b L b L s L C C C s L b L s L b L b L s L s L b L s L s L s L b L b L s L b L (a) (b) (c) Flavor-changing Effects from Coloron Exchange: interplay between mixing and coupling strengths

16 Flavor Limits on Top-Coloron Model M C HTeVL 5 Allowed...depends on α l 2 KK mixing may exclude l 2 ë LHC dijets exclude KK mixing may exclude l 2 ë 3 BB mixing and b! s exclude KK mixing certainly excludes Cotw R.S. Chivukula, EHS, N. Vignaroli (2013) Θ

17 Scalar Bosons R.S.C., Elizabeth Simmons, N. Vignaroli PRD 88 (2013) Bogdan Dobrescu and Yang Bai JHEP 1107 (2011) 100

18 Colored Scalars and Their Potential _ Most general renormalizable (3,3) potential: For an appropriate range of parameters: vev singlet fields eaten by colorons { Color Octet Scalars Quark couplings fixed from above!

19 Octet Scalar Production G H Double Production LHC LHC-8 LHC-7 Tevatron M GH HGeVL

20 Octet Scalar Decay Dijets: G H g G H g G H µ G H G H g G H G H µ g μ related to singlet pseudoscalar mass c L t R + t R c L :

21 Top + Charm Often Very Large! M I HGeVL BR to t+c or c+t pseudo-scalar mass M GH HGeVL octet mass Octet pair production can lead to same-sign tops (dileptons)!

22 Experimental Constraints HG H Æ ggl di - jets ATLAS CMS M I HGeVL HG H Æ tcl CMS SSD + jets Singlet mass dependence from behavior of BRs M GH HGeVL References: CMS PAS SUS ATLAS arxiv: CMS arxiv:

23 Flavor- Universal Constraints On Scalars R.S.C., Arsham Farzinnia, Jing Ren, and Elizabeth Simmons PRD 88 (2013) and in press

24 Scalar Potential: Higgs and Mixing Scalar potential includes Higgs boson as well: V (, ) h 6 v 2 h m v 2 h 2 Tr v 2 s 2 Higgs portal coupling: mixing between electroweak and color sectors h =cos h 0 sin 0R

25 Precision Electroweak Constraints T GeV 150 GeV 3000 GeV 230 GeV S - T contour at 95% C.L. 450 GeV sin c = 0.5 sin c = 0.2 Excluded region ms HGeVL Excluded by S - T at 95% C.L S W ±,Z h, R sin c S-T contours from Gfitter, arxiv:

26 New States Contribute to Higgs Production! Colorons Scalars Spectator Fermions

27 ATLAS Higgs Observation Moriond EW 2013, LP2013 ATLAS-CONF ,012,013

28 CMS Higgs Observation Moriond EW 2013, LP2013 CMS-PAS-HIG ,2 CMS-PAS-HIG

29 Constraints from Higgs Observation Coloron and colored scalar contributions to production... h! I I allowed Note scale for vs! CMS-PAS-HIG ATLAS-CONF Yao, Moriond EW 2013

30 Illustration of Combined Results u=1000 GeV mgh= 500 GeV u=5000 GeV mgh= 2000 GeV Unitarity Unitarity Higgs production S-T allowed S-T Higgs production allowed Illustrates interplay of different constraints... and of direct and indirect bounds

31 Heavy Singlet Boson LHC Reach in σ*br/(σ*br)sm Higgs TeV m Hgg Æ s Æ VVL current 14 TeV, 300 fb -1 projected 14 TeV, 3000 fb m s HGeVL CMS-PAS-HIG /3 ATLAS-CONF /030

32 LHC Singlet Boson Reach Projection with 300 fb 14 TeV Discovery Region Excluded by current heavy Higgs search 125 GeV Higgs production exclusion (one spectator fermion) Illustrates that direct limits/searches will dominate!

33 Conclusions

34 Conclusions Many models predict extended strong interactions Is this extended dynamics flavor-universal or not? Introduced a flavorful top-coloron model Constraints from FCNCs favor NMFV. Same-sign tops, and therefore dileptons, an interesting signature for new colored scalars. Additional effects of extended strong interactions? Color symmetry breaking sector can mix with EWSB Constraints on Higgs mixing and from observed properties of Higgs boson Discovery potential for heavy states at 14 TeV