Fermionic Top Partners at 100 TeV Lian-Tao Wang University of - PowerPoint PPT Presentation

Fermionic Top Partners at 100 TeV Lian-Tao Wang University of Chicago Workshop on Physics at a 100 TeV Collider, SLAC, April 23, 2014 Wednesday, April 23, 14

Why top partner ⇔ 100 TeV - Understanding EWSB requires going beyond LHC. - Top quark plays a significant role in EWSB. It’ s a main source of its puzzles. - Therefore, as part of many possible “answers”, top partners. - More than just a new particle. We will learn something from the search of top partner! Wednesday, April 23, 14

The top partner in everybody’ s mind ˜ t t ˜ t h 0 h 0 + h 0 ) = + - SUSY stop. - Talk on SUSY simplified models later in this workshop Wednesday, April 23, 14

This talk: fermionic top partner T’ - Plays a qualitatively similar role in non-SUSY models. - Not as well studied as the stop. (for me, 8 yrs ago) - I will Survey of possible signals. Make some guestimate for 100 TeV . (scaling up) - Hopefully serves as a todo list. Wednesday, April 23, 14

Why fermionic T’ - Unlike stop, T’ comes in larger varieties. New kinds of signals. - In many cases, M T’ “setting the scale” for the Higgs potential. - Leading indicator of fine-tuning ∝ ! M T’2 No severe tuning: M T’ = 600-ish GeV . - Strong correlation with Higgs mass in large class of composite Higgs models. Panico, Wulzer et al, 2012 Wednesday, April 23, 14

Stop like T’ t T c T h 0 h h h h - T’ can cancel top quadratic divergence, implemented with some symmetry in couplings (Little Higgs Model). - Really stop-like, safe from tree-level corrections. Z 2 parity, similar to R-parity. For example, T-parity. Stable LTP, T’ → t + LTP. Wednesday, April 23, 14

Stop like T’ search at hadron collider 3 5 10 10 Production cross-section [pb] Production cross-section [pb] MadGraph5 MadGraph5 4 10 Fermion Fermion 2 10 Scalar Scalar 3 10 QCD top QCD top ttZ ttZ 2 10 10 10 1 1 -1 -1 10 10 -2 10 -2 10 -3 10 14 TeV 100 TeV -3 -4 10 10 600 800 1000 1200 1400 2000 4000 6000 8000 m [GeV] m [GeV] T T - Larger production rate than the stop. - Studied quite a bit back then, as a “counter example” of SUSY . Meade and Reece, Han, Mabhubani, Walker and LTW, etc Wednesday, April 23, 14

Reach 9 9 [TeV] [TeV] MadGraph5, 100 TeV, 140 PU, 3000 fb MadGraph5, 100 TeV, 140 PU, 3000 fb Scalar Scalar 5 discovery 95% CL exclusion σ 8 8 Fermion Fermion χ χ m m 7 7 6 6 5 5 4 4 -1 -1 3 3 2 2 1 1 0 0 0 2 4 6 8 0 2 4 6 8 m [TeV] m [TeV] T T - pp → T’T’, T’ → t + LTP - Crude estimate. Scaled up from the stop result by matching the signal rate and mass gap. Stop result from Snowmass report, 1311.0299 Wednesday, April 23, 14

We can hide T’ very well. T ′ T ′ T ′ h T ′ h h - Top partner not colored. Twin Higgs. Chacko, Harnik, et al General Higgs portal. - Study to be done! Reach probably very limited, 100s GeV (my guess) Wednesday, April 23, 14

Anything else we can do? 10.0 5.0 ds Zh > 2.5 % 2.0 n f = 1 1.0 ds Zh @ % D T’ ds Zh > 0.5 % 0.5 0.2 n f = 6 0.1 200 400 600 800 Wavefunction renormalization m f @ GeV D Induce shift in Higgs coupling. Craig, Englert, McCullough, 2013 - A case for precision Higgs measurement. Wednesday, April 23, 14

More generic top partners - Similar quantum number as top. Mixes with top. - Probably not chiral 4th generation. - Almost “everywhere”. Playing crucial role in the electroweak symmetry breaking in composite Higgs modes. Also in other places, such as help raising Higgs mass in SUSY . Wednesday, April 23, 14

Minimal model T 0 T 0 + cy t ht L T 0 + y t ht L t R + h.c. L = M T ¯ - Singlet top partner. - Branching ratio for large M T’ 0.5 BR(T’ → Wb) = BR(T’ → Zt) = BR(T’ → ht). Wednesday, April 23, 14

Single vs pair production T ′ V + . . . X b T ′ De Simone, Matsedonskyi, Rattazzi, Wulzer, 1211.5663 1000 100 � � fb ⇥ bT’ 10 T’T’ 1 tT’ 0.1 500 600 700 800 900 1000 ⇥ � GeV ⇥ M T Importance of the single production have been emphasized For example: Perelstein, Peskin, Pierce, 2003; Han, Logan, McElrath, LTW, 2003 Wednesday, April 23, 14

LHC vs 100 TeV (pair production) 95% exclusion projection for m T comparing analysis and parton luminosity scaling using arXiv:1309.0026 (Bhattacharya, et al.) with 3000 fb − 1 PDF set 14 TeV 33 TeV 100 TeV 33 TeV 100 TeV MSTW2008nnlo68cl 1 . 8 TeV 3 . 4 TeV 7 . 4 TeV 3 . 4 TeV 7 . 4 TeV NNPDF23 nnlo as 0018 1 . 8 TeV 3 . 4 TeV 7 . 5 TeV 3 . 4 TeV 7 . 5 TeV CT10nlo 1 . 8 TeV 3 . 4 TeV 7 . 3 TeV 3 . 4 TeV 7 . 4 TeV 5 σ discovery projection for m T comparing analysis and parton luminosity scaling using arXiv:1309.0026 (Bhattacharya, et al.) with 3000 fb − 1 PDF set 14 TeV 33 TeV 100 TeV 33 TeV 100 TeV MSTW2008nnlo68cl 1 . 5 TeV 2 . 8 TeV 5 . 8 TeV 2 . 6 TeV 5 . 5 TeV NNPDF23 nnlo as 0018 1 . 5 TeV 2 . 8 TeV 5 . 9 TeV 2 . 6 TeV 5 . 5 TeV CT10nlo 1 . 5 TeV 2 . 7 TeV 5 . 8 TeV 2 . 6 TeV 5 . 4 TeV - Scaling up using parton luminosity. Salam and Weiler http://collider-reach.web.cern.ch/collider-reach/ - Possible improvement: single production, ... Wednesday, April 23, 14

Variation on the BR. e.g., S. Martin, 0910.2732 = � U H u q 3 U + � ′ U H u Qu 3 − � D H d Qd 3 , Extended top partner sector. U: singlet, Q: doublet 1 1 t ’ Branching Ratios t ’ Branching Ratios 0.8 0.8 ht 0.6 0.6 Wb Zt 0.4 0.4 ht 0.2 0.2 Zt Wb 0 0 300 400 500 600 700 800 300 400 500 600 700 800 m t ’ [GeV] m t ’ [GeV] 𝟅’ U ¡ ¡dominated 𝟅 U ¡ ¡dominated Wednesday, April 23, 14

Current LHC searches (general BR) Ht) ATLAS Preliminary 1 1 1 m = 350 GeV m = 400 GeV m = 450 GeV Status: Lepton-Photon 2013 Forbidden T Forbidden T Forbidden T → 0.8 0.8 0.8 ∫ -1 s = 8 TeV, L dt = 14.3 fb BR(T 0.6 0.6 0.6 95% CL exp. excl. 95% CL obs. excl. Ht+X [ ATLAS-CONF-2013-018 ] 0.4 0.4 0.4 Same-Sign [ ATLAS-CONF-2013-051 ] 0.2 0.2 0.2 Zb/t+X [ ATLAS-CONF-2013-056 ] Wb+X [ ATLAS-CONF-2013-060 ] 0 0 0 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1 SU(2) singlet SU(2) (T,B) doub. 1 1 1 1 m = 500 GeV m = 550 GeV m = 600 GeV m = 650 GeV Forbidden T Forbidden T Forbidden T Forbidden T 0.8 0.8 0.8 0.8 0.6 0.6 0.6 0.6 0.4 0.4 0.4 0.4 0.2 0.2 0.2 0.2 0 0 0 0 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1 1 1 1 1 m = 700 GeV m = 750 GeV m = 800 GeV m = 850 GeV T T T T Forbidden Forbidden Forbidden Forbidden 0.8 0.8 0.8 0.8 0.6 0.6 0.6 0.6 0.4 0.4 0.4 0.4 0.2 0.2 0.2 0.2 0 0 0 0 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1 BR(T Wb) → Reasonable coverage up to 650 GeV. On the “border” of getting into more tuned region Wednesday, April 23, 14

Going up to 100 TeV - Again, room for improvement by using single production, boosted technique, etc. Wednesday, April 23, 14

Top partner in a multiplet. For review, see De Simone, Matsedonskyi, Rattazzi, Wulzer, 1211.5663 B ∆ m 2 ∼ y 2 v 2 T Coset SO(5)/SO(4). Top partner in 4 of SO(4) ∆ m 2 ∼ y 2 f 2 X 2 / 3 ∆ m 2 = 0 X 5 / 3 t - BR(X 2/3 → Zt) ≈ BR(X 2/3 → ht) ≈ 50%. XbW coupling suppressed. Wednesday, April 23, 14

Single production 1000 500 V 100 X Σ � fb ⇥ 50 10 t 5 1 400 500 600 700 800 900 1000 M X 2 ⇤ 3 � GeV ⇥ De Simone, Matsedonskyi, Rattazzi, Wulzer, 1211.5663 - Single production dominated by t+X channel. - Signal, X decay + extra top. Wednesday, April 23, 14

X 5/3 : new exotic top partner. t + X 5 / 3 100% W + - Both pair production and single production t+X. - Multi-top + W(s) final state. Same sign dilepton, trilepton, etc. Wednesday, April 23, 14

X 5/3 : new exotic top partner. t + X 5 / 3 100% W + - Both pair production and single production t+X. - Multi-top + W(s) final state. Same sign dilepton, trilepton, etc. 95% exclusion projection for m T ( Q = +5 / 3) with 3000 fb − 1 comparing analysis and parton luminosity scaling using arXiv:1312.2391 (CMS, 19 . 5 fb − 1 ) Scaling up pair PDF set 8 TeV 14 TeV 33 TeV 100 TeV production search MSTW2008nnlo68cl 0 . 8 TeV 2 . 2 TeV 4 . 2 TeV 9 . 6 TeV NNPDF23 nnlo as 0018 0 . 8 TeV 2 . 2 TeV 4 . 2 TeV 9 . 6 TeV CT10nlo 0 . 8 TeV 2 . 2 TeV 4 . 3 TeV 9 . 6 TeV Wednesday, April 23, 14

Seeing everything at the LHC 14? Wednesday, April 23, 14

Seeing everything at the LHC 14? - That would be great. Wednesday, April 23, 14

Seeing everything at the LHC 14? - That would be great. - But, unlikely. Wednesday, April 23, 14

Seeing everything at the LHC 14? - That would be great. - But, unlikely. - Top partner usually not the full story. Cancellation at 1-loop, part of full composite model... Wednesday, April 23, 14

Seeing everything at the LHC 14? - That would be great. - But, unlikely. - Top partner usually not the full story. Cancellation at 1-loop, part of full composite model... the rest O(TeV) Light top partner “As natural as possible” Wednesday, April 23, 14