More 2HDM checks Nick Amin October 27, 2018 Overview Goal is to - PowerPoint PPT Presentation

More 2HDM checks Nick Amin October 27, 2018

Overview ⚫ Goal is to compare 2HDM results from CMS + ATLAS +N. Craig's paper results on equal footing ⚫ And also I have some misc plots/dumps 2 2 β ) [pb] β ATLAS ATLAS tan tan Excluded region Excluded region ATLAS Observed limit 1.8 1.8 -1 -1 Expected limit s = 13 TeV, 36.1 fb Observed s = 13 TeV, 36.1 fb Observed -1 t s = 13 TeV, 36.1 fb t ± 1 σ Expected Expected → 1.6 SS dilepton / trilepton + b-jets 1.6 SS dilepton / trilepton + b-jets 2 ± σ 2HDM type-II H t t → 1 1 ± 1 σ ± σ BR(H All limits at 95% C.L. 2HDM type-II H t t 2HDM type-II A/H → t t → 2 SS dilepton / trilepton + b-jets ± 2 σ ± σ 1.4 1.4 Theory (NNLO): All limits at 95% C.L. All limits at 95% C.L. tan β = 0.3 1.2 1.2 × tan β = 0.5 H) 1 − 10 tan = 1.0 β 1 1 t t → 0.8 0.8 (pp 0.6 0.6 2 − 10 σ 0.4 0.4 0.2 0.2 3 − 10 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 400 500 600 700 800 900 1000 400 500 600 700 800 900 1000 m [TeV] m [GeV] m [GeV] H H H/A (b) -1 -1 CMS CMS 35.9 fb (13 TeV) 35.9 fb (13 TeV) 160 160 ) (fb) ) (fb) scalar pseudoscalar σ 95% CL Observed 95% CL Observed σ theory theory t 140 t 140 t 95% CL Expected ± 1 and ± 2 σ t 95% CL Expected ± 1 and ± 2 σ experiment experiment → → BR(H BR(A 120 120 (a) (b) × × 100 100 ,tW,tq)+A) ,tW,tq)+H) 80 80 60 60 t t (t (t → → (pp (pp 40 40 σ σ 20 20 0 0 350 400 450 500 550 350 400 450 500 550 m (GeV) m (GeV) � 2 H A Figure 8: Limits at 95% CL on the production cross section for heavy scalar (a) and pseudoscalar

Technical Details ⚫ Using 2HDMtII_NLO model out of the box with the proc card below • Default (dynamical) MG factorization/renormalization scales, nn23lo1 PDF • Using 5FS via define p = p b b~ ⚫ Scan over particle mass, tan( 𝛾 ), sin( 𝛾 - 𝛽 ) for ttX, ttX+1jet, tXW, tXq for X=h2 (H), h3 (A) ⚫ Important note: • Cannot decay via " pp > t t~ h2, h2 > t t~ " since the widths for h2 and h3 are set to 1.0 by default. Without properly recalculating the widths as a function of mass/other parameters, the output cross-sections are meaningless. • This means I’m just calculating the production cross-section and can’t decay the h2/h3 in MG, but the numbers will then be directly comparable with values for 𝜏 (pp → tt ̅ H/A) × BR(H/A → tt ̅ ). set nb_core 10 set automatic_html_opening False import model 2HDMtII_NLO define tpm = t t~ define wpm = w+ w- define p = p b b~ define j = g u c d s u~ c~ d~ s~ b b~ define qpm = u c d s u~ c~ d~ s~ b b~ generate p p > tpm tpm h2 output output_scan_v1/thw -nojpeg launch set param_card mass 25 125 # h1 set param_card frblock 1 scan:[0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,1.0,1.1,1.2,1.4,1.6,1.8,2.0,2.2,2.5,3.0,3.5,4.0] set param_card frblock 2 1.0 # sinbma � 3 set param_card mass 35 scan:[350,400,450,500,550,600,650,700,750,800,850,900,1000]

Reproducing ATLAS xsecs ⚫ Take ATLAS cross sections for 2HDM at tan 𝛾 =0.3,0.5,1.0 assuming sin( 𝛾 - 𝛽 )=1 log for alignment limit (solid lines on right) and compare against what I get from NLO MG (dotted lines of the same color) • This is only considering tt ̅ H • My calculated ones are ~15-20% lower, though the trend is identical between the two • For reference, dashed purple line on right is what we used in 2016 for tt ̅ H → agreement with dashed blue line suggests we have been using tan 𝛾 =1 ⚫ Possible di ff erences • ATLAS writes "NNLO" on their plot while I’m using NLO • ATLAS could also not be using sin( 𝛾 - 𝛽 )=1 exactly • Di ff erent PDFs/scales? • Turning a log scale plot into x,y pairs ) [pb] ATLAS Observed limit Expected limit -1 linear t s = 13 TeV, 36.1 fb t 1 ± σ → 2 ± σ 2HDM type-II H t t → 1 All limits at 95% C.L. BR(H SS dilepton / trilepton + b-jets Theory (NNLO): tan = 0.3 β tan = 0.5 × β H) 1 − 10 tan = 1.0 β t t → (pp 2 − 10 σ 3 − 10 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 m [TeV] H � 4

Confirming our tan 𝛾 ⚫ As a less rigorous check of what our tan 𝛾 was in 2016, make use of some numerology ⚫ Focus on the m(H/A)=400 GeV point only • ATLAS only considers tt ̅ H/A, while CMS considers the two separately but adds (tt ̅ +tW+tq)H/A • Fortunately this works out nicely if I use the 2016 cross-sections ‣ ttH+ttA is ~40fb ‣ (tt ̅ +tW+tq)A is ~40fb ‣ So I should be able to compare the expected exclusion points ( ★ ) which correspond to the same cross-section ‣ (Well, the CMS one is 410GeV, not 400, but it’s close still) • Again, this seems to indicate we had tan 𝛾 ~1 in 2016 CMS -1 35.9 fb (13 TeV) 2 160 β ) (fb) ATLAS tan pseudoscalar 95% CL Observed σ Excluded region theory 1.8 -1 s = 13 TeV, 36.1 fb Observed t 140 95% CL Expected 1 and 2 t ± ± σ experiment Expected → 1.6 SS dilepton / trilepton + b-jets ± 1 σ BR(A 120 2HDM type-II A/H t t → ± 2 σ 1.4 (b) All limits at 95% C.L. × 100 1.2 ,tW,tq)+A) 1 80 0.8 60 t (t 0.6 → (pp 40 0.4 σ 0.2 20 400 500 600 700 800 900 1000 0 550 350 400 450 500 550 m [GeV] � 5 m (GeV) H/A A cross section for heavy scalar (a) and pseudoscalar

Other processes ⚫ Plot our new NLO calculated cross-sections in solid lines for ttH, ttA, tHq, tAq, tHW, tAW with their 2016 counterparts 🙃 ttH/A agree within 5-7% ☹ tHq/tAq scale di ff erently ☹ tHW/tAW xsecs di ff er by an order of magnitude log linear � 6

Adding an extra parton to ttH ⚫ Add another jet to ttH • define j = g u c d s u~ c~ d~ s~ b b~ • generate p p > t t~ h2 • add process p p > t t~ j h2 ☹ xsecs increase by more than a factor of 2 (compare with s4) � 7

sin( 𝛾 - 𝛽 )<1 ⚫ How much di ff erent are xsecs for slightly lower sin( 𝛾 - 𝛽 )<1 (approximate alignment limit) • For ttH with tan 𝛾 =1, using sin( 𝛾 - 𝛽 )=0.999/0.99/0.9 gives 10/20/80% lower xsec • Small changes in s 𝛾𝛽 can change xsec by a lot ⚫ ttA xsec independent of sin( 𝛾 - 𝛽 ), and since the ttA xsec is a bit larger than ttA, this flattens out the dependence on sin( 𝛾 - 𝛽 ) a little bit � 8

Other stu ff � 9

Cross-section vs tan 𝛾 ⚫ Just for reference, plot 𝜏 [pb] vs tan 𝛾 for a fixed m(H/A) mass of 400 GeV log linear � 10

Comparing with another ATLAS 2HDM exclusion ⚫ 8TeV ATLAS analysis in https://arxiv.org/pdf/1707.06025.pdf uses H/A → tt ̅ interference with regular tt ̅ to set 2HDM limits • 2HDM, alignment limit, mH/mA considered separately and also mH=mA degenerate case • At mA=mH=550GeV, excludes tan 𝛾 <0.92 (1.1), expected (observed) • The ATLAS SS paper excludes tan 𝛾 <0.85 (0.6), expected (observed) ⚫ At higher masses (700+), SS has tighter exclusion than tt ̅ interference analysis √ s = 8 TeV, 20.3 fb − 1 , all limits at 95% CL Obs. Exp . ± 1 σ / 2 σ Signal Samples 2.0 1.5 tan β 1.0 0.5 500 550 600 650 700 750 500 550 600 650 700 750 500 550 600 650 700 750 m A [GeV] m A = m H [GeV] m H [GeV] Figure 3: The 95% CL observed and expected exclusion regions for the type-II 2HDM ( µ = 1) considering only a pseudoscalar A (left), only a scalar H (middle), and the mass-degenerate scenario m A = m H (right). Blue points indicate parameter values at which signal samples are produced. Table 3: The 95% CL observed and expected exclusion limits on tan β for a type-II 2HDM in the alignment limit considering only a pseudoscalar A (left), only a scalar H (middle), and the mass-degenerate scenario m A = m H (right). A bar (–) indicates that no value of tan β ≥ 0 . 4 is excluded. Mass m A m H m A = m H [GeV] tan β : obs. exp. obs. exp. obs. exp. 500 < 1 . 00 < 1 . 16 < 1 . 00 < 0 . 77 < 1 . 55 < 1 . 50 550 < 0 . 69 < 0 . 79 < 0 . 72 < 0 . 52 < 1 . 10 < 0 . 92 600 – < 0 . 59 < 0 . 73 – < 1 . 09 < 0 . 93 650 – – – – – < 0 . 62 � 11

BDT vs cut-based ⚫ Not really relevant to 2HDM stu ff , but I saw the plots in Nathaniel’s paper comparing BDT and cut-based analyses for ttH → tttt ⚫ Lowest mass is 0.5TeV, close to SM tttt ⚫ Solid orange line (BDT) is at 1.05fb and dashed line (cut-based) is at 1.15 ( ~10% better ) • Grows to 0.19fb vs 0.38fb ( ~50% better ) at mass of 2TeV where presumably MET/ HT/Boostedness helps a lot 5 5 � ( pp � H / AtW ± � tttW ± ) [ fb ] � ( pp � H / Att � tttt ) [ fb ] 2 2 1 1 0.3 0.3 0.1 0.1 0.5 0.75 1 1.5 2 0.5 0.75 1 1.5 2 m A [ TeV ] m A [ TeV ] (a) pp → t ¯ tH ( A ) → t ¯ tt ¯ (b) pp → tWH ( A ) → tW ± t ¯ t t Figure 10 : (a) Model independent exclusion (orange) and discovery (green) limits at the 14 TeV LHC in the four-top channel. (b) Exclusion (orange) and discovery (green) limits in the three-top channel. The dashed limits are derived with the cut based analysis presented in Section 4.2 while the solid limits are derived with the BDT analysis presented in Section 4.3. � 12