I discuss recent calculations of higher-order corrections to charged Higgs
production through various partonic subprocesses. Particular attention is paid
to H- production in association with a top quark at the LHC.Comment: 10 pages, 9 figures, invited talk at cHarged 2008, Prospects for
  Charged Higgs Discovery at Colliders, 16-19 September 2008, Uppsala, Swede

Kidonakis, Nikolaos

English

arXiv

I discuss recent calculations of higher-order corrections to charged Higgs production through various partonic subprocesses. Particular attention is paid to H− production in association with a top quark at the LHC

DigitalCommons@Kennesaw State University

Higher order corrections to H productionNikolaos Kidonakis(Kennesaw State University) Hproduction channels Higher-order corrections Charged Higgs production at the LHCN. Kidonakis, cHarged 2008, Uppsala, September 2008 1Charged Higgs: sure sign of new physics (MSSM or other 2HDM)LHC has good potential for discoveryProduction processesbg   tH  Zhu (’01) [NLO QCD]; Belyaev, Garcia, Guasch, Sola (’01,’02) [1-loop SUSY];(gg  b̄tH  ) Plehn (’02) [NLO QCD+SUSY]; Berger, Han, Jiang, Plehn (’03) [NLO QCD+SUSY];Jin, Li, Oakes, Zhu (’99) [Yukawa], (’00) [SUSY electroweak];Alwall, Rathsman (’04) [matching];Kidonakis (’04) [soft-gluons, approx NNLO], (’05) [approx NNNLO]gg   HW  Barrientos et al (’98,’00); Brein, Hollik, Kanemura (’00) [quark, squark loops];bb̄   HW  Hollik, Zhu (’01); Gao, Li, Li (’07) [NLO QCD]Eriksson, Hesselbach, Rathsman (’06) [decays of H, W  ]gg   HH  Jiang et al (’97); Krause, Plehn, Spira, Zerwas (’97); Brein, Hollik (’99) [LO loops]bb̄   HH  Hou et al (’05) [NLO]; Alves, Plehn (’05) [NLO]gg   bb̄HH  Moretti, Rathsman (’03) [LO]qq   qqVV   qqHH  Moretti (’01) [LO]N. Kidonakis, cHarged 2008, Uppsala, September 2008 2Associated H  and top quark productionLO: bg   tH gbbH tgbttH Born cross section ∝ ααs m2b tan2 β m2t cot2 βuse MS mb in the coupling; mb  0 elsewhereN. Kidonakis, cHarged 2008, Uppsala, September 2008 3Associated H  and top quark productionNLO: bg   tH  (virtual corrections)bg   tH  ggg   tH  b̄ qq̄   tH  b̄bq   tH  q bq̄   tH  q̄bb   tH  b bb̄   tH  b̄QCD corrections largeReduced scale dependenceSUSY corrections significantIssues: bottom parton distributiongluon splitting to bb̄ in collinear approximationvalid for small b-quark pTN. Kidonakis, cHarged 2008, Uppsala, September 2008 4gg   b̄tH ggbbb̄ H tggb̄btH tMatching [Alwall, Rathsman]Find reliable description for all b-quark pTlarge pT : use matrix elementssmall pT : use parton showerssimple adding gives double counting for small pTN. Kidonakis, cHarged 2008, Uppsala, September 2008 5bg   tH resums large logarithms αs lnµF /mb n for small pT2  3 process described by gluon splitting times matrix element of 2  2 processgg   b̄tH outgoing b-quark described by 2  3 matrix element for large pTMatch  analytic double-counting subtraction term:σ  σ2  2σ2  3  σDC[Alwall, Rathsman]can be implemented in event generators (PYTHIA, HERWIG) smooth differential distributionsN. Kidonakis, cHarged 2008, Uppsala, September 2008 6Production near thresholdbpb  gpg   tpt  H  pHDefine s pb pg 2, t pb  pt 2, u pg  pt 2and s4  s t  u  m2t  mH2At threshold s4 0Soft correctionslnls4/m2Hs4Near threshold soft corrections are dominant and provide excellent approximations tothe full cross sectionFor the order αns corrections l2n  1LL: l=2n-1NLL: l=2n-2Calculate NLO and NNLO corrections at NLL accuracyThe hadronic cross sectionσ  ∑fdx1dx2 φ f1/px1, µFφ f2/ p̄x2, µFσ̂s, t, u, µF , µR, αsN. Kidonakis, cHarged 2008, Uppsala, September 2008 7Resummed cross sectionResummation follows from factorization properties of the cross section- performed in moment spaceσ̂resN  exp ∑iE fiNiexp ∑i2sµFdµµγi/iNi, αsµ  exp ∑i2sµRdµµβαsµ H fi fjαsµR  S̃ fi fj αssÑexp  s/Ñsdµµ2ReΓ fi fjSαsµ where∑iE fiNi   ∑iCi10dzzNi  1   11   z 11  z 	2dλλαsλsπ αs 1   z 2sπ  α2sCi CF   N2c   1  /  2Nc  , B1	q 3CF /4 for quarks; Ci CA Nc, B1	g β0/4 for gluonsΓS is the soft anomalous dimension - a matrix in color spaceΓ1	S CF ln   t  m2tmts CA2ln  u  m2t  t  m2t CA21   iπN. Kidonakis, cHarged 2008, Uppsala, September 2008 8NNNLO expansions of resummed cross sectionInvert back to momentum space and expand to arbitrary orderNLO soft gluon correctionsσ̂ 1  FB αsµ2Rπc3lns4/m2Hs4 c21s4 cµ1 δs4with c3  2CF CANNLO soft gluon correctionsσ̂ 2  FB α2sµ2Rπ212c23	ln3s4/m2Hs432c3 c2 β04c3 	ln2s4/m2Hs4  NNNLO soft gluon correctionsσ̂ 3  FB α3sµ2Rπ318c33	ln5s4/m2Hs458c23 c2 524β0 c23 	ln4s4/m2Hs4  N. Kidonakis, cHarged 2008, Uppsala, September 2008 9Charged Higgs production at the LHC200 400 600 800 1000mH- (GeV)11.11.21.31.41.51.61.71.8K-factorNLO-exact/LONLO-NLL/LONLO-NLL/NLO-exactbg --> tH-  at  LHC     S1/2=14 TeV     µ=mH-+mt200 400 600 800 1000mH- (GeV)0.80.911.11.21.31.4σ(µ) / σ(mH- )BornNLO-NLLNNLO-NLLbg --> tH-  at  LHC      S1/2=14 TeV       µ=mH-+mt,  (mH-+mt)/2various choices of central scale in the literatureN. Kidonakis, cHarged 2008, Uppsala, September 2008 10200 400 600 800 1000mH- (GeV)0.0010.010.11σ  (pb)LONLO-NLLNNLO-NLLNNNLO-NLLbg --> tH-  at  LHC    S1/2=14 TeV    tanβ=30    µ=mH-200 400 600 800 1000mH- (GeV)11.21.41.61.82K-factorNLO-NLL / LONNLO-NLL / LONNNLO-NLL/LObg --> tH-  at  LHC      S1/2=14 TeV      µ=mH-K factorsMass (GeV) NNLO-NLL NNNLO-NLL200 1.34 1.47300 1.43 1.53400 1.49 1.59500 1.53 1.65600 1.57 1.69700 1.60 1.72800 1.63 1.75900 1.66 1.791000 1.68 1.81N. Kidonakis, cHarged 2008, Uppsala, September 2008 11Scale dependence of the cross section200 400 600 800 1000mH- (GeV)0.0010.010.11σ  (pb)LONLO-NLLNNLO-NLLNNNLO-NLLbg --> tH-  at  LHC    S1/2=14 TeV    tanβ=30    µ=mH-/2, 2mH-0.1 1 10µ / mH-00.050.10.150.2σ  (pb)LONLO-NLLNNLO-NLLNNNLO-NLLbg --> tH-  at  LHC    S1/2=14 TeV    tanβ=30    mH-=500 GeVReduced scale dependence over large range of scale 0.1   µ/mH   10σmax/σmin  3.39 1.50 1.38 1.32   LO NLO-NLL NNLO-NLL NNNLO-NLLN. Kidonakis, cHarged 2008, Uppsala, September 2008 12Dependence of the cross section on tan β and top quark mass0 10 20 30 40 50tan β0.010.11σ  (pb)BornNLO-NLLNNLO-NLLNNNLO-NLLbg --> tH-  at  LHC    S1/2=14 TeV    µ=mH-=500 GeV150 160 170 180 190 200mt (GeV)00.050.10.150.2σ  (pb)BornNLO-NLLNNLO-NLLNNNLO-NLLbg --> tH-  at  LHC    S1/2=14 TeV    tanβ=30    µ=mH-=500 GeVtan β shape same for all curves Mild mt dependenceN. Kidonakis, cHarged 2008, Uppsala, September 2008 13Associated Hand W  production, bb̄   HW bb̄h0, H0W Hbb̄tW H10-111010 210 3200 400 600 800 1000mH± (GeV)σ (fb) tan β=50tan β=1010-210-11200 400 600 800 1000mH± (GeV)BR(H± )→τν tan β=50tan β=10Eriksson, Hesselbach, Rathsman (’06)N. Kidonakis, cHarged 2008, Uppsala, September 2008 14Associated pair production gg   HH    	 	 	  		    	 	  		 10-210-1110100 150 200 250 300 350 400total cross sectionwithout trianglecontribution√s = 14TeVmH  [GeV]pp→gg→H+H−σtot [fb]tanβ = 30tanβ = 6tanβ = 1.5−+10-11101 10√s = 14TeVmH   = 200 GeVpp→gg→H+H−σtot [fb]tanβ+−2 3 4 5 6 7 8 20 30 40Krause, Plehn, Spira, Zerwas (’97)N. Kidonakis, cHarged 2008, Uppsala, September 2008 15Associated pair production bb̄   HH      	     	 10-210-1110200 250 300 350 400 450 500mH[GeV]σtot,bb (pp→H+H−) [fb]tanβ = 10qq,sumggbb10-1110200 250 300 350 400 450 500mH[GeV]σtot,bb (pp→H+H−) [fb]tanβ = 20sumqqggbb10-1110200 250 300 350 400 450 500mH[GeV]σtot,bb (pp→H+H−) [fb]tanβ = 30sumqqggbb10-111010 2200 250 300 350 400 450 500mH[GeV]σtot,bb (pp→H+H−) [fb]tanβ = 50sumggqqbbAlves, Plehn (’05)N. Kidonakis, cHarged 2008, Uppsala, September 2008 16gg   bb̄HH dominant pair production mode at large tan βrelevant for triple-Higgs couplingsconsider signature: 4 b-jets + 2 q-jets+ τ +pmissTMoretti, Rathsman (’03)N. Kidonakis, cHarged 2008, Uppsala, September 2008 17Summary Several production processes for Hat the LHC NLO QCD and SUSY corrections bg   tH  , gg   b̄tH  at the LHC - matching bg   tH  Soft and collinear corrections through NNNLO bg   tH  Large K factors -reduced scale dependence Associated production with a W Charged Higgs pair productionN. Kidonakis, cHarged 2008, Uppsala, September 2008 18

Higher Order Corrections to H± Production

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Higher order corrections to H+- production

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