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LHC, Prague, July 2003Filip Moortgat, University of Antwerpen LHC Praha 2003 Detection of MSSM Higgs bosons using supersymmetric decay modes.

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Presentation on theme: "LHC, Prague, July 2003Filip Moortgat, University of Antwerpen LHC Praha 2003 Detection of MSSM Higgs bosons using supersymmetric decay modes."— Presentation transcript:

1 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen LHC Praha 2003 Detection of MSSM Higgs bosons using supersymmetric decay modes at CMS

2 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Topics neutral Higgs to SUSY charged Higgs to SUSY SUSY to Higgs (hep-ph/0304093) (hep-ph/0304095) (hep-ph/0112046) Introduction Conclusion & outlook

3 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen MSSM Higgs sector masses & couplings depend at tree level only on 2 parameters, say m A & tan  : MSSM contains 2 Higgs doublets, therefore 5 physical Higgs states: h 0, H 0, A 0, H  looks like H SM (but m h < 130 GeV) ~ degenerate in mass for high m A radiative corrections can be important (e.g. for h 0 !!) (1< tan  <60)

4 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen MSSM Higgs masses

5 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Couplings H f H f Higgs couplings to fermions: _ proportional to mass  3 rd generation favoured tan  enhances couplings to down-type fermions

6 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen SM channels … so main production mechanism for A 0 and H 0 : and use decay mode:

7 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Discovery search COVERED Need new ideas to cover low tan  - high m A region … discovery of the heavy MSSM Higgses limited to upper triangle in m A – tan  plot note: the h 0 can always be found problem is that production mechanism (e.g. bbA 0,H 0 ) needs tan  enhancement

8 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen New channels? Split problem up in two pieces: production and decay Let’s first assume ‘classical’ production mechanism: and lets look at the decays …

9 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Couplings revisited H V V H V for m A > 200 GeV, cos(  -  ) ≈ 0.01 Higgs couplings to bosons?? H H V H V

10 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Light sparticles … interesting coupling: H0H0 A0A0 Z0Z0 doesn’t work for SM, but remember SUSY … ~ ~ =  0 (neutralinos) only SUSYSM + SUSY

11 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Neutralino decays Leptonic decays would be preferred experimentally … BR goes down with tan  BR goes down with slepton mass

12 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Sparticle modes  x BR The signature looks like: 4 isolated leptons (e,  ) + E T miss powerful signature against the SM + SUSY backrounds @ LHC fb intermediate sleptons

13 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Selection criteria

14 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Some distributions kept

15 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen A case study

16 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Table for case 1 Number of events after successive cuts (100 fb -1 )

17 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Case 2

18 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Discovery reach A/H    4 leptons seems to prefer low tan , complementary to A/H   !! Typical discovery reach:

19 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Charged Higgs to sparticles H    2,3 0  1,2   3l + E T miss Analogue decay mode: + Analogue production mechanism for H  :  only 3 leptons, need to reconstruct additional top (t  bjj)

20 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen More tricky this time M. Bisset (Uni. Bejing), F. Moortgat (Uni. Antwerpen), S. Moretti (Uni. Southampton) works only for small region in MSSM parameter space … LEP excluded in red area we can do it!!

21 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Charged Higgs selection

22 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Event selection Many backgrounds considered:

23 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Discovery Reach MSSM parameters: M 2 = 210 GeV,  = 135 GeV, M sleptons = 110 GeV, M squark, gluino = 1TeV

24 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen try to exploit MSSM Higgs bosons production in SUSY particle cascades h0h0 H0H0 A0A0 H±H± Second branch So we tried new decay modes … what about new production mechanisms? A. Datta (Uni. Florida), A. Djouadi (Uni. Montpellier), M. Guchait (TIFR Mumbay), F. Moortgat (Uni. Antwerpen),

25 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Scenarios Scenario 1 (big cascades) g (600 GeV) ~ q (720 GeV) ~ ~ ~ ~ ~ h 0, H 0, A 0, H ± (170 GeV) (95 GeV) ~ (340 GeV) Scenario 2 (little + big cascades) ~ h0h0 g (900 GeV) ~ q (1080 GeV) ~ ~ ~ ~ ~ h 0, H 0, A 0, H ± (270 GeV) (145 GeV) ~ (480 GeV) ~

26 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Scenarios (cont’d) g (1200 GeV) ~ q (800 GeV) ~ ~ ~ ~ ~ h 0, H 0, A 0, H ± (150 GeV) (110 GeV) ~ (375 GeV) ~ g (1200 GeV) ~ q (800 GeV) ~ ~ ~ (400 GeV) (200 GeV) ~ h 0, H 0, A 0, H ± Scenario 3 (big cascades) Scenario 4 (little cascades) ~ ~ (1000 GeV) ~

27 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Cross section x BR’s Scenario 1 Scenario 3 Scenario 2 Scenario 4 m A =150 GeV tan 

28 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Selection strategy look for main decay modes of neutral and charged Higgses: first thing to do: make sure triggering is guaranteed, then separate SUSY cascades from SM background let’s look at some kinematical distributions … using ISASUSY 7.58 + HERWIG 6.4 + CMSJET 4.801 + HDECAY + TAUOLA + ISAWIG h 0, A 0, H 0  bb H ±   (cause m H± = 170 GeV)

29 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Kinematics Jet multiplicity in SUSY cascade signal vs. SM tt background -

30 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Kinematics (2) E T (hardest jet) in SUSY cascade signal vs. SM tt background -

31 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Kinematics (3) Missing E T in SUSY cascade signal vs. SM tt background -

32 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Kinematics (4) Total transverse energy in SUSY cascade signal vs. SM tt background: -

33 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Selection criteria for neutral Higgses we require the event to contain at least 5 jets the hardest jet in the event should have E T > 300 GeV the transverse missing energy E T miss > 150 GeV the effective mass > 1200 GeV the event should contain at least two b-tagged jets, with 45 GeV 3.

34 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Results: scenario 1 30 fb -1  : susy signal  : susy bkg  : SM tt bkg

35 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Results: scenario 2 30 fb -1 h0h0  : susy signal  : susy bkg  : SM tt bkg

36 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Results: scenario 3 30 fb -1 h0h0 H 0, A 0  : susy signal  : susy bkg  : SM tt bkg

37 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Results: scenario 4 30 fb -1 h0h0 H 0, A 0  : susy signal  : susy bkg  : SM tt bkg

38 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Selection criteria for charged Higgses we require the event to contain at least 5 jets the hardest jet in the event should have E T > 300 GeV the transverse missing energy E T miss > 200 GeV the event should at least contain one hadronic  -jet, i.e. a narrow jet with a hard charged track (one prong), isolated in calo and tracker, with E T > 80 GeV more than 75% of the  -jet transverse energy should be carried by the charged track (= polarization effect)

39 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Charged Higgs results m H+ =170 GeV tan  H + effect visible in Sc4, but not so convincing since no invariant mass peak

40 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen tan  dependence Scenario 3 tan  tan 

41 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Discovery reach at 30fb -1 region where H 0 and A 0 can be found in SUSY cascade decays h 0 can be found in full plane!! Scenario 3

42 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Conclusions we have studied supersymmetric decay channels of the MSSM Higgs bosons in CMS for the heavy neutral Higgs bosons, we have found an interesting complementarity between the reach of the A, H   2 0  2 0  4l + E T miss and the SM channels works also for charged Higgses, but only in small region of parameter space

43 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Conclusions (2) we also explored a new mechanism that can abundantly produce neutral and charged Higgs bosons we have shown a discovery potential for heavy MSSM Higgs bosons with this production mechanism, complementary to both the standard channels and the sparticle channels we have shown a potential for the production of the light Higgs from heavy gauginos, which could complement the standard searches in the difficult 100 < m h < 130 GeV region.

44 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen look again at A, H   i 0  j 0 and try to access high mass region (Bisset-Moortgat-Moretti) look at A, H   instead of A, H  bb look closer at scenario 1 and 2 (squarks heavier than gluinos) look closer at H , especially interested in mass region around m top where other channels don’t work can we reconstruct cascade decay chains with Higgs bosons in the final state (bb instead of dileptons)? (Datta-Djouadi-Guchait-Moortgat) Outlook SUSY  Higgs Higgs  SUSY

45 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Backup slides

46 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Discovery reach at 100fb -1 region where only h 0 can be found region where H 0 and A 0 can be found in SUSY cascade decays Scenario 3 h 0 can be found in full plane!!

47 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Results Let’s consider two cases:  x BR

48 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Dilepton edges Dilepton edge at M 2 -M 1 is clearly visisble Double dilepton edge!!

49 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Slepton mass effect Dependence of on higgsino and slepton masses: Other MSSM parameters: M A = 350 GeV, tan  = 5, M 1 = 75 GeV, M 2 = 150 GeV, M squark, gluino = 1TeV

50 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Why is low tan  prefered? At higher tan  : taus instead of electrons/muons … # events = A x B x C 2 ABC

51 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Charged Higgs search + Dominant production: We can exploit t(b)H  associated production! reconstruct additional top (t  bjj)

52 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Branching ratios H    H   tb Main channels:

53 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen H   polarization effect Main backgrounds: tt, Wtb, W + jets reconstruct hadronic  reconstruct hadronic top (t  bjj) W and H ± have different spin  exploit  polarization effects !! (D.P. Roy) _ harder pions from H ± … Strategy:

54 Physics @ LHC, Prague, July 2003Filip Moortgat, University of Antwerpen Discovery reach all  channels:  jet + jet  lepton + jet  lepton + lepton


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