1 / 19

V.A. K hoze (IPPP, Durham)

Diffractive processes as a tool for testing the MSSM Higgs sector at the LHC. V.A. K hoze (IPPP, Durham). (in collaboration with S. H einemeyer, M. R yskin, W.J. S tirling, M. T asevsky and G. W eiglein ). main aim: to show that the Central Diffractive Processes

usoa
Télécharger la présentation

V.A. K hoze (IPPP, Durham)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Diffractive processes as a tool for testing the MSSM Higgs sector at the LHC V.A. Khoze (IPPP, Durham) (in collaboration with S. Heinemeyer, M. Ryskin, W.J. Stirling, M. Tasevsky and G. Weiglein ) main aim:to show that the Central Diffractive Processes may provide an exceptionally clean environment to search for and to identify the nature of Higgs bosons at the LHC FP-420 H

  2. Forward Proton Taggersas a gluonicAladdin’s Lamp • (Old and NewPhysics menu) • Higgs Hunting(the LHC ‘core business’)Bialas & Landshoff-91K(KMR)S- 97-06,M. Boonekamp et al, V.Petrov et al, • E.Levin et al, B.Cox et al, J.Ellis et al. • Photon-Photon, Photon - HadronPhysics KMR-02, A.Bzdak et al • ‘Threshold Scan’:‘Light’ SUSY …KMR-02 ,M.Boonekamp et. al. • Various aspects of DiffractivePhysics (soft & hard ). KMR-01, K. Goulianos • High intensityGluon Factory(underrated gluons)KMR-00, KMR-01 • QCD test reactions, dijet P-luminosity monitor • Luminometry R.Orava+KMR-01 • Searches for new heavy gluophilic statesKMR-02, KMRS-04, J.Forshaw et al • FPT • Would provide a unique additional tool to complement the conventionalstrategies at theLHCandILC. Higgs is only a part of the broad EW, BSM and diffractiveprogram@LHC wealth of QCD studies, glue-glue collider, photon-hadron, photon-photon interactions… FPT  will open upan additional richphysics menu ILC@LHC

  3. KMR predn of s(pp p + H + p) Implemented in ExHume MC contain Sudakov factor Tg which exponentially suppresses infrared Qt region  pQCD H (High sens. to str. functs) S2 is the prob. that the rapidity gaps survive population by secondary hadrons  soft physics  S2=0.026(LHC)S2=0.05(Tevatron) s(pp  p + H + p) ~ 3 fb at LHC for SM 120 GeV Higgs recent activity- J.Bartels et al- Hard Diffr. Contrib.

  4. The main advantages ofCED Higgs production • Prospects for high accuracy mass measurements • (irrespectively of the decay mode). • Quantum number filter/analyser. • ( 0++dominance ;C,P-even) • H ->bb opens up (Hbb- coupl.) • (gg)CED bb inLO ; NLO,NNLO, b- masseffects - controllable. • For some areas of the MSSM param. spaceCEDP may become adiscovery channel! • H→WW*/WW - an added value (less challenging experimentally + small bgds.) • New run of the MSSM studies is underway. • New leverage –proton momentum correlations (probes of QCD dynamics , CP- violation effects…) H  LHC : ‘after discovery stage’,Higgs ID…… How do we know what we’ve found? mass, spin, couplings to fermions and Gauge Bosons, invisible modes…  for all these purposes the CEDP will be particularly handy ! FP420(B. Cox)

  5. ☻Experimental Advantages Measure the Higgs mass via the missing mass technique Mass measurements do not involve Higgs decay products Cleanness of the events in the central detectors. Experimental Challenges Tagging the leading protons Selection of exclusive events & backgrounds Triggering at L1 in the LHC experiments. bb-mode requires special attention. Uncertainties in the theory (Unusually& uncomfortably) large higher-order effects, model dependence of predictions (soft hadronic physics is involved after all)  Talks by R.Orava, B. Cox, M.Tasevsky There is still a lot to learn from present and future Tevatron diffractive data (KKMRS- friendly so far). Talks by K. Goulianos & M. Gallinaro

  6. The MSSM and more exotic scenarios If the coupling of the Higgs-like object to gluons is large, double proton tagging becomes very attractive • The intense coupling regime of the MSSM (E.Boos et al, 02-03) • CP-violating MSSM Higgs physics ( B.Cox et al 03, KMR-03; J. Ellis et al-05) Potentially of great importance for electroweak baryogenesis • an ‘Invisible’ Higgs(BKMR-04) • NMSSM( with J. Gunion and A. De Roeck )

  7. Theoretical Input a ‘simplest’ extension of the minimal Higgs sector

  8. (h  SM-like, H/A- degenerate.) GOOD NEWS!

  9. Ongoing studies ( S.Heinemeyer, V.A. Khoze , W.J.Stirling, M. Ryskin, ,M. Tasevsky and G. Weiglein ) • ● Hbb in the high mass range(MA180-250 GeV) • -unique signature for the MSSM, • cross-sections overshoot the SM case by orders of magnitude. • -possibility to measure the Hbb Yukawa coupling, • -nicely complements the conventional Higgs searches • - CP properties, separation of H from A, • unique mass resolution, • -may open a possibility to probe the ‘wedge region’ !? • -further improvements needed ( going to high lumi ?....) • (more detailed theoretical studies required ) • ● h, Hbb, in the low mass range(MA < 180 GeV) • -coverage mainly in the large tan  and low MA region, • -further improvements (trigger efficiency….) needed in order to increase • coverage • -

  10. ● h,H  in the low mass range (MA<180 GeV) • essentially bkgd –free production, • need further improvements, better understanding.., • -possibility to combine with the bb-signal • (trigger cocktail …) • -can we trigger on  without the RP condition ? • ● h WW • -significant (~4) enhancement as compared to the SM case • in some favourable regions of the MSSM parameter space. • ● small and controllable backgrounds • ● Hunting the CP-odd boson, A • a way out : to allow incoming protons to dissociate(E-flowET>10-20 GeV)KKMR-04 • pp p + X +A +Y +p • At the moment thesituation looks borderline

  11. Hbb PRELIMINARY

  12. Current understanding of the bb backgrounds for CED production (Myths & Reality) for reference purposes SM (120 GeV)Higgsinterms of S/B ratio (various uncrt. cancel)  First detailed studies by De Roeck, Orava +KMR, 2002)  Preliminary results– work still in progress S/B1 at ΔM 4 GeV Four main sources (~1/4 each)  gluon-b misidentification (assumed 1% probability) Prospects to improve in the CEDP environment ? Better for larger M.  NLO radiative contributions Correlations, optimization -to be studied. (off ‘active’ & screened gluons).  admixture of |Jz|=2 contribution; mass- unsuppressed, cut-nonreconstructible (NNLO) contributions. b-quark mass effects in dijet events Further studies of the higher-order QCD (most troublesome technically) effects- in progress. ( e.g. Non-Sudakov DL, FKM-97 )

  13. The complete background calculations are still in progress (unusually large high-order QCD and b-quark mass effects).  Optimization, MC simulation- still to be done Mass dependence of theSM(CEDP):SH~1/M³ Bkgd : ΔM/Mfor , ΔM/Mfor  ( ΔM ,triggering, tagging etc improving with rising M) 6 8 5 discovery plots, based on the CMS Higgs Group procedure- HKRSTW, (on the conservative side)

  14. (M. Tasevsky) Adapted from a preliminary plot of HKRSTW.

  15. Hunting the CP-odd boson, A (LO)selection rule – an attractive feature of the CEDPprocesses, but…… the flip side to this coin: strong ( factor of ~ 10² )suppression of the CED production of the A boson. A way out : to allow incoming protons to dissociate(E-flowET>10-20 GeV)KKMR-04 pp p + X +H/A +Y +p(CDD) in LO azim. angular dependence: cos² (H), sin² (A), bkgd- flat A testing ground for CP-violation studies in the CDD processes (KMR-04) challenges: bb mode – bkgd conditions -mode- small (QED)bkgd, but low Br

  16. CDD results at  (RG) >3, ET>20 GeV within the (MS) MSSM, e.g.mh scenarios with  =±200 (500) GeV, tan=30-50 CDD(A->bb) ~ 1-3 fb, CDD(A->) ~ 0.1-03 fb CDD(H)~-CDD(A) max bb mode –challenging bkgd conditions (S/B ~1/50). -mode- small (QED) bkgd, but low Br situation looks borderline at best  ‘best case’ (extreme) scenario mh with =-700 GeV , tan =50, mg =10³GeV max

  17. in this extreme case : (Agg) Br(Abb)22-24MeV at MA=160-200GeV ,tan 50, CDD (A bb) is decreasing from 65fb to 25fb (noangular cuts) CDD (A) 0.8-0.3fb A S/B ~ (A->gg) Br (A->bb) / MCD  5.5 /MCD(GeV) currentlyMCD ~ 20-30 GeV… (12GeV at 120 GeV) Prospects of A- searches strongly depend, in particular, on the possible progress with improving MCD in the Rap. Gap environment We have to watch closely the Tevatron exclusion zones There is no easy solution here, we must work hard in order to find way out .

  18. CONCLUSION FPThas the potential to make measurements which are unique at LHC and challenging even at a ILC. For some MSSM scenarios theFPT may be the Higgs discoverychannel. FPT offers a sensitive probe of the CP structure of the Higgs sector.

More Related