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The Key Selling Points for Proton Tagging at the LHC

The Key Selling Points for Proton Tagging at the LHC. Main Aims :.  To illustrate the theoretical motivations behind the recent proposals to add F orward P roton T aggers to the LHC experiments  To show that C entral E xclusive D iffractive P rocesses

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The Key Selling Points for Proton Tagging at the LHC

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  1. The Key Selling Points for Proton Tagging at the LHC Main Aims : To illustrate the theoretical motivations behind the recent proposals to add Forward Proton Taggers to the LHC experiments To show that Central Exclusive Diffractive Processes may provide an exceptionally clean environment to search for ,and to identify the nature of, new objects at the LHC based on works in collaboration with A. De Roeck, A.Kaidalov, A.Martin, R.Orava, M.Ryskin & W.J. Stirling

  2. CMS &ATLAS were designed and optimised to look beyond • the SM • -> High -pt signatures in the central region • But… ( from the ILC motivation list) • Main physics ‘goes Forward’ • Difficult background conditions. • The precision measurements are limited by systematics • (luminosity goal of δL ≤5%) • Lack of : • Threshold scanning • ILC chartered territory • Quantum number analysing • Handle on CP-violating effects • Photon – photon reactions p p RG Is there a way out? ☺ YES-> Forward Proton Tagging Rapidity Gaps Hadron Free Zones Δ Mx ~δM (Missing Mass) X RG p p

  3. PLAN • 1. Introduction • (a gluonic Aladdin’s lamp) • 2. Prospects for CED Higgs production. • the SM case • MSSM Higgses in the troublesome regions • MSSM with CP-violation • 3. Exotics • 4. Conclusion • .

  4. Forward Proton Taggersas a gluonic • Aladdin’s Lamp • (rich Old and NewPhysics menu) • Higgs Hunting (currently a key selling point). • J.Forshaw,A.De Roeck, C.Royon, VAK • Photon-Photon Physics.K.Piotrzkowski • ‘Light’ SUSY ( sparticle ‘threshold’ scan). KMR-02 • Various aspects of Diffractive Physics • A.Kaidalov,M.Ryskin, R. Peschanski, A.Martin, P.Landshoff, U.Maor,A.White, • K.Eggert, K.Goulianos, S.White, W.Guryn • (strong interest from cosmic rays peopleJ.Knapp) • Luminometry P.Grafströrm, KMOR-01 • High intensity Gluon Factory. KMR-02 • (lower lumi run, RG trigger…) R.Orava, J.Lamsa • Searches for new heavy gluophilic states KMR-02 • (radions ,gluinonia,….), KK gravitons.. • FPT • Would provide a unique additional tool • to complement the conventional • strategies at theLHCandILC. • a ‘ time machine’ • Not as ‘either the Higgs or nothing’

  5. High price to pay for such aclean environment: σ (CEDP) ~ 10 -4 σ( INCL) J.Forshaw Rapidity Gapsshould survive hostile hadronic radiation damages and ‘partonic pile-up ‘ W = S² T² • Colour charges of the ‘digluon dipole’ are screened • only at rd ≥ 1/ (Qt)ch • GAP Keepers (Survival Factors) , protecting RG against: • the debris of QCD radiation with 1/Qt≥ ≥ 1/M(T) • soft rescattering effects (necessitated by unitariy) (S) Forcing two (inflatable) camels to go through the eye of a needle H P P

  6. pp pp->p +M +p α² αs²/8 (S²)γγ =0.86

  7. The advantages of CED Higgs production • Prospects for high accuracy mass measurements • measurements (ΓH in some MSSM cases) • mass windowM = 3 ~ 1 GeV (the wishlist) • ~4 GeV(currently feasible) • R.Orava,K.Osterberg. • Valuable quantum number filter/analyser. • ( 0++dominance ;C,P-even) •  No obvious way toestablish theHiggsCP • at the LHC conventionally. • (an important ingredient of pQCD approach, • otherwise, large|Jz|=2 …effects, ~(pt/Qt)2!) • H ->bb ‘readily’ available • (gg)CED bbLO (NLO,NNLO) BG -> studied • SM HiggsS/B~3(1GeV/M) • complimentary information to the • conventional studies( also ՇՇ) • H->WW*,especially for SM Higgs with M≥ 135GeV • an added value(A.De Roeck et al) • New leverage –proton momentum correlations • (probes of QCD dynamics, pseudoscalar ID, • CP violation effects.) KMR-02, A.Kupco

  8. Current consensus on the LHC Higgs • search prospects • (e.g, A.Djouadi, Vienna-04; G.Weiglein, CMS, 04; A.Nikitenko,UK F-m,04)) • SM Higgs : detection is in principle guaranteed ☺ • for any mass. • In the MSSMh-boson most probably cannot ☺ • escape detection ,and in large areas • of parameter space other Higgses can be found. • But there are still troublesome areas of the  • parameter space: • intense coupling regime, • MSSM with CP-violation….. • More surprises may arise in other SUSY • non-minimal extensions • After discovery stage (Higgs identification): • The ambitious program of precise measurements of the mass, width, couplings, • and, especially of the quantum numbers and • CP properties would require an interplay • with a ILC

  9. 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) • The MSSM with explicit CP violation (A.Pilaftsis,98;M.Carena et al.,00-03, B.Cox et al 03, KMR-03) • an ‘Invisible’ Higgs (BKMR-04)

  10. Higgs couplings (G.Weiglein)

  11. (a )The intense coupling regime • MA≤ 120-150GeV, tanβ>>1( E.Boos et al,02-03) • h,H,A- light, practically degenerate • largeΓ, must be accounted for • the ‘standard’ modes WW*,ZZ*, γγ…-strongly suppressed v.s. SM • the best bet – μμ -channel, • in the same time – especially advantageous for CEDP: ☺ • (KKMR 03-04) • σ(Higgs->gg)Br(Higgs->bb) - significantly exceeds SM. • thus ,much larger rates. • Γh/H~ ΔM, • 0- is filtered out, and the h/H separation may • be possible • (b) The intermediate regime: MA ≤ 500 GeV, • tan β< 5-10 • (the LHC wedge, windows) • (c) The decoupling regime • (in reality, MA>140 GeV, tan β>10) • h is SM-like, H/A -heavy and approximately degenerate, • CEDP may allow to filterAout ~ ~

  12. The intense coupling regime of the MSSM KKMR-03 The intense coupling regime is where the masses of the 3 neutral Higgs bosons are close to each other and tan b is large suppressed enhanced 0++ selection rule suppresses A production: CEDP ‘filters out’ pseudoscalar production, leaving pure H sample for study for 5 swith300(30)fb-1

  13. decoupling regime: mA ~ mH large h = SM intense coupl: mh ~ mA ~ mH ,WW.. coupl suppressed • with CEDP: • h,Hmay be • clearlydistinguishable • outside130+-5 • GeV range, • h,Hwidths are quite different

  14. SMpp  p + (Hbb) + p S/B~11/4(M) with M (GeV) at LHC with 30 fb-1 e.g. mA = 130 GeV, tan  = 50 (difficult for conventional detection, but CEDP favourable) S B mh = 124.4 GeV 71 3 mH = 135.5 GeV 124 2 mA = 130 GeV 1 2 x M/ 1GeV incredible significance (10 σ) for Higgs signal even at 30 fb -1

  15. The intermediate regime. The ‘LHC window’. With CEDP the mass range up to 160-170 GeV can be covered at 300 fb-1

  16. Probing CP violation in the Higgs Sector A ‘CPX’ scenario KMR-04 CP even

  17. X M 1 GeV Summary of CEDP • The missing mass method may provide unrivalled Higgs mass resolution • Real discovery potential in some scenarios • Very clean environment in which to identify the Higgs,for example, in the CPX scenario • Azimuthal asymmetries may allow direct measurement of CP violation in Higgs sector • Assuming CP conservation, any object seen with 2 tagged protons has positive C parity, is (most probably) 0+, and is a colour singlet e.g. mA = 130 GeV, tan b = 50 (difficult for conventional detection, but exclusive diffractive favourable) L = 30 fb-1 S B mh = 124.4 GeV 71 3 events mH = 135.5 GeV 124 2 mA = 130 GeV 1 2

  18. ExoticsGluinoniumsAn ‘Invisible’ Higgs ~ ~  Gluinonium (gluinoball) : G=gg scenarios where gluino g is the the LSP (or next- to-LSP) currentntlyhit of the day -split -SUSY the lowest-lying bound state 0++(³ P ) the energies of P-wave states En= -9/4 mg αs²/n² (n ≥2) G – a ‘Bohr atom’ of the g g- system ΓG= (MG/100 GeV) 0.33 MeV, σG=30 fb (MG/100 GeV) ~ 0 ~ ~ ~ 5 -2 (S/B)gg= 0.25 !0 (1/ΔM) (MG/ 100 GeV) detection is challenging even with angular cuts

  19. an ‘Invisible ‘ HiggsKMR-04 M.Albrow & A .Rostovtsev -00 • several extensions of the SM: a fourth generation, • some SUSY scenarios, • large extra dimensions • (one of the LHC headaches ) • the advantages of the CEDP – a sharp peak in the MM spectrum, mass determination, quantum numbers • strong requirements : • triggering directlyon L1 on the proton taggers • low luminosity : L= 10³² -10³³cm-2 sec-1 (pile-up problem) , • forward calorimeter(…ZDC) (QED radiation , soft DDD), • veto from the T1, T2- type detectors (background reduction, improving the trigger budget) various potential problems of the FPT approach reveals themselves  however there is a (good) chance to observe such an invisible object, which otherwise may have to await a ILC many other goodies: White Pomeron etc…

  20. EXPERIMENTAL CHECKS • Up to now the diffractive production data are consistent with K(KMR)S results • Still more work to be done to constrain • the uncertainties • Very low rate of CED high-Et dijets ,observed yield • of Central Inelastic dijets. • (CDF, Run I, Run II) K.Goulianos, K.Terashi • ‘Factorization breaking’ between the effective diffractive structure functions measured • at the Tevatron and HERA. • (KKMR-01 ,a quantitative description of the results, • both in normalization and the shapeof the • distribution) • The ratio of high Et dijets in production with one • and two rapidity gaps K.Goulianos • The HERA data on diffractive high Et dijets in • Photoproduction. • (Klasen& Kramer-04 NLO analysis) • Preliminary CDF results on exclusive charmonium • CEDP. Higher statistics is on the way. • Energy dependence of the RG survival (D0, CDF) • …..in the time of writing has still survived theexclusion limits • set by the Tevatron data…. (M.Gallinaro, hep-ph/01410232)

  21. CONCLUSION Forward Proton Taggingwouldsignificantlyextend the physics reachof the ATLAS and CMS detectors by giving access to a wide range of exciting new physics channels. For certain BSM scenarios the FPT may be the discovery channel within the first three years of low luminosity running  Nothing would happen unless the experimentalists come FORWARD and do the REAL WORK

  22. of Forward Proton Tagging • 1. Thoushalt not worship any other god but the First Principles, • and even if thoulikest it not, go by the Book. • Thou shalttreat the diffractive experimental data in ways • that show great consideration and respect. • 3.Thou shalt drawthy daily guidance from the standard • candleprocesses for testing thy theoretical models. • 4. Thou shalt remember the speed of light to keep it holy • (trigger latency) • 5.Thou shalt notdishonour backgrounds and shaltstudy • them with great care. • 6.Thou shalt notforget about the pile-up (an invention ofSatan). • 7.Though shalt notexceed the trigger threshold. • 8.Thou shalt not exceed the L1 saturation limit. • Otherwise thy god shall surely punish thee for thy arrogance.

  23. 9. Thou shalt not annoy machine people. 10. Thou shalt not delay, the LHC start-up is approaching

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