e-e-, gamma-gamma and e-gamma options for a Linear Collider A.De Roeck CERN Amsterdam, April 2003
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e-e-, gamma-gamma and e-gamma options for a Linear Collider A.De Roeck CERN Amsterdam, April 2003 1 In this study • Gamma-gamma and e-gamma option – Working group on gamma-gamma/e-gamma collider technology K. Moenig and V. Telnov – Working group on gamma-gamma physics M. Kraemer, M. Krawczyk, S. Maxfield, ADR, (S. SoldnerRembold) • 4+2 meetings during this study • During ECFA/DESY, integrated with other physics groups/ worked well! • Many new results • e-e- option – No new studies in the context of this workshop/ 2 meetings St Malo/Amsterdam C. Heusch • Will remind some key issues based on Snowmass/Jeju reports 2 e-e-option Advantages of e-e-: Large polarization for both beams: eL,eR Exotic quantum numbers (H--) Larger sensitivity in some processes Some very clean processes Sensitivity to contact interactions No s-channel, lower luminosity Non-Commutative QED …Majorana neutrinos 3 e-e- option Higgs production Supersymmetry CP viol. phases But: No detector simulation, IR, beamstrahlung, selectron width… 4 e-e- option Parameters (Snowmass 2001) Study for TESLA (S. Schreiber) Luminosity 5-(10)•1033 cm-2 s-1 L e-e- = 1/6 –(1/3) L e+eStability ~OK with intra-train feedback system 5 e-e- option S. Schreiber No major changes required in IP or accelerator Future control room at the FLC?? e-e- is the option which will be most easily to realize (for TESLA) Has to be kept on the roadmap 6 Gamma-gamma and e-gamma Compton backscattering on laser photons Needs second interaction point Needs crossing angle Peaked but smeared spectrum Hence: needs extra effort Is it worthwile? Jeju panel discusion: Yes! Examples of advantages Higher cross sections for charg. particles Different JPC state than in e+e Higgs s-channel produced Higher mass reach in some scenarios CP analysis opportunities Can test precisely couplings to photons… 7 Gamma-gamma and e-gamma • TESLA-TDR/ PLC workshop Hamburg 2000 Golden processes identified Starting point in Krakow Only light Higgsbb and QCD processes simulated (simplified) • This study: Level of detail in as good as in e+e– SIMDET simulation for more golden processes • H WW, ZZ , Heavy MSSM H & A, WW production, Susy – Cross checks/elaborate for key process Higgs bb – Further opportunities: CP studies, Extra Dimensions, NC QED,.. – Real luminosity spectra/polarization used (CIRCE, CompAZ) – B search using ZVTOP – Adding overlap events – QCD backgrounds in NLO – QCD Monte Carlo tuning to existing data • Direct contact & exchange with the US studies/exchange tools 8 Gamma-gamma and e-gamma • Backgrounds and Luminosity – Luminosity/polarisation measurement (& corresponding syst.) – Background studies (pairs, photons, neutrons) – Evaluate design of IP/Mask/vertex detectors • Technology – R&D efforts in Europe and the US 9 Golden Processes hep-ph/0103090 Higgs SUSY N T O D W R Tril/quart. Top QCD Being done or ready: should be ready for the writeup promised 10 Golden Processes Added at/since the Krakow meeting: Non-commutative QED e for ED’s Light gravitinos Radions Gluino production H (US groups) HH+H- (US groups) CP analyses in the Higgs sector More (as yet uncovered/lower priority at present) ee* Leptoquarks Strong WW scattering eeH As always: still room for volunteers (next workshop) 11 Gamma-gamma and e-gamma On our group web page… Information on lumi spectra, special SIMDET version, background… 12 Luminosity Spectra TDR parameters Luminosities files with PHOCOL (V. Telnov) Can be used via CIRCE (T. Ohl) Analytical approximation COMPAZ (A. Zarnecki) 13 Luminosity Measurement • Proposals – ee ee () / not for J=0 – ee ee () – ee 4 leptons • Precision ~0.1% (stat) • For Higgs (J=0) e.g. ee ee Moenig,Marfin,Telnov For e collisions - e e - e eee 14 Monte Carlos & Tuning SHERPA Generator (F. Kraus et al.) • Amegic & Wing Tuning of the Monte Carlo models via JETWEB (M. Wing) Resolved Direct A tune for LC studies has been produced 15 Background studies backgrounds studied for TESLA IP layout Study beam related background Moenig et al 1st layer 2nd layer… # of QCD events overlapping now under control ( 1 evt@ 200 GeV and 2.5 evts @500 GeV). All groups agree (D. Asner, ADR, Telnov, Warsaw) # of hits in the layers of the pixel detector per bunch crossing Incoherent pair production: essentially the same as for e+e Coherent pair production: High! but ok, similar to e+e same vertex detector as for e+e(Moenig,Sekaric) Neutrons? Probably ok (V. Telnov) 16 QCD QCD had been mostly studied --at detector level-- for the TDR Not revisited this time Exceptions (using new data) Total cross section parametrizations (Kwiecinski, Motyka,Timneanu) & (Pancheri, Grau, Godbole, ADR) Structure functions PDFs (Krawczyk et al.) To be used in the Monte Carlo programs 18 Higgs Heralded as THE key measurement for the gamma-gamma option • From the TDR (Jikia, Soldner-Rembold) • This workshop – Study H bb, with realistic spectra, background, B-tagging efficiency,… – Study H WW,ZZ – Study model separation power 10 – Study spin of Higgs in H WW,ZZ – Study CP properties of the Higgs 3 – Study MSSM Higgs (H,A): extend e+e- reach – Study of the Charged Higgs (US) 250 350 19 SM Higgs analyses P. Niezurawski 1 year/84 fb-1 Corrected inv. mass Using NLO backgrounds (Jikia…) Next question: Systematics…?? 20 SM Higgs Analysis A. Rosca • Analysis of a second group (Zeuthen) – Taking into account the QCD radiative corrections to the background process (Pythia + NLO Xsec.) through a reweighting procedure. – Adopting a b-quark tagging algorithm based on a neural network. = 1.9% L 80 fb-1 . N sig 6018 events N bkg 7111 events 21 SM Higgs: HWW,ZZ A. Zarnecki Simultaneous determination of the Higgs Boson width and phase H WW and H ZZ measurements (full detector simulation) / = 3-10% MH< 350 GeV 22 SM Higgs Analysis Warsaw group 2HDM SM-like versus SM (Ginzburg et al.) MHbb (GeV) 120 / 1.8 Different masses 130 140 150 160 1.9 2.2 3.0 6.8 23 MSSM H/A Higgs Extend the detailed analysis to H/A bb P. Niezurawski One year running and s 500 GeV A0 detectable for MA > 300 GeV beyond the e+e- reach 24 MSSM H/A Higgs e+e- Study for a e+e- collider at 630 GeV D.Asner/J.Gunion (LCWS02) Extends e+e- reach Need few years to close the LHC wedge European study in progress 25 Angular distributions in hZZlljj and hWW4j Higgs spin and parity A. Zarnecki D. Miller et al. hep-ph/0210077 Detector effects are large, but sensitivity left 26 CP studies via tt R. Godbole et al. hep-ph/021136 & LCWS02 Exciting possibility to analyse CP structure of the scalar Construct combined asymmetries from intial lepton polarization and decay lepton charge Done with Compton spectra Using COMPAZ reduces sensitivity with factor 2 Needs detector simulation 27 Triple Gauge Couplings Study WW eW Includes detector simulation/3D fits real /parasitic L ·10-4 ·10-4 Ee= 450 GeV ∫Lt=110 fb-1 0.1% E= 400 GeV ∫Lt=110 fb-1 0.1% 10 / 10 / (9.9) 15 / 22/ (2.6) 6.7 6.0 Sekaric, Moenig Bosovic, Anipko Eee= 500 GeV ∫Lt=500 fb-1 3.1 4.3 sensitivity ~ proportional to the momentum of the particles involved in the triple gauge boson vertex Studies starting for quartic couplings in WW and WWZ I Marfin Use of optimal variables F. Nagel et al. 28 Extra Dimensions tt ADD type extra dimensions Sensitivity to mass Ms P. Poulose Realism reduces sensitivity: Ms=1.7 TeV to 1.4 TeV =-1 see= 500 GeV SM+2 SM-2 =+1 Ideal Compton spectrum Ms COMPAZ spectrum Ms 30 Supersymmetry Several analyses starting Theoretical studies: gluinos charginos squarks eslepton neutralino Will be pursued up to the detector level Interesting but needs simulation E.g. Kraus, Wengler Klasen, Berge 31 Technology • Photon collider IP introduces new challenges – Laser – Optics – Stability & control in the IP (1nm?) /length control in cavity – Extraction line… • Both Europe & US groups have and R&D effort. – Europe: use a cavity to reduce laser power – US: full power laser design • US: laser commissioning 20 J pulses at 10 Hz / Full power next year – interferometery for alignment – ½ size focusing optics setup in lab – beam-beam deflection feedback system study – PC testbed at SLAC? Proposal under preparation • Europe : study cavitiy option – Make 1:9 size test cavity? Wait for funding/technology decision? Funding is an issue to continue R&D! 32 Interferometric Alignment System Testbed at LLNL J. Gronberg • Half-scale prototype of optics / alignment system to test mirror quality and alignment scheme – Optics and laser interferometer currently installed 33 Engineering Test Facility at SLC Revive SLC and install beampipe with optics to produce luminosity 30 GeV Beam Energy 1100 / 50 DR x,y (m-rad) 1600 / 160 FF x,y (m-rad) 8 / 0.1 mm x / y 0.1 – 1.0 mm z 1500/55nm x,y 6.0E9 N 34 G. Klemz New proposal 35 Conclusions • Lot of activity on gamma-gamma during this workshop series – Good balance found between gamma-gamma specific meetings and integration with the other groups • Good progress on tools/background etc, for gamma-gamma studies • Many detailed studies – The light Higgs results confirmed and extended / ~ 2% – Higgs channels in WW,ZZ studied / ~ 3-10% – H/A study confirms reach for high masses, beyond e+e– CP, Higgs spin etc studies starting – Detailed study of the TGCs measurement competitive with e+e– First results on SUSY and Extra Dimensions/alternatives explore during the continuation of the workshop Confirms /e as an exciting option for a LC ! • Progress also with hardware plans (PC testbed/Berlin studies) Big thanks to all participants, particularly the Warsaw and Zeuthen Groups 36