Forward Detectors @ LHC Present coverage Possible upgrade projects Slogan: Q C D HERA for LHC physics and detectors Kerstin Borras (DESY) DESY-LHC Standardmodel Workshop Zeuthen 24.10.2006

Forward Detectors @ ATLAS (C.Royon,S.White) relative luminosity Cerenkov integrating detector (Counter !) absolute luminosity Roman Pots with scintillating fibres later diffraction Roman Pots with silicon detectors photoproduction neutron tagging Copper / Tungsten scintillating fibres rapidity gaps Copper / Liq. Ar Kerstin Borras (DESY) DESY-LHC Standardmodel Workshop Zeuthen 24.10.2006

Forward Detectors @ CMS/Totem CMS: HF cal & CASTOR Totem: T1,T2, RP1, (RP2), RP3 Kerstin Borras (DESY) DESY-LHC Standardmodel Workshop Zeuthen 24.10.2006

LHC Experiments: pT-h coverage (R.Orava @ Diffraction 2006) CMS fwd calorimetry up to |h|  5 + Castor + ZDC Exp B (T) pT (GeV) ALICE 0.2-0.5 0.1-0.25 ATLAS 2.0 0.5 CMS 4.0 0.75 LHCb 4Tm 0.1 1000 CMS ATLAS 100 coverage not complete: CASTOR FWDCAL (charged particles) T1 T1 pT (GeV) 10 T2 T2 1 RP CASTOR CASTOR RP 0.1 ZDC FWDCAL FWDCAL ZDC pTmax ~ s exp(-h) -12 -10 -8 -6 -4 -2 +2 +4 +6 +8 +10 +12 h

Possible Upgrades @ CMS/Totem CASTOR: contribute to project use of ZEUS - FPC on one side FWDCAL: re-use of H1 SPACAL & ZEUS HES Preliminary ! Need to negotiate the re-use of components with H1 and ZEUS Kerstin Borras (DESY) DESY-LHC Standardmodel Workshop Zeuthen 24.10.2006

Physics with CASTOR Multi-parton interactions & underlying event dynamics: forward energy & particle flow Low-x dynamics: parton saturation, BFKL / CCFM dynamics reach in x down to x~10-7 Luminosity determination: QED process: pp ppee  calculable to 1% In general: extend the coverage in η  enhance hermiticity and improve measurement of missing transverse energy  beneficial for searches for new physics Only some examples Kerstin Borras (DESY) DESY-LHC Standardmodel Workshop Zeuthen 24.10.2006

Contribution to CASTOR Project CASTOR was initiated in the framework of Heavy Ion physics @ LHC, but new collaborators interested in low-x physics joined soon after start . As HI project  late installation possible  need to speed up the project to be able to measure at low luminosity in the early LHC phase. Contributions in different areas possible: construction, DAQ (software), Monte Carlo studies … Kerstin Borras (DESY) DESY-LHC Standardmodel Workshop Zeuthen 24.10.2006

A possible CASTOR Alternative ZEUS Forward Plug Calorimeter: CAL hardware fits in lengths, radius for beam hole a bit too small  two separate halves, physics similar as in ZEUS due to equivalent position in η, radiation hard for the first fb-1 Kerstin Borras (DESY) DESY-LHC Standardmodel Workshop Zeuthen 24.10.2006

FWDCAL for charged particles Zero Degree Calorimeter @ 135m detects only neutral particles  try to add a hadronic calorimeter for charged particles: H1-SPACAL and ZEUS-HES moderate radiation level sufficient resolution with shower shape cuts achievable despite 40cm effective beam pipe thickness V.Andreev HERA-LHC workshop Kerstin Borras (DESY) DESY-LHC Standardmodel Workshop Zeuthen 24.10.2006

Possible FWDCAL Constructions Re-arranged H1 SPACAL (L.Lytkine) Si pad diodes of Hadron-Electron-Separator of ZEUS needs to be combined with an appropriate absorber Active area : 3.32×2.96 cm2 enough diodes to cover the required space. Recycle diodes of ZEUS HES Kerstin Borras (DESY) DESY-LHC Standardmodel Workshop Zeuthen 24.10.2006

Summary Multiple interactions are crucial for all searches and high pT phenomena. Need to understand the dynamics of the underlying event, simple tuning the parameters of a Monte Carlo generator might lead to wrong results and includes large systematic uncertainties  need coverage at large η ! Different possibilities explored by a collaboration of DESY and Russian institutes as a combined effort of experts in forward physics and forward detector components at HERA. Kerstin Borras (DESY) DESY-LHC Standardmodel Workshop Zeuthen 24.10.2006