1. Diffractive Higgs studies with CMS and TOTEM: Status, plans and possibilities for Torino Monika Grothe TO-CMS meeting October 8 2004

2. H gap -jet  Diffractive Higgs Production Exclusive diffractive Higgs production pp  p H p : 3-10 fb Inclusive diffractive Higgs production pp  p+X+H+Y+p : 50-200 fb p p beam p’ roman pots dipole Advantages Exclusive:  Jz=0 suppression of gg  bb background  Mass measurement via missing mass E.g. V. Khoze et al M. Boonekamp et al. B. Cox et al. …

3. Status:  Discussion on how collab TOTEM/CMS should look like still on-going  For time being: Joint diffractive and low-x working group as part of the PRS SW group  CMS aims at LOI on diffraction and fwd physics by March 2005 o circa 20 CMS groups have so far signed up for contribution o Albert de Roeck coordinates effort o for more details see Albert’s talk in last CMS week, on Sept. 27  Recent new initiative in UK: R&D program for detectors at ~400m o UK groups requested 1.2 Mio. pounds for 2005-2008 for R&D to develop cryostat that can house detectors (3-D silicon one possibility) and for trigger studies o bolstered by interest from ATLAS and CMS o cryostats with embedded detectors could be installed in LHC upgrade after 2008, no interference with initial LHC startup o more details: see Albert’s 2nd talk in last CMS week, on Sept 27

4. Status concerning trigger issues:  TOTEM to use from beginning CMS trigger and DAQ system o CMS GT reserved 16 bits for TOTEM trigger o Roman pots at 200m will go into the L1 trigger o Detectors at 400m can only go into HLT if L1 trigger has to occur within CMS L1 latency of 3.4  s  On-going work with CMS DAQ group, contact S. Erhan  Contact between TOTEM and CMS L1 group up to now sporadic => I’m in contact with E. Radicioni and Marco Deile My plan for LOI:  L1 rate and efficiency numbers for diff Higgs, generated with EDDE, without pileup and with pileup at Lumi 2x10 33 and 10 34, first using only central CMS detector (Et/Ht algorithm)  Time permitting, study impact of using TOTEM T1/T2 veto counter which are available in OSCAR  Would also like to use Roman Pots, but for the moment only available in FAMOS, though porting to OSCAR should be simple (LUTs)

5. Level-1 Jets and H T ECAL HCAL PbWO4 crystal veto patterns Trigger tower  4x4 trigger towers = region  Search for jets with sliding 3x3 regions window  Jet = 3x3 region with E T in central region above some threshold and with E T > E T in any of 8 outer regions  Jet = if veto off in all 9 regions H T = sum of scalar E T of all jets Advantage over total scalar E T :  Sums only over E T around local energy maxima  More robust against noise and minimum bias events Diff Higgs at L1: L1 cut on E T (2jets)/H T

6. Current involvement of Torino:  My ‘Rientro dei cervelli’ grant for “Diffraction and diffractive Higgs production with CMS”  Plan to concentrate on L1 trigger studies for diff Higgs  Have been working on these studies at U Wisconsin with S. Dasu (author of L1 simulation code) and C. Hogg (first year PhD student)  Marta Ruspa currently visiting U Wisconsin to learn about the L1 Calo trigger and its simulation code in ORCA -> L1 ORCA code hasn’t been updated since L1 TDR in 2000 -> none of on-going PRS studies take L1 trigger into account => turn Marta into a competent user of the L1 ORCA code => side-effects: o Torino group gains expertise in using CMS OSCAR/ORCA o U Wisconsin gets much-needed feedback on their code o CMS physics analyses will be able to include L1 efficencies We made good progress so far, might even be able to have first rate plots for diff Higgs by end of Marta’s stay, in any case in time for LOI

7. Current involvement of Torino (cont):  Side remarks: Bristol group (GCT) has new PhD student at CERN interested in L1 studies for diff Higgs => I’ll be back in Europe full-time by Dec. to take care of coordination Other possibilities for Torino involvement: Even if it is not possible to use detectors at 400m in L1, want to use them in HLT:  Need to develop trigger  R&D program for 400m detectors just starting up, installation would happen only well after initial LHC start  This means will become full-fledged hardware effort only after muon chamber installation finished  In the meantime: Need MC studies