1. The FP420 R&D Project
LOI to LHCC signed by 29 institutes from 11 countries - more in the process of joining
The aim of FP420 is to install high precision silicon tracking and fast timing detectors close to the beams at 420m from ATLAS and / or CMS
FP420 is basically a spectrometer using LHC magnets to bend protons with small momentum loss out of the beam (moveable silicon tracker ~ 8m long)
“The LHCC acknowledges the scientific merit of the FP420 physics program and the interest in its exploring its feasibility.” - LHCC
“The panel believed that this offers a unique opportunity to extend the potential of the LHC and has the potential to give a high scientific return.” - UK PPRP (PPARC)

2. The FP420 R&D Project At low luminosity (~ 30 fb-1) we can :
Motivation from KMR calculations (e.g. hep-ph )
Selection rules mean that central system is (to a good approx) 0++
If you see a new particle produced exclusively with proton tags you know its quantum numbers
CP violation in the Higgs sector shows up directly as azimuthal asymmetries
Proton tagging may be the discovery channel in certain regions of the MSSM
Tagging the protons means excellent mass resolution (~ GeV) irrespective of the decay products of the central system
At low luminosity (~ 30 fb-1) we can :
Establish the quantum numbers of SM Higgs
Be the discovery channel in certain regions of the MSSM
Make high precision measurements of WW / ZZ couplings
Host of interesting QCD measurements (0.002 < xIP < )

3. The FP420 R&D Project At low luminosity (~ 30 fb-1) we can :
Motivation from KMR calculations (e.g. hep-ph )
Selection rules mean that central system is (to a good approx) 0++
If you see a new particle produced exclusively with proton tags you know its quantum numbers
CP violation in the Higgs sector shows up directly as azimuthal asymmetries
Proton tagging may be the discovery channel in certain regions of the MSSM
Tagging the protons means excellent mass resolution (~ GeV) irrespective of the decay products of the central system
At low luminosity (~ 30 fb-1) we can :
Establish the quantum numbers of SM Higgs
Be the discovery channel in certain regions of the MSSM
Make high precision measurements of WW / ZZ couplings
Host of interesting QCD measurements (0.002 < xIP < )

4. The FP420 R&D Project
Motivation from KMR calculations (e.g. hep-ph )
Selection rules mean that central system is (to a good approx) 0++
If you see a new particle produced exclusively with proton tags you know its quantum numbers
CP violation in the Higgs sector shows up directly as azimuthal asymmetries
Proton tagging may be the discovery channel in certain regions of the MSSM
Tagging the protons means excellent mass resolution (~ GeV) irrespective of the decay products of the central system
In addition, at higher luminosity (~ 100 fb-1) we can :
Make direct observation of CP violation in some SUSY Higgs scenarios
Disentangle wide range of SUSY scenarios, including nearly degenerate Higgs sectors

5. The FP420 R&D Project
Motivation from KMR calculations (e.g. hep-ph )
Selection rules mean that central system is (to a good approx) 0++
If you see a new particle produced exclusively with proton tags you know its quantum numbers
CP violation in the Higgs sector shows up directly as azimuthal asymmetries
Proton tagging may be the discovery channel in certain regions of the MSSM
Tagging the protons means excellent mass resolution (~ GeV) irrespective of the decay products of the central system
FP420 turns the LHC into a glue-glue (and ) collider where you know the beam energy of the gluons to ~ 2 GeV.

6. FP420 Schematic Outline
Spectrometer using LHC magnets to bend protons with small momentum loss out of the beam
M ~ 30 GeV
M ~ 200 GeV

7. The 420m region at the LHC

8. The 420m region at the LHC
Warm beam pipes in air
Detectors

9. The 420m region at the LHC

10. How will the redesign be achieved ?
~ £110k from PPRP to fund cryogenic engineering from Cockcroft Institute + CERN designer (current 420m cryostat designer). Managed by Keith Potter at CERN

11. Movement Mechanism Designs
Louvain + Torino + Helsinki

12. Movement Mechanism Designs
Impact of near-beam structures on LHC beams - 1 RA from PPRP working with Roger Jones + Rob Appleby at Cockcroft
Louvain + Torino + Helsinki

13. FP420 Silicon Detector Stations
7.2 mm x 24mm (7.2 x 8 mm2 sensors)
5 years at 1035 cm-2 s-1

14. FP420 Fast timing Detectors
US R&D funded
1% events at LHC have diffractive proton track in FP420
@ 2 x 1033 cm-2s-1, 7 interactions / bunch crossing
-> 30% of FP420 events have an additional track
Matching mass and rapidity of central system removes large fraction of these
Of the remaining, 97.4% rejected by fast timing detectors with 10ps timing resolution (2.1 mm)
Preliminary studies give s(overlap) = s(signal) for Higgs -> bb 2 x 1033 cm-2s-1 .

15. FP420 Acceptance and Resolution
3 mm + 3 mm
7.5 mm + 3 mm
3 mm
25 mm
30 mm
5 mm
7.5 mm
10 mm
22 mm
MB apertures

16. FP420 alignment
@ 1 x 1033 cm-2 s-1 expect ~ 100 - events / fill with standard trigger thresholds
Simulations (Louvain) indicate precision is better than necessary (theoretical limit is LHC beam energy uncertainty , 0 = 0.77 GeV ~ 50 microns)
(also WW, M> 200 GeV, 100 fb -> very high sensitivity to anomalous quartic couplings)

17. FP420 alignment
5 m will be possible - test bench under construction at CERN
Helene Mainaud-Durand, CERN

18. FP420 L1 Trigger
Trigger latency does not allow for 420m detectors to be included in L1 at ATLAS or CMS in standard running mode
Problem for low-mass Higgs -> bb jets
@ 1 x 1032, no pile-up, isolation criteria allows L1 di-jet trigger
(rate 2.6 KHz 2 jets ET > 40 GeV reduced to < 1 KHz with isolation + topological cuts)
@ 2 x 1033, 7 pile-up events, tag at 220m + topological cuts OK
@ 1034 require increase in trigger latency from 3.2 -> 4 s (SLHC ~ 6.4 s)
20% bb events can be saved with triggers at all luminosities
All other channels, e.g. WW(*) ,  decays, fine.

19. The KMR Calculation of the Exclusive Process
q -> Proton
Dominant uncertainty: KMR estimate factor of 2-3. Independent estimate by Lund group “definitely less than 10”.
Divergent: controlled by Sudakov
Power of QT, 6 for pseudo-scalar
Jeff Forshaw, this workshop

20. The benchmark : Standard Model Higgs Production
B.E. Cox. et al, Eur. Phys. J. C 45, (2006)

21. The benchmark : Standard Model Higgs Production
WW* : MH = 120 GeV s = 0.4 fb
MH = 140 GeV s = 1 fb
MH = 200 GeV s = 0.5 fb
MH = 140 GeV : 5 (10) signal (1 (2) “gold platted” dl), negligible background in 30 fb-1 H
b jets : MH = 120 GeV s = 2 fb
MH = 140 GeV s = 0.7 fb
MH = 120 GeV : 11 signal, S/B ~ 1 in 30 fb-1
0++ Selection rule
Also, since resolution of taggers > Higgs width:
QCD Background ~
The b jet channel is possible, with a good understanding of detectors and clever level 1 trigger
The WW* channel is extremely promising : no trigger problems, better mass resolution at higher masses (even in leptonic / semi-leptonic channel)
If we see Higgs + tags - the quantum numbers are 0++
B.E. Cox. et al, Eur. Phys. J. C 45, (2006)

22. FP420 Physics Highlights suppressed enhanced MA = 130 GeV, tan b = 50
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
MA = 130 GeV, tan b = 50
Mh = 124 GeV : 71 signal / 10 background in 60 fb-1
MH = 135 GeV : 124 signal / 5 background in 60 fb-1
MA = 130 GeV : 1 signal / 5 background in 60 fb-1
Well known difficult region for conventional channels, tagged channel may well be the discovery channel, and is certainly a powerful spin/parity filter

23. Probing CP violation in the Higgs Sector
Azimuthal asymmetry in tagged protons provides direct evidence for CP violation in Higgs sector
‘CPX’ scenario s in fb
CP odd active at non-zero t
CP even
Ongoing work - are there regions of MSSM parameter space where there are large CP violating couplings AND enhanced gluon couplings?
B.C., Forshaw, Lee, Monk and Pilaftsis Phys. Rev. D. 68 (2003)
Khoze, Martin and Ryskin Eur. Phys. J. C 24 (2004) 327

24. CP violation in the Higgs Sector
bb decay
tt decay
tt decay
J. Ellis et al hep-ph/

25. Evidence for Exclusive Production
B. C. and A. Pilkington, Phys.Rev.D72:094024,2005

26. Evidence for Exclusive Production
JZ=0 -> for colour singlet bbar production, the born level contributions of a) and b) cancel in the limit mb -> 0

27. Evidence for Exclusive Production
10 GeV < M<20 GeV
Evidence for Exclusive Production

28. FP420 Key Milestones 12/12 First draft Design Report
WP3
28/03 specify candidate designs
Aug - Internal and external review
WP1
WP2
WP4
17/06 complete drawings for candidates
25/08 Final Spec.
05/09 Test Beam

29. FP420 Collaboration
We are at present reviewing FP420 membership, there are jobs still to be done.
Contacts :
(ATLAS)
(CMS)

30. FP420 Summary
We have built a strong international collaboration with the manpower and expertise to deliver forward proton tagging at high luminosity to the LHC
FP420 adds real discovery potential to ATLAS / CMS.
12 month R&D study fully funded from UK, US and Belgium (~1000K CHF)
Funding bids and significant manpower from Italy, Germany, Finland, Canada
Agreed list of key R&D areas (with CERN) to address machine safety issues and physics goals.
Technical design by Feb 2007 (Manchester 2006) and (if successful) TDRs to LHCC from ATLAS / CMS spring 2007.
First opportunity for installation is autumn 2008, dependent on LHC schedule.
Physics returns potentially huge