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The FP420 Project:Physics Potential

Albert De Roeck CERNand University of Antwerp and the IPPP Durham

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• 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

• Tagging the protons means excellent mass resolution (~ GeV) irrespective of the decay products of the central system. LO QCD backgrounds suppressed

•Proton tagging may be the discovery channel in certain regions of the MSSM.

• Unique access to a host of interesting QCD processes

Very schematically: exclusive central production is a glue – glue collider where you know the beam energy of the gluons - source of pure gluon jets - and central production of any 0++ state which couples strongly to glue is a possibility …

Exclusive Central Production

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FP420: Detectors at 420m

Low *: (0.5m): Lumi 1033-1034cm-2s-1 215m: 0.02 < < 0.2 300/400m: 0.002 < < 0.02 Detectors in the cold region are needed to access the low values

TOTEM(ATLAS/RP220)

FP420

FP420 R&D Study

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FP420 R&D Study• Feasibility study and R&D for the development of detectors to

measure protons at 420 m from the IP, during low optics at the LHC– Main physics aim pp p+ X + p

• Higgs, New physics • QCD/diffractive studies• Photon induced interactions

– Study aims• Redesign 420 m (cryostat region)• Mechanics/stability/services for detectors• Tracking detectors to operate close to beam • Fast timing detectors (10-20 picosecond resolution)• RF issues, integration, precision alignment, radiation,

resolution,…• Trigger/selection issues/pile-up for highest luminosity To be built/deployed by ATLAS and/or CMS, when successful

• Collaboration web page: http://www.fp420.com

Excellent collaboration with machine/cryo groups; Keith Potter mediator

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Hgap gap

b

b -jet

-jet

Central Exclusive Higgs ProductionCentral Exclusive Higgs production pp p H p : >3 fb (SM) ~10-100 fb (MSSM)

p p

beam

p’

p’roman pots roman pots

dipole

dipole

22 )''( ppppM H

E.g. V. Khoze et alADR et al.M. Boonekamp et al.B. Cox et al. V. Petrov et al…Brodsky et al.

M = O(1.0 - 2.0) GeV

A way to get informationon the spin of the Higgs

FP420 R&D Projecthttp://www.fp420.com

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H

b jets : MH = 120 GeV s = 2 fb (uncertainty factor ~ 2.5)

MH = 140 GeV s = 0.7 fb

MH = 120 GeV : 11 signal / O(10) background in 30 fb-

1

WW* : MH = 120 GeV s = 0.4 fb

MH = 140 GeV s = 1 fb

MH = 140 GeV : 8 signal / O(3) background in 30 fb-1

Standard Model Higgs

•The b jet channel is possible, with a good understanding of detectors and clever level 1 trigger (need trigger from the central detector at Level-1, possibly with O(10) KHz rate)

•The WW* (ZZ*) channel is extremely promising : no trigger problems, better mass resolution at higher masses (even in leptonic / semi-leptonic channel)

Exclusive Higgs production

with detector cuts

with detector cuts

Generator studies with detector cuts

hep-ph/0207042

hep-ph/0505240

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Higgs Studies

Kaidalov et al.,hep-ph/0307064

100 fb

1fb

Cross section factor> 10 larger in MSSM(high tan) Few 100 events with ~ 10 background eventsfor 30 fb-1

Study correlations between the outgoingprotons to analyse the spin-parity structure ofthe produced boson 120 140

A way to get informationon the spin of the HiggsADDED VALUE TO LHC

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Measuring the Azimuthal Asymmetry

Azimuthal correlationbetween the tagged protons

Allows to eg to differentiateO+ from O-

Khoze et al., hep-ph/0307064

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MSSM Scenario Studies

MA = 130 GeV tan = 50 HbbS. Heinemeyer et alto appear

Contours of ratio of signal events in the MSSM over the SM

No-mixing scenario

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Mhmax MSSM scenario: Hbb

(mA=120 GeV, tan = 40, 150 fb-1)

Taking into accountacceptance, triggerefficiencies etc.

An example of what forward proton tagging can do

Invariant masscalculated withthe two protons

Events / 1 GeV

Cox, Loebinger and PilkingtonarXiv:0709.3035

Mass GeV

Also promising studies in Haa (NMSSM; J. Gunion et al.)

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“lineshape analysis”

J. Ellis et al.hep-ph/0502251

Scenario with CPviolation in the Higgs sector and tri-mixing

Needs ~ 1 GeV mass resolution and a few 100 pb-1 for this scenario

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Experimental issues at nominal luminosity

Pile-up

Can be reduced by- Correlations between central detector and RP measurements- Vertices- Event multiplicities- Fast Timing ( K. Piotrzkowski)

Trigger For Hbb

Detailed studies in theCMS/TOTEM LOILHCC-2006-039talk this morning

Allow higher L1 rate O(10) KHz and use protons from tagger at HLT?

13 Also: Observation of exclusive 2 photon and di-lepton events in CDF

CDF e.g. arXiv:0705.3804

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Long Lived Gluinos at the LHC

P. Bussey et alhep-ph/0607264

Gluino mass resolution with 300 fb-1

using forward detectors and muon system

The event numbers includes acceptance in the FP420 detectors and centraldetector, trigger…

Measure the gluino mass with a precision (much) better than 1%

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Exotics Anomalous WW Production?

Alan White: theory of supercritical pomeron reggeized gluon+many (infinite) wee gluons

• color sextet quarks required by asymptotic freedom, have strong colour charge, (at least) few 100 GeV constituent mass

• Sextet mesons EWSB • UDD neutron dark matter candidate• Explain high energy cosmic rays, Knee?• Color sextet quarks couple strongly to W and Z and to the

pomeron• Phenomenology: Anomalous production of WW when above

threshold ie. At the LHC (with possibly some onset already detectable at the Tevatron

color colortriplets sextets

u c t Ud s b D

Measure exclusive WW,ZZ cross sections in DPE at the LHC Expected cross section to be orders of magnitude larger than in SM

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Process

WWA spectrum

pp

CMS Near beam Detectors

Photon-photon and photon-proton @ LHC

Extensive Program , ee QED processes QCD (jets..) ZZ/WW anomalous couplings top pairs Higgs Charginos…

…and p

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QED Processes for Alignment

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FP420CERN-LHCC-2005-025LHCC-I-015FP420 : An R&D Proposal to Investigate the Feasibility of Installing Proton Tagging Detectors in the 420m Region at LHC

FP420 R&D Funding (ATLAS & CMS) :“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)R&D funding : £500k from UK (Silicon, detector stations, beam pipe + LHC optics and cryostat design), $100k from US (QUARTIC, Andrew Brandt/UTA), €100k Belgium (+Italy / Finland) (mechanics)

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Schematic of Extremely High Precision Proton Spectrometer

High precision(~ 5 m) BPM

High precision(~ 5m) BPM420m of vacuum pipe

120m of 8T dipolesPrecision ~ 5 m on track displacementand ~ 1 rad on angle w.r.t. beam.

CMS

Layout schematic ...Still being optimized

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Final cryostat design launched (TS/MME group at CERN)

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CRCLouvain-la-NeuveCRCLouvain-la-Neuve

Integration of the moving beampipe and detectors

Benoît Florins, Krzysztof Piotrzkowski, Guido Ryckewaert

ATM

Vacuum Space

BPM

Pockets

ATM

Line X

Bus Bar Cryostat

BPM

Vacuum Space

Transport side

QRLFixed Beampipe

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OCTOBER

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FP420 test beam 11-16 October 2007

27 FP420 Test Beam 11-16 October 07

180 GeV/c pionsTelescope pitch 50x50m2

Vbias= 30V

x-y 3D correlation with Sitelescope

Single detectorHit map

Time OverThreshold

Full 3D silicon blades response PRELIMINARY

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Working on the test-beam (Oct 07)

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Summary

• Near beam detectors at 420m will extend the physics potential of the central detectors ATLAS and CMS.– Main physics aim pp p+ X + p

• Higgs, in particular in the MSSM, New physics, Exotic physics • QCD/diffractive studies• Photon induced interactions

– Consider FP420 an ‘extension’ of the ATLAS/CMS baseline detectors• R&D program ongoing since a few years. Next steps include

– R&D conclusions report of FP420, to be submitted to CMS & ATLAS complete draft for November, including costing.

– Detectors in testbeam: July at FNAL, October at CERN – Collect feedback for ATLAS and CMS for LOI/TDR preparation, if project

approved within the collaboration.• Start-up of discussions within CMS &ATLAS to include FP420 detectors. Referees installed for CMS. Decision within the next few months• Installation at LHC: Earliest during 2009-2010 Shutdown

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RESERVE

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Preliminary planning of interconnection:Preliminary planning of interconnection:

Days

1

3

5

7

9

11

13

15

17

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25

Dismantling of interconnection

Reconditioning of interconnection

Removal of C.C.

Installation of FP420 cryostat.

Interconnection

Last operation & commissioning.

T. Colombet (At-MCS)

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Very active R&D programme

Proton optics and LHC accelerator issuesCryogenic by-passMoving pipe mechanicsTrack detectors (3D Si) and precision mounting.Beam position monitorsFast timing detectorsReference time signalInfrastructureDAQ and TriggersSimulationsBackgroundsPreliminary cost estimateTimeline

CMS groups in FP420: Antwerp, CERN, Fermilab, (Helsinki,)Lawrence Livermore (LLNL), Louvain, Moscow(ITEP), Protvino, Rio de Janeiro, Rockefeller, Torino/Novara

Summary I

R&D on FP420: tiny but v.high precision tracking, timing, BPMBest particle spectrometer ever, using part of LHC.Important gain in physics potential for modest cost.

Committed group that is interested to pursue this project within CMS

Next step: R&D conclusions report of FP420, to be submitted to CMS & ATLAS (and LHCC?) complete draft for August including costing

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Test of Theoretical Predictions

Some central exclusive production (QCD) processes are accessibleat the Tevatron and are studied in CDF:

c b J Jχ , χ , JJ, b b , γγ

c b J Jχ , χ , JJ, b b , γγ

Of these, is the cleanest as FS not strongly interactingγγ

“Durham” group: Uncertainties in skewed gluon distributions,gluon , Sudakov form factors. Claim uncertainty ~ 3.Tk

MGA et al., hep-ex/0511057

Khoze, Martin and Ryskin, hep-ph/0111078, Eur.Phys.J. C23: 311 (2002)KMR+Stirling hep-ph/0409037

( ) 5 GeV,| ( ) | 1.0

( ) 38 / 3

CDF : 2 candidates

90 fb (preliminary)

TE

th fb

pp p p

Implication: Exclusive Higgs production must happen

2 EM showersNo tracks

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Simulation of beam line/detectors

• Two tools for beam transport available (FPTRACK, HECTOR) used for

– acceptance studies– mass resolution studies– alignment studiesNB HECTOR in FAMOS and CMSSW (developed by CMS-Louvain group and interfaced to CMSSW by IHEP-Protvino)

• G4 simulation of the beam line under development

– geometry set up– shower formation coming soon – suitable for integration in CMS full simulation?

• G4 simulation of the detector region available (ITEP Moscow/Antwerp)– effect of multiple interactions quantified; results used to finalize single

detector geometry and station number and layout– track reconstruction under development– integrated into CMSSW

35 J. de Faverau, K. Piotrzkowski, X. Rouby, Louvain

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ATM Reshuffling Module. X Line

Superfluid He (X) Line. Existing raw interfaces

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Assembly Detector stations

D. Dattola, INFN-Torino

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Detector Box (In work)

QUARTIC

Silicon 3D

GASTOF

D. Dattola, INFN-Torino

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Detector optimization ongoing with Geant4 tools

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Include high precision timing counters.Suggested in Tevatron LOI: Quartz Cerenkov + ~ Microchannel PMTThen said 30 ps(?). Now tested (Japanese Gp) 10 psOther option: Gas CerenkovCheck that p’s came from same interaction vertex (& as central tracks)

tL tRx

tL

tR

z_vtx

z

t

t_int

Fast Timing Detectors

Expected to be particularly useful/essential at high luminosity/pile-up

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Longer term possibilities (Tracker upgrade time):Develop thin (Si, 3D?) fast timing layers.Pads ~ cm2. Find true event time and matchwith t(pp).Further pile-up rejection ~ 20 may be possible.Forward discs also: reject events with forward tracks

QUARTICs : 8 measurements/proton2 in beam 16 measurements on “timetrack”

Before insertingbars and wrapping GASTOF (Louvain)

Could have two GASTOFs+ 2 QUARTICS.

Resolution still dominated by electronics ... can do better

QUARTIC (Fermilab)

SiPMT +Quartzalso studied

ps67t

eduncorrelat if ps 20(prelim.) ps/channel80t

Had two generations of detector and Electronics in Fermilab test beam Sept 2006 and Mar 2007 ... next run July 07.

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Detectors at 420m can be included in the HLT Would need to increase L1 latency for inclusion in L1, which might be possible in special runs(use post-L1Accept event buffers as pre-L1Accept storage)

For standard CMS running triggering with forward detectors has been studied in great detail, see trigger appendix in CMS PTDR-II CMS trigger menus in PTDR-II foresee 1% of the bandwidth on L1 and HLT for a dedicated forward detectors trigger stream

H(140GeV) -> WW: Can trigger ~20% of events via the standard L1 muon trigger

H(120GeV) -> bb: Can trigger 10% of the events via the standard L1 muon trigger Can gain an additional 10% from the jet trigger when combining jet trigger and tag at 220m, because can lower dijet ET thresholds substantially, to about 40GeV per jet, for bandwidth limit of 1kHz In order to retain this 10% gain from the jet trigger on L1 and stay within bandwidth limit of 1Hz, need FP420 information on HLT

Triggers for Exclusive Processes

Last word on trigger not yet said…

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TOTEM

xL=P’/Pbeam=

det@420

d(

ep

eXp

)/d

x L [n

b]

Number of PU events with protons within acceptance of near-beamdetectors on either side:

~2 % with p @ 420m

~6 % with p @ 220m

Translates into a probability of obtaining a fake DPE signature caused by protons from PU:

Depends critically on the leading proton spectrum at the LHC which in turn depends on size of soft rescattering effects (rapidity gap survival factor) !

Eg at 2x 1033 cm-2s-1 10% probability for a fake DPE signature for any background source thatlooks identical to the signal in the central CMS detector only.This is independent of the type of signal.

Pile-up

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Can be reduced by:

Requiring correlation between ξ, M measured in the central detector andξ, M measured by the near-beam detectors

Fast timing detectors that can determine whether the protons seen in the near-beam detector came from the same vertex as the hard scatter within 3mm

Condition that no second vertex befound within 3mm vertex windowleft open by fast timing detectors

Additional cuts exploiting difference inmultiplicity between diff signal and non-diffbackground

; 1 2 s = M2

(p tagger)

(je

ts)

CEP H(120) bb incl QCD di-jets + PU

M(2-jets)/M(p’s)

CEP of H(120 GeV) → b bbar andH(140 GeV) → WW:S/B of unity for a SM Higgs

Pile-up

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• Beam halo induced by betatron cleaning collimatorsin contact with collimator group (Assman et al.)

• Beam halo induced by momentum cleaning collimators available (IHEP-Protvino)• Beam gas

results from Protvino group to come• IP secondaries

simulation results from machine group with tracking down to 214m available, on going extention down to 420m

Machine induced backgrounds

Beam Halo induced by beta-cleaning collimators• Count hits at FP420 location in x, x’, y, y’, dp/p until all protons are absorbed at collimators or other aperture limits (not FP420)• Normalization to the expected loss rate• Conclusion: at 10 sigma (3 mm) we may have a problem!

– we move out at 15 sigma

– we propose to move IN collimators

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HV-LV supplies

• Investigated 3 commercial solutions (CAEN, Eplax, Wiener) and ‘home-made’ option. CAEN and Wiener have ‘off-the-shelf’ radiation-tolerant products

• LV/HV crates under the adjacent magnets

• CAEN solution is an all-in-tunnel with short HV-LV cables

• Wiener solution has LV in tunnel and HV in counting room

• CAEN ok up to 140Gy (Atlas certified) except for A3501 (HV) which may need to be tested (though same components as A3540, tested ok by Atlas)

• Some customization needed for CAEN solution:– CAN modules (transmission speed over 500m cable), currently being

investigated– A3501 (HV), may need to increase max HV to 120 V

• Wiener not radiation-tested but advertised as radiation-tolerant (Wiener ”ready

to test acccording to instructions”)

Radiation!

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CAEN solution

A3009 LV

A3501 HV

A3009 LV

A3501 HV

A3486 48V Power

•Delivery not possible before summer 2008 due to LHC production bottleneck. Only few samples by mid 2007.

•CAN bus link over 500++m require slow down to 250kbit/s. This is not yet tested but should be ok. Requires modification of firmware:

•High voltage only up to 120V (requires modification from 100V nominal)

Cable:500m

H. Larsen, INFN-Torino

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Wiener MPod-in-tunnel solution

LV in the tunnel. 1Crate per site!

HV in the counting room.

BUT: Has not been radiation tested. This has to be done.

We would like also the HV crate in tunnel to avoid the long cables. This will need discussions with Wiener.

Communciation: CAN 125kBit/s. on cable SCEM 04.21.52.124.4

H. Larsen, INFN-Torino

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Very active R&D programme

Proton optics and LHC accelerator issuesCryogenic by-passMoving pipe mechanicsTrack detectors (3D Si) and precision mounting.Beam position monitorsFast timing detectorsReference time signalInfrastructureDAQ and TriggersSimulationsBackgroundsPreliminary cost estimateTimeline

CMS groups in FP420: Antwerp, CERN, Fermilab, (Helsinki,)Lawrence Livermore (LLNL), Louvain, Moscow(ITEP), Protvino, Rio de Janeiro, Rockefeller, Torino/Novara

Summary I

R&D on FP420: tiny but v.high precision tracking, timing, BPMBest particle spectrometer ever, using part of LHC.Important gain in physics potential for modest cost.

Committed group that is interested to pursue this project within CMS

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Summary II

• Next step: R&D conclusions report of FP420, to be submitted to CMS & ATLAS (and LHCC?) complete draft for June, including costing. – Input for ATLAS and CMS for eventual LOI/TDR preparation, if

approved within the collaboration.• Consider FP420 an ‘extension’ of the CMS baseline detector• Start discussions within the CMS. Similar steps being taken in ATLAS.

– A CMS-Subgroup of FP420 assessing capabilities and uncovered items. Eg the detectors (default: 3D/synergy with the CMS upgrade program?). Add expertise from CMS tracking?

• Need to discuss within CMS with experts eg on interfacing (HLT/DAQ/Slow/run control…). Needs blessing! A coordinator for this integration study? Non-interefence with baseline program is understood

• Funding request can start only after a positive signal from CMS– Installation: aim for full installation 2009-2010…

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RESERVE

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HV-LV supply segmentation

Damage depends on distance from the beam. Required bias voltage and current increase with radiation dose.

Drawing: From Ray Thompson

PT1000 Temperature sensor?

Pixels:50x400um and 400x50um

MCC: Module Controller Chip

1 Superlayer =

2 Hybrids/Blades4 2D detectors1 MCC1 Read-out interface

Now only 2 det. not 3 as shown

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Draft proposal of Si detectors mounting on box cap and reference system

D. Dattola, INFN-Torino

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3D view Detector station

D. Dattola, INFN-Torino