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Status of RP220 project

Marek Taševský (Physics Inst. Prague)

Forward Physics workshop - Antwerp 25/10 2007

Forward and diffraction physics

RP220 project

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Rich program for Forward Physics at LHC

Diffraction

F2p at very low x

Two-photon interactions

- Absolute lumi calibration- Calibration, resolution for FPS- Factorization breaking in hard diffr.

Underlying event/Multiple interactions

Long dist. Correl. in rap.(need to cover fwd region)

Huge differences for diff.generators and diff. tunes

Average mult. transv. to leading jet at LHC

Saturation at very low x ?

Evidence for CEP?

[C.Buttar et al., HERA-LHC proc.]

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Central Exclusive Diffraction: Higgs production

b, W

b, WH

- Khoze, Martin, Ryskin hep-ph/0111078- Central system is 0++

- If you see a new particle produced exclusively and with proton tags you know its quantum numbers- Roman Pots give much better mass resolution than central detectorDiscovery difficult in SM but well possible in MSSM

Pile-up is issue for Diffraction at LHC!

But can be kept under control !

5sigma contours:H→bb, mhmax scen., μ=-500GeV [Heinemayer, Khoze, Ryskin, Stirling, M.T., Weiglein]

Log S/Bpu

Offline cuts

Rejectionpower

[CMS-Totem : Prospects for Diffractive and Fwd physics at LHC]

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Forward detectors at LHC

14 m 16 m 14 0 m 1 4 7 m - 2 2 0 m 4 2 0 m

I P 1

I P 5

TOTEM -T2 CASTOR ZDC/FwdCal TOTEM-RP FP420

LUCID ZDC ALFA/RP220 FP420

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Proton taggers for high luminosity

14 m 16 m 14 0 m 1 4 7 m - 2 2 0 m 4 2 0 m

I P 1

I P 5

TOTEM-RP FP420

RP220 FP420

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Proton taggers for high luminosity • At CMS: TOTEM: Roman Pots at 147 and 220m Excellent coverage in and t at low luminosity optics (*=90, 1540m) Coverage 0.02<<0.2 at high luminosity optics (*=0.5m)

• At ATLAS: RP220 Roman Pots (of Totem design) at 220m Coverage similar to TOTEM at high luminosity optics

• At CMS and ATLAS: FP420: R&D project, aim to instrument region at 420m 0.002<<0.02 (high luminosity optics only)

detectors@420m

FP420

TOTEM-

RP220

xL=P’/Pbeam=

Log

Logt

*=0.5

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Michigan State Univ.

Univ. of Chicago, Argonne (timing det.)

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TOTEM on CMS sideRP220 on ATLAS sideFP420

How to measure the protons

• Cold region of LHC• Too far for L1 trigger FP420

(ATLAS)

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Roman Pot acceptances for Totem and CMS

[CMS-TOTEM: Prospects for Diffractive and Fwd physics at LHC]

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Acceptance for RP220 and FP420 at ATLAS

[W.Plano and P.Bussey, FP420]

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Integration into LHC structure Diffraction protonsdeflected horizontallyand away from the ringOnly horizontal pots from outside needed!

BEAM 2

Diffractionp’s deflectedhorizontallybut insidethe ring

[A.Kupčo, RP220]

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Tracking - ResolutionsRequirements:

Close to the beam => edgeless detectors

High lumi operation => very radiation hard Beam en.smearing σE = 0.77 GeV

Few μm precision, 1μrad precision Beam spot smearing σx,y = 10 μm

Suppress pile-up => add fast timing det. Detector angular resolution = 1, 2 μrad

ATLAS, 1.5 mm (220) and 5 mm (420) from beam

[P.Bussey, FP420]

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Candidates for tracking detectors

• Baseline: “3D” Pixels detectors (S. Parker)Under development for FP420Stanford, VTT, Sintef

• Backup: Silicon strips:Experienced technologyCanberra, Hamamatsu

Jean-François Genat, RP220 meeting, Oct 17-19th 2007 Krakow, Poland

Readout chip (ATLAS)

50m strips (Canberra) Semi-3D detector (VTT, Finland)

3D (Stanford)

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Silicon strips tests in Prague (July 2007)

-5

0

5

10

15

20

25

30 Current (nA)

1 31 61 91 121 151 181 211 Voltage (V)

One strip

Canberra detectors: Reverse current measurement depending on the strip position typically 25 nA OK.Further tests need a full detector wire-bonded and biased.Breakdown voltage 110-130 V OK

Jean-François Genat, RP220 meeting, Oct 17-19th 2007 Krakow, Poland

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Test stand at Saclay

Jean-François Genat, RP220 meeting, Oct 17-19th 2007 Krakow, Poland

- CERN provided a test stand with hybrids equipped with regular ABCDs chips used for the ATLAS SCT thanks to Shaun Roe and Francis Anghinolfi

VME readout module driven by a PC installed at Saclay

- Follow up tests in November:

- Test the ABCDs hybrids provided by CERN at Saclay Get ABCD pedestals

- Wire bond detectors to hybrids at CERN Test bias current

- Test detectors with laser and source at Saclay Get Signal/Noise

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Fast timing detectorsFast development on several fronts for several applications !FP420 and RP220 need to reduce PILE-UP background heavily

At least for H->bb: overlay of 3 events (2 SD + non-diffr. dijets) fakes signal perfectly and

with prob. 1010 x higher than signal. Can be reduced by applying strict central-matching-RP

conditions + fast timing det.

10ps (2-3mm) resol.

may separate different

vertices

Rejection of up to 40

FP420: UTA/ Alberta/ FNAL/ Louvain: first tests with Quartic det. RP220: collaboration with Univ. Chicago, Stony Brook, Argonne and Photonis see also workshop on timing det.: Saclay, 8-9.3.2007, http://www-d0.fnal.gov/royon/timing

200 GHz electronicsMultiChannel Plates Simul. tools

[A.Kupčo and M.T]

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Level 1 TriggerFP420: cannot be put directly into L1 – only in special runs with larger L1 latency

available triggers: 2j, μ (L1 threshold for 2μ is 3 GeV), e, j+lepton

- μ-triggers can save up to 20%

of bb signal

- WW signal saved by lepton triggers

RP220: Can be put into L1: A BIG added value to FP420! Very similar trigger rates

as for foreseen CMS-TOTEM L1 trigger:

CMS-TOTEM L1 trigger STUDY

RP220 L1 trigger study

Total reduction: 10 (RP) x 2 (jet isol) x 2 (2 jets same hemisph as p) = 40

ETjet > 40 && RP220-1side

[A.Pilkington,FP420]

[A.Kupčo,RP220]

[M.Grothe et al., CMS Note 2006-054]

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RP220 in L1

[P. Le Du, RP220]

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Design for RP220

Design for RP220 not yet fixed. Still need to consider:

1) Alignment and calibration: BPMs themselves should be quite precise (about 10 μm?). But we need physics processes to cross-check and also for the detector calibration. The price for that is high: 2 additional vertical RPs.

2) Fast timing detector: not enough space in the current RP (Totem) design because fast timing det. need large radiators to collect a good number of

photons → put movable beam pipe behind RP

3) Size of 3D-Si sensors: what is the best size of sensors in the (x,y) -region of interest wrt yield?

4) L1 trigger: 3D-Si: standard pixel trigger is just YES/NO for the full detector,while we need to know which strip is hit at L1 to measure ξ or mass at L1 →needs to develop a new trigger card. Si-strips: needs to include trigger in ABCNext chip, unfortunately not first

priority for CERN

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Machine induced background

Horizontal beam profiles for nominalbeam optics and momentum spread

σbeam1 = 250 μmσbeam2 = 180 μm

RP220: SIGNAL/Background ~ 10

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RP220 Timetable

In addition to FP420 project, there is a strong complementary program to upgrade the

220 region with horizontal pots at ATLAS, which adds significant value to FP420

• Aim is to submit proposal for a sub-detector upgrade this year for 420 and 220 upgrades

• If accepted by ATLAS (and/or CMS) this would lead to TDR from experiment to LHCC in early 2008

• RP220 Roman Pots and baseline detectors designed to be ready in 2010

• Collaboration between FP420 and RP220 getting more intensive. There was

a common and fruitful meeting in Paris last September

NEW COLLABORATORS WELCOME!

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B A C K U P S L I D E S

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