FP@LHC, UK 8-12 Dec 2007 Alignment and Calibrations K. Goulianos 1

Alignment and Calibrations Konstantin GoulianosThe Rockefeller University

Forward Physics at the LHCManchester, UK, 8-12 Dec 2007

FP@LHC, UK 8-12 Dec 2007 Alignment and Calibrations K. Goulianos 2

The Forward Detectors of CDF

FP@LHC, UK 8-12 Dec 2007 Alignment and Calibrations K. Goulianos 3

The MiniPlugs @ CDF

FP@LHC, UK 8-12 Dec 2007 Alignment and Calibrations K. Goulianos 4

MiniPlug Construction

About 1500 wavelength shifting fibers of 1 mm dia. are ‘strung’ through holesdrilled in 36x¼” lead plates sandwiched between reflective Al sheets and guided

into bunches to be viewed individually by multi-channel photomultipliers.

FP@LHC, UK 8-12 Dec 2007 Alignment and Calibrations K. Goulianos 5

Measurements w/the MiniPlugs

ADC counts in MiniPlug towersin a pbar-p event at 1960 GeV.• “jet” indicates an energy cluster and may be just a hadron.• 1000 counts ~ 1 GeVMultiplicity of SD and ND events

ENERGY

MP TOWER

STRUCTURE

MULTIPLICITY

@ POSITION

NIM A 430 (1999)

NIM A 496 (2003)

NIM A 518 (2004)

s

eEΣξ

iηiTiCAL

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RPS Tracking Calibration

withRPS

tracking

0.055<

ξRPS<0.060 slice

FP@LHC, UK 8-12 Dec 2007 Alignment and Calibrations K. Goulianos 7

Diffractive Dijet Signal

s

eEΣξ

iηiTiCAL

Low InstLum ~0.5E302002-2003 data: <InstL> ~1.5E31

constantlogξd

dσ

ξ

1

dξ

dσ

BG ND dijet + soft SD

FP@LHC, UK 8-12 Dec 2007 Alignment and Calibrations K. Goulianos 8

Dynamic Alignment of RPS DetectorsMethod: iteratively adjust the RPS X and Y offsets from the nominal beam axis until a maximum in the b-slope is obtained @ t=0.

Limiting factors

1-statistics2-beam size3-beam jitter

@ CDF W/lowlum data μm30

FP@LHC, UK 8-12 Dec 2007 Alignment and Calibrations K. Goulianos 9

PL Balance MW

TEmissingν

Tp

calL

pbeam

pξ)(1νLp

S/iηe

iTEiΣξ

CAL

MW

MW - data vs. expectation

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ETjet Calibration

Calibrate Etjet or , as you

wish!

use RPS information to check jet energy corrections

FP@LHC, UK 8-12 Dec 2007 Alignment and Calibrations K. Goulianos 11

thank you