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Plans/ideas for next funding period• ALICE upgrades

– Discussion has started– Timeslots for potential upgrades

» 2013: ½ year shutdown (minor upgrades)» 2016/2017: 1 year shutdown (major upgrades, e.g. beam line modifications)

– Potential projects» New pixel layers (close to beam, higher resolution)» Forward calorimeter

• Compressed Baryonic Matter (CBM) experiment at FAIR/GSI (ESFRI project)

– First beam: not before 2015

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ALICE upgrade: forward physics at LHC

• Measurements at small angle/large pseudorapidity

• Main physics topic– p(d)+A

» low-x region » study of ”cold”

nuclear matter » probing the

initial condition

310-6 10-4 10-2 100

x

108

106

104

102

100

M2 (

GeV2

)

Kinematics

RHIC example• At 4° (y~3 for pions) and pT=1 GeV/c

one can reach values as low of x2 ~ 10-4

• This is a lower limit, not a typical value: most of the data collected at 4° would have x2~0.01

Guzev, Strikman, and Vogelsang (hep-ph/0407201)

y=rapidity of (xL, k) system

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2

21 process

22 process

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Initial and final effects – dAu

• Initial effectsWang, Levai, Kopeliovich, Accardi

• Especially at forward rapidities:

Eskola, Kolhinen, Vogt, Nucl. Phys. A696 (2001) 729-746HIJINGD.Kharzeev et al., PLB 561 (2003) 93

• OthersB. Kopeliovich et al., hep-ph/0501260J. Qiu, I, Vitev,hep-ph/0405068R. Hwa et al., nucl-th/0410111D.E. Kahana, S. Kahana, nucl-th/0406074

“Cronin effect”Initial state elastic multiple scattering leading to Cronin enhancement (RAA>1)

Gluon saturationdepletion of low-x gluons due to gluon fusion”Color Glass Condensate (CGC)”

broaden pT

Nuclear shadowingdepletion of low-x partons Anti

ShadowingShadowing

r/ggg

Suppression due todominance of projectile valence quarks, energy loss, coherent multiple scattering, energy conservation, parton recombination, ...

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Comparison pQCD vs CGC

d’Enterria

Conclusions (dAu at RHIC)• The suppression and in particular the inversion vs. centrality of RdAu at high rapidity may be a signature for the gluon saturation and the small-x evolution.• Stronger gluon shadowing -> EPS08 • Alternate explanations e.g. suppression due to large xF effects work quite well too (suppression effects at SPS!)

LO pQCD calculation (nuclear shadowing) vs CGC

Global analysis of nPDFs including BRAHMS data

K.J. E

skola, H. P

aukkunena, C.A

. Salgadoc,

hep-ph 08020129v1 (2008)

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LHC prospects• Predictions

• pseudorapidity asymmetry for d+Pb -> pi0+X at 8.8 ATeV for |eta| < 0.9 and 2.4 < |eta| < 4.0.• Solid line: EPS08 nPDFs, dashed line: HIJING with the inclusion of multiscattering, dot-dashed line: HIJING without multiscattering.

A. Adeluyi et al., arXiv:0808.0682v1

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Upgrade idea

• Forward meson spectrometer– Goals

» Study low-x phenomena» Jet quenching in less dense

matter» Pt spectra of identified

particles» Nuclear modification factor» Correlation studies

forward-midrapidty– Requirements

» x < 10-5

» Acceptance• y 4...5• 0 GeV/c < pt < 30 GeV/c

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Upgrade idea

• Forward meson spectrometer– Conceptual design

» EM-Calorimeter for gamma, pi0, eta, J/Psi at y=5 » O(10) meters away from IP » large dynamic range» high occupancy (A+A)» two separation (0 -> 2 kinematics)

cm 2cm 20m) 50(L00038.00038.0

74274(GeV/c) 101(GeV/c)

min2

tot

T

pp

highly segmented (also longitudinally) tracking calorimeter ala CALICE?

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Challenge• Where to put the calorimeter

– Large distance from IP (50m)» ”Standard” calorimeter design» Conflict with LHC magnets, new beamline

– Close to the IP (5-20m)» Very high segmentation (ala CALICE)

FoCal

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CBM experiment at FAIR/GSI • Facility for Antiproton and heavy Ions

Research• Funded, construction will start soon• CBM experiment

– super-dense baryonic matter– in-medium properties of hadrons

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Conjectured Phase Diagram for Nc = 3

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RHIC

LHC

SPS

FAIR

AGS

Confined

No Baryons

N ~0(1)

Not Chiral

Confined

Baryons

N ~ NcNf

Chiral

Debye Screened

Baryons Number

N ~ Nc

Chiral

2

Color Superconductivity

Liquid Gas Transition

Critical Point

Baryon energy density ~ Meson energy density

Quark Gluon Plasma

Quarkyonic Matter

Confined Matter

T

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CBM

13

CBM

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CBM• Physics interest

– QCD critical point - fluctuations– Chiral symmetry restoration – in-medium modifications of hadrons

• Possible instrumentation activities– Monolithic Active Pixel Sensor readout (3D stacking)– Projectile Spectator Detector (forward calorimeter)– Online event reconstruction