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Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1.Strangeness at LHC...

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Strange Prospects for LHC energies Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1. Strangeness at LHC energies Extrapolations / Motivations 2. Strange probes with ALICE Detector and Simulations 3. First p+p Collisions and beyond First measures to target Hot Quarks 2006 Boris HIPPOLYTE for the ALICE Collaboration, IPHC Strasbourg
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Page 1: Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1.Strangeness at LHC energies Extrapolations / Motivations 2.Strange probes with.

Strange Prospects for LHC energiesStrange Prospects for LHC energies

Hot Quarks 2006 - Sardinia - 16/05/06

1. Strangeness at LHC energies Extrapolations / Motivations

2. Strange probes with ALICE Detector and Simulations

3. First p+p Collisions and beyondFirst measures to target

Hot Quarks 2006

Boris HIPPOLYTE for the ALICE Collaboration, IPHC Strasbourg

Page 2: Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1.Strangeness at LHC energies Extrapolations / Motivations 2.Strange probes with.

05/2006 Hot Quarks 2006 - Villasimius 2

Wroblewski factor extrapolation to LHC energies

Extrapolation at the LHCA+A ~0.45 p+p ~0.25

< >2

< >+< >λ s

ss

uu dd

Wroblewski factor:

Using thermal model description with corresponding system formalism (canonical or grand-canonical), extrapolation is straightforward.

Data compilation using Becattini et al., PR C64 (2001) 024901, hep-ph/0002267 and references therein

Page 3: Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1.Strangeness at LHC energies Extrapolations / Motivations 2.Strange probes with.

05/2006 Hot Quarks 2006 - Villasimius 3

Excitation functions of hyperons yields in A+A

dN/dy extrapolations at the LHCfor : 10~30for : 3~6for : 0.4~0.7

Expected modificationstotal multiplicity scalingnon-equilibrium scenario

Page 4: Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1.Strangeness at LHC energies Extrapolations / Motivations 2.Strange probes with.

05/2006 Hot Quarks 2006 - Villasimius 4

Equilibrium vs non−equilibrium scenarii in A+A

Eq. [ Oeschler et al., to be published ] [ Andronic et al., nucl-th/0511071 ]Non Eq. [ Rafelski et al., Eur. J. Phys. C45 (2006) 61 ]

Expectations at the LHC energies (eq.):

Tch ~170 MeV B ~1 MeV

Scenarii for s

Calculations fromKraus et al., (Eq.)Rafelski et al., (Non Eq.)

Page 5: Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1.Strangeness at LHC energies Extrapolations / Motivations 2.Strange probes with.

05/2006 Hot Quarks 2006 - Villasimius 5

Hadronization via coalescence at LHC energiesFries and Müller, EJP C34, S279 (2004)

Calculation implies assumption on transverse radial flow extrapolation

Amplitude for mixed ratio is the same at LHC than for RHIC but the limit is pushed to higher pT

Probing baryon/meson differences at LHC energies implies PID over a large pT range and ALICE is perfectly designed for this.

But first ALICE data will be elementary collisions check magnitude of this behaviour then assume

coalescence mechanisms if needed.

Page 6: Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1.Strangeness at LHC energies Extrapolations / Motivations 2.Strange probes with.

05/2006 Hot Quarks 2006 - Villasimius 6

The central detectors of the ALICE experiment

High-MomentumParticle Identification

Detector

PHOtonSpectrometer

Time ProjectionChamber

Inner Tracking System

Time Of Flight

Transition-Radiation Detector

-0.9< < 0.9azimuth 2length 5 mactive volume 88 m3

-0.9< < 0.9azimuth 2length 7.45 mactive area 141 m2

-0.6< < 0.6azimuth 57.61°

active area 10 m2

-0.9< < 0.9silicon layers 6

pixel/drift/strip 2/2/2 cells(M) 9.84/23/2.6

area 0.21/1.31/4.77 m3

Page 7: Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1.Strangeness at LHC energies Extrapolations / Motivations 2.Strange probes with.

05/2006 Hot Quarks 2006 - Villasimius 7

Fiducial volume and reconstruction strategies

Standard / extended fiducial volume leading to high purity / efficiency for strange particle reconstruction

Expected raw spectra extrapolated to 107 central events (first year Pb+Pb data).

Page 8: Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1.Strangeness at LHC energies Extrapolations / Motivations 2.Strange probes with.

05/2006 Hot Quarks 2006 - Villasimius 8

PID Range of ALICE at mid−rapidityEstimates as in the Physics Performance Report Vol.II

for one year of Pb+Pb data-taking (central events)

107 central Pb+Pb events

Page 9: Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1.Strangeness at LHC energies Extrapolations / Motivations 2.Strange probes with.

05/2006 Hot Quarks 2006 - Villasimius 9

Baryon/Meson pT ratio in p+p @ 630 and 1800 GeV Extracting mixed ratio from UA1 spectra (1996) and from CDF spectra (2005)

Ratio vs pT already surprisingly high in p+p data at high energies

Page 10: Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1.Strangeness at LHC energies Extrapolations / Motivations 2.Strange probes with.

05/2006 Hot Quarks 2006 - Villasimius 10

Extrapolations and PYTHIA: p+p @ 14 TeV LHC extrapolation: “ATLAS tuning” min. bias and underlying event

Different sets of parameters (tuning) for LHC energies:a) extrapolation of Tevatron data (CDF tune A);b) data for jets and high-pT phenomena;

Low pT description implies specific treatment a) O.M.I (v6.2): different pars for und. event & min. bias first PYTHIA v6.2 description of soft domain @ LHC (different rescaling factor for und. event)b) N.M.I in PYTHIA 6.3: multiple part-part int. (+ i/fsr)

simulation samples: 1M p+p events

Page 11: Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1.Strangeness at LHC energies Extrapolations / Motivations 2.Strange probes with.

05/2006 Hot Quarks 2006 - Villasimius 11

PYTHIA Baryon/Meson pT ratio: p+p @ 14 TeV

Ratios and differences between min. bias and underlying event description

Checking uncertainty for parameters energy dependence: PYTHIA authors’ suggestions : 2~0.08 0.25

Comparison between ATLAS tuning and underlying event description

Little light/strange flavor dependence in this region Underlying event description needed/enough for production of hadrons in intermediate pT region ?

Page 12: Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1.Strangeness at LHC energies Extrapolations / Motivations 2.Strange probes with.

05/2006 Hot Quarks 2006 - Villasimius 12

Recent extrapolation from the Les Houches Working Group

Major evolutions for LHC extrapolation: PYTHIA: v6.2 v6.3 New multiple interaction (N.M.I) treatment part.-part. interactions and i/fsr

PDF: CTEQ5 CTEQ6main change in gluon distribution function visible at low Q2

preprint hep-ph/0604120

Better but still missing a factor of ~2 wrt RHIC UA1 CDF extrapolations

investigating NLO contribution, baryon creation mechanisms (diquark, popcorn

scenario, and gluonic baryon junctions).

Page 13: Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1.Strangeness at LHC energies Extrapolations / Motivations 2.Strange probes with.

05/2006 Hot Quarks 2006 - Villasimius 13

Conclusion

Using strangeness as a powerfull probe at LHC energies

with the PID capabilities of the ALICE experiment

a) Equilibrium vs non-equilibrium scenariob) Hadronization and coalescence validity at LHC

strange particles (specific probes and PID) !

First measurements of strange particles in p+p to obtain:

1) Interesting for studying baryon production mechanisms

2) Constrains for underlying event description3) Set references for Pb+Pb (mandatory)

WARNING: minimum bias trigger for p+p !

Page 14: Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1.Strangeness at LHC energies Extrapolations / Motivations 2.Strange probes with.

05/2006 Hot Quarks 2006 - Villasimius 14

Complementary slides

Page 15: Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1.Strangeness at LHC energies Extrapolations / Motivations 2.Strange probes with.

05/2006 Hot Quarks 2006 - Villasimius 15

Hard/soft/min.bias CDF spectra: p+p @ 1800 GeV Extrapolation using CDF strange particle publication: PR D72 (2005) 052001

Main difference between preprint and final publication is a comparison with PYTHIA 6.216

After PYTHIA tuning with pions, the bottom line is min. bias spectra is close but K0s is slightly

overestimated

Page 16: Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1.Strangeness at LHC energies Extrapolations / Motivations 2.Strange probes with.

05/2006 Hot Quarks 2006 - Villasimius 16

Table of Parameters for v6.214

References: QEHwg05 AliPythia Config.C

ATLAS tune OldUEr1 OldUEr2 OldUEr3 Simple Popcorn Advanced PopcornInput Page: Default= (+ATLAS) (+ATLAS)

(p/320)

MSTP(51) (p196/205:D=7) kCTEQ5LMSTP(52) (p197/205 :D=1)MSTP(68) (p301/322: D=1/3) 1MSTP(70) (p/322: D=/1)MSTP(81) (p316/347: D=1) 1 1 1 1MSTP(82) (p317/348: D=1/3) 4 4 4 4MSTP(88) (p/350: D=1) 2 2MSTJ(1) (p363/401: D=1) 1 1MSTJ(12) (p364/402: D=2) 3 5

(p371/409) (p372/410)

PARP(67) (p302/323: D=1/4) 1 4 4 4PARP(71) (p302/323: D=4) 4 4 4PARP(82) (p320/353: D=1.9/2.0) 1.8 2 2 2PARP(83) (p320/354: D=0.5) 0.5 0.5 0.5 0.5PARP(84) (p320/354: D=0.2/0.4) 0.5 0.4 0.4 0.4PARP(85) (p320/354: D=0.33/0.9) 0.33 0.9 0.9 0.9PARP(86) (p320/354: D=0.66/0.95) 0.66 0.95 0.95 0.95PARP(89) (p320/354: D=1000/1800) 1000 1800 1800 1800PARP(90) (p321/354: D=0.16) 0.16 0.25 0.16 0.08PARJ(1) (p368/406: D=0.1) Dx1.2 Dx2PARJ(18) (p369/407: D=1) 0.19PARJ(81) (p299/319: D=0.29) 0.29 0.29 0.29

v6.2146.215References: 6.215 / 6.400

PYPARS Switchs

PYPARS Parameters

6.4

Page 17: Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1.Strangeness at LHC energies Extrapolations / Motivations 2.Strange probes with.

05/2006 Hot Quarks 2006 - Villasimius 17

Min. Bias CDF parameter sets: p+p @ 1800 GeV

Page 18: Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1.Strangeness at LHC energies Extrapolations / Motivations 2.Strange probes with.

05/2006 Hot Quarks 2006 - Villasimius 18

PYTHIA flavor dependence for Baryon/Meson pT ratio

Page 19: Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1.Strangeness at LHC energies Extrapolations / Motivations 2.Strange probes with.

05/2006 Hot Quarks 2006 - Villasimius 19

New multiple interaction description andunderlying event tuning parameters

ε

T min 2( ) (1.9 GeV)

1TeV

sp s

2T min

/ 4 2hard T min T2

T

( )s

p

dp dp

dp

hard parton-parton hard scattering cross section and

total rate given pQCD (validity?)

divergent for pTmin 0

pTmin assumed to increase with s just as total hadronic cross

section: power ≈ 0.08

New M.I: each interaction has its own set of isr and fsr and not only the hardest parton-parton interaction

Page 20: Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1.Strangeness at LHC energies Extrapolations / Motivations 2.Strange probes with.

05/2006 Hot Quarks 2006 - Villasimius 20

Table of Parameters for v6.326

References: QEHwg05 AliPythia Config.C

Min. Bias NewUEr1 NewUEr2 NewUEr3 Simple Popcorn Advanced PopcornInput Page: Default= (+Min. Bias) (+Min. Bias)

(p/320)

MSTP(51) (p196/205:D=7) (->10042) kCTEQ6L kCTEQ6L kCTEQ6L kCTEQ6LMSTP(52) (p197/205 :D=1) 2 2 2 2MSTP(68) (p301/322: D=1/3) 1 1 1 1MSTP(70) (p/322: D=/1) 2 2 2 2MSTP(81) (p316/347: D=1) 1 1 1 1MSTP(82) (p317/348: D=1/3) 4 4 4 4MSTP(88) (p/350: D=1) 2 2MSTJ(1) (p363/401: D=1) 1 1MSTJ(12) (p364/402: D=2) 3 5

(p371/409) (p372/410)

PARP(67) (p302/323: D=1/4)PARP(71) (p302/323: D=4)PARP(82) (p320/353: D=1.9/2.0) 2.3 2.6 2.6 2.6PARP(83) (p320/354: D=0.5) 0.5 0.5 0.5 0.5PARP(84) (p320/354: D=0.2/0.4) 0.5 0.3 0.3 0.3PARP(85) (p320/354: D=0.33/0.9) 0.9 0.9 0.9 0.9PARP(86) (p320/354: D=0.66/0.95) 0.95 0.95 0.95 0.95PARP(89) (p320/354: D=1000/1800) 1800 1800 1800 1800PARP(90) (p321/354: D=0.16) 0.2 0.24 0.16 0.08PARJ(1) (p368/406: D=0.1) Dx1.2 Dx2PARJ(18) (p369/407: D=1) 0.19PARJ(81) (p299/319: D=0.29) 0.29 0.29 0.29

PYPARS Switchs

PYPARS Parameters

References: 6.215 / 6.400

6.215 v6.3266.4

Page 21: Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1.Strangeness at LHC energies Extrapolations / Motivations 2.Strange probes with.

05/2006 Hot Quarks 2006 - Villasimius 21

PDF comparison CTEQ6 vs. CTEQ5

J. Pumplin et al., preprint hep-ph/020195

Page 22: Strange Prospects for LHC energies Hot Quarks 2006 - Sardinia - 16/05/06 1.Strangeness at LHC energies Extrapolations / Motivations 2.Strange probes with.

05/2006 Hot Quarks 2006 - Villasimius 22

Extrapolations for LHC comparison: ATLAS tuning vs. Les Houches working group Min.bias tuning

preprint hep-ph/0604120


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