project na60:part deux

05-07-2005 David J Hover

Project NA60:Part Deux

HBT Interferometery

Advisors: ->Atila Neves: Lisbon, Portugal

->Sanja Damjanovic: University of Heidelberg

->Hans J. Specht: University of Heidelberg

->Hiroaki Ohnishi: Riken, Japan

NICE

->Fixed Target (Lead, Indium) collisions run at the SPS (Super Proton Synchotron). Several Runs of Data over last few years. Currently in analysis phase.Notice Name, NA60. No, there wasn't 60 previous projects performing the same task but with NA60 a radiation hard pixel silicon detector was added PC muon chamber. This provided better vertex and momentum resolution.


Physics Motivation:Review• Quark-Gluon Plasma (QGP)

– QGP describes the early, Post-Big-Bang universe.– Want to map out point (phase transition) where Deconfined

Patronic Matter becomes Confined Hadronic Matter– Freeze out temperature? Fireball radius?– Significance evidence shown in past SPS and offsite

experiments but need to nail down facts.

What is the Threshold???

NICE

->We've all heard of it...but to most, including me, it is still just a buzz word like nanotech and quantum computers.->At a certain high temperature, or high density, fireball forms and all quarks are deconfined->Dimuon events is the major trigger for data intake. Reconstruction works by examining muons in MC and matching them to those found in the VT. Next find momentum which allows us to calculate the invariant mass of the mother particle.


Bose-Einstein Correlations (HBT)

• Glorified double slit experiment using intensity instead of amplitude.– Argues two similarly charged bosons are correlated in the same event.– Mixed events = not correlated

• Correlate a variety of variables: Qo,Ql,Qs,Qinv and Qt. (240 plots!!!)• Separate by different charge combinations and targets

21

1 2

{ }( )

{ }

pP

p p

n n SC q

n n B


Is there a Correlation?

BACKGROUND

More pairs the better: decreases error but with

increase in time.

SOURCE

Or

Correlated

C=S/B: MM is Correlated?

C=S/B: PM not Correlated?


We Don’t Know Yet

• Coulomb Corrections: – Trajectory/momentum-difference is also perturbed by

pesky electromagnetic forces. We must remove them.

– PM dataset has same magnitude of perturbance but without correlation. Extract the facts!

• Momentum Smearing:– How does limited momentum resolution, especially at

small differences, affect correlation?– Using event generation and reconstruction in MC to

test.


“Fun” Slide

Presentation Inspired By:

They wear cats as hats in Switzerland.

Contrary to libelous rumors, I broke my arm saving 30 starving orphans

from a burning building. Who wants to sign it?????

“The universe works on a math equationthat never even ever really ends in the endInfinity spirals out creation. We're on the tip of its tongue, and it is saying: We aint sure where you stand. You aint machines and you aint land”

project na60:part deux

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