Transcript PHENIX Physics Agenda and Detector Upgrades

PHENIX Physics Agenda and
Detector Upgrades
Axel Drees, SUNY Stony Brook
QCD at RHIC 12/8/2000
 Overview
 Completion of the PHENIX “baseline” program

heavy ion and spin physics program

completion of PHENIX detector

running plan for the next 5 years
 Physics beyond the reach of the baseline detector

heavy ion physics program

spin physics program

proton-Nucleus Program
 Detector upgrades

improvements of existing detectors

concept for additional detector systems

technical solutions

cost guesstimate and timelines
Overview:
PHENIX Physics Program for the Next Decade

first phase




complete initial heavy ion and spin physics program
complete experimental setup
enhance detector capabilities
second phase:

heavy ion physics:
systematic study of high T, r QCD
address important issues not or only partially
covered by original detector
• lepton pair continuum below and above the f
• charm and bottom production
• Drell-Yan continuum
• upsilon spectroscopy: Y(1S), Y(2S), Y(3S)
• QCD energy loss , g-jet correlations and more

spin structure of the nucleon:
enhance capabilities, increase kinematical acceptance
• W-boson production
• heavy flavor production
• inclusive jet production
• gluon distribution function
• transversity
• spin effects in fragmentation

proton-nucleus physics
exploit the unique features of RHIC
• quark and gluon content of nuclei
• parton density at small x
• parton energy loss as fct of (A, pt, x)
• hard diffractive processes
Axel Drees
23-May-16
PHENIX Heavy Ion Program
Required Available
Timescale
Initial Collision
Probe
Hard Scattering
Single "jet" via leading particle
photon + "jet"
Deconfinement
E or W
E and W
Yes
Yes?
N, S, E+W
N,S
Observation
No
r, w, f mass, width
E+W
Yes?
f branching ratios
E+W
Yes?
E
E
Yes
Yes
High-Mass Vector Mesons
J/Y , Y ' screening
U (non)screening
Chiral Restoration
Elements Year-1?
Low-Mass Vector Mesons
QGP Thermalization Photons
0
p , h, h '
continuum direct; very soft
QGP Thermalization Dileptons
non-resonant: 1-3 GeV
soft continuum, <1 GeV
N,S,E+W
E+W
Yes?
No
QGP Thermalization Heavy Quark Production
open charm
open charm via single lepton
Hadronization
E
E
E
Yes
Yes
Yes
E, MVD
Yes
Global Variables
ET, dN/dy
Axel Drees
No
Yes
Hadrons
HBT Interferometry, p /K
strangeness production: K, f
spectra of identified hadrons
Hydrodynamics
(N or S) + E
N,S,E
23-May-16
PHENIX “Core” Program
designed to measure penetrating “rare” probes

central detector:
vector mesons
photons
high pt pions
w, f, J/y -> e+e-
vector mesons
J/y, U -> m+m-
po, p+, p-

muon arms:

combined central and muon arms:
charm production DD -> em
focus on electromagnetic probes
well matched to requirements of spin physics program
Axel Drees
23-May-16
PHENIX configuration for 2000

West Arm

tracking:
DC,PC1
electron ID:
RICH, EMCal
photons
EMCal



East Arm

tracking:
DC, PC1, TEC, PC3
hadron & electron ID:
RICH,TEC, TOF,
EMCal
photons:
EMCal



Other Detectors


vertex & centrality:
ZDC, BBC,
partially equipped systems
MVD, MuID
initial physics program:
Axel Drees
global observables
identified hadron spectra
inclusive high pt ~ 4 GeV/c spectra
inclusive electrons ~ 3 GeV/c
23-May-16
Preliminary Physics Results
identified hadrons:
e+
p+
h- and p0:
inclusive
K+
p
p
Ke-
p-
inclusive electrons:
Axel Drees
23-May-16
Enhanced Setup for Next Run 2001-2002

West Arm



tracking:
DC,PC1, PC2, PC3
electron ID:
RICH,
EMCal
photons
EMCal

East Arm




tracking:
DC, PC1, TEC, PC3
hadron& electron ID:
RICH,TEC, TOF, EMC
photons:
EMCal
Other Detectors


Vertex
& centrality:
ZDC, BBC,
MVD
South Arm


tracking:
MuTr
muon ID:
MuID
full heavy ion program and major fraction of spin program:
vector mesons f and w
J/y production
direct photon out to 10 GeV (Au-Au) or 30 GeV (pp)
high pt inclusive out to 10 GeV
jet-like angular correlation
Axel Drees
23-May-16
2003 and Beyond

additional detector upgrades:


PC2
TRD/TEC
tracking:
east arm PC2
electron ID:
east arm TRD/TEC

North Arm



tracking:
MuTr
muon ID:
MuID
DAQ and Trigger



de-multiplexing
L2 trigger
upgraded EVB
high statistics studies with 2 1027 cm-2s-1 Au-Au and 2 1032 cm-2s-1 pp:
Au-Au
p-p
increase pt range to 20 GeV direct g to 40 GeV
precision J/y and y’
high mass Drell-Yan pairs
first data on Y
bottom production
g-jet correlations
W-boson production
Axel Drees
23-May-16
Upgrades of Baseline Setup
significantly enhance detector performance
at moderate effort and cost

PC2 east:


$500k
in beam experience:
redundant (3d) tracking needed to suppress no-vertex background
vital for high pt > 6 GeV/c and jet-jet correlations
TRD/TEC:
$700k

extend electron identification to pt > 6 GeV

p / K separation above 2 GeV/c ??
Axel Drees
23-May-16
Other Possible Baseline Upgrades

DAQ and Trigger






$3,000k
issue: tracking at highest multiplicities
need to wait for in beam experience
TRD/TEC for west arm


increase rate capability as luminosity increases
includes needs for second phase upgrades
anode readout for MuTr

partially funded + 800k
$1300k
extended electron identification
improved momentum resolution
pre-shower detector



increase radiation length  improve energy resolution
longitudinal segmentation  improve hadron rejection
higher granularity  improve g /po separation
Axel Drees
23-May-16
Proton-Nucleus Physics
has been discussed in length at previous workshop

there are no p-A data at s = 200 GeV

has been essential in understanding “non-exotic”
multi-body effects:



Strangeness enhancements
J/Y production/absorption
Gluon shadowing
example:
Drell Yan pair acceptance
and
statistical errors for 2x 15 weeks
pp and pd running
 FNAL E866
 MMN
 MMS
 MMS+MMN

Central
Axel Drees
23-May-16
Possible Run Plan
assume ~22 weeks/year heavy ions and
~10 weeks/year polarized protons

Year-2: (2001-2002)




Year-3: (2003)

High luminosity Au+Au
(60%) of HI time
High luminosity light ions (40%) of HI time
Detailed examination of A*B scaling of J/Y yield

DG/G production run with polarized proton

first p-A measurements



Year-4: (2004)





Au+Au, crude p-p comparison run
first look at J/Y production, high pT
first polarized proton run
p-d/p-p comparisons
baseline data for rare processes
W-boson production with polarized protons
Drell-Yan study in p-A
Year-5: (2005)



“Complete” p-A program with p-Au
energy scan
Systematic mapping of parameter space
Axel Drees
23-May-16
Beyond the PHENIX Baseline Program
profit from investments made,
exploit further possibilities to measure rare processes:
electromagnetic radiation and hard scattering

Heavy Ion Physics

shift of focus from establishing the existence of QGP and
first studies of its properties
to systematic study of QCD high T, r

focus on key measurements not or only partially
addressed by original PHENIX setup:
pair continuum below and above the f
charm and bottom production
Drell-Yan continuum
upsilon spectroscopy, Y(1S), Y(2S), and Y(S3)
QCD energy loss via g -jet angular correlations
for these measurements
the PHENIX central and muon spectrometer are essential
but not sufficient !
Axel Drees
23-May-16
Continuum Lepton-Pair Physics
resonances addressed by
original PHENIX setup
pair continuum
not yet
accessible at RHIC

large excess of continuum radiation observed in heavy ion
collisions at CERN



has been attributed to melting of resonance's, dropping masses
 look at vector mesons w, f
however, recent theoretical discussion focuses again on thermal
radiation
q
e, m -
q
e, m +
anomalous lepton pair production in pp collisions not excluded


excluded only within ~15-30% systematic errors at low energies
completely open at higher energies!
Axel Drees
23-May-16
Electron Pairs at Low Mass
in p-Be collisions well described by
neutral meson decays within 15-30%
systematic errors
Dalitz decays:
p  ge+eh  ge+ew  p e+e-
vector mesons: r  e+ew  e+ef  e+e-
anomalous lepton pairs
at s = 200 GeV??
enhanced e+e- production in Pb-Au collisions:
at CERN SPS
0.25 < m < 0.75 GeV
D/S ~ 2.6  0.5  0.6
• threshold near 2mp
• different spectral shape
• no r resonance structure
Axel Drees
23-May-16
Radiation from Hot and Dense Matter
pp-annihilation contribution

p
e-
r*
g*
p
e+
pp resonance structure: r-meson
formfactor described by vacuum values
mr = 770 MeV
Gr = 150 MeV
characteristic shape
not observed in data
solution:
modification of
meson properties in
dense matter


melting r resonance
dropping r mass (Brown-Rho scaling)
data seem to require modification of meson properties
related to chiral symmetry restoration
Axel Drees
23-May-16
More Recent Calculations

data stimulated more than 100 theoretical paper
 origin of continuum radiation not yet clarified

recent new development:
thermal radiation from QGP
(Schneider & Weise)
a lot of interesting physics in lepton pair continuum
Axel Drees
23-May-16
Experimental Challenge

huge combinatorial pair background due to copiously
produced photon conversion and Dalitz decays :
photon conversion
g  e+ e false
Dalitz decays
“combinatorial pair”
o
+
p  g e e
In PHENIX:
combinatorial background
factor > 1000 larger than signal
Note: resonances f and w
can be measured due to
excellent mass resolution
need rejection of > 90% of g  e+ e - and po  g e+ e  active recognition and rejection of background pairs

Axel Drees
23-May-16
Dalitz and Conversion Rejection

mass of virtual photon small  small pair opening angle
central arm ~ 200 MeV momentum cut off
~ 70% of pairs
one track > 200 MeV
2nd track < 200 MeV
can not be reconstructed
in central arms

need tracking at low momentum
and sensitivity to opening angle
cut
rejection
degree
%
pion with
with
pileup e/p   e/p  
%
24
3
0.5
10
77
20
89
79
11
2
30
94
100
23
5
40
96
100
39
8
40

detector requirements:


possible mode of operation
tracking in low or field free region to preserve opening angle
tracking and electron ID
over 2x (25+90+25) degree  Df ~ 2p
Axel Drees
23-May-16
Direct Radiation vs Open Charm

NA50: mm -pairs at intermediate masses (1 < m < 3 GeV)
M.C. Abreu et al, Nucl.Phys A661 (99) 538c
R.Rapp & E.Shuryak, Phys.Lett B473 (2000) 13
thermal radiation
(Ti ~220 MeV)
q
m-
q
m+
or
open-charm
enhanced by
factor ~3-4
Question: can PHENIX baseline pin down charm x-section
accurate enough?
via inclusive e,m and ee, mm, em pairs
Axel Drees
23-May-16
Precision Vertex Tracking to Detect Charm

physics interest in charm and bottom production
charm and bottom decays compete with thermal pair
radiation
charm can be produced thermally  charm enhancement
probably not at CERN, but maybe at RHIC energies
best reference for J/y and Y production
once charm and bottom are known
 access to Drell Yan continuum





displaced vertex distinguishes prompt electrons (thermal)
form decay electrons (charm and bottom)
m
GeV
D0 1865
D± 1869
ct
mm
 eX
%
125
317
6.75
17.2
e
D
B0 5279
B± 5279
464
496
5.3
5.2
e
ct
Au
Au
easy to achieve >20 mm tracking resolution
issue: multiple scattering in first detector layer

possible solutions to reduce effect of multiple scattering:


high pt cut
move first detector as close to beam pipe as possible
Axel Drees
23-May-16
Measurement of Displaced Vertex

toy detector model: 2x 2p silicon pixel tracking layers
standard detectors with 50x425 mm2
a) R ~ 2.5 cm
X/Xo ~ 1%
srf ~ 15 mm
s ~ 115 mm
b) R ~ 10 cm
ditto
tracking resolution in rf:
detector:
sd ~ 16 mm
mult. scattering: sms ~ 28 mm
} s ~ 32(at mm
1 GeV/c)
d
occupancy of inner layer < 1%

PYTHIA simulation of D mesons for s = 200 GeV





track decay electrons
simulate multiple scattering in layer a)
simulate detector resolution
pt cut of 750 MeV
track back to vertex
Axel Drees
23-May-16
Study for Decay Electron Detection
displacement to vertex in x-y projection

decay electrons




prompt electrons
(same electrons but
tracked to decay vertex)


Axel Drees
retrieve decay length
with multiple scattering
with detector resolution
point back to vertex
within 100 mm
what works for D’s
definitely will work for B’s
given sufficient luminosity
23-May-16
Upsilon Spectroscopy
Upsilon

original PHENIX capability:
Y(1S)
Y(2S)
mass
(GeV)
9.460
10.023
Br(mm)
%
2.48
1.31
relative
yield
1
0.36
Y(3S)
10.355
1.81
0.27
north muon arm:
sm ~ 190 MeV
south muon arm
sm ~ 240 MeV
22 week of Au-Au at 2 1026 cm-2s-1
total of ~ 400 Y decays
(~ 1/10 in central arms)

luminosity upgrade to 8 1026 cm-2s-1 or 8 1027 cm-2s-1



muon spectrometer accumulates ~ 16000 Y per 22 weeks
central spectrometer accumulates ~ 2000 Y per 22 weeks
improved momentum resolution in central spectrometer
(shown later in this talk)
CDF data
~ 1000 Y
PHENIX comparable to CDF:
2 Y
sm ~ 40 MeV
Axel Drees
23-May-16
Jet-Quenching and QCD Energy Loss
Suppose we find indications for jet quenching at RHIC
next step: gain detailed understanding of QCD energy loss
systematic studies of many questions:






How accurate can we measure dE/dx ?
How does dE/dx depend on x?
How does dE/dx depend on pt?
Do gluons lose more energy than quarks?
What is the flavor dependence of dE/dx?
Is there dE/dx in cold matter?
experimental tools (rare processes):






g - jet correlations
jet - jet correlation
flavor tagged jets
tagged gluon jets ( K / p comparison)
centrality and A dependence
p-A and p-p comparision
upgraded PHENIX detector well suited to address these issues
requires highest possible luminosity
Axel Drees
23-May-16
Spin Physics Program
Recall: spin crisis of nucleon was discovered by
extending kinematical coverage of original EMC measurement

Increase kinematic coverage and measure






W boson production
isolation cuts on leptons
central arm tracking: Df = 2p, Dh= 1
muon arms: forward calorimeter
heavy flavor production
precision vertex tracking to tag decay electrons
jet production
large acceptance tracking & momentum measurement
gluon distribution function
g - jet angular correlations
transversity and spin effect in fragmentation
enhanced tracking acceptance
Detector upgrade requirements:


Df = 2p, Dh= 1 precision vertex tracking
forward calorimetry
detector requirements similar to those from heavy ion program
Axel Drees
23-May-16
Lepton Isolation Cuts

Isolation cut:


count activity around lepton
distance of lepton from jet axis
lepton
Jet
Jet
lepton
background

significantly enhances:




heavy flavor jet
heavy flavor tagging
Wl
Drell Yan process
technical solution:


vertex tracking for central arms
forward calorimeter for muon arms
Axel Drees
23-May-16
Jet Reconstruction with Charged Particles Only

Kt Jet algorithm (hep-ex/0005012)
PYTHIA: QCD JET at
s = 500GeV
(pt > 20GeV)
all particles
Dh 
Df  2 p
perfect sE
ktjet
PYTHIA

only charged particles
 Dh  1
 detector resolution (20%)
DR
0.08
0.1
0.1
sE/E
30%
30%
36%
jet reconstruction with ~ 40% sE/E feasible
Axel Drees
23-May-16
Detector Requirements
enhanced spin and heavy ion physics program
addressed by one multi-detector detector system:
vertex spectrometer around beam pipe

precision vertex tracking with large acceptance




electron identification



p < 1 GeV for Dalitz rejection
e / p ~ 50
flexible magnetic field configuration



Df = 2p and Dh   
 mm single track resolution
reasonable momentum resolution (sp/p ~ 3-4% p)
no field in vertex region for Dalitz rejection
high field for high pt physics
high rate capability


Au-Au
p-p
Axel Drees
L ~ 8 1027 cm-2s-1
L ~ 2 1032 cm-2s-1
23-May-16
PHENIX Vertex Spectrometer: Scenario A
“last nights sketch”
central arm acceptance
 22o  Dh ~ 0.7
 20 cm IR region
magnet coils
1m
micro pad chamber
layer 3 15 cm
layer 2 7.5 cm
layer 1 3 cm
forward calorimeter
Silicon Pixel
HBD
beam axis and
vacuum pipe
hadron blind detector
1m
40.4o
h~1
for  10 cm
IR region
Scenario B: replace HBD by TPC (or TEC)
Axel Drees
23-May-16
Vertex Spectrometer

Silicon Pixel Detectors



Hadron-Blind-Detectors




proximity focusing He-Cherenkov counter
CsI based photocathode
GEM based readout
“historical” R&D by Stony Brook group
new collaboration at Weizmann Institute on CsI & GEM
interest to collaborate with BNL instrumentation
Micro Pad Chambers


3 layer system (?) Df = 2p and Dh   
standard pixel devices 50x425 mm2
contacts with LHC developments for ALICE and NA6i
possible new collaboration with CERN
(other options D0 or CMS, ATLAS)
MWPC with pad readout
further development of existing PHENIX pad chambers
LUND, Vanderbilt ….
Forward “Nose-Cone” Calorimeter
lost of experience within PHENIX

DAQ and Trigger ???

new inner magnet coil
Axel Drees
23-May-16
Modified Central Magnet Configuration
add second - inner - coil
foreseen in PHENIX magnet design

Three field configurations



1.2
+
new field 0
original configuration
+new field reversed polarity
0 field along beam axis
++
new field same polarity
field from
CDR
toBdl
0.78 Tm
factor
~1.7scaled
increased
B dl
1
to drift chamber
++ 1.25 Tm
Bz (Tm)
0.8
0.6
+ 0.73 Tm
0.4
0.2
DC at 220 cm
+- 0.22 Tm
0
0
50
100
150
200
250
300
350
-0.2
R (cm)
Axel Drees
23-May-16
Field Integral of New Magnet System
field from CDR scaled to 0.78 Tm
1.4
B dl
to drift chamber
1.2
++ 1.25 Tm
1
+ 0.73 Tm
Bz (Tm)
0.8
0.6
DC at 220 cm
0.4
0.2
+- 0.22 Tm
0
0
-0.2
50
100
150
200
250
300
350
R (cm)

Two future operation modes of PHENIX:

+- field free region out to 50 cm
sensitive to pair opening angle
essential for pair continuum measurement

++ increase field integral by factor 1.7
increased momentum resolution
important for high pt physics
Axel Drees
23-May-16
Momentum Resolution with Inner Tracking

momentum resolution with new field configuration
and inner tracking
+- configuration:
similar to original setup
++ configuration:
improved by factor ~3.5

silicon tracking only
( 3 point estimate)
sp/p ~ 0.03 p
sE/E ~ 40% for 20 GeV jet
Axel Drees
23-May-16
Proton-Nucleus Physics Program
Significant fundamental interest beyond AA comparison run
motivation discussed in detail at previous workshop

Issues to be addressed





quark and gluon structure of nucleus
parton density at small x
propagation of partons trough nuclei
hard diffractive processes
standard tools




di-leptons from Drell-Yan process
prompt photons
g - jet and jet - jet coincidences
heavy quark production

similar requirements like heavy ion and spin program

to fully exploit RHIC’s unique opportunities


additional equipment to tag forward going baryons
(upgraded ZDC’s and Roman Pots)
extend muon acceptance to forward angles to extend x2
coverage below 10-3
Axel Drees
23-May-16
Detector Upgrades for p-A Physics

Roman Pots and ZDC

forward muon spectrometer
magnet
Tracking chamber
Axel Drees
23-May-16
Summary: Cost Guesstimate
Based on: detectors build by PHENIX, experience with technology,
or similar detectors build elsewhere
30 - 75% contingency, depending on stage of design and
our knowledge of the technology

baseline upgrades:






500 k
700 k
800 k
3000 k
1300 k
6300 k
vertex tracking system






PC2 east
TRD east
DAQ&Trigger
muon anode electronics
TRD/TEC west
magnet
silicon pixel
HBD (or TPC)
micro Pad chamber
forward calorimeter
700 k
12000 k
17000 k
3000 k
2000 k
34700 k
special p-Nucleus upgrades


ZDC & Roman Pots
forward muon spect.
550 k
3000 k
3550 k
total: ~ $45 M

R&D


mostly silicon pixel & HBD (or TPC)
$3-4 M over next three years (FY02 - FY04)
Axel Drees
23-May-16
Summary: Timeline

2001-2002
Au-Au
first polarized p-p

2003
high-L Au-Au
high-L light ions
polarized p-p
first p-A

2004
pp/pd comparison
high-L pol. p-p

2005
south muon arm
all central arm electronics
PC2,PC3 West
70% MVD
start R&D
north muon arm
PC2 east
TRD/TEC east
complete MVD
continue R&D
complete R&D
Conceptual Design Report
ZDC & roman pots
forward muon spectrometer
upgrade construction
p-A program
energy scan

2006
first polarized p-p
& Au-Au

upgrade construction &
installation
2007 - 2010
enhanced heavy ion &
spin physics program
Axel Drees
23-May-16