Transcript No Slide Title

ZEUS experiment 2001
• Installation of Microvertex Detector
• Hera upgrade for higher collision rates
Nikhef Jamboree
ZEUS Dec. 2001
• Data analyses
Silicon Microvertex Detector
• Proposal, design and construction took 4 years
• February 2001 final transport from NIKHEF to
DESY
Feb/March full system test
March 27th installation in ZEUS
July short cosmic run
December first collision(s)
Nikhef Jamboree
ZEUS Dec. 2001
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Layout Microvertex Detector
32 cm
electrons
protons
60 cm
Support cylinder
divided in 2 halves
Cross section wheel
=
Cross section barrel
Nikhef Jamboree
ZEUS Dec. 2001
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Barrel Sensors
2 half modules
Ladder
Hybrid side
Nikhef Jamboree
ZEUS Dec. 2001
Detector side
MVD assembly
112 wheel modules
8 half wheels
Nikhef Jamboree
ZEUS Dec. 2001
300 barrel half modules
30 ladders
Nikhef Jamboree
ZEUS Dec. 2001
MVD assembly (2 halves)
Nikhef Jamboree
ZEUS Dec. 2001
MVD assembly (two halves)
Full System test
200 k readout channels have to function together
test final setup for the cabling
setting/monitoring low voltage front end readout
setting/monitoring bias voltage sensors
test complete readout chain analog datalink/ADC,
triggers for pedestals and testpulses
• cooling
• slow control monitoring
• measure cosmics
• Full system operational, No bad surprises
• about 1% of channels give problems
Nikhef Jamboree
ZEUS Dec. 2001
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Full System Test
• Cosmic Ray setup at DESY
Scintillator
at the side
Scintillator
towers
x-y plane
z-y plane
Nikhef Jamboree
ZEUS Dec. 2001
Scintillator
plates for
forward
wheels
Full System test
• First Results Reconstruction Cosmic Rays
Event display
single track event
Nikhef Jamboree
ZEUS Dec. 2001
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E.Maddox
Full System Test
• First Results Reconstruction Cosmic Rays
• Distribution of residuals track fit obtained with
default geometry, more survey data to be
included.
Residual (mm)
Z hits
Residual (mm)
Nikhef Jamboree
ZEUS Dec. 2001
R Phi hits
Full System Test
• Response ‘inclined’ Tracks
clustersum
clustersum
 
angle
0
angle beta
1.5 rad
0
angle alpha
1.5 rad
Nikhef Jamboree
ZEUS Dec. 2001
clustersum
Status of the new tracking software
Detailed Monte Carlo
simulations exist for MVD
Impact parameter resolution at
vertex for fitted single tracks
Up to NOW,CTD only
GEANT
xy
0.4mm
z
2.2mm
With MVD included!
MC tracks
0.07mm
z
E.Maddox
0.08mm
Nikhef Jamboree
ZEUS Dec. 2001
xy
MVD assembly (cooling)
Stainless steel tube
Manifold water cooling
(two mounted on top of each
other, input/output)
Nikhef Jamboree
ZEUS Dec. 2001
Polyurethane tubes
Cooling Performance
• Monitoring Cooling system as function of Time
(hor.scale hist. 12 hours)
Water temp. (14C)
Water press (1.6bar)
Humidity in MVD
Temp. ladder ~18C
Temp. ladder ~18C
Temp. ladder ~18C
Temp. wheel ~23C
Temp. in MVD ~18C
Temp. in MVD ~18C
Monitor 1
Monitor 2
Nikhef Jamboree
ZEUS Dec. 2001
Switch on low voltage
MVD in ZEUS
Inserted in front (proton side)
Cables at the rear
Nikhef Jamboree
ZEUS Dec. 2001
March 27th 2001 in ZEUS Hall
Documentation
4 years of design and construction
work beautifully documented on
web page and put on CD by
Marco Kraan
Nikhef Jamboree
ZEUS Dec. 2001
1 year assembly
and installation work
compiled on a 25’
video by
Els Koffeman
HERA +ZEUS upgrade
Install quadrupoles near interaction point
install spinrotators, long.polarized e-beams
1000 pb-1
end 2005
Nikhef Jamboree
ZEUS Dec. 2001
Luminosity
x5
Radiation damage FE electronics
HELIX chips (AMS 0.8m CMOS)
•tested up to 500Krad
• worse performances (S/N)
• partly recoverable changing
operation point
J.Velthuis
Nikhef Jamboree
ZEUS Dec. 2001
Single sensor
Monitor Background Radiation
34 mm
• irradiation from IP
negligible
• off momentum e-  g and
e- (<20 GeV)
• Synchrotron radiation,
backscattered from
collimators (<100 keV g)
complex pattern
• Proton beam loss
(accidents)
28 mm
diodes
Nikhef Jamboree
ZEUS Dec. 2001
Monitor radiation background
with pin diodes near the
beampipe inside the MVD.
Physics at HERA
test and understanding QCD
Proton structure
-evolution equations
-parton densities
Gluon radiation
- first and higher order
Hadronization
- many MonteCarlo generators
‘hard scale’ : high Q2, high ET jets,
high mass…...
-Diffractive events
-Deep inelastic scattering
-multi jet events
-heavy quark production
….
DGLAP,BFKL,CCFM,MRS,GRV,CTEQnn,..
HVQDIS,DISENT,JETNLO,DISASTER,..
HERWIG,RAPGAP,EPSOFT,PHOJET,LEPTO,
ARIADNE,CASCADE,PYTHIA,
DJANGO,HERACLES….
Nikhef Jamboree
ZEUS Dec. 2001
What do we observe?
Proton structure function
e
d 2  2 2

(1  (1  y) 2 ) F2  y 2FL  (1  (1  y) 2 ) xF3
2
4
dxdQ
xQ


Q2 four-momentum transfer squared e
x fractional four-momentum of struck quark
y inelasticity
N. Tuning
Nikhef Jamboree
ZEUS Dec. 2001
(PhD thesis Sept.2001)
Proton structure function F2
N. Tuning
Nikhef Jamboree
ZEUS Dec. 2001
Highest x-bins
Proton structure function xF3
d 2  2 2

(1  (1  y) 2 ) F2  y 2FL  (1  (1  y) 2 ) xF3
2
4
dxdQ
xQ


- e-running, balance samples
- progress theory (NNLO), better fits
Nikhef Jamboree
ZEUS Dec. 2001
HERA II: -improve high x,Q2 data
Open Charm Production in DIS
e
F2
c
Any sign of charm production
D  Dπ
*
c e .. S.Schagen
M(K  s ) - M(K )
M(Kπ)
Nikhef Jamboree
ZEUS Dec. 2001
 K
Open Charm Production in DIS
c e ..
S.Schagen
Nikhef Jamboree
ZEUS Dec. 2001
D*  D
Kinematical quantities
Open Charm Production in DIS
Contribution of charm to proton structure function F2
Nikhef Jamboree
ZEUS Dec. 2001
S.Schagen
Beauty Production in Photoproduction
Available data very still very scarce
HERA II:
+ MicroVertex gives proper b- data
+ MicroVertex gives more c-decay channels, smaller
Background, smaller kin extrapolations--> better measurement
Nikhef Jamboree
ZEUS Dec. 2001
Reconstruct jets and look for electrons or muons
rel
in jet as function of p t
More Open Charm Production in DIS
Nikhef Jamboree
ZEUS Dec. 2001
Any difference D* productionin e- versuse data?
More Open Charm Production in DIS
No special triggers required
All DIS events accepted
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M K K-
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M 
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M K0 3   M K0 2
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M   -

M K0
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
Nikhef Jamboree
ZEUS Dec. 2001
M K  K -  
HERA: a Charm factory
f (c  Ds1 )  1.24  0.18(stat.)00..08
06 (syst.)  0.14(br.)%
Nikhef Jamboree
ZEUS Dec. 2001
•Use the large number of D*
collected in ZEUS (~31K)
•Select D+s1 D*+K0S 
(K-++S)(+-) + c.c.
•From the well measured
f(c  D*+) we get the fragment.
fraction f(c  D+s1)
Just an example
HERA: a Charm factory
Many new results
• D* production in diffractive DIS
• Charm in Photoproduction vs NLO
• Charm dijet photoproduction vs LO
and NLO
• Huge D* sample in photoproduction
charm fragmentation universal?
spectroscopy of D mesons
probe rare decays
..
f(c  D*)
BUT
HERA II + MicroVertex will do better
+ improved triggers
Nikhef Jamboree
ZEUS Dec. 2001
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ZEUS Dec. 2001
Nikhef Jamboree
ZEUS Dec. 2001
Nikhef Jamboree
ZEUS Dec. 2001
Nikhef Jamboree
ZEUS Dec. 2001
Nikhef Jamboree
ZEUS Dec. 2001
Nikhef Jamboree
Proton structure function
d 2  2 2

(1  (1  y) 2 ) F2  y 2FL  (1  (1  y) 2 ) xF3
2
4
dxdQ
xQ


Q2 four-momentum
transfer squared
Q 2  k  k 
Q2
x
2pq
pq
y
pk
2
W  p  k
2
x fractional four-momentum
of struck quark
y inelasticity
Nikhef Jamboree
ZEUS Dec. 2001
W photon-proton centre of
mass energy
MVD assembly (two halves)
Nikhef Jamboree
ZEUS Dec. 2001
• Install Beampipe on lower MVD half
• Carbonfiber tube surrounds Beampipe
– protection silicon
– electrical shielding beam
• Turn upper MVD half upside down
• Mount both halves together with help precision pins on
support frames
• Connect both halves electrically and create Faraday cage for
the front end readout
• keep supportframes attached until installation in ZEUS
HERA +ZEUS upgrade
Rear end MVD
Nikhef Jamboree
ZEUS Dec. 2001
Super conducting magnet
buried in MVD cables