The STAR Experiment at Brookhaven National
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Summer Research Opportunities in Nuclear and Particle
Physics at VU:
The STAR Experiment at Brookhaven National
Laboratory
Understanding the Spin of the Proton
and nEDM Searches (at Los Alamos, Oak Ridge
National Laboratories)
Adam Gibson-Even
Valparaiso University
For Shirvel Stanislaus, Don Koetke, Dave Grosnick, Paul
Nord, Hal Spinka, etc.
Valparaiso University
Department of Physics and Astronomy Colloquium
January 17, 2020
On the boundary between particle and nuclear
Proton physics: the proton spin puzzle. How does it add
to ½?
Spin
u
d u d
Gluons
u
d u
u
s d
Sea
s u
Valence
Quarks d Quarks
Polarized Proton Collisions
Spinning Spinning quark or
Spinning
Proton gluon Proton
Quark, gluon,
photon, or ?
p. 3 January 17, 2020
Brookhaven National Lab
From
space
RHIC ring
p. 4 January 17, 2020
p. 5 January 17, 2020
Solenoidal Tracker at RHIC
Jet reconstruction utilizes
TPC + Barrel + Endcap
EMC and a new forward
calorimeter
π0 Reconstruction, for our
analysis, uses
Endcap EMC + FMS
Summer 2019:
JD Snaidauf, Andrew Edwards, and Claire Covarik
worked on aspects of π0 reconstruction and analysis
and hardware for the forward calorimeter upgrade
Summer 2020: Plan for 4 students in NY, 1 at VU
January 17, 2020
PHYSICAL REVIEW D 89, 012001 (2014)
Neutral pion cross section and spin asymmetries p
atffiffi intermediate
pseudorapidity in polarized proton collisions at s ¼ 200 GeV
1 23 21
Including,
. Adamczyk, J.now graduated,
K. Adkins, VU students
G. Agakishiev, Billy
M. Pochron 35
M. Aggarwal, and Z. Ben
Ahammed, Barber 54
(along
I. Alekseev, with19 aJ. Alford
32 21 4 4 21 27
Anson,
half a14A. Aparin,
dozen otherD.4Valpo Arkhipkin, names, E. C. andAschenauer,
hundreds G.
of S.friends
Averichev, from J.STAR)
Balewski, as A. Banerjee,54 B. B
co-authors
rnovska, D. R. Beavis, R. Bellwied,50 M. J. Betancourt,27 A. Bhasin,20 A. K. Bhati,35 P. Bhattarai,49 H. Bi
13 14 4 • Relates19 to work done 46 by Adam22Clark, 5
J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, W. Borowski, J. Bouchet, A. V. Brandin
idgeman, 2 6 33 21 Stephen4 Place, Sam Brandt, 41 Erik 58
than S.40 G.
MeV Brovko,
to exclude S.spurious
Bültmann, events,I.e.g.,Bunzarov,
beam gas T. P. Burton, J. Butterworth, H. Caines, M. Calder
Counts per 10 MeV/c2
264
6 non-collision6 backgrounds events. 5 Langholz, Lauren Skiniotes, 48Tae Kim,
D. Cebra, R. Cendejas,36 M.All Cervantes,48
Residual 13 STAR data
arca Sánchez,
and other
265 C. possi- P.
5000 Chaloupka,
Signal Region Z. Chang, 0
π s S. Chattopadhya
. F. Chen,ble 43
266 pairs of photons45
J. H. Chen,
0
that satisfy these
L. Chen, 9
J. requirements
Cheng, 51
M. are
Cherney, and 12 other current/recent
A. Chikanian, 58
W. students
Christie, 4
Other B.G.
ConversionJ. B.G.
Chwastows
considered 49 as π candidates.
Counts per 10 MeV/c2
267
27 56 54000 43 16 49
M. Codrington, R. mass
Residual
The invariant Corliss,of photonJ. G.pairs
Cramer,STAR
can be H.
data J.
expressed Crawford, X. Cui, S. Das, A. Davila Leyva,
Template Sum
L. C. De
• Pions are abundantly
de Souza,8produced
268
0
4 Region21
. Debbe, 5000 T. G. Signal
Dedovich, J. ! Deng,44Otherπ s
A. A. B.G. Derevschikov, 37
3000R. Derradi S. Dhamija,18 B. di R
4 φγγ
idenko,4 C. Dilks,
269 Mγγ 36 = (E + Eγ6) A.1 Dion,
F. γDing,
1 2
2 sin
− zγγ , B.G.(1) 48 X. Dong,
P.2Djawotho,
Conversion particles 26
J. in
L. proton
Drachenberg, 53
collisions, J. E. andDraper,can6 C. M
4000
Dunkelberger,7 J. C. Dunlop,4 L. G. Efimov, 21Sum
J. Engelage,5decay 52
G. Eppley,41 L. Eun,26 O. Evdok
Template 2000
K. S. Engle,
to two photons.
atemi,233000 4 Eγ represent the 21 energies of the two 23 pho- 21 58 4 6
where Eγ and
S. Fazio, J. Fedorisin, R. G. Fersch, P. Filip, E. Finch, Y. Fisyak, C. E. Flores, C. A. Gag
270 1 2
tons, zγγ 32
271 represents the two-photon
38 energy
41 asymmetry 53 • By 1000
studying
55 their2 assymetries, 53 we 43
Gangadharan,
zγγ = |Eγ −D. EγGarand,
| / (Eγ + EF. γ ),Geurts, A. Gibson,
and φγγ represents the M. Girard, S. Gliske, D. Grosnick, Y. Guo, A. G
can 0 learn about e.g. the role of
272 1 2 1 2
20 2000 4 6 13 48 45 31 58
pta, W. Guryn,
opening
273 angleB. Haag,theO.two
between Hajkova,
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0.15 Harris, 0.25 J. P. 0.3 Hays-W
18 photo-statistics in each
He, S. 274
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A. Hirsch, 38 cause a cluster of 49
G. W. Hoffmann, D.gluons
J. Hofman, in making
10
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MHuang, 4
γ γ [GeV/cH.
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9 1000energy deposited 32 by a single 7 shower to appear18as two clus-24 31
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ck, T. ters
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uder,10This
277 H. 9
00 W. Ke, D. Keane,
“false splitting” effect accounts
22
A. Kechechyan,
for a large fraction
21
A. Kesich,FIG.
6
3. Z. H. Khan,
(Color online)
10
D. P. Kikola,
Invariant mass
38
I. Kisel,
distribution for
15
the A. K
of π 53
candidates with 15
invariant mass below38 0.1 GeV/c233 . 23 30 30
D. Koetke,
278
0 T.0.05
Kollegger, 0.1 J. Konzer,
0.15 0.2 I.0.25
Koralt,0.3 W.two-photon
Korsch, system L. Kotchenda,
with 7 < pT < 8P.GeV/c. Kravtsov, K. Krue
Also included
False
15 splitting can22 be somewhat mitigated
11 by a “merg- 2 4 on the plot are the template
4 7 4
ulakov,ing”L.procedure.
Kumar, Simulation R. A. Kycia, M.M A.γ γ C. Lamont, J. M. Landgraf, K.shifted
D.functions
Landry, J. Lauret, A. Leb
279
for the signal and two
studies indicate [GeV/c
that when] backgrounds (scaled and according 51to the fit results),
280
21 4 27 4 43 45 38 47
ednicky,a false
281 J. H.
splitLee,
resultsW. in Leight, M. J. LeVine,
multiple reconstructed C. Li, the
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282 with p32
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(Color online)
0
within a radius
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Invariant massD. P. Mahapatra,
distribution R. Majka, R. Manweiler, S. Margetis, C. Mark
p. 7 26 Ifsystem
two-photon
284 two π with candidates
267 < pT are < 8found
GeV/c. within
41 Also a radius
included 12 37 January 48 17, 2020
. Masui, of 0.05H.then
S. Matis, D. McDonald,
these candidates are replaced T.
320 withS. aMcShane,
new, ulated N.trigger
G. Minaev,
requirement, S. Mioduszewski,
with thresholds of 4.3 B.GeV Mohan
on285the plot are
48 the template functions
37 for the signal and
42 two 38 26 17
Planned Forward Upgrade for the 2020’s
• Forward Calorimeter System (FCS)
– Refurbish a portion of the PHENIX ECal, new Fe-scintillator HCal
– Forward di-jets will extend gluon polarization to x
ECal Calorimeter Structure
SiPMs/FEE
card mounted
here
Photons trigger a shower in the sampling
cell.
9
Gluing ECal Light Guides
Several supermodules originally used in the
PHENIX detector have been repurposed for
the STAR forward upgrade.
Light guides/mixers were installed in order to
optimize the connection to the new silicon
photomultiplier (SiPM) readout.
Front-End Electronics (FEE) card SiPM board
(digital readout) (converts to electric
signal)
Light guide (combines signals from Fiber bundle (collects
multiple fibers into readout) light from shower) 10ECal Summary
JD and Andrew glued 1500 light
guides to 1500 channels, a process
which took ~4 weeks.
They checked a sample of 31
modules and found that all were
within tolerances for the connection
to the SiPMs.
ECal “stacked” October 2019
11Scintillators for the HCal
The new hadronic calorimeter will require 18,720
scintillating tiles. The machining, polishing, and painting of
these tiles will be accomplished over the next months at
contributing universities and labs.
JD and Andrew polished and painted the first batch of 600
tiles, machined at UCLA.
The tiles are 95x97 mm; the longer sides are polished while
the shorter sides are painted.
12Polishing Procedure
The polish is placed on the rotating table, which is
set to spin at a moderate speed. Tiles are held
vertically so that the polish flows beneath them.
Changing the location of the tile on the rotating
surface and twisting back and forth helps ensure
even polishing.
Finally, the surface and edges are wiped and the tile
is visually inspected to ensure that polishing is
complete.
13Polishing Results
Visual inspection: easier to check a stack than individual tiles
14Presenting Our Research at DNP Conferences p. 15 January 17, 2020
p. 16 January 17, 2020
• 2020 Fall Meeting of the APS Division of Nuclear Physics • October 29- Nov 1, 2020 • New Orleans, LA p. 17 January 17, 2020
Plans For This Summer With STAR
• Work will continue on STAR
– Continue with the pi0 research programs, adding new datasets, perhaps transverse
polarization, perhaps etas
• Additional papers planned, perhaps on a time frame that will be interesting for summer work
• Plan to hire 5 students for STAR
– 4 to be based at Brookhaven/BNL for ~10 weeks, starting shortly after finals
– Some travel may be involved during the summer (Argonne, Fermilab, Brookhaven, etc.)
– And perhaps in the fall as well (DNP 2020 New Orleans)
– With oral and poster presentations at Valpo, and hopefully a poster or talk in New
Orleans
• Some knowledge of C++ a plus
– Or other programming experience is a good start
– PHYS 243 is useful background; but we’ve often hired freshmen without programming
experience or PHYS 243- so please apply!
– On the job you’re likely to: gain experience with programming, learn the ROOT analysis
package, data analysis techniques, get some experience with hardware and with nuclear,
particle, and collider physics
• Applications due soon!
p. 18 January 17, 2020The nEDM Experiment at the
Oak Ridge National
LaboratoryWhat is the nEDM experiment about?
It is about the charge of the neutron.
u
+2/3
Neutrons are neutral, they have zero net charge.
Neutrons are made up of quarks that have charge.
d d
-1/3 -1/3
Is the charge uniformly distributed inside or are they separated?
OR OR
? ? ? 20
20 January 17, 2020The Design of the Experiment
Design of the Experiment
Requires very large and well understood E and B fields
Intense source of neutrons
Very cold temperatures (for He and for the neutrons!)
High technology in exotic environmentsMagnetic Field Mapper – Summer 2019
Vuk Miodrag
p. 22 January 17, 2020p. 23 January 17, 2020
Plans For nEDM this Summer
• Work will continue with Prof. Stanislaus
– In Valpo and at Los Alamos
• May hire one student to work (probably at Los Alamos?) for the summer
– Depending on funding
p. 24 January 17, 2020Nuclear-Particle Group, Summer 2019 p. 25 January 17, 2020
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