Sea Quest KEKABC Florian SanftlA BCSea Quest Collaboration

フェルミ研ドレル・ヤン実験Sea. Questのテストラン結果東大理、KEKA、理研B、山形大理C 宮坂翔、柴田利明、中野健一、Florian Sanftl、澤田真也A、　後藤雄二B、宮地義之C、他Sea. Quest Collaboration Contents • Sea. Quest experiment • Sea. Quest spectrometer • Commissioning run • Performance of the detectors • Splat event • Schedule in coming year • New St. 3 - construction • Summary 2021/2/25 JPS meeting 2012 Autumn 1

Sea. Quest experiment • Beam Energy: 120 Ge. V / 800 Ge. V 2021/2/25 JPS meeting 2012 Autumn 2

Sea. Quest spectrometer on r I d i l , So agnet ing M Focus absorber n Hadro am dump e and b n 1: o i t a t S array e p o sc Hodo tracking C MWP n 4: o i t a t rray S a e p g sco Hodo be trackin tu Prop 3: d n a 2 n Statio ope array king c sc Hodo amber tra h Drift C eas. M . m Mo gnet) a M (KTe. V St. 3+ DC 4. 9 m St. 3 - DC orber s b A n Hadro n Wall) (Iro Beam , and d , 2 H 2 Liquid rgets ta solid 2021/2/25 25 m Drawing: T. O’Connor and K. Bailey JPS meeting 2012 Autumn 3

Commissioning run • Late February 2012 – April 30 th 2012 – 120 Ge. V/c protons, 19 ns intervals (53 MHz) – Beam intensity: 1 E 12 p/s, 5 s spill at 1 minute intervals • First muon incident by proton beam was observed on March 8 th • Typical problem were solved in March. • Target commissioning – 7 targets (H 2, Empty Flask, D 2, “no target”, Fe, C, W) – Successfully done • Detector commissioning (Hodoscope + Drift chamber) – mapping, noise & hot channel • Trigger & DAQ – Large hit multiplicities termed “splat events” 2021/2/25 JPS meeting 2012 Autumn 4

Performance of drift chambers • No trip with at most 1. 3 E 12 p/s. • Hot channel, Dead channel Station Dead channels Hot channels Station 1 DC 66 0 Station 2 DC 1 0 Station 3+ DC 2 0 Station 3 - DC 5 0 HV 供給部分の故障 2021/2/25 JPS meeting 2012 Autumn 5

Performance of drift chambers Magnet on + - • Muon hit distribution 2021/2/25 JPS meeting 2012 Autumn Magnet off 6

Performance of drift chambers • Station 1 DC – Dead region, old – New Station 1 • Station 2 DC • works are on-going • Generate tracking algorithm • Drift chamber alignment • Calibration – Works well • Station 3+ DC – Works well • Station 3 - DC – Gas leak, old – New Station 3 New St. 3 - drift chamber being constructed 2021/2/25 JPS meeting 2012 Autumn 7

“Splat” event • Large number of hits on all the spectrometer (“Splat”) • Trigger hodoscopes to see the time structure of beam intensity Event Display – Sizable 60 Hz components – Main injector power supply? • “Splat block” was applied Splat block: Turn off triggers during high intensity beam based on an integral of beam intensity ~1. 5 million di-muon events were recorded 2021/2/25 JPS meeting 2012 Autumn 8

Schedule in coming year 2012/ May Commissioning run 2013/ May Upgrade Physics run (2 years) • Upgraded Stations 1 and 3 - will expand acceptance to larger xt • Zero suppressed TDCs – improve live time significantly. • Beamline monitor is funded – Feedback to the accelerator control room – Generate DAQ veto – Produce accurate luminosity • Physics run will start in May 2013 2021/2/25 JPS meeting 2012 Autumn 9

New Station 3 - DC construction 2021/2/25 JPS meeting 2012 Autumn 10

Summary • 2021/2/25 JPS meeting 2012 Autumn 11

Backup slide 2021/2/25 JPS meeting 2012 Autumn 12

Splat-Block • Goal: Turn off triggers during high intensity beam based on an integral of beam intensity • Problem: No spill-by-spill intensity monitor independent of targets— used hodoscopes Cartoon • Counted total number of hits for n buckets before and after the trigger. • Blocked triggers this running count was above a threshold 2021/2/25 JPS meeting 2012 Autumn 13

Hit distributions with magnet off 2021/2/25 JPS meeting 2012 Autumn 14

Occupancy • Occupancy on drift chambers – – Definition of the occupancy for each layer in each event # of hits[chamber][plane] / # of elements[chamber][plane] Definition of the occupancy for each drift chamber in each run Sum of # of hits[chamber] / ( # of elements[chamber] * # of events) Occupancy on the 3 rd drift chamber Occupancy on the 1 st drift chamber Run dependence on the occupancy Occupancy depends on the beam intensity and splat block threshold 2021/2/25 JPS meeting 2012 Autumn 15

• • • Occupancy for each layers Definition of occupancy[chamber][plane] = # of hits[chamber][plane] / # of elements[chamber][plane] Run 2173, trigger = FPGA 1 (di-muon trigger) Remove. After. Pulse and Hodo. In. Time. Cut was applied Y axis: count, X　axis : Occupancy DC 1 DC 2 DC 3 p DC 3 m 2021/2/25 Occupancy study 16

Occupancy with single-muon-trigger 2021/2/25 JPS meeting 2012 Autumn 17

• Correlation to run • Y axis: Occupancy for each chamber (mean value), X axis: Run ID DC 1 DC 2 DC 3 p DC 3 m • With FPGA 2(single trigger) (Run: 2166, 2167, 2168), the occupancy was low. • 2021/2/25 It is because of trigger type. Occupancy study 18

Comparing run 2173 & run 1705 • • Beam intensity = 6 E 11, Trigger type = di-muon trigger # of event: run 2173… 23641, run 1705… 20386 2021/2/25 Occupancy study 19

Due to the splat block, the occupancy was suppressed. 2021/2/25 Occupancy study 20

2021/2/25 JPS meeting 2012 Autumn 21

Drift Chambers • High voltages applied were stable • Wires were stable. Only few wires in St. 1 DC was broken and fixed soon in the beginning of the run. • Typical issues with mapping is resolved. • Hot channel and dead channel were found and fixed. • St. 1 DC- Vplane has dead region (~60 channels) • St. 3 minus DC had a gas leak problem Ar: CO 2 was used last 2 weeks. • Efficiency analysis needs to be done. • Calibration is on-going. • T 0 was defined preliminary, further study is being done • New Station 1 and Station 3 - chambers for next run! 2021/2/25 Polarized Drell-Yan Meeting @Yamagata 22

Readout electronics for drift chambers Wire chamber Amplifier card (ASDQ card) Amplifier Card Control Board (LS board) TDC To DAQ Noise PC • Set threshold • Send test pulse • All systems worked. • Communication problem between Control room (PC) and the Amplifier card control board Set independent network • Feedback from TDC caused noise Ferrite core was attached to remove the noise. 2021/2/25 Polarized Drell-Yan Meeting @Yamagata 23

Hodoscopes Very stable hodoscope performance from the beginning of Run I to its end ● Efficiency: ○ PMT voltages adjusted according to the hit ratios, indicating an (plane) efficiency of 98%99% (H 1 only 90%) ○ Additional runs recorded for further detailed efficiency studies using full track reconstruction ● Timing: ○ Adjusted by varying cable length between patch panel and amp. / discrim. ○ Large fluctuations (+/- 7 ns) in H 4 (mean timers? work in progress!) ○ Pulse width adjusted (10 ns < width < 15 ns) 2021/2/25 St. 1 Hodoscopes ● Matrix 1 H 1 ● Contains More lower-occupancy events Needs to be understood Polarized Drell-Yan Meeting @Yamagata 24

Expected Mass Spectrum • How is the nucleon sea generated? Filter out resonances, and focus on DY. Mass spectra from E 866/Nu. Sea ECT* Conference, Trento, Italy May 2012

Nuclear Modification in DIS - Shadowing at low x - Enhancement below x ~0. 3 - Suppression at larger x - Structure functions include both quark and anti-quark contributions - Measured for a broad range of targets (Ann. Rev. Nucl. Part. Phys. , Geesaman, Sato and Thomas) Nuclear Modification in Drell-Yan (E 772) - Drell-Yan accesses the anti-quark component - Binding mediated by pion exchange - Exchanged mesons contain anti-quarks enhancement PRL 64 (1990) 2479 No evidence of anti-quark enhancement in nuclei where did the pions go? 26 ECT* Conference, Trento, Italy May 2012

Nuclear Modification: E 906 Nuclear Targets: Carbon, Iron, Tungsten • Nuclear Modification- complementary with DIS, extends previous Drell-Yan measurements – Extend to x ~ 0. 45 • E 772: 800 Ge. V proton beam • Models must explain both Drell-Yan and DIS. 27 ECT* Conference, Trento, Italy May 2012

Why J/ ? • Are gluon distributions similar between p and n? • cc deconfinement J/ suppression in QGP – J/ suppression competing against multiple effects: Absorption, CNM induced nuclear dependence Often assumed, but not necessarily fundamental • qq annihilation dimuon pair gluon-gluon fusion ECT* Conference, Trento, Italy May 2012

J/ Production: p-d, p-p • gluon-gluon fusion Lingyan Zhu et al. , PRL, 100 (2008) 062301 (ar. Xiv: 0710. 2344) • Gluon distributions between p and n are very similar • E 866: Upsilon production • E 906: J/ production ECT* Conference, Trento, Italy May 2012

Again, what about bound systems? • cc deconfinement J/ suppression in QGP – J/ suppression during QGP formation competing against multiple effects: absorption, energy loss within nuclei, etc How can we understand these “other processes”? ECT* Conference, Trento, Italy May 2012

J/ Nuclear Dependence Suppression of J/ yield per nucleon • absorption ~ x. F=0? – cc dissociation through interaction within nucleus or with comoving secondaries • parton/gluon energy loss? – loss in both initial and final states q, g Cannot account for the suppression remains a mystery ECT* Conference, Trento, Italy May 2012

Partonic Energy Loss: p. A 1/p. A 2 • An understanding of partonic energy loss in both cold and hot nuclear matter is paramount to elucidating RHIC data. • Energy loss through cold nuclear matter • Pre-interaction parton moves through cold nuclear matter and loses energy • Apparent (reconstructed) kinematic values (x 1 or x. F)is shifted • Fit shift in x 1 relative to deuterium (E 906) n Models: • Galvin and Milana • Brodsky and Hoyer • Baier et al. 32 ECT* Conference, Trento, Italy May 2012

• • • • Energy loss ~ 1/s Fits on E 866 data reveal no energy loss. – larger at 120 Ge. V Correct for shadowing with DIS Sufficient statistics to remove – X 2 anti-correlates with x 1 and x. F shadowing contribution for low x shadowing contributions at large x 2 1 • Measurements instead of limits – Caveat: A correction must be made for shadowing because of x 1—x 2 correlations – E 866 used an empirical correction based on EKS fit to DIS and Drell. Yan. • Better data outside of shadowing region needed E 906 expected uncertainties Shadowing region removed LW 10504 Ene limi rgy lo s ts b ase s uppe Dre d on E r 866 mea ll-Ya sure n men t 33 ECT* Conference, Trento, Italy May 2012

Drell-Yan fixed target experiments at Fermilab • What is the structure of the nucleon? ➡ What is ? ➡ What is the origin of the sea quarks? ➡ What is the high x structure of the proton? • What is the structure of nucleonic matter? ➡ Where are the nuclear pions? ➡ Is anti-shadowing a valence effect? • Do colored partons lose energy in cold nuclear matter? • Sea. Quest: 2012 -2014 ➡ significant increase in physics reach • Beyond Sea. Quest ➡ Polarized Drell-Yan ➡ Pionic Drell-Yan 34

Tracking • • Removing off-time hits Track seeding Fitting Tracking Frame work over view & status of sagitta Status of Kalman filter 2021/2/25 JPS meeting 2012 Autumn 35

Drift chamber performance • TDC distribution • RT curve from the TDC distribution • Efficiency curve (single muon with low intensity beam) 2021/2/25 JPS meeting 2012 Autumn 36