Experimental Summary Selected Workshop Slides

Experimental Summary
Selected Workshop Slides
With editorial comments P. A. Souder Syracuse University Mark Pi- 8/4/16 1 Outline
•  PVES Goals and Challenges
•  Apparatus
–  Spectrometers/backgrounds
–  Detectors
–  Targets
•  Systematic errors
•  Hadronic physics
8/2/16 2 PVES Theory
For physics with Λ>>Q2, PVES can be described by the Lagrangian with independent parameters Ci: Or measure Λ for each combinaFon of the η’s. Compare to non-­‐PVES experiments 8/2/16 3 Which Ci is most important???
8/2/16 Measure as many C’s as you can as well as you can 4 Goals for Active Experiments
SebasFan Baunack Different experiments use different η’s 8/2/16 5 Excitement at the LHC: di-­‐photons Results presented without CERN seminar MW is hard to measure at the LHC: Ma-hias Scho- 8/4/16 6 BSM: Low Energy
Lepto-­‐phobic Z’ only at intermediate E Dark Z’ only seen at low E 8/2/16 7 Experimental Challenges
•  Measure small asymmetries APV
•  Small errors in the APV
•  Small errors in ΔAPV/APV
8/2/16 8 SebasFan Baunack 8/4/16 9 AT Results
Anselm Esser 8/4/16 10 Apparatus Requirements
Isolate desired reaction with high rate
Understand backgrounds.
Measure Q2
Measure Pe
Avoid helicity-correlated beam
systematics
•  Other systematics
• 
• 
• 
• 
• 
8/2/16 11 First Generation Spectrometers
SAMPLE
A4
Open geometry
Fast counting
calorimeter for
background rejection
open geometry,
integrating
Precision
spectrometer,
integrating
HAPPEX
Superconducting
Coils
G0
Particle
Detectors
Electron Beam
Open geometry
Fast counting with magnetic
spectrometer + TOF for
background rejection
LH2 Target
target
E158
Concrete shielding
8/2/16 Spectrometer magnets
Detector
cart
12 Present Generation Spectrometers
SoLID Qweak MOLLER 8/2/16 P2 13 and…The EIC is coming!
Not a dedicated parity apparatus; sort of like the HRS spectrometers in Hall A 8/2/16 14 MIT engineering coil supports for
MOLLER
Spectrometers are very complex devices Julie-e Mammei August 5-­‐9, 2016 ECT*Trento 15 Backgrounds for Integrating
Experiments
•  P2
•  Moller
•  Qweak
8/2/16 16 Background Woes
•  Dilute asymmetry—lose statistics
•  Add a large and unknown asymmetry
–  Al windows in Qweak, radiative inelastic
scattering in MOLLER
•  Complicated dead-time corrections
–  Hyperons in SoLID
•  Arise from helicity-correlated halo
–  Beam plug in Qweak
8/3/16 17 8/2/16 DusFn McNulF 18 Separation of Backgrounds
8/4/16 19 Solenoidal Focus: P2
SebasFan Baunack 8/2/16 20 Simulated Backgrounds for P2
8/2/16 21 Dominik Becker 8/4/16 22 Qweak Backgrounds
8/2/16 23 Integrating Detectors
σA =
1
N
2
1+
σq
q
2
Michael Gericke 8/4/16 24 Thin Quartz Detector
Development
Beam test at Mainz: Relevant for Qweak, P2, MOLLER, PREx, CREx Kathrin Schier 8/4/16 25 Counting PVDIS: SoLID
8/2/16 Seamus Riodan 26 SoLID GEM Prototype
Nilanga Liyanage 8/5/16 27 SoLID PID
8/2/16 28 Qweak LH2 Target
David Armstrong 8/2/16 29 Prospects for MOLLER based
on Qweak Experience
Key to progress: CFD-­‐Driven Target Design 8/3/16 Silviu Covrig 30 Qweak SystemaFc Errors Lessons for future experiments Two Categories: 1.  IdenFfied in the proposal 2.  Discovered during the run -­‐  Final result will be staFsFcs-­‐limited 25× as much data as Run 0 result -­‐  One remaining systemaFc error to nail down: secondary sca-ering effect -­‐  Other leading systemaFcs (in order of decreasing size): •  Q2 calibraFon •  Target Window (Aluminum) asymmetry •  Beamline Background •  Target Window (diluFon) Dave Armstrong •  Polarimetry !!! AnFcipate unblinding the result in a few months. 8/2/16 31 Polarized Electron Source
SystemaFc errors start at the source Christoph Matejeck 8/3/16 32 Arne Freyberger JLab Accelerators:
Jlab and
MESA
Kurt Aulenbacher Many non-­‐PVES users SystemaFc errors may be amplified or suppressed by the accelerator 8/5/16 33 MESA Slow Reversal:
Wien Flip
Key to measuring small APV Cancel false asymmetries Show that false asymmetries are small JLab 8/4/16 34 Jürgen Diefenbach 8/4/16 High beam quality Quality beam monitors 35 Even be-er beam monitors needed for the future Avoids phase driq in cables 8/4/16 36 JLab Beam Monitors
Mark Pi- PosiFon OK Intensity: progress 8/4/16 37 Beam Jitter: Good or Bad?
•  Larger beam jitter means longer time to
identify systematic helicity correlations.
•  Beam jitter provides useful information on
systematic errors if it is larger than
instrumental noise.
•  Controversy: specify correlations in beam
noise?
•  Does reducing beam noise reduce beam
systematics?
8/5/16 38 Emittance and Synchrotron
Radiation at JLab
8/4/16 Emi-ance growth due to synchrotron radiaFon forces good accelerator tune: 39 good for PVES Quality of Jlab 11 GeV Beam Era
How do you study beam quality in parasite mode? 8/2/16 Caryn Palatchi 40 Beam Polarimetry
Originally, was expected to be largest systematic uncertainty
.
Møller polarimeter
– 
– 
– 
– 
Compton polarimeter
–  Installed for Q-weak
–  Runs continuously at high
currents
–  Statistical precision: 1% per hour
–  Electron Detector: Diamond
strips
Precise, but invasive
Thin, polarized Fe target
Brute force polarization
Limited to low current
Detect both recoil electron and photon. 41 08/01/2016 Armstrong ECT* Qweak Beam Polarimetry Preliminary Run 2 PolarizaFon Compton (Edet) Møller Good agreement between Møller & Compton (electron detector)
Compton photon detector: issues with PbWO4 calorimeter
(afterglow?)
Systematics:
-
Compton (Edet) : ∆P/P = 0.42%
-
Møller:
Combined Total:
∆P/P = 0.65%
∆P/P = 0.61% (systematics + statistics + scaling)
(see Bob Michaels’ talk) 8/2/16 Serious progress!! Compton: A. Narayan et al, Phys. Rev. X 6.011013 (2016) 42 Polarimetry progress in Jlab Hall A
MagneFzaFon of Fe target 8/4/16 Compton spectrometer works at high energy Robert Michaels 43 Kurt Aulenbacher Gold standard for beam polarimetry 8/5/16 44 8/3/16 45 Niklaus Berger 8/5/16 46 Annoying Qweak Systematic
Effects
•  Backgrounds from beam halo
–  Many possible parameters
–  Hard to make reliable corrections
–  What is the cause?
•  Transverse asymmetry in detectors
8/5/16 47 Mark Pi- 8/4/16 48 Secondary Sca-ering •  Spin precession of sca-ered electron in QTor magnet: some transverse polarizaFon PT •  PT analyzed by sca-ering in Pb pre-­‐radiators → transverse asymmetry in detectors: opposite sign in the two PMTs ( + &− ) in each detector Adiff = ​𝐴↓+ − ​𝐴↓− Parity Signal = ​𝐴↓+ + ​𝐴↓− /2 ∴ Effect cancels to first order •  Analyzing power in Pb: 1.  Beam-­‐normal single spin asymmetry (high energy): 2𝛾 exchange 2.  Mo- sca-ering (low energy in shower) Adiff is of same scale (hundreds of ppb) as APV 8/2/16 49 Qweak SystemaFc Errors Lessons for future experiments Two Categories: 1.  IdenFfied in the proposal 2.  Discovered during the run -­‐  Final result will be staFsFcs-­‐limited 25× as much data as Run 0 result -­‐  One remaining systemaFc error to nail down: secondary sca-ering effect -­‐  Other leading systemaFcs (in order of decreasing size): •  Q2 calibraFon •  Target Window (Aluminum) asymmetry •  Beamline Background •  Target Window (diluFon) Dave Armstrong •  Polarimetry !!! AnFcipate unblinding the result in a few months. 8/5/16 50 Hadronic Physics
• 
• 
• 
• 
• 
• 
Inelastic PVES
CSV
Induced CSV
Higher twist
g1γZ
Anapole moments
8/2/16 51 PVES π Production form A4
ApplicaFons 1.  ν sca-ering at DUNE 2.  RadiaFve correcFons 8/5/16 52 CSV and HT with SoLID
Ian Cloet 8/3/16 53 Additional CSV if N≠Z?
Seamus Riordan ApplicaFons 1. Explain νTEV expt. 2. Explain EMC effect 8/3/16 54 PVDIS by Flipping PT at the EIC
8/2/16 55 Sensitivity to Δs
Wally Melnichouk Yuxiang Zhao 8/2/16 56 Summary
•  Exciting new experiments launched.
•  Aiming towards unprecedented precision.
•  Fabulous new technologies applied.
8/5/16 57 Solid Targets
8/3/16 58 SoLID Tracking
8/2/16 59 8/2/16 60 Seamus Riordan 8/4/16 61