D. Keller UVA
Spin Physics
● Spin in nuclear reactions ● Research polarizing mechanisms ● Nucleon helicity structure ● 3D Structure of the Nucleon ● Polarized beam, sources, targets technology ● Spin aspects of fundamental symmetries ● Beyond standard model testing with spin Investigation of spin degrees of freedom using polarization technologies to extract polarized observables
Spin Physics
3-D Tomography Quark OAM/spin
Nucleon Spin
Spin Degrees of Freedom
QCD Factorization
QCD Dynamics Probing Structure
● GPD and TMD Phenomenology ● Hadron Spectroscopy
● Deep Inelastic Scattering ● Helicity Correlations
● Inclusive and Semi-Inclusive DIS ● Quasi-elastic
Facilities TUNL at Duke Fermilab
LHC at Cern
12 GeV electrons (photons) Hall A: Hi Res Hall B: Large Acc Hall C: Hi Res Hall D: Large Acc
Jefferson Lab Theory of Internal Nucleon Structure
● Theoretical Framework ● Data: Multivariate Extraction ● Machine Learning Processing ● 3D structure of the nucleon ● Improve Resolution of Image
Our Groups Research
Solid Polarized Targets:
We are unique among university based research groups as we have the capability to develop, build, and maintain the cryogenic polarized targets critical for investigating spin physics and helicity correlations. We focus primarily on high cooling power evaporation systems and low temperature frozen spin systems. We are also heavily involved in target material research and optimizing polarization techniques improving the overall figure of merit in large scale scattering experiments. Spin Physics and Polarized Observables:
The group focuses on studies of spin effects in highly polarized proton, neutron, and deuteron targets. These polarized scattering experiments use the world-class solid polarized targets, which are developed and tested right here in our Lab. We concentrate on experiments that use spin degrees of freedom (i.e. using polarized targets and beams) with photon, electron, and nucleon beams on nucleon targets to extract new information about the properties of the fundamental building blocks of nature. Nuclear and Particle Physics Experiments:
We are interested in a wide energy range and have projects and affiliations at Fermi National Accelerator Facility, Dukes Triangle Universities Nuclear Laboratory, Jefferson National Accelerator Facility, Los Alamos National Labs, and Oak Ridge National Labs. (See our Experiments) Theory and Phenomenology in Nuclear and Medium Energy:
We are involved in studying the quark and gluon structure of hadrons. Our group works with the nuclear theory group researching techniques to exploit helicity correlations using machine learning to support our experimental effort. We are interested in the quark and gluon structure of nuclei including generalized parton and transverse momentum distributions. Theory and Computational in Nuclear Spin Dynamics:
We are involved in theoretical research of the polarization mechanisms in solid materials at low temperature. This work requires modeling different aspects of dynamic nuclear polarization and nuclear magnetic resonance for the purpose of optimizing and measuring bulk spin alignment in a variety of materials. We are also developing simulations of these mechanisms which can be used to better understand spin dynamics in a variety of field and temperature conditions. This research can be used to improve the overall figure of merit of helicity sensitive particle physics experiments. Some Spin Physics Projects
● ORNL: DNP proton crystallography with a neutron beam at Spallation Neutron Source (DNP-SNS) ● LHCb: QCD-spin physics in nucleon structure and hadron spectroscopy (SMOG, LHC-SPIN) ● Fermilab: New spin physics program with polarized target and liquefier (E906, E1027, E1039) ● HIGS-TUNL: Spin physics program at Duke with polarized beam and soon polarized target (P-12-16, P-20-09) ● Next Gen HIGS: New design with higher energy and intensity with an active polarized target (HIGS2) ● NIST: Scattering production of paramagnetic complex and target sample experiments (NIST-PTexp)
Spokesperson Project Involvement JLAB Experiments ● Hall A (E12-11-108) SIDIS with transversely polarized proton target (E12-11-108A) Target single spin asymmetries using SoLID (LOI-12-16-004) Timelike Compton Scattering with SoLID ● Hall B (E12-06-109) Longitudinal spin structure of the nucleon (E12-07-107) Spin-Orbit Correlations with a longitudinally PT (E12-09-009) Spin-Orbit Correlations in kaon electroproduction in DIS (E12-12-001) EMC effect in spin structure functions (C12-15-004) DVCS on the neutron with a longitudinally PT (C12-11-111) SIDIS on a transversely polarized target (C12-12-009) Di-hadron production in SIDIS on transversely PT (C12-12-010) DVCS on a transversely polarized target in CLAS12 ● Hall C (E12-14-006) Helicity correlations in wide-angle Compton scattering (E12-17-008) Polarized Observables in WACS (C12-13-011) The deuteron tensor structure function b1 (C12-15-005) Tensor Asymmetry in the x<1 Quasielastic Region (C12-18-005) Timelike Compton Scattering with T-PT at 11 GeV (LOI-12-14-001) Search for exotic gluonic states in the nucleus ● Hall D (LOI-12-15-001) Physics Opportunities with Secondary KL beam at JLAB (LOI12-16-005) Target Helicity Correlations in GlueX
Spokesperson Project Involvement So What is Polarization
● Polarization is the simplest Orientation metric of a quantum spin with the outside world ● Defined by the number of spin states (with an intrinsic magnetic moment) pointed in a specific direction with respect to the rest ● Measured in an ensemble using the characteristic frequency associated with electron spin ESR and nuclear spin NMR
What is a Polarized Target
● A marriage of sciences for the purpose of improving the interaction rate of a particular helicity (for fixed targets) ● Reach for the Highest Possible Figure of Merit by maximizing the statistical significance of the process of interest Best Way To Get Things Done
● Dynamic Nuclear Polarization - Dope target material with paramagnetic centers: chemical or irradiation doping to just the right density (1019 spins/cm3) - Polarize the centers: Just stick it in a magnetic field - Use microwaves to transfer this polarization to nuclei: mutual electron-proton spin flips re-arrange the nuclear Zeeman populations to favor one spin state over the other ● Optimize so that DNP is performed at B/T conditions
where electron t1 is short (ms) and nuclear t1 is long (minutes or hours)
A Conglomeration of Nuclear Science
● Nuclear and Particle Physics ● Radiation Physics/Chemistry ● Super Conducting Magnets ● Nuclear Chemistry ● Microwave Technology ● Solid-State Chemistry ● Solid-State NMR ● RF-circuits
● Bulk Spin Dynamical Theory ● Low Temperature Physics ● CW-NMR Theory/Phenomenology ● Low Temperature Electronics ● Polarization Mechanisms ● Cryogenics ● CW-NMR Experiments ● Large Scale pumps and High Vacuum Technology Solid Polarized Target
The Polarized Targets
● Beam : Neutron, Photon, Electron/Positron, Proton, Muon ● Target : Proton, Neutron, Deuteron ● System Types: Evaporation and Dilution
UVA Polarized Target System Microwave Target Insert Pumps Two Parallel 2063H 63 m3/Hour
ROOTS: 600 m3/Hour
ROOTS: Two Parallel 2000 m3/Hour
1W (~0.121 Torr) Magnet
Low Temp Dilution Fridge
An Example Project at Fermilab
Proton Spin Puzzle
Where is the missing spin?
Quark Transverse Momentum and Sivers TMD
Experimental Setup for E1039
Polarized Target Setup
Putting it all Together
Putting it all Together
Test Full System
Drell-Yan Fridge
Target Insert in Fridge
Results of All the Work
Summer Cooldown Group
Three Things to Keep in mind
● Choose something Interesting ● Exposure to high level computing ● Make sure you get paid!
Contact Info
● Dustin Keller: [email protected] ([email protected]) Take a look: twist.phys.virginia.edu