1. Experimental Nuclear Physics at UMass UMass, February 1st, 2010

2. E’ 4-momentum transfer θ E Elastic Electron Scattering (Kumar) Jefferson Laboratory Nuclear charge distribution Measure σ as a function of Q2 Neglecting recoil and spin: Obtain Fourier transform of charge distribution We now know that electrons interact with nuclei also via the weak force Z0 This is a rare process; tough to isolate: sophisticated measurement technique

3. The PREX Experiment http://hallaweb.jlab.org/parity/prex Neutron Star Lead Nucleus • Neutron star has solid crust over liquid core. • Heavy spinless nucleus has neutron skin. 10 km 10 fm crust skin Rp ~ 5.5 fm Rn-Rp ~ 0.1 to 0.3 fm? Both neutron skin and neutron star crust are made out of neutron rich matter at similar densities. δ(APV) ~ 3% Construction Ongoing; Data run ~ March-June 2010 Q2 ~ 0.01 GeV2 APV ~ 0.5 ppm Faculty: Krishna Kumar Postdocs: Juliette Mammei, Dustin McNulty Graduate Students: Luis Mercado, Jon Wexler, Sereres Johnston Undergraduates: Patrick Rogan, Kyle Schmoll, Vireak Yim δ(Rp-Rn) ~ 1% • Next Project: The MOLLER Experiment • Precision test of the weak force to search for clues about the early universe • Complementary to Large Hadron Collider experiments

4. Probing Mysteries in the Spin Structure of the Proton Amaresh Datta, Mikhail Stepanov, Dave Kawall, UMass http://www.phenix.bnl.gov UMass, February 1st, 2010

5. Probing Mysteries in the Spin Structure of the Proton

6. 2νββ 0νββ Double beta decay: EXO (Kumar, Pocar) ×10-6 ×10-2 extremely rare decay in which a nucleus simultaneously emits two electrons electron kinetic energy standard second order weak process 2νββ New physics? exciting possibility of a non-standard 0νββ process 0νββ • neutrinos are their own antiparticles • violation of lepton number • measurement of the absolute νmass • relevant to particle physics and cosmology • sensitivity to ≥1025 y lifetimes: • ultra-low background • underground location • large source mass

7. e- e- e- e- e- EXO-200: 136Xe detect the 2 electrons (ionization + scintillation) 136Xe →136Ba++ + 2e- (+ 2νe) 200 kg Xe (80% 136 isotope) time projection chamber (TPC) detector 3D reconstruction of events + energy fully commissioned deep underground salt mine in New Mexico (WIPP site) TPC installed in cryostat at WIPP Design sensitivity for 0νββ lifetime : 6×1025 years

8. EXO at UMass people: Krishna Kumar, Andrea Pocar Tim Daniels - postdoc Peter Morgan, Jessica Cook - grad Chris Sterpka, Kyle Schmoll - ug • activities: • EXO-200 data analysis (for the coming 4-5 years) • EXO-200 running at WIPP (includes regular shifts WIPP) • EXO-200 calibration campaigns • work on the EXO-200 muon detector • GEANT4 simulations (EXO-200 and future larger EXO experiment) • EXO lab at UMass (for various aspects of EXO R&D): • scintillation detection in LXe and LAr • tagged Ba ion source (Ton-scale EXO R&D)