SAMPLE: Parity Violating Electron Scattering from Hydrogen and Deuterium Kellogg Radiation Lab, Caltech Pasadena, CA Nuclear Physics Lab, Univ. of Illinois, Urbana, IL MIT-Bates Linear Accelerator Center, Middleton, MA Univ. of Maryland, College Park, MD Virginia Polytechnic Institute, Blacksburg, VA Louisiana Tech, Ralston, LA University of Kentucky, Lexington, KY College of William and Mary, Williamsburg, VA Argonne National Laboratory, Argonne, IL 2001: plus MIT, Grenoble

Parity Violating Electron Scattering polarized electrons, unpolarized target for a proton: forward angles backward angles Beyond 1st order... electroweak radiative corrections Z exchange anapole

NUCLEON ANAPOLE MOMENT Musolf+Holstein, PRD43 (1991) 2956 General electromagnetic coupling: Anapole (TRI , PV) Electric dipole (TRV, PV) Modeled by Musolf+Holstein (1990) using DDH parameters Recent updates: Zhu, Puglia, Holstein, Musolf, PRD62 (2000) 033008 Maekawa, Veiga, van Kolck, PLB 488 (2000) 167 D. Riska, NPA 678 (2000) 79

SAMPLE Experiment Schematic Polarized Injector Beam position feedback Lumi Beam current feedback Wien Filter Position, Angle, Charge Halo SAMPLE Detector Beam Current K11 Moller Polarimeter Accelerator E = 200 MeV 600 pulses/s Ipk = 3 mA Iave = 44 A PB = 36% Energy Fast phase shift feedback

E = 200 MeV P  36 %

SAMPLE 1998/1999 1998: 136 Coulombs delivered 1st use of piezo feedback after 10 days running T. Averett, et al., NIM A438, 246 (1999). D. Spayde et al., PRL 84, 1106 (2000). 1999: 174 Coulombs delivered R. Hasty et al., Science 290, 2117 (2000).

at Q2=0.1 (GeV/c)2

Mott Asymmetry in p(e,e’) ‘ S. Wells, et al., Phys.Rev. C63 (2001) 064001 transverse beam pol’n + full f-coverage of detector gives access to possible spin dependent terms in elastic cross section. lowest order is 2-g exchange 1st measurement at “high” energy no calculations for spin-1/2 target

SAMPLE E00-04: D(e,e’) at 125 MeV spokesperson: T. Ito, Caltech Q2 = 0.04 (GeV/c)2 Different systematic effects: A120 = 0.3 A200 s120 = 1.4 s200 background similar, so improved S/B similar sensitivity to , unique opportunity to measure other systematic errors comparable in 2 month run, expect test run April/May 2001, production run Oct 2001

PMT Signal Breakdown “LIGHT”: Cerenkov “non-LIGHT”: EM showers Scintillation “non-LIGHT”: EM showers neutrons separate w/ pulse counting “shutter closed” Dependence of background on beam energy is weak

Contributions to the Deuteron Asymmetry Pollock, PR D42 (1990) 3010. Musolf + Donnelly, NP A546 (1992) 509. Elastic and threshold breakup negligible at 200 MeV may need to consider threshold bkup at 125 MeV

PV QUASIELASTIC (e,e’) from DEUTERIUM “static” approximation: nuclear model uncertainties small Hadjimichael, Poulis + Donnelly, PR C45 (1992) 2666. meson exchange/two-body currents Schramm + Horowitz, PRC 49 (1994) 2777 Kuster + Arenhovel, NPA 626 (1997) 911 at SAMPLE kinematics: e.g. q=154 Diaconescu, Schiavilla, and van Kolck, PRC 63 (2001) 044007 many-body effects are few % at 200 MeV  energy dependence?

SUMMARY SAMPLE III is unique opportunity to measure low energy behavior of 125 MeV beam tune has been established Backgrounds demonstrated to be similar to that at 200 MeV Will use high polarization crystal if performance is good