Low Energy Standard Model Tests with Parity-Violating Electron Scattering

Transcription

1 Acknowledgements: The E158, SOLID & MOLLER collaborations Low Energy Standard Model Tests with Parity-Violating Electron Scattering University of Massachusetts, Amherst Elba X11 Workshop Isola d Elba June 29, 2012

2 Outline Indirect Searches for physics beyond the Standard Model Neutral Weak Interactions at Low Energy PV Electron Scattering and the Standard Model Anatomy of the apparatus: pioneering experiment SLAC E122 Quick reminder of the first PVES measurements on nuclei First measurement of the weak charge of the electron: SLAC E158 Current and Future Program Lepton-quark weak neutral current couplings Qweak (covered in separate talk) Deep Inelastic Scattering at 6 GeV and 12 GeV (SOLID) MOLLER: New project to improve on E158 by a factor of 5 at JLab Summary 2

3 The Intensity Frontier Direct and Indirect Searches for Physics Beyond the Standard Model Compelling arguments for New Dynamics at the TeV Scale A comprehensive search for clues requires: Large Hadron Collider as well as Lower Energy: Q 2 << M 2 Z 3

4 The Intensity Frontier Direct and Indirect Searches for Physics Beyond the Standard Model Compelling arguments for New Dynamics at the TeV Scale A comprehensive search for clues requires: Large Hadron Collider as well as Lower Energy: Q 2 << M 2 Z Violations of Accidental(?) Symmetries CP, T (EDMs, Decays), CPT, Charged Lepton Flavor, Lepton Number 3

5 The Intensity Frontier Direct and Indirect Searches for Physics Beyond the Standard Model Compelling arguments for New Dynamics at the TeV Scale A comprehensive search for clues requires: Large Hadron Collider as well as Lower Energy: Q 2 << M 2 Z Violations of Accidental(?) Symmetries CP, T (EDMs, Decays), CPT, Charged Lepton Flavor, Lepton Number Dark Matter Searches 3

6 The Intensity Frontier Direct and Indirect Searches for Physics Beyond the Standard Model Compelling arguments for New Dynamics at the TeV Scale A comprehensive search for clues requires: Large Hadron Collider as well as Lower Energy: Q 2 << M 2 Z Violations of Accidental(?) Symmetries CP, T (EDMs, Decays), CPT, Charged Lepton Flavor, Lepton Number Dark Matter Searches Neutrino Masses and Mixing 0νββ decay, reactor θ13, long baseline experiments 3

7 The Intensity Frontier Direct and Indirect Searches for Physics Beyond the Standard Model Compelling arguments for New Dynamics at the TeV Scale A comprehensive search for clues requires: Large Hadron Collider as well as Lower Energy: Q 2 << M 2 Z Violations of Accidental(?) Symmetries CP, T (EDMs, Decays), CPT, Charged Lepton Flavor, Lepton Number Dark Matter Searches Neutrino Masses and Mixing 0νββ decay, reactor θ13, long baseline experiments Precision Electroweak Measurements at Q 2 << MZ 2 flavor conserving and flavor changing neutral current amplitudes, charged current amplitudes, muon g-2 Intense beams, ultra-high precision, exotic nuclei, tabletop experiments, rare processes... 3

8 Indirect Clues Electroweak Interactions at scales much lower than the W/Z mass E Dynamics involving particles with m > Λ Many theories predict new forces that disappeared when the universe cooled Λ (~TeV) M W,Z (100 GeV) courtesy V. Cirigliano H. Maruyama L = L SM + 1 L L 6 + Heavy Z s and neutrinos, technicolor, compositeness, extra dimensions, SUSY higher dimensional operators can be systematically classified flavor changing as well as flavor diagonal charged current as well as neutral current Measurements with the potential to indirectly access the TeV scale involve pushing one or more experimental parameters to the extreme 4

9 Indirect Clues Electroweak Interactions at scales much lower than the W/Z mass E Dynamics involving particles with m > Λ Many theories predict new forces that disappeared when the universe cooled Λ (~TeV) M W,Z (100 GeV) courtesy V. Cirigliano H. Maruyama L = L SM + 1 L L 6 + Heavy Z s and neutrinos, technicolor, compositeness, extra dimensions, SUSY Measurements with the potential to indirectly access the TeV scale involve pushing one or more experimental parameters to the extreme higher dimensional operators can be systematically classified flavor changing as well as flavor diagonal charged current as well as neutral current new contact interactions 1 2 L 6 must reach! ~ several TeV 4

10 Electroweak 1-Loop Precision Measurements of Electroweak (EW) Parameters For electroweak interactions, 3 input parameters needed: 1. electron g-2 anomaly 2. The muon lifetime 3. The Z line shape Scale of electromagnetism i.e. the fine structure constant Scale of the weak interaction i.e. the W boson mass Weak mixing angle i.e. the ratio of W and Z boson masses 5

11 Electroweak 1-Loop Precision Measurements of Electroweak (EW) Parameters For electroweak interactions, 3 input parameters needed: 1. electron g-2 anomaly 2. The muon lifetime 3. The Z line shape Scale of electromagnetism i.e. the fine structure constant Scale of the weak interaction i.e. the W boson mass Weak mixing angle i.e. the ratio of W and Z boson masses 4th and 5th best measured parameters: MW and sin 2 θw precise values differ from tree level predictions: indirect access to heavy physics higher order terms in the perturbative expansion W t b t t W Muon decay Z production Z Z Known heavy physics: the top quark Assumed heavy physics : the Higgs boson A 0,b fb A l (SLD) m W March 2012 LEPEWWG M H [GeV] 5

12 Electroweak 1-Loop Precision Measurements of Electroweak (EW) Parameters For electroweak interactions, 3 input parameters needed: 1. electron g-2 anomaly 2. The muon lifetime 3. The Z line shape Scale of electromagnetism i.e. the fine structure constant Scale of the weak interaction i.e. the W boson mass Weak mixing angle i.e. the ratio of W and Z boson masses 4th and 5th best measured parameters: MW and sin 2 θw precise values differ from tree level predictions: indirect access to heavy physics higher order terms in the perturbative expansion W t b t t W Muon decay Z production LHC Higgs? Z Z Known heavy physics: the top quark Assumed heavy physics : the Higgs boson A 0,b fb A l (SLD) m W March 2012 LEPEWWG M H [GeV] 5

13 Low Q 2 Neutral Currents Search for New Flavor Conserving Contact Interactions l 1 l 1 Z 0 f 2 f 2 amplitudes can be very precisely predicted Allows searches for new physics at the TeV scale via small measurement deviations 1 2 L 6 All flavor-conserving weak neutral current amplitudes are functions of sin 2 θ W sensitive to TeV-scale contact interactions iff: δ(sin 2 θw) 0.5% away from the Z resonance Precision Neutrino Scattering New Physics/Weak-Electromagnetic Interference opposite parity transitions in heavy atoms parity-violating electron scattering 6

14 Low Q 2 Neutral Currents Search for New Flavor Conserving Contact Interactions l 1 l 1 Z 0 f 2 f 2 amplitudes can be very precisely predicted Allows searches for new physics at the TeV scale via small measurement deviations 1 2 L 6 All flavor-conserving weak neutral current amplitudes are functions of sin 2 θ W sensitive to TeV-scale contact interactions iff: δ(sin 2 θw) 0.5% away from the Z resonance Precision Neutrino Scattering New Physics/Weak-Electromagnetic Interference opposite parity transitions in heavy atoms parity-violating electron scattering Electromagnetic amplitude interferes with Z-exchange as well as any new physics A + A Z + A new 2 A 1 2 AZ + 2 A Anew + 2 A 6

15 Anatomy of a Parity Experiment E122 at SLAC (1978): PV Deep Inelastic Scattering unpolarized target 10 4 Need few x events Count at ~ 100 khz δ(a PV ) ~ few ppm 7

16 Anatomy of a Parity Experiment E122 at SLAC (1978): PV Deep Inelastic Scattering unpolarized target 10 4 Need few x events Count at ~ 100 khz δ(a PV ) ~ few ppm Optical pumping of a GaAs wafer: black magic chemical treatment to boost quantum efficiency Rapid helicity reversal: polarization sign flips ~ 100 Hz to minimize the impact of drifts Helicity-correlated beam motion: under sign flip, beam stability at the micron level 7

17 Anatomy of a Parity Experiment E122 at SLAC (1978): PV Deep Inelastic Scattering unpolarized target 10 4 Optical pumping of a GaAs wafer: black magic chemical treatment to boost quantum efficiency Rapid helicity reversal: polarization sign flips ~ 100 Hz to minimize the impact of drifts Helicity-correlated beam motion: under sign flip, beam stability at the micron level Tiny signal buried in known background Need few x events Count at ~ 100 khz δ(a PV ) ~ few ppm Lockin Amplifier output modulator apparatus lockin input 7

18 Anatomy of a Parity Experiment E122 at SLAC (1978): PV Deep Inelastic Scattering unpolarized target 10 4 Optical pumping of a GaAs wafer: black magic chemical treatment to boost quantum efficiency Rapid helicity reversal: polarization sign flips ~ 100 Hz to minimize the impact of drifts Helicity-correlated beam motion: under sign flip, beam stability at the micron level Tiny signal buried in known background Need few x events Count at ~ 100 khz δ(a PV ) ~ few ppm Lockin Amplifier output injector accelerator target spectrometer detector 7

19 Anatomy of a Parity Experiment C.Y. Prescott, et al. 8

20 Anatomy of a Parity Experiment C.Y. Prescott, et al. ² Beam helicity sequence is chosen pseudo-randomly Helicity state, followed by its complement Data analyzed as pulse-pairs 8

21 Anatomy of a Parity Experiment C.Y. Prescott, et al. Beam Monitors to measure helicity-correlated changes in beam parameters High-power cryotarget 30 cm long for high luminosity 8

22 Anatomy of a Parity Experiment C.Y. Prescott, et al. Polarimetry 8

23 Anatomy of a Parity Experiment C.Y. Prescott, et al. Magnetic spectrometer directs flux to backgroundfree region Flux Integration measures high rate without deadtime 8

24 Anatomy of a Parity Experiment C.Y. Prescott, et al. e - e - Parity Violation in Weak Neutral Current Interactions Z * γ * sin 2 θ W = ± 0.020: same as in neutrino scattering A PV 10 4 (A PV ) 10 5 Glashow, Weinberg, Salam Nobel Prize awarded in

25 PV Elastic Electron Scattering 1980 s: Nuclear Targets & Capabilities for sub-ppm measurements Elastic scattering from (J,T) = (0 +, 0) nuclei Feinberg (1975) APV in elastic scattering at forward angle insensitive to nuclear structure: measure complementary vector hadronic coupling combination Quasi-elastic backward angle scattering from nuclei Hoffman and Reya (1979) APV in quasi-elastic scattering at backward angles can be expressed in terms of nucleon form factors: access to axial-hadronic couplings 9

26 PV Elastic Electron Scattering 1980 s: Nuclear Targets & Capabilities for sub-ppm measurements Elastic scattering from (J,T) = (0 +, 0) nuclei Feinberg (1975) APV in elastic scattering at forward angle insensitive to nuclear structure: measure complementary vector hadronic coupling combination Quasi-elastic backward angle scattering from nuclei Hoffman and Reya (1979) APV in quasi-elastic scattering at backward angles can be expressed in terms of nucleon form factors: access to axial-hadronic couplings Quasi-elastic scattering at backward angles off 9 Be at Mainz: A PV =( 9.4 ± 1.8 ± 0.5) 10 6 W. Heil et al (1989) Elastic scattering at forward angles off 12 C at MIT-Bates: A PV = (1.69 ± 0.39 ± 0.06) 10 6 P. Souder et al (1990) 9

27 PV Elastic Electron Scattering 1980 s: Nuclear Targets & Capabilities for sub-ppm measurements Elastic scattering from (J,T) = (0 +, 0) nuclei Feinberg (1975) APV in elastic scattering at forward angle insensitive to nuclear structure: measure complementary vector hadronic coupling combination Quasi-elastic backward angle scattering from nuclei Hoffman and Reya (1979) APV in quasi-elastic scattering at backward angles can be expressed in terms of nucleon form factors: access to axial-hadronic couplings Quasi-elastic scattering at backward angles off 9 Be at Mainz: A PV =( 9.4 ± 1.8 ± 0.5) 10 6 W. Heil et al (1989) Elastic scattering at forward angles off 12 C at MIT-Bates: A PV = (1.69 ± 0.39 ± 0.06) 10 6 P. Souder et al (1990) First measurements of electron-nuclear weak interactions Pushed experimental technology Low energy tests of electroweak theory 9

28 TeV-Scale Sensitivity SLAC E158: First Measurement of the Electron s Weak Charge (g A eg V T +β g V eg A T) g V and g A are function of sin 2 θ W electron & proton target: Q W = 1 4 sin 2 W Weak Charge QW highly suppressed 10

29 ~ 1999: electron-electron weak attractive force had never been measured! TeV-Scale Sensitivity SLAC E158: First Measurement of the Electron s Weak Charge (g A eg V T +β g V eg A T) g V and g A are function of sin 2 θ W electron & proton target: Q W = 1 4 sin 2 W Weak Charge QW highly suppressed Fixed Target Parity-Violating Møller Scattering Purely leptonic reaction! 10

30 ~ 1999: electron-electron weak attractive force had never been measured! TeV-Scale Sensitivity SLAC E158: First Measurement of the Electron s Weak Charge (g A eg V T +β g V eg A T) g V and g A are function of sin 2 θ W electron & proton target: Q W = 1 4 sin 2 W Weak Charge QW highly suppressed Fixed Target Parity-Violating Møller Scattering Purely leptonic reaction! A PV = (GeV ) 1 E beam (GeV ) (1 4sin 2 W ) Tiny! 10

31 ~ 1999: electron-electron weak attractive force had never been measured! TeV-Scale Sensitivity SLAC E158: First Measurement of the Electron s Weak Charge (g A eg V T +β g V eg A T) g V and g A are function of sin 2 θ W electron & proton target: Q W = 1 4 sin 2 W Weak Charge QW highly suppressed Fixed Target Parity-Violating Møller Scattering Purely leptonic reaction! A PV = (GeV ) 1 E beam (GeV ) (1 4sin 2 W ) / 1 E lab Figure of Merit rises linearly with E lab Tiny! 10

32 ~ 1999: electron-electron weak attractive force had never been measured! TeV-Scale Sensitivity SLAC E158: First Measurement of the Electron s Weak Charge (g A eg V T +β g V eg A T) g V and g A are function of sin 2 θ W electron & proton target: Q W = 1 4 sin 2 W Weak Charge QW highly suppressed Fixed Target Parity-Violating Møller Scattering Purely leptonic reaction! A PV = (GeV ) 1 E beam (GeV ) (1 4sin 2 W ) / 1 E lab 45 & 48 GeV Beam 85% longitudinal polarization LH2 Figure of Merit rises linearly with E lab SLAC E158: mrad Tiny! End Station A at the Stanford Linear Accelerator Center (SLAC) 10

33 A PV = (-131 ± 14 ± 10) x 10-9 The Legacy of E158 Phys. Rev. Lett (2005) Tree-level prediction: ~ 250 ppb 11

34 A PV = (-131 ± 14 ± 10) x 10-9 The Legacy of E158 Phys. Rev. Lett (2005) Tree-level prediction: ~ 250 ppb 11

35 A PV = (-131 ± 14 ± 10) x 10-9 The Legacy of E158 Phys. Rev. Lett (2005) Tree-level prediction: ~ 250 ppb significant theory extrapolation error sin 2 θ w 11

36 > θ (M ) A PV = (-131 ± 14 ± 10) x 10-9 The Legacy of E158 Phys. Rev. Lett (2005) Tree-level prediction: ~ 250 ppb sin 2 W Z Erler and Ramsey-Musolf (2004) Cesium APV SLAC E158 Moller NuTeV ν-dis Z-pole Q [GeV] 11

37 > θ (M ) A PV = (-131 ± 14 ± 10) x 10-9 The Legacy of E158 Phys. Rev. Lett (2005) Tree-level prediction: ~ 250 ppb sin 2 W Z Erler and Ramsey-Musolf (2004) Cesium APV SLAC E158 Moller 3% NuTeV ν-dis Z-pole Q [GeV] 11

38 A PV = (-131 ± 14 ± 10) x 10-9 The Legacy of E158 Phys. Rev. Lett (2005) Tree-level prediction: ~ 250 ppb Limits on New Physics 95% C.L SM current proposed 2010 PDG 17 TeV 16 TeV sin 2 θ W (μ) Q W Cs (APV) SLAC E158 Q W (e) 3% NuTeV screening ν-dis LEP 1 anti-screening Tevatron 0.8 TeV 1.0 TeV (Z χ ) SLC μ [GeV] 0.01 G F 11

39 3 Decades of Technical Progress Continuous interplay between probing hadron structure and electroweak physics Parity-violating electron scattering has become a precision tool SLAC MIT-Bates Mainz Jefferson Lab Beyond Standard Model Searches Strange quark form factors Neutron skin of a heavy nucleus QCD structure of the nucleon Mainz & MIT-Bates in the mid-80s JLab program launched in the mid-90s E158 at SLAC measured PV Møller scattering 12

40 3 Decades of Technical Progress Continuous interplay between probing hadron structure and electroweak physics Parity-violating electron scattering has become a precision tool SLAC MIT-Bates Mainz Jefferson Lab Beyond Standard Model Searches Strange quark form factors Neutron skin of a heavy nucleus QCD structure of the nucleon Mainz & MIT-Bates in the mid-80s JLab program launched in the mid-90s E158 at SLAC measured PV Møller scattering State-of-the-art: sub-part per billion statistical reach and systematic control sub-1% normalization control photocathodes, polarimetry, high power cryotargets, nanometer beam stability, precision beam diagnostics, low noise electronics, radiation hard detectors 12

41 Current and Future Program SM published ongoing proposed sin 2 θ W (μ) Q W(Ra) KVI Q W (Cs) Boulder Mainz Q Weak JLab SLAC E158 Q W (e) JLab Q Weak JLab PVDIS 6 GeV SOLID NuTeV ν-dis screening JLab LEP SLC CMS anti-screening Tevatron μ [GeV] 13

42 Current and Future Program SM published ongoing proposed Elastic Electron-Proton Scattering Qweak at JLab has completed the datataking phase (talk by J. Birchall) New ideas to improve Qweak by a further factor of 2 at Mainz and at JLab FEL sin 2 θ W (μ) Q W(Ra) KVI Q W (Cs) Boulder Mainz Q Weak JLab SLAC E158 Q W (e) JLab Q Weak JLab PVDIS 6 GeV SOLID NuTeV ν-dis screening JLab LEP SLC CMS anti-screening Tevatron μ [GeV] 13

43 Current and Future Program SM published ongoing proposed Deep Inelastic Scattering off Deuterium 6 GeV JLab experiment completed: analysis recently completed SoLID: New Apparatus with a large solenoid using 11 GeV beam sin 2 θ W (μ) Q W(Ra) KVI Q W (Cs) Boulder Mainz Q Weak JLab SLAC E158 Q W (e) JLab Q Weak JLab PVDIS 6 GeV SOLID NuTeV ν-dis screening JLab LEP SLC CMS anti-screening Tevatron μ [GeV] 13

44 Current and Future Program SM published ongoing proposed Møller Scattering MOLLER: New project to improve E158 by a factor of 5 sin 2 θ W (μ) Q W(Ra) KVI Q W (Cs) Boulder Mainz Q Weak JLab SLAC E158 Q W (e) JLab Q Weak JLab PVDIS 6 GeV SOLID NuTeV ν-dis screening JLab LEP SLC CMS anti-screening Tevatron μ [GeV] 13

45 Semi-leptonic Couplings Elastic and deep-inelastic electron-nucleon scattering A V V A L PV = G F 2 [e µ 5e(C 1u u µ u + C 1d d µ d) +e µ e(c 2u u µ 5 u + C 2d d µ 5 d)] 14

46 Semi-leptonic Couplings Elastic and deep-inelastic electron-nucleon scattering A V V A L PV = G F 2 [e µ 5e(C 1u u µ u + C 1d d µ d) +e µ e(c 2u u µ 5 u + C 2d d µ 5 d)] A PV in elastic e-p scattering: For a 1 H target, nucleon structure contribution well-constrained from measurements Z * N N p Q weak = 2C 1u + C 1d 1 4sin 2 ϑ W proposal for factor of 2 improvement at Mainz. Talk by J. Birchall 14

47 Semi-leptonic Couplings Elastic and deep-inelastic electron-nucleon scattering A V V A L PV = G F 2 [e µ 5e(C 1u u µ u + C 1d d µ d) +e µ e(c 2u u µ 5 u + C 2d d µ 5 d)] A PV in elastic e-p scattering: For a 1 H target, nucleon structure contribution well-constrained from measurements e - N N Z * N p Q weak = 2C 1u + C 1d 1 4sin 2 ϑ W proposal for factor of 2 improvement at Mainz. Talk by J. Birchall A PV in deep elastic e-d scattering: For a 2 H target, assuming charge symmetry, structure functions largely cancel in the ratio e - Z * γ * A PV = G a(x) = 3 F Q 2 10 (2C 1u C 1d )+... p [a(x)+f(y)b(x)] " # X 2 b(x) = 3 2C 2u C 2d ) u v(x)+d v (x) +... Q 2 >> 1 GeV 2, W 2 >> 4 GeV 2 10 u(x)+d(x) 14

48 Broad Low Energy Search C 2q / (g eq RR )2 Access several flavor and chiral combinations C 1q / (g eq RR )2 +(g eq RL )2 (g eq RL )2 +(g eq LR )2 + (g eq LR )2 new physics (g eq LL )2 (g eq LL )2 X i,j=l,r L f1 f 2 = (g 12 ij )2 2 ij f 1i µ f 1i f2j µ f 2j PV elastic e-p scattering, Atomic parity violation PV deep inelastic scattering 15

49 Broad Low Energy Search C 2q / (g eq RR )2 Access several flavor and chiral combinations C 1q / (g eq RR )2 +(g eq RL )2 C 2q s involve axial hadronic currents: large theoretical uncertainties when accessed via elastic scattering (g eq RL )2 +(g eq LR )2 + (g eq LR )2 new physics (g eq LL )2 (g eq LL )2 X i,j=l,r L f1 f 2 = (g 12 ij )2 2 ij 6 GeV PVDIS measurement at JLab Hall A f 1i µ f 1i f2j µ f 2j PV elastic e-p scattering, Atomic parity violation PV deep inelastic scattering 15

50 Broad Low Energy Search C 2q / (g eq RR )2 Access several flavor and chiral combinations C 1q / (g eq RR )2 +(g eq RL )2 C 2q s involve axial hadronic currents: large theoretical uncertainties when accessed via elastic scattering (g eq RL )2 +(g eq LR )2 + (g eq LR )2 new physics (g eq LL )2 (g eq LL )2 X i,j=l,r L f1 f 2 = (g 12 ij )2 2 ij 6 GeV PVDIS measurement at JLab Hall A f 1i µ f 1i f2j µ f 2j PV elastic e-p scattering, Atomic parity violation PV deep inelastic scattering publication imminent 15

51 Current and Projected Constraints C 2q s largely unconstrained Qweak 11 GeV SOLID SAMPLE E122 Cs Red ellipses are PDG fits This box matches the scale of the C 1q plot Blue bands represent expected data: Qweak (le;) and PV- DIS- 6GeV (right) 16

52 Current and Projected Constraints SOLID: Measure A PV for e- 2 H DIS to 0.6% fractional error (stat + syst + theory) at high x, y C 2q s largely unconstrained Qweak 11 GeV SOLID SAMPLE E122 Cs Red ellipses are PDG fits This box matches the scale of the C 1q plot Blue bands represent expected data: Qweak (le;) and PV- DIS- 6GeV (right) Green bands are the proposed measurement of SOLID unique TeV-scale sensitivity 16

53 PV Deep Inelastic Scattering e - N off the simplest isoscalar nucleus and at high Bjorken x Z * γ * e - X A PV = G F Q F Z 1 g A F 1 + g V f(y) 2 Q 2 >> 1 GeV 2, W 2 >> 4 GeV 2 A PV = G F Q2 [ a(x) + f (y)b(x)] 2πα F Z 3 F 1 17

54 PV Deep Inelastic Scattering e - N off the simplest isoscalar nucleus and at high Bjorken x Z * γ * e - X A PV = G F Q F Z 1 g A F 1 + g V f(y) 2 Q 2 >> 1 GeV 2, W 2 >> 4 GeV 2 A PV = G F Q2 [ a(x) + f (y)b(x)] 2πα F Z 3 F 1 At high x, A iso becomes independent of pdfs, x & W, with well- defined SM prediccon for Q 2 and y 17

55 PV Deep Inelastic Scattering e - N off the simplest isoscalar nucleus and at high Bjorken x Z * γ * e - X A PV = G F Q F Z 1 g A F 1 + g V f(y) 2 Q 2 >> 1 GeV 2, W 2 >> 4 GeV 2 A PV = G F Q2 [ a(x) + f (y)b(x)] 2πα F Z 3 F 1 At high x, A iso becomes independent of pdfs, x & W, with well- defined SM prediccon for Q 2 and y Interplay with QCD Parton distribuions (u, d, s, c) Charge Symmetry ViolaIon (CSV) Higher Twist (HT) Nuclear Effects (EMC) 17

56 The SOLID EW Program Requires 12 GeV upgrade of JLab and a large superconducting solenoid Requirements High Luminosity with E > 10 GeV Large scattering angles (for high x & y) Better than 1% errors for small bins x-range W 2 > 4 GeV 2 Q 2 range a factor of 2 for each x (Except at very high x) Moderate running times statistical error bar σ A /A (%) shown at center of bins in Q 2, x standard model test sea quarks higher twist 2 months at 6.6 GeV charge symmetry violation 4 months at 11 GeV Strategy: sub-1% precision over broad kinematic range: sensitive Standard Model test and detailed study of hadronic structure contributions 18

57 The SOLID EW Program Requires 12 GeV upgrade of JLab and a large superconducting solenoid Requirements High Luminosity with E > 10 GeV Large scattering angles (for high x & y) Better than 1% errors for small bins x-range W 2 > 4 GeV 2 Q 2 range a factor of 2 for each x (Except at very high x) Moderate running times statistical error bar σ A /A (%) shown at center of bins in Q 2, x standard model test sea quarks higher twist 2 months at 6.6 GeV charge symmetry violation 4 months at 11 GeV Strategy: sub-1% precision over broad kinematic range: sensitive Standard Model test and detailed study of hadronic structure contributions & 1 2# A = A$ 1+ β HT + β 3 2 CSV x! % (1 x) Q " If no CSV, HT, quark sea or nuclear effects, ALL Q 2, x bins should give the same answer within statistics modulo kinematic factors! 18

58 New Physics Examples MSSM sensitivity if light super-partners, large tanβ MSSM SUSY loops Does Supersymmetry provide a candidate for dark matter? B or L violation (R-parity violation) Ramsey-Musolf and Su, Phys. Rep. 456 (2008) B and/or L need not be conserved: neutralino decay Depending on size and sign of deviation: could lose appeal as a dark matter candidate 19

59 New Physics Examples MSSM sensitivity if light super-partners, large tanβ MSSM SUSY loops Does Supersymmetry provide a candidate for dark matter? B or L violation (R-parity violation) Ramsey-Musolf and Su, Phys. Rep. 456 (2008) B and/or L need not be conserved: neutralino decay Depending on size and sign of deviation: could lose appeal as a dark matter candidate Virtually all GUT models predict new Z s arxiv: v1 LHC reach ~ 5 TeV, but... Buckley and Ramsey-Musolf Little sensitivity if Z doesnt couple to leptons Leptophobic Z as light as 120 GeV could have escaped detection Since electron vertex must be vector, the Z cannot couple to the C1q s if there is no electron coupling: can only affect C2q s Leptophobic Z SOLID can improve sensitivity: GeV range 19

60 SOLID Apparatus Overview GEM Sashlyk gas Cerenkov collimator 20 o - 35 o, E ~ GeV δp/p ~ 2% some regions 10 s of khz/mm 2, Pion rejeccon with Cherenkov + segmented calorimeter Several large solenoids would work (Zeus, Babar): present design focuses on CLEO- II Requirements: Solenoid contains low energy backgrounds (Møller, pions, etc) Baffling to cut backgrounds: significant engineering Trajectories measured a;er baffles Fast tracking GEM, parccle ID, calorimetry, and pipeline electronics Precision polarimetry (0.4%) Compton and atomic hydrogen Moller 20

61 Broad Program Inclusive and Semi-inclusive deep inelastic scattering 21

62 Broad Program Inclusive and Semi-inclusive deep inelastic scattering 2 H Parity Violation Experiment Search for nucleon charge symmetry violation (CSV at the partonic level) Could be partial explanation of NuTeV anomaly Search for a very special category of higher twist dynamics PVDIS off 2 H isolates quark-quark correlations PV-DIS with Other Targets PVDIS off 1 H Totally clean (free of nuclear dynamics) measurement of d/u as Bjroken x 1 PVDIS off 12 C and 208 Pb (perhaps even more relevant for NuTeV anomaly) Search for new source of CSV in nuclei (isospin-rotated manifestation of EMC effect) Double-Polarized Semi-Inclusive DIS on 3 He & 1 H at 11 GeV 21

63 Broad Program Inclusive and Semi-inclusive deep inelastic scattering 2 H Parity Violation Experiment Search for nucleon charge symmetry violation (CSV at the partonic level) Could be partial explanation of NuTeV anomaly Search for a very special category of higher twist dynamics PVDIS off 2 H isolates quark-quark correlations PV-DIS with Other Targets PVDIS off 1 H Totally clean (free of nuclear dynamics) measurement of d/u as Bjroken x 1 PVDIS off 12 C and 208 Pb (perhaps even more relevant for NuTeV anomaly) Search for new source of CSV in nuclei (isospin-rotated manifestation of EMC effect) Double-Polarized Semi-Inclusive DIS on 3 He & 1 H at 11 GeV E : Transverse Single Spin Asymmetry 3 He (90 days) E : Single and Double Spin Asymmetry 3 He (35 days) PR : Single and Double Spin Asymmetries on Transverse Proton (received full approval last week) 21

64 JLab An ultra-precise measurement of the weak mixing angle using Møller scattering Q W = 1 4 sin 2 W L 6 L e1 e 2 = i,j=l,r g 2 ij 2 2 ē i µe i ē j µ e j 11 GeV Beam Detector Array LH mrad APV = 35.6 ppb δ(q e W) = ± 2.1 % (stat.) ± 1.0 % (syst.) Luminosity: 3x10 39 cm 2 /s! Hybrid Toroid Ebeam = 11 GeV 75 μa 80% polarized 28 m δ(apv) = 0.73 parts per billion Upstream Toroid Liquid Hydrogen Target Electron Beam 22

65 JLab An ultra-precise measurement of the weak mixing angle using Møller scattering Q W = 1 4 sin 2 W 1 11 GeV Beam LH2 Detector Array mrad 2 L 6 L e1 e 2 = i,j=l,r g 2 ij 2 2 ē i µe i ē j µ e j = 7.5 TeV grr 2 g2 LL best contact interaction reach for leptons at low OR high energy Ebeam = 11 GeV 75 μa 80% polarized 28 m δ(apv) = 0.73 parts per billion APV = 35.6 ppb δ(q e W) = ± 2.1 % (stat.) ± 1.0 % (syst.) Luminosity: 3x10 39 cm 2 /s! Hybrid Toroid Upstream Toroid Liquid Hydrogen Target Electron Beam To do better for a 4-lepton contact interaction would require: Giga-Z factory, linear collider, neutrino factory or muon collider Compositeness scale: g 2 RR g2 LL = 2 Length scale probed: = 47 TeV m 22

66 New Physics at LHC Assume either SUSY or Z discovered at LHC RPV SUSY QWeak (ep) JLab, 1,165 GeV P2 (ep) Mainz, 137 MeV MOLLER (ee) JLab, 11 GeV MSSM MSSM sensitivity if light super-partners, large tanβ Does Supersymmetry provide a candidate for dark matter? B and/or L need not be conserved: neutralino decay Ramsey-Musolf and Su, Phys. Rep. 456 (2008) Depending on size and sign of deviation: could lose appeal as a dark matter candidate 23

67 RPV SUSY New Physics at LHC QWeak (ep) JLab, 1,165 GeV P2 (ep) Mainz, 137 MeV Assume either SUSY or Z discovered at LHC MOLLER (ee) JLab, 11 GeV MSSM Ramsey-Musolf and Su, Phys. Rep. 456 (2008) MSSM sensitivity if light super-partners, large tanβ Does Supersymmetry provide a candidate for dark matter? B and/or L need not be conserved: neutralino decay Depending on size and sign of deviation: could lose appeal as a dark matter candidate Virtually all GUT models predict new Z s LHC reach ~ 5 TeV, but... For light 1-2 TeV, Z properties can be extracted Suppose a 1 to 2 TeV heavy Z is discovered at the LHC Can we point to an underlying GUT model? α cos β β M Z = 1.2 TeV x + Z u-int x Zd/ MOLLER PVDIS x ZB-L x ZL1 x Z ψ x Z N x Z I x Z S x Z χ x Z η x Z L/ J. Erler and E. Rojas x Zp/ x ZLR x ZR1 x Z ALR x Z R Z n/ x E158 Q W (H) x Y 23

68 SM Higgs at LHC sin 2 θ W (μ) m W and sin 2 ϴ W are powerful indirect probes of the m H SM published ongoing proposed Q W(Ra) KVI Q W (Cs) Boulder Mainz Q Weak Z f γ JLab Q W (e) Z W γ SLAC E158 JLab Q Weak JLab PVDIS 6 GeV W NuTeV ν-dis screening JLab SOLID W LEP SLC γ CMS ν e W anti-screening Tevatron use standard model electroweak radiative corrections to evolve best measurements to Q ~ M Z μ [GeV] MOLLER projected δ(sin 2 θw) = ± (stat.) ± (syst.) precise enough to affect the central value of the world average 247

69 SM Higgs at LHC sin 2 θ W (μ) m W and sin 2 ϴ W are powerful indirect probes of the m H SM published ongoing proposed Q W(Ra) KVI Q W (Cs) Boulder Mainz Q Weak Z f γ JLab μ [GeV] Z W γ SLAC E158 Q W (e) JLab Q Weak JLab PVDIS 6 GeV MOLLER projected δ(sin 2 θw) = ± (stat.) ± (syst.) W NuTeV ν-dis screening JLab SOLID W LEP SLC γ CMS ν e W anti-screening Tevatron sin 2 θ eff (e) use standard model electroweak radiative corrections to evolve best measurements to Q ~ M Z H Z (Courtesy: J. Erler) Ruled out A FB (b) World average central value Ruled out MOLLER E158 precise enough to affect the central value of the world average APV (Cs) M H [GeV] Allowed A LR (had) 247

70 SM Higgs at LHC sin 2 θ W (μ) m W and sin 2 ϴ W are powerful indirect probes of the m H SM published ongoing proposed Q W(Ra) KVI Q W (Cs) Boulder Mainz Q Weak Z f γ JLab μ [GeV] Z W γ SLAC E158 Q W (e) JLab Q Weak JLab PVDIS 6 GeV MOLLER projected δ(sin 2 θw) = ± (stat.) ± (syst.) W NuTeV ν-dis screening JLab SOLID W LEP SLC γ CMS ν e W anti-screening Tevatron sin 2 θ eff (e) use standard model electroweak radiative corrections to evolve best measurements to Q ~ M Z H Z (Courtesy: J. Erler) Ruled out A FB (b) World average central value Ruled out MOLLER E158 precise enough to affect the central value of the world average Bill Marciano: We forgot to nail sin 2 W APV (Cs) M H [GeV] Allowed A LR (had) 247

71 New Physics Beyond LHC Doubly-charged Scalars e - H -- e - e - L = 2 e - 2G F M PV (Q e W)= h ee L,R 2 2M 2 L e L 1 (7.5 TeV) 2 M µ e L e µ L L e L h ee L 5.3 TeV improves reach significantly beyond LEP

72 New Physics Beyond LHC Doubly-charged Scalars e - H -- e - e - L = 2 e - Heavy Photons: The Dark Sector e - e - e - 2G F M PV (Q e W)= h ee L,R 2 2M 2 L A, e L Hypothesis could explain (g-2)µ discrepancy as well as several intriguing astrophysical anomalies related to dark matter e - 1 (7.5 TeV) 2 M µ e L e µ L L e L h ee L 5.3 TeV improves reach significantly beyond LEP

73 New Physics Beyond LHC Doubly-charged Scalars e - H -- e - e - L = 2 e - Heavy Photons (Z): The Dark Sector e - e - e - 2G F M PV (Q e W)= h ee L,R 2 2M 2 L Z, e L Hypothesis could explain (g-2)µ discrepancy as well as several intriguing astrophysical anomalies related to dark matter e - 1 (7.5 TeV) 2 M µ e L e µ L L e L h ee L 5.3 TeV improves reach significantly beyond LEP

74 Heavy Photons (Z): The Dark Sector New Physics Beyond LHC Doubly-charged Scalars e - H -- e - e - L = 2 e - e - e - e - 2G F M PV (Q e W)= h ee L,R 2 2M 2 L Z, e L Hypothesis could explain (g-2)µ discrepancy as well as several intriguing astrophysical anomalies related to dark matter Beyond kinetic mixing: introduce mass mixing with Z Davoudiasl, Lee, Marciano arxiv: v2 e - 1 (7.5 TeV) 2 M µ e L e µ L L e L h ee L 5.3 TeV improves reach significantly beyond LEP-200 Z = m Z d M Z omplementary to direct heavy photon searches: Lifetime/branching ratio model dependence vs mass mixing assumption ε MOLLER reach: red dashed lines E774 a e E141 a Μ a Μ explained APV KLOE Moller MESAAPEX Test Combined MAMI BaBar For m Zd MeV 25

75 ~ 150 GHz scattered electron rate MOLLER Status Director s Review chaired by C. Prescott: positive endorsement Technical Challenges Design to flip Pockels cell ~ 2 khz 80 ppm pulse-to-pulse statistical fluctuations 1 nm control of beam centroid on target Improved methods of slow helicity reversal > 10 gm/cm 2 liquid hydrogen target 1.5 m: ~ 5 85 µa Full Azimuthal acceptance with θ lab ~ 5 mrad novel two-toroid spectrometer radiation hard, highly segmented integrating detectors Robust and Redundant 0.4% beam polarimetry Pursue both Compton and Atomic Hydrogen techniques MOLLER Collaboration ~ 100 authors, ~ 30 institutions Expertise from SAMPLE A4, HAPPEX, G0, PREX, Qweak, E158 4th generation JLab parity experiment ~ 20M$ project funding sought 3-4 years construction 2-3 years running 26

76 Summary Parity-violating electron scattering has played a major in the development and tests of electroweak interactions over the past 3 decades The physics results and the technical progress have set the stage for the next era of ultra-precise measurements: TeV-scale electroweak physics beyond the Standard Model Neutron skin of a heavy nucleus QCD structure of the nucleon (auxiliary measurements of SOLID) MOLLER at JLab is a compelling new opportunity ultra-precise weak mixing angle comparable to best collider measurements Might emerge as critical: depends on discovery (or lack thereof) of the Higgs boson & its mass unique TeV-scale sensitivity to complement/decipher potential LHC anomalies unique use of the extraordinary qualities of the JLab electron beam 27

77 Backups 28

78 SOLID Status neutron background study Strong collaboration being formed ~ 130 collaborators, ~ 35 institutions Parity and DIS expertise Significant international participation: Italy, Germany, China ~ 5 Postdoc FTEs now focused on simulation and R&D Significant hardware R&D potential GEMs, Shashlyk, pipeline electronics, collimator engineering... Timeline Would run in Hall A on and off between 2016 and 2022 JLab is currently negotiating with Cornell to move CLEOII magnet ~ 2014 R&D and Design ~ 2-3 years Funding strategies (total cost M$) unlikely to be a one CD-funded project must consist of several sub-projects JLab wants to single out hardware that might be of multi-purpose use 29

79 Charge Symmetry Violation We already know CSV exists: u- d mass difference δm = m d - m u 4 MeV δm = M n - M p 1.3 MeV electromagneic effects Direct sensicvity to parton- level CSV Important implicacons for PDF s Could be parcal explanacon of the NuTeV anomaly SOLID sensitivity R CSV = For A PV in electron- 2 H DIS SensiCvity will be enhanced if u+d falls off more rapidly than δu- δd as x 1 bag model (solid) Radionov et al. QED splitting (dashed) Glueck et al. δd δu x Significant effects are predicted at high x 30

80 A Special HT Effect The observacon of Higher Twist in PV- DIS would be excicng direct evidence for diquarks following the approach of Bjorken, PRD 18, 3239 (78), Wolfenstein, NPB146, 477 (78) Isospin decomposicon before using PDF s A PV = G F Q2 [ a(x) + f (y)b(x)] 2πα = hvvi hssi hvvi + hssi a(x) / F Z 1 / F 1 Higher- Twist valence quark- quark correlacon Zero in quark- parton model (c) type diagram is the only operator that can contribute to a(x) higher twist: theoretically very interesting! σ L contributions cancel Castorina & Mulders, 84 Use ν data for small b(x) term. 31

81 Nuclear Medium Modification Cloet, Bentz, Thomas, arxiv They propose that a neutron or proton excess in nuclei leads to an isovector-vector mean field dominated by ρ exchange shifts quark distributions: apparent CSV violation Isovector EMC effect: explain 2/3 of NuTeV anomaly 32

82 Apparent CSV in Nuclei Suppose one completes a 2 H APV measurement, then repeat with 208 Pb The ratio of ratios (heavy nucleus vs deuterium) as a function of x should show a measurable effect if model is correct Measuring the EMC effect along a different isospin axis 5% Would be a smoking gun demonstration of nuclear medium modification of quark distributions Another classic example of interplay between EW and QCD physics 33

83 Physics with Hydrogen d(x)/u(x) as x 1 Longstanding issue in proton structure PV-DIS off the proton (hydrogen target) SU(6): Valence Quark: Perturbative QCD: d/u~1/2 d/u~0 d/u~1/5 A PV = G F Q2 [ a(x) + f (y)b(x)] 2πα Deuteron analysis has large nuclear corrections (Yellow) A PV for the proton has no such corrections 3-month run The challenge is to get statistical and systematic errors ~ 2% 34

84 ~ 1999: electron-electron weak attractive force had never been measured! SLAC E158 Proposal ~ 10 ppb statistical error at highest E beam, ~ 0.4% error on weak mixing angle A large number of technical challenges 10 nm control of beam centroid on target R&D on polarized source laser transport elements 12 microamp beam current maximum 1.5 meter Liquid Hydrogen target 20 Million electrons per 120 Hz 200 ppm pulse-to-pulse statistical fluctuations Electronic noise and density fluctuations < 10-4 Pulse-to-pulse monitoring resolution ~ 1 micron Pulse-to-pulse beam fluctuations < 100 microns 100 Mrad radiation dose from scattered flux State-of-the-art radiation-hard integrating calorimeter Full Azimuthal acceptance with θ lab ~ 5 mrad Quadrupole spectrometer Complex collimation and radiation shielding issues 35

85 SLAC E158 Data g-2 spin precession 45 GeV: 14.0 revs 48 GeV: 14.5 revs Phys. Rev. Lett (2005) 36

86 SLAC E158 Data A PV = (-131 ± 14 ± 10) x 10-9 A PV E beam P beam (1 4sin 2 ϑ W ) 250ppb Phys. Rev. Lett (2005) 36

87 A Landmark Result Does the weak neutral current amplitude interfere with the electromagnetic amplitude? E122 at SLAC rate ~ 10 khz C.Y. Prescott et al, 1978 e - e - Parity Violation in Weak Neutral Current Interactions Z * γ * sin 2 θ W = ± 0.020: same as in neutrino scattering A PV 10 4 (A PV ) 10 5 Glashow, Weinberg, Salam Nobel Prize awarded in

88 Spectrometer Concept meters Lab Scattering Angle (mrad) Scattered Electron Energy (GeV) Moller s ep s first toroid hybrid toroid meters y (m) x (m) 38

89 Spectrometer Concept meters Lab Scattering Angle (mrad) Scattered Electron Energy (GeV) Moller s ep s first toroid hybrid toroid meters 10 rate (GHz) r (m) 38

90 neutrals Detector Systems pion luminosity Auxiliary Detectors Tracking detectors 3 planes of GEMs/Straws Critical for systematics/ calibration/debugging Integrating Scanners quick checks on stability Collaboration physicists will continue to define and optimize the full suite of detectors Integrating Detectors: Moller and e-p Electrons: radial and azimuthal segmentation quartz with air lightguides & PMTs pions and muons: quartz sandwich behind shielding luminosity monitors optimized for robust background subtraction ee s ep s Moller Peak Detectors CAD design in progress 39

91 Signal & Backgrounds 10 parameter cross-section 75 μa pair stat. width (1 khz) value 45.1 μbarn 135 GHz 82.9 ppm rate (GHz) e + e e + e e + p e + p (+ γ) δ(araw) ( 6448 hrs) ppb δ(astat)/a (80% pol.) 2.1% δ(sin 2 θw)stat e + p e + X (+ γ) r (m) photons and neutrons mostly 2-bounce collimation system dedicated runs to measure blinded response pions and muons real and virtual photo-production and DIS prepare for continuous parasitic measurement estimate 0.5 ppm 0.1% dilution Elastic e-p scattering well-understood and testable with data 8% dilution, 7.5±0.4% correction Inelastic e-p scattering sub-1% dilution large EW coupling, 4±0.4% correction variation of APV with r and φ 40

92 Simulations Initial and final state radiation effects in target rate (GHz) different phi distributions one-seventh of the azimuth behind primary collimator behind primary collimator open sector 0.2 rate (GHz) φ wrap rate (GHz) elastic e-p e-e (millirad) laboratory scattering angle θ lab r (m) 41

93 Statistics & Systematics parameter MOLLER E158 Qweak Rate 135 GHz 3 GHz 6 GHz pair stat. width 82.9 ppm 200 ppm 400 ppm δ(araw) ppb 11 ppb 4 ppb δ(astat)/a 2.1% 10% 3% Accuracy goals are factors of 2 to 10 beyond those of E158 & Qweak δ(sin 2 θw)stat Irreducible Backgrounds: Elastic e-p scattering well-understood and testable with data 8% dilution, 7.5±0.4% correction Inelastic e-p scattering sub-1% dilution large EW coupling, 4±0.4% correction variation of A PV with r and φ source of error % error absolute value of Q beam second order 0.4 longitudinal beam polarization 0.4 inelastic e-p scattering 0.4 elastic e-p scattering 0.3 beam first order 0.3 pions and muons 0.3 transverse polarization 0.2 photons and neutrons 0.1 Total

94 Systematic Errors source of error % error absolute value of Q beam second order 0.4 longitudinal beam polarization 0.4 inelastic e-p scattering 0.4 elastic e-p scattering 0.3 beam first order 0.3 pions and muons 0.3 transverse polarization 0.2 photons and neutrons 0.1 Total 1.0 longitudinal beam polarization strive for redundant, continuous monitoring pursue both Compton and Atomic Hydrogen transverse beam polarization kinematic separation allows online monitoring slow feedback using Wien filter Absolute value of Q 2 dedicated tracking and scanning detectors experience with HAPPEXII & Qweak easier than elastic e-p scattering I order beam helicity correlations position to 0.5 nm, angle to 0.05 nrad active intensity, position and angle feedback II order beam helicity correlations control laser spotsize fluctuations to 10-4 slow flips with Wien filter and g-2 energy flip X position difference nm micron ± RMS = 2.77 μm HAPPEXII X angle difference 0.26 ± 0.24 nrad RMS = 1.23 μrad μrad 43

95 Polarized Beam High doping for 10-nm GaAs surface overcomes charge limit. Low doping for most of active layer yields high polarization. Electrons per pulse New cathode Old cathode No sign of char limit! Laser Power (µj) 44

96 E158 Collaboration & Chronology Parity-Violating Left-Right Asymmetry In Fixed Target Møller Scattering At the Stanford Linear Accelerator Center Goal: error small enough to probe TeV scale physics E158 Collaboration Berkeley Caltech Jefferson Lab Princeton Saclay SLAC Smith Syracuse UMass Virginia 8 Ph.D. Students 60 physicists E158 Chronology Feb 96: Workshop at Princeton Sep 97: SLAC EPAC approval Mar 98: First Laboratory Review 1999 : Design and Beam tests 2000 : Funding and construction 2001 : Engineering run : Physics 2004: First PRL 2005: PRL on full statistics 45

97 Raw Asymmetry Statistics E158 A i A A i A σ i σ i 200 ppm N = 85 Million σ i σ i 600 ppb N =

98 Beam Asymmetries E158 Charge asymmetry at 1 GeV Charge asymmetry agreement at 45 GeV Energy difference agreement in A line Energy difference in A line Position differences < 20 nm Position agreement ~ 1 nm 47

99 E158: Kinematics 48

100 E158: Systematic Control Source Laser Room CID Gun Vault 49

101 E158: Systematic Control Source Laser Room IA Feedback Loop IA cell applies a helicity-correlated phase shift to the beam. The cleanup polarizer transforms this into intensity asymmetry. CID Gun Vault 49

102 E158: Systematic Control Source Laser Room POS Feedback Loop Piezomirror can deflect laser beam on a pulse-to-pulse basis. Can induce helicity-correlated position differences. CID Gun Vault 49

103 E158: Systematic Control Source Laser Room CID Gun Vault Double Feedback Loop Adjusts Δ CP, Δ PS to keep IA & Piezo corrections small (~ ppm & ~100 nm). Very slow feedback (n = 24k pairs). 49

104 E158: Systematic Control Source Laser Room 49

105 E158: Beam Monitoring Event by event monitoring at 1 GeV and 45 GeV σ energy 1 MeV σ BPM 2 microns σ toroid 30 ppm Agreement (MeV) Resolution 1.05 MeV 50

106 E158: Beam Monitoring σ energy 1 MeV σ BPM 2 microns σ toroid 30 ppm Agreement (MeV) Resolution 1.05 MeV 50

107 E158: Liquid Hydrogen Refrigeration Capacity 700 W Operating Temperature 20 K Length 1.5 m Flow Rate 5 m/s Vertical Motion 6 inches 51

108 E158: Spectrometer Collimation target Concrete shielding Detector cart Spectrometer magnets 52

109 E158: Spectrometer Collimation 52

110 E158: Spectrometer Collimation Precision Collimators Critical for the Control of Backgrounds Significant Simulation, Design and Fabrication Effort 52

111 E158: Spectrometer Collimation Precision Collimators Critical for the Control of Backgrounds Significant Simulation, Design and Fabrication Effort 52

112 E158: Spectrometer Collimation Precision Collimators Critical for the Control of Backgrounds Significant Simulation, Design and Fabrication Effort 52

113 E158: Detector Concept Data from Profile Detectors 53

114 E158: Integrating Calorimeter 20 million 17 GeV electrons per pulse at 120 Hz 100 MRad radiation dose: Cu/Fused Silica Sandwich - State of the art in ultra-high flux calorimetry - Challenging cylindrical geometry Single Cu plate ep ring Møller ring End plate Lead shield Light guide PMT holder Lead shield 54

115 E158: Detector Cart Profile Detector wheel PMT Lead Holder/shield PMT Lead Holder/shield Profile Detector wheel Luminosity Monitor region 55

116 Basic Idea: E158 Analysis electron flux : quartz : copper air light guide shielding PMT Radial and azimuthal segmentation Corrections for beam fluctuations Average over runs Statistical tests Beam polarization and other normalization 56