PVDIS June 2, 2011 PVDIS overview

Outline Review of Physics and how to optimize spectrometer Summary of Progress Open Issues June 2, 2011 PVDIS overview

PVDIS: Electron-Quark Scattering Moller PV is insensitive to the Cij PV elastic e-p scattering, APV C1u and C1d will be determined to high precision by Qweak, APV Cs PV deep inelastic scattering C2u and C2d are small and poorly known: one combination can be accessed in PV DIS New physics such as compositeness, leptoquarks: Deviations to C2u and C2d might be fractionally large June 2, 2011 PVDIS overview

Deep Inelastic Scattering a(x) and b(x) contain quark distribution functions fi(x) e- N X Z* * 1 at high x For an isoscalar target like 2H, structure functions largely cancel in the ratio at high x At high x, APV becomes independent of x, W, with well-defined SM prediction for Q2 and y New combination of: Vector quark couplings C1q Also axial quark couplings C2q Sensitive to new physics at the TeV scale Unknown radiative corrections for coherent processes PVDIS: Only way to measure C2q June 2, 2011 PVDIS overview 4

Search for CSV in PV DIS For APV in electron-2H DIS: Strategy: u-d mass difference electromagnetic effects Direct observation of parton-level CSV would be very exciting! Important implications for high energy collider pdfs Could explain significant portion of the NuTeV anomaly For APV in electron-2H DIS: Sensitivity will be further enhanced if u+d falls off more rapidly than u-d as x  1 measure or constrain higher twist effects at x ~ 0.5-0.6 precision measurement of APV at x → 0.8 to search for CSV Strategy: June 2, 2011 PVDIS overview

Subject of a workshop at Madison, Wisconsin Higher Twist Subject of a workshop at Madison, Wisconsin  APV sensitive to diquarks: ratio of weak to electromagnetic charge depends on amount of coherence (elastic He vs PVDIS) Do diquarks have twice the x of single quarks? If Spin 0 diquarks dominate, likely only 1/Q4 effects June 2, 2011 PVDIS overview

Need Full Phenomenology Start with Lorentz Invariance There are 5 relevant structure functions BIG Small; use ν data (Higher twist workshop at Madison, Wisconsin) June 2, 2011 PVDIS overview

Why HT in PVDIS is Special Bjorken, PRD 18, 3239 (78) Start with CVC (deuteron only) Wolfenstein, NPB146, 477 (78) Zero in QPM Isospin decomposition before using PDF’s HT in F2 may be dominated by quark-gluon correlations Higher-Twist valance quark-quark correlations Vector-hadronic piece only June 2, 2011 PVDIS overview

Quark-Quark vs Quark-Gluon What is a true quark-gluon operator? Parton Model or leading twist Quark-gluon diagram u u u d Quark-gluon operators correspond to transverse momentum QCD equations of motion Di-quarks Might be computed on the lattice June 2, 2011 PVDIS overview

OOPS: Higher Twist in b(x) is now Background Talks by Mantry and Owens on this subject are scheduled for PAVI11 These hadronic corrections can be obtained from charged-current neutrino scattering data June 2, 2011 PVDIS overview

Statistical Errors (%) vs Kinematics Strategy: sub-1% precision over broad kinematic range for sensitive Standard Model test and detailed study of hadronic structure contributions Error bar σA/A (%) shown at center of bins in Q2, x 4 months at 11 GeV 2 months at 6.6 GeV June 2, 2011 PVDIS overview

Coherent Program of PVDIS Study Strategy: requires precise kinematics and broad range Fit data to: C(x)=βHT/(1-x)3 Measure AD in NARROW bins of x, Q2 with 0.5% precision Cover broad Q2 range for x in [0.3,0.6] to constrain HT Search for CSV with x dependence of AD at high x Use x>0.4, high Q2, and to measure a combination of the Ciq’s x y Q2 New Physics no yes CSV Higher Twist Errors on fit used to optimize spectrometer. June 2, 2011 PVDIS overview

Sensitivity with PVDIS June 2, 2011 PVDIS overview

Sensitivity: C1 and C2 Plots 6 GeV World’s data PVDIS Precision Data PVDIS Qweak Cs June 2, 2011 PVDIS overview

PVDIS on the Proton: d/u at High x Independent FOM Deuteron analysis has large nuclear corrections (Yellow) APV for the proton has no such corrections (complementary to BONUS) 3-month run The challenge is to get statistical and systematic errors ~ 2% June 2, 2011 PVDIS overview

Which Magnet? Criteria are: Acceptance (for 30 sectors) Resolution (Probably non-issue) Length of Cerenkov detectors—big issue? June 2, 2011 PVDIS overview

Possible Magnets BaBar CDF CLEO Zeus Hall D For PVDIS, we haven’t ruled out any of these magnets. (Need 5 Monte Carlo’s) June 2, 2011 PVDIS overview

Will determine number of GEM Tracking GEM wires not orthogonal. GEM produces analog output that must be interpreted. Plan to use code developed for SBB spectrometer. Will determine number of planes required. June 2, 2011 PVDIS overview

MC Ready for New Issues Momentum calibration. Need MC Accidentals and dead time. Trigger: 10 kHz/sector; 100x more pions. Errors due to pion backgrounds (1% contamination?). June 2, 2011 PVDIS overview

Higher-Twist fit to ν-Data June 2, 2011 PVDIS overview

A New Design for Precision PV DIS Physics Over a Broad Kinematic Range High Luminosity on LH2 & LD2 Better than 1% errors for small bins x-range 0.25-0.75 W2 > 4 GeV2 Q2 range a factor of 2 for each x (Except x~0.75) Moderate running times Solenoid (from BaBar, CDF or CLEOII ) contains low energy backgrounds (Moller, pions, etc) trajectories measured after baffles Fast tracking, particle ID, calorimetry, and pipeline electronics Precision polarimetry (0.4%) June 2, 2011 PVDIS overview