1. The CERN Near Detector(s) initiative

2. An European ND forum
Strong interest in Europe for Near Detectors activities for future LBL experiments, both in US and Japan
Interest extends outside of the “neutrino community”
At CERN: Neutrino Platform, EP-nu group, TH-nu group: can act as catalysers
 CERN proposes to coordinate the European effort on ND
Addressing physics first:
4 WPs focussing on the main sources and handles on systematics (flux, cross-section, TH-models, ..)
Best ND technology derived by the outcome of the physics studies
R&D will start once the needs will be defined
Keep coordination with DUNE Near Detector Concept Study and initiatives for T2K/HK

3. https://twiki.cern.ch/twiki/bin/view/CENF/NearDetector
Mailing list : now sending invitations
Working groups WG1: Measurement of neutrino flux WG2: Cross sections, theory WG3: Cross sections, experimental WG4: Sensitivity studies WG5: Requirements for detectors and R&D

4. WG1:Measurement of neutrino flux
The e-scatter method : define requirements for detector, needed exposure, study dependence on nu angle, possibility to measure nu energy, precision achievable, limitations.
The low-nu method: requirements for detector, needed exposure, reliability at low energies, precision achievable, limitations.
Hadroproduction
Beam monitoring and synergies with muon monitors
Other ideas (nu-prism...), but also the “spectrometer” for DUNE beam, enubet
Example studies of “real” detectors..
Near-to-far extrapolation

5. WG2Cross sections, theory
Review status of neutrino generators vs data, identify areas of development
Comparisons with electron scattering data if available in the generators
Generate a test database with available data
Stimulate new/complementary experimental programs where needed
Address in detail the electron-muon and neutrino-antineutrino differences, extrapolate achievable precision
Cross sections, theory

6. WG3: Cross sections, experimental
Target nucleus
Detector effects on event identification
Detector effects on energy reconstruction
Needed coverage (is 4pi necessary?)
Need magnetic field ?
Identify “control samples” or distributions to validate models and reconstruction
Near-far extrapolation if expt. technique not exactly the same (Gas vs Liquid)

7. WG4: sensitivity studies
Analyze the relative contribution of different systematic errors to the final sensitivity
Compare different methods: VALOR, Minos, Nova, Mach3...
Evaluate need for / develop new tools
Provide guidelines to WG1-WG3 in terms of required systematic/statistics

8. WG5: Requirements for detectors and R&D
Gather detector requirements from other Wgs
Search for detector techniques possibly matching the requirements
Steer R&D efforts

9. First Steps Send out invitations, hopefully fill the mailing lists..
First (videoconf) meeting soon, common to all wgs
Define WG conveners (possibly already at first meeting)