Bending crystals for magnetic and electric dipole moment measurements Material from A. Stocchi (LAL Orsay), S. Redaelli, D. Mirachi, W. Scandale (CERN)

Introduction Work presented here is from UA9 collaboration and LHC collimation team. Main idea: crystals can be used to deflect hadrons: To extract protons from LHC beam halo and send it to a target To bend particles produced in a target and send them into an experiment Different setups under consideration: dedicated experiment at the SPS re-using an existing experiment around the LHC ring, in parasitic mode

Bending of hadrons in crystal Huge magnetic field used for precession measurements, see N. Neri talk

Circulating beam extraction tests at SPS

Circulating beam extraction tests at SPS Major difficulty at the LHC

Crystal collimation at the LHC Crystals can be used as collimators at the LHC

First proton channeling at 6.5 TeV

Crystals for dipole moment measurements D.Mirarchi1, S. Redaelli1, W. Scandale1,2, A. Stocchi2. 1CERN, 2LAL. “Physics Beyond Colliders Kickoff Workshop”, Geneva, September 6th and 7th 2016 Crystals for dipole moment measurements Setup with two crystals: the first one deflects the beam halo to a target, the second one attached to the target produces a strong magnetic field where the moments of produced particles precess.

Proposal for a setup in the LHC D.Mirarchi1, S. Redaelli1, W. Scandale1,2, A. Stocchi2. 1CERN, 2LAL. “Physics Beyond Colliders Kickoff Workshop”, Geneva, September 6th and 7th 2016 Proposal for a setup in the LHC

Possible layout around LHCb D.Mirarchi1, S. Redaelli1, W. Scandale1,2, A. Stocchi2. 1CERN, 2LAL. “Physics Beyond Colliders Kickoff Workshop”, Geneva, September 6th and 7th 2016 Possible layout around LHCb

Losses expected in IR8-IR1 D.Mirarchi1, S. Redaelli1, W. Scandale1,2, A. Stocchi2. 1CERN, 2LAL. “Physics Beyond Colliders Kickoff Workshop”, Geneva, September 6th and 7th 2016 Losses expected in IR8-IR1 These predicted losses are too high to allow parasitic running during LHC standard operation, a large reduction has to be obtained to be able to do so: major challenge

Conclusions Successful tests of crystal channelling and collimation obtained in the last years at SPS and LHC Use of double crystal setup for dipole moment measurement is compatible with LHC and LHCb geometry and acceptances, but a long way before a fully effective scenario Next steps for the design: Full layout Compatibility with the LHC collimation system and with the LHCb detector because of losses Optimize for the physics measurements: The beam energy The target and the crystal length to maximize the production of Λc and their channeling efficiency The crystal bending angle for an optimal acceptance of the Λc fragments into LHCb Investigate the alternative option of an experiment with an extracted beam (SPS or LHC) Propose tests in the SPS and H8 in the North Area and then in the LHC, to investigate before LS2 The optimal assembly Target&Crystal2 The efficiency of the double crystal scenario The compatibility with the crystal collimation scenario the compatibility with LHCb and with the collimation system The parasitic mode operation The background and the data taking rates Very challenging project and schedule