Measuring parcle momenta via Mulple Coulomb Mulple Coulomb Scaering MicroBooNE Scaering in the MicroBooNE Time Projecon Chamber ● Whenever a parcle is passing through maer it suffers a

● The MicroBooNE detector will be the largest Liquid Argon large number of small angle scaers Time Projecon Chamber (LArTPC) operang in the United Leonidas N. Kalousis (Virginia Tech) – Coulomb interacons with (mainly) atomic nuclei States, US. for the MicroBooNE Collaboraon – Large number of interacons, stochasc process ● Main movaon for building MicroBooNE is the inves- x gaon of the MiniBooNE low-energy excess Modified Highland formula Modified Highland formula

● Nonetheless, MicroBooNE will also: Δθ – Perform neutrino cross-secon measurements on argon – Study the background relevant for proton decay in LArTPCs

– And, of course, further advance the LArTPC technology θ0 : RMS of the Δθ distribuon (mrad) p : parcle momentum (GeV/c) : material thickness (cm) ● Addionally, it could contribute to more exoc searches X : radiaon length (cm) A maximum likelihood technique x 0 – Neutrinos from Supernovae explosions References – Burst neutrinos J. Beringer et al., Phys. Rev. D 86 (2012) 010001 Basic algorithm: H. A. Bethe, Phys. Rev. 89 (1953) 1256 – Break up the parcle track in segments of equal length (Δs) Experimental layout – Find the direcon (in zy and zx) of each segment Why Mulple Coulomb Scaering ?

● MicroBooNE, just like MiniBooNE, will be installed along – Calculate the angular deflecon (Δθ) for two segments separated by • the Booster Neutrino Beam (BNB) at Fermi Naonal Calorimetric informaon (wires) can be used to measure parcle energy (and thus momentum) in MicroBooNE Laboratory. θ3 • Adequate technique for fully contained events θ2 Target and Horn Dirt • Excellent resoluon, 2% at 1 GeV • Fails when the parcle exits the TPC θ1 (parally contained events) • In the case of parally contained events, momentum and Decay tunnel MicroBooNE energy can be determined by means of Mulple Coulomb Accelerates – Say that you focus on the i-th and j-th segments, Δθij = θj – θi Scaering (MCS) protons to 8 GeV ~ 800 MeV neutrinos • A technique employed within neutrino physics by – The probability to measure Δθij between i and j is: DONUT, OPERA, MACRO and ICARUS • Placed at a distance of ~470 m from the proton target, in Find E0 that maximizes: • In the MicroBooNE detector, a large number of charged the Liquid Argon Test Facility (LArTF). current interacons will have a muon escaping the TPC • It is will start data taking in the end of 2014 and run for 2 - • No magnec field or muon range detectors 3 years in the neutrino mode accumulang 6.6 1020 POT. • These events can be reconstructed using MCS

The MicroBooNE detector Results – σij depends on the inial energy E0 (momentum) since, Detecon technique(s) ● This technique has been applied to Monte-Carlo muons

– The energy at the i-th segment of the track can be found using the – Parcle tracks taken from Monte-Carlo truth informaon, δθ0 = 0 ● Ionizaon electrons dried along ΔE – Muons simulated upstream the MicroBooNE LArTPC with momenta informaon on the wires, Ei = E0 – i macroscopic distances (2.5 m, 1.6 ms) between 0.5 to 5.0 GeV/c

● Scinllaon photons (a few ns) Detector resoluon : – Note though that the algorithm probably can not be used above 2.5 - 3 GeV/c due to the measurement errors Characteriscs – Δθ The angular deflecons ( ij) are smeared Momentum determination via MCS ● Three planes of wires (3mm pitch) 6 by the intrinsic detector resoluon (measurement errors) Truth Monte-Carlo muon tracks o – in GeV/c 5 A collecon plane at 0 from vercal ●

θ given by the Highland formula reco 0 Ideal scenario, p =p reco true – Two inducon planes at ±60° p 4 ● δθ0 corresponds to the measurement uncertaines 3 ● Opcal system of 32 8’ cryogenic 10.4 m × 2.5 m × 2.3 m – The likelihood becomes a funcon of both E and δθ PMTs and 4 light guide prototypes Uniform E field, 500 V/cm 0 0 2 170 tons of purified LAr ● Measure δθ0 in situ, or esmate it through Monte-Carlo 1 ● Excellent energy resoluon (83 m3 of acve volume) LAr, simulation, preliminary 0 ● Fit simultaneously E and δθ 0 1 2 3 4 5 0 0 p in GeV/c ● Robust tracking and PID capabilies true