ENUBET: a monitored beam for the precision era of neutrino physics

Fabio Iacob, University of Padova and INFN Padova, on behalf of the NP06/ENUBET Collaboration This project has received funding from the European Research Council (ERC) under the TAUP 2021 - Valencia: International Conference on Topics in Astroparticle and Underground Physics European Union's Horizon 2020 research and innovation programme (grant agreement N. 681647) Shashlik to lateral WLS NP06/ENUBET OVERVIEW readout design migration for THE DEMONSTRATOR ENUBINO fibers NP06: CERN Neutrino Platform experiment number 6 attenuating SiPM Scintillator 2

- × 18 reduction

radiation damage. m c

ENUBET: Enhanced NeUtrino BEams from Tagging 1 Deliverable of the - Hadronic cal + 훾veto T O prototype beam ENUBET ERC project is P GOAL: developing a new narrow-band exposure at CERN-PS neutrino beam in which the flux and the tagger flavor composition are known at 1% demonstrator, a Longitudinal coordinate along tagger (cm) level, and the energy with O(10%) Start of ERC grant & Systematics budget portion of the initial shashlik design finalization & instrumented decay precision. beam exposure at CERN-PS demonstrator DEMONSTRATOR MOTIVATION supported by the European Strategy construction tunnel: for Particle Physics Deliberation document ● Under construction, (page 5): to be finished in “To extract the most physics from DUNE and 1979 2016 2017 2018 2019 2021 2022 2022 for beam exposure at CERN. The ENUBINO prototype is a single Hyper-Kamiokande, a complementary programme of azimuthal portion ● Dimensions: azimuthal experimentation to determine neutrino cross- Iron (3 radial LCM) of the demonstrator: quarter-of-circle, sections and fluxes is required. [...]. The SiPM irradiation campaign ● Scintillator tiles frontally possible implementation and impact of a at INFN-LNL and beam length 1.65 m. coupled to WLS-fibers. exposure of irradiated ● facility to measure neutrino cross-sections at Instrumented with ● 10-fibers bundle (1 LCM) read by a sensors at CERN-PS electronics in 4 x 4 mm2 RGB SiPM. the percent level should continue to be Demonstrator beam studied.” exposure at CERN-SPS central 45 degrees. “The possibility of using & conceptual design Target tagged-neutrino beams in high- report energy experiments must have Neutron shield Calorimeter + 훾-veto absorber occurred to many people.” (30 cm 5% borated polyethylene) (11 cm radial iron part) Proton B. Pontecorvo, Lett. Nuovo ● Neutron reduction factor = 18 beam Cimento, 25 (1979) 257 Dec ay ENUBET becomes a CERN (e + tun / + ne Neutrino Platform experiment � t l dump & agg er) Range-meter )

+ .

(� monitor) u

THE .

THE PROTON TARGET a (

r

The design of the cylindrical target has been TRANSFER LINE o t c

studied to optimize the challenging trade-off e

Calorimeter functional block is the LCM: t t

THE DECAY TUNNEL tagging between heat dissipation and yield loss due a e ● Focusing quadrupoles d LCM = Lateral Compact Module x to re-interactions in the target. u r 3 ● Aperture radius 15 cm l a ● ● F f Lepton deposited energy in LCM dimensions: 3 × 3 × 10 cm (4.3 X0) NP06/ENUBET will be the � energy (GeV)

innermost layer: ● ] Made of scintillator and iron T ➢ + O first > 28 MeV for e P + + + / ● 2 e /� /� discrimination capabilities - ➢ + 0 Assuming a realistic operation in [5, 15] MeV range for � 1

“monitored neutrino beam”: [

at CERN-SPS corresponding to s

n 19 ● flux monitored by o 4.5 × 10 POT/year, the newly �e a

● K

훾 suppression from t0-layer simulated transfer line TLR6 f o

tagging in would ensure, in a far r e

● b detector displaced 50 m instrumented decay hadronic bkg suppression m u permitted by longitudinal, N downstream its end, the channel. occurrence of 104 � - CC transverse, and radial Target length [cm] e ● � flux monitored by � segmentation of calorimeter. interactions in about 2 years. tagging in Hadron dump ● Neural Network is applied ● instrumented decay Bending dipoles 3 radial layers: graphite for optimal signal- Instrumented core, iron coating, and channel and range-meter ● Normal conducting background discrimination. decay line Proton dump outer borated concrete in the hadron dump. ● 1.5 T field ● Neutron backscattering ● 14.8° total bend from proton beam-line attenuation of 0.2

EXAMPLE: consider as observable the position Z Tagged in Photon veto rings are made of scintillator doublets: The hadro-production parameters 3 �-FLUX along the calorimeter of the muons from K-decays. decay tunnel ● 3 are constrained to the values Scintillator dimension 3 × 3 × 0.5 cm (0.012 X0) maximizing the likelihood ● Rejects gammas from �0 decay SYSTEMATICS 1 Photon veto Lepton monitoring Tagged in data coming from Construct from range-meter working principle the calorimeter MC simulation and range-meter the PDF of Z,and Rel. � e+ topology (signal) �0 topology (backgr.) �+ topology (backgr.) can constrain the store it as a ] % [

hadro-production histogram �

3 cm e

and beamline v i t a

parameters, l e R implying a 0.5 cm (0.012 X0) Given the lepton monitoring data-set {Z} reduction of the i systematic 2 compute the likelihood for various values ● The ERC ENUBET Project site: https://enubet.pd.infn.it/ REFERENCES uncertainty on the of the hadro-production parameters � 휈 energy bins ● F. Acerbi et al., CERN-SPSC-2021-013, SPSC-SR-290, Geneva, 2021 neutrino flux. Simplified hadro-production toy model ● F. Acerbi et al., The ENUBET tagger prototype: construction and testbeam performance, JINST 15 P08001, 2020 shows systematic uncertainty reduction ● G. Ballerini et al., Test beam performance of a shashlik calorimeter with fine-grained longitudinal segmentation, JINST 13 P01028, 2018. from initial 15% down to 1.8%. Complete ● A. Longhin, L. Ludovici and F. Terranova, A novel technique for the measurement of the electron neutrino cross section, Eur. Phys. J. C 75 155, 2015. study of systematics budget ongoing.