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Dark Neutrino Simulationswith GENIE on SBNDIker Loïc de Icaza Astiz for the SBND Collaborationi.de-icaza-astiz@sussex.ac.ukNew Directions in Neutrino-Nucleus Scattering, NuSTEC Workshop15 th March 2021
BSM Physics on SBNDo One of the outstanding puzzles in neutrino physicsare the 1 eV2 anomalies, particularly the LowEnergy Excess observed by MiniBooNE.MiniBooNE Low Energy ExcessØ It merits different avenues of research, BeyondStandard Model physics one of them.SBND qualities that enable a rich program of newexotic searches: 1mm specialresolutionHigh yield photondetection systemExcellent particleidentificationHigh flux beamand large statisticsFine calorimetrysampling15/03/21Phys. Rev. D. 103, 052002Dark Neutrino Simulations with GENIE on SBND Iker de Icaza2
Dark Neutrino Portal to Explain MB New Dark Sector with a dark neutrino and dark gauge boson Both with masses in the range of 10 to 100 MeV The process goes: beam neutrino ν interacts coherent quasi elastically with Ar nucleusupscatters to dark neutrino ND , which in turn decays toneutrino ν and dark boson ZD , this last one decays toe e-, aka the signalsmall hadronic interaction, if at all detectable Explain MiniBooNE Low Energy Excess:ee is highly boosted such that MB can’t distinguish themand are construe as νe CCQE-like Main reference 115/03/21Dark Neutrino Simulations with GENIE on SBND Iker de IcazaDNus(student version)3
Cross Section and Free pertyDefault Value Fairly simple cross sectionequation𝑀!!Dark Mediator0.420 GeV Economically computed andintegrated𝑀"Dark Neutrino0.03 GeV Currently set to the values used inthe reference paper𝜀Kinetic Mixing1.66e-4𝑈# (Squared) Flavour Mixing(1e-10, 9e-7, 1e-10)𝛼%Dark Gauge Coupling0.25 These parameters modify the crosssection formula and ultimately therelevant observable kinematicvariablesØ Reweighting is notstraightforwardDark Neutrino Simulations with GENIE on SBND Iker de Icaza4
DNus in GENIEv With the guidance of M. Roda (U. Liverpool), I have created a fullyfunctional module which generates Dark Neutrinos.Nucl.Instrum.Meth.A614 (2010) 87-104v Decays of ND and ZD handled within GENIE, with the 3 10 decaychannels relevant to the energy range implemented.v Form Factor suitable for this interaction (Phys. Lett. B. 1191.264:114-119)v 7 model parameters integrated and controlablev Extensively stress tested:v 100 isotopes,v 6 neutrinosv Energies up to 1PeVv Available in GENIE v3.2.15/03/21Dark Neutrino Simulations with GENIE on SBND Iker de Icaza5
Truth Variables of DNus in ArEvhtempEntriesMeanStd Dev60001000001.3950.38085000BNB numu energy dist400030002000100000.511.522.533.54EN4.55Evh E NEntriesMeanStd Dev90001000001.3950.381580007000Dark neutrinoenergy dist600050004000The dark neutrino energy is very closeto the initial neutrino energy30002000100000115/03/212345EN [GeV]Dark Neutrino Simulations with GENIE on SBND Iker de Icaza6
Truth Variables of DNus in ArfeeEvish E visEntriesMeanStd Dev50001000000.70090.4382h phi ee25000EntriesMeanStd Devpeaks at 3 degrees1000000.23030.2824200004000Energy of electrons150003000Angle between electron and positronmean at 13 [GeV]000.20.40.6Dark Neutrino Simulations with GENIE on SBND Iker de Icaza0.811.21.41.61.8fee2[rad]7
Truth Variables of DNus in ArTT EnergyNucleus RecoilGap between initial interactionDecay Lengthand start of e-e tracksh decay lengthEntriesMean1000001.85e 12Std Dev 2.033e 1218008000h T TEntriesMean1000000.0001204Std Dev 7.504e-05peaks at 0.1 MeV70001600600014001 cm1200500010004000800300060077% of events would decaywithin 3 mm4002000100020000Target kinetic energy-3910002000300040005000600070008000 109000 10000 D x [fm]000.10.20.30.40.5TT [GeV] 10There’s a fraction of events where displacedtracks from a tiny blip, are an extra handle foridentifying DNu events15/03/21Dark Neutrino Simulations with GENIE on SBND Iker de Icaza8
Dark NeutrinoEvent in SBND All technical challenges related to theintegration of the generator module to oursimulation framework have been overcomeand I can routinely simulate DNu events, ontheir own or along with standard neutrinointeractions.V projectionü energy deposition 500 MeVü opening angle 10 degreesü two electrons readily identified The goal is for this process to be part of thesuit of simulations available for the broaderLArTPC and neutrino community.Y projection15/03/21Dark Neutrino Simulations with GENIE on SBND Iker de IcazaSimulation9
Tagging Dark NeutrinoEvents in SBNDAgnostic Approach:ü energy deposition 500 MeVü opening angle 10 degreesü two electrons readily identified Look for events that have two clearelectron interactions coming from acommon neutrino vertex Require little to no hadronicinteraction Expect more on this soonSimulation15/03/21Dark Neutrino Simulations with GENIE on SBND Iker de Icaza10
Summary and Next Stepsq Fully working Dark Neutrino module implemented in GENIE available in v3.2.q Infrastructure in place to expand model to have more interactions types and otherenergy ranges and physics outcomes.q Breaking ground on SBND and creating technical expertise to integrate new BSMmodels with our simulations framework.q Ongoing: reconstruction and selection analysis of ee pairs in SBND simulations,that is agnostic to specific model parameters.q Dark Neutrinos search is a good prospect for SBN program, specially SBND, as itleverages the superb qualities of LArTPCs and the high flux of interactions.15/03/21Dark Neutrino Simulations with GENIE on SBND Iker de Icaza11
Backup
Additional observations It has several routes to be expanded: Neutrino masses model, might become relevant for DUNEenergies Similar observables but through other internal mechanism Add NC, RES interactions which are relevant for otherenergy ranges None of which I plan to tackle for the foreseeable future Unlike oscillations, there’s no L/E dependence so it’s observablein SBND and ICARUS. Will be much more common in SBNDdue to the high fluxπ0 are The decay ofa source of background, but can besuppressed by requiring the absence of a gap between vertexand showers and no hadronic interaction15/03/21Dark Neutrino Simulations with GENIE on SBND Iker de Icazastudentnotes13
Dark Neutrinos on mineral oil Reference paper provides aset of parameters values thatclosely follows the shape ofMB LEE By default my module runswith these values15/03/21Dark Neutrino Simulations with GENIE on SBND Iker de14
Dhandled within GENIE, with the 3 10 decay channels relevant to the energy range implemented. vForm Factor suitable for this interaction (Phys. Lett. B. 1191.264:114-119) v7 model parameters integrated and controlable vExtensively stress tested: v100 isotopes, v6 neutrinos vEnerg
