Monoenergetic Neutrino Beam for Long Baseline Experiments Joe Sato (Saitama & TUM) hep-ph/0503144 Joe Sato hep-ph/05????? Mark Rolinec , Joe Sato

Introduction Precision Measurement 　Precise Energy Determination for Neutrino New Idea to determine Neutrino Energy at a Detector ?

Basic Idea Control Neutrino Energy and Get Monoenergetic Neutrino Beam Electron Capture Neutrino Energy at Rest ：Definite Boosting Mother Nuclei by Control Neutrino Energy and Get Monoenergetic Neutrino Beam

Experimental Setup Concept Ionized Neutral Injection Remove

Condition on (and ) Neutrino Energy in Lab (Which Energy Range ?) Highest Energy (Which Energy Range ?) Assuming a beam pointing to a detector: At first glance determines

to get higher intensity beam Neutrinos “fly” Baseline in rest frame Inverse of “Quality Factor” (Zucchelli) Larger Preferable to get higher intensity beam Lower better

Find a nuclei with lower Longer lifetime However, Lower for mother nucleus Constraint from “our (experiment)” lifetime : At most several years Upper bound for “Lower bound” for Find a nuclei with lower and shorter

Theoretical Aspects Neutrino Energy in rest frame Case (i) : Purely monoenergetic neutrino No positron emission Consider 4.11 hour Mass difference Excited Energy Binding Energy Neutrino Energy in rest frame

Acceleration of Baseline in the rest frame 　L independent 　　(Q dependent)

For “All/2” hit a detector with diameter D=176m! Lifetime in lab Oscillation maximum is covered Lifetime in lab Baseline length in the rest frame “All/2” hit a detector with diameter D=176m! Detector Rest frame of 2D (= 176+176)m 176m

Compare Very Preliminary 0.01% (nufact) ,1% (beta beam) neutrinos are used Comparable with Very Preliminary NO optimization, rough estimate

Neutrino Energy as a function of R Detector position from beam center For a detector size D For example Very wide range of neutrino energy

Energy resolution Much better than others For the position resolution ～ 30 cm for SK Energy uncertainty is related with δR Much better than others Detection Position = Neutrino Energy !!

Energy Distribution neutrino beam uniformly distributed in its energy In a solid angle in rest frame the number of neutrinos distribute uniformly The solid angle is related with detector position neutrino beam uniformly distributed in its energy Optimum , baseline ? How large detector ? Under consideration

Candidate Nucleus Up to A=114

Case (ii) : Monoenergetic and Continuous energy neutrino If Both Electron capture and Positron Emission occur Still Lower Q Nucleus Energy distribution in rest frame

Optimum combination of ‘s ? is high is small At a detector, neutrinos from EC are monoenergetic EC dominates in decay of By varying we can survey oscillation with definite energy resolution Optimum combination of ‘s ?

both line spectrum and continuum spectrum ? EC and Emission almost half and half Can we make use of both line spectrum and continuum spectrum ? Appropriate ? First maximum ? Second maximum ?

Summary and Discussion Electron Capture : Definite Neutrino Energy at rest frame Control Neutrino Energy at lab by boosting mother nuclei For very low Very large If large enough, almost all neutrinos hit a detector Very efficient use of neutrinos Very good “quality factor”

Neutrino energy as a function of detector position Furthermore we can survey very wide range of neutrino energy simultaneously and energy is extremely “measured” by the detector position Neutrino energy as a function of detector position Simultaneous experiment with definite energy Position is determined very precisely Can we remove backgrounds more efficiently !?

For not low Both Electron capture and Positron Emission occur EC dominates in decay of Monoenergetic Neutrino at a detector due to lower By varying we can survey oscillation with definite energy resolution EC and Emission almost half and half Efficient ? Making use of both continuous and line spectrum?

1. Even under a usual beta beam context, Discussion 1. Even under a usual beta beam context, Is better candidate than ? Merit 1: lower Q 633 KeV ( positron emission) 3935 KeV Lower Q value by 6 Less nuclei by 40 Merit 2: much easier to create Even a medical doctor can create Demerit : longer life ... But, If we can circulate nuclei during one month or more, will be better source

2. Other Problems CP/T conjugate channels? How to create anti-neutrino beam ? How to create muon-neutrino beam ? Otherwise Rely on parameter fitting? Some of Correlation resolved Very Preliminary No optimization

ありがとうございました (Arigatou Gozaimashita) Vielen Danke