TAUP2007 Sep. 11-15, 2007 Sendai, Japan

1. TAUP2007 Sep. 11-15, 2007 Sendai, Japan Constraints of oscillation parameters through MSW effect of Supernova neutrinos Shiou KAWAGOE The Graduate University for Advanced Studies (SOKENDAI) / NAOJ JSPS Research Fellow T. Kajino, The Graduate University for Advanced Studies (SOKENDAI) / NAOJ H. Suzuki, Tokyo University of Science/NAOJ K. Sumiyoshi, Numazu College of Technology S. Yamada Waseda University

2. Outline 1．Introduction 2. Purpose 3．Result and Discussions ・The adiabatic prompt explosion model ・The observation of supernova neutrinos 4．Summary

3. Introduction (1) Collapse-driven Supernova Gravitational Collapse Neutrino trapping Shock wave Neutrino Supernova

4. νe Wilson’s model νe Flux (count / MeV) νx Energy (MeV) Introduction (2) Supernova Neutrinos ・The gravitational energy: ・All of kinds of neutrinos are generated. ・T < O(100) MeV → ・The energy spectrum is different.

5. 23 Introduction (3) Neutrino Oscillations The mass squared difference The mixing angle ? Normal Inverted

6. Inverted Normal H L L H Introduction (4) The Matter (MSW) Effect ●H-resonance ： adiabatic Is large.and Is small. . shock Is large. non adiabatic Is small.or . ●L-resonance ： adiabatic m2 ne ne

7. Purpose The shock wave is influenced on neutrino oscillation. --MSW effect--- We estimate the supernova neutrino events which observed with Super-Kamiokande and SNO. ★We study how the influence of the shock wave appears in neutrino oscillations. ★Can we constrainθ１３ and the mass hierarchy?

8. 105 Density [g/cm3] 103 1010 R [cm] The Adiabatic Prompt Explosion Model • ・Implicit lagrangian code • for general relativistic • spherical hydrodynamics • Yamada et al. 1997 • One-dimensional simulation • Adiabatic prompt • explosion model • 15Msolar star • Woosley and Weaver,1995 We succeeded in calculating propagation of shock waves from iron core through the envelopes in single step.

9. The Calculation of Event Number ☆Survival Probability of neutrino ☆Neutrino spectra ☆Event number spectra Original spectra Spectrum ( 5 < E < 60MeV) Efficiency Target number Distance of supernova → 10kpc Cross section

10. Event rate of Super-Kamiokande ☆target : pure water (32,000 ｔ) ☆ Normal hierarchy Inverted hierarchy Event Rate [/s] Event Rate [/s] [shock / no shock] [shock / no shock] Time [s] Time [s] ☆inverted mass hierarchy → The event rates are depending on the parameters.

11. Event rate of SNO ・・・ has stopped（≧ω≦）. ☆heavy water (1,000 t) ☆ Inverted hierarchy Normal hierarchy Event Rate [/s] [shock / no shock] ☆normal mass hierarchy → The event rates are depending on the parameters.

12. Result ☆The event rates of SK change greatly. 　　→θ13 is large and the hierarchy is inverted. ☆The event rate of SNO change greatly. 　　→θ13 is large and the hierarchy is normal. ☆The event rates of SK and SNO decrease simply. 　　→θ13 is small.

13. Summary ☆The event rates are different depending on the value of θ13. →There is possibility that we can constrain the parameters whether θ13 is large or small. ☆θ13 is large. →The influence of the shock wave appears to the event rates. 　 →We can suggest the mass hierarchy by the observation. ☆We will calculate other detector . ☆Improvement underway Detailed studies of the cooling effect of the proto-neutron star are underway.