S-2S meeting

1. S-2S meeting Toshi Gogami 17July2014

2. Contents Missing mass correction by the information of energy loss in the target

3. Simulation setup K+ Production points were randomly moved CH2 target 4.65/9.30 [g/cm2] K-

4. Summary of the last week discussion Missing mass resolution of 12ΞBe • FWHM = 2.6 MeV with 4.65 g/cm2 CH2 target • FWHM = 3.7 MeV with 9.3 g/cm2 CH2 target • Assumed momentum resolution ( in FWHM) • Incident K-: • K+:

5. Missing mass vs. Energy loss in the target (9.3 g/cm2 CH2) SIMULATION SIMULATION Energy Losses of K- and K+ [MeV] Energy Losses of K- and K+ [MeV] Fitting with a linear function (test) Before correction After correction SIMULATION SIMULATION [Counts / 0.4 MeV] [Counts / 0.4 MeV] FWHM ~ 1.9 MeV FWHM ~ 4.0 MeV -BΞ + 4.5[MeV] -BΞ + 4.5[MeV]

6. Missing mass vs. Energy loss in the target (4.65 g/cm2 CH2) SIMULATION SIMULATION Energy Losses of K- and K+ [MeV] Energy Losses of K- and K+ [MeV] Fitting with a linear function (test) Before correction After correction SIMULATION SIMULATION [Counts / 0.4 MeV] [Counts / 0.4 MeV] FWHM ~ 2.1 MeV FWHM ~ 2.8 MeV -BΞ + 4.5[MeV] -BΞ + 4.5[MeV]

7. Summary うまく、エネルギーロスを用いた補正をかければ FWHM = 2.0 MeV 程度は達成できる。 • The natural width was not taken into account. • dE resolution was not considered. • Effect of the inverse transfer matrix is zero. • Assumed momentum resolution ( in FWHM) • Incident K-: • K+: