T. Inagaki - Academia.edu (original) (raw)
Papers by T. Inagaki
Nuclear Physics B, 1973
ABSTRACT The differential cross sections for the reaction gamma + n --> pi0 + n have been ... more ABSTRACT The differential cross sections for the reaction gamma + n --> pi0 + n have been measured at pions angles of 45°, 60°, 105°, 120° and 140° in the c.m.s. for photon energies of 500-900 MeV. Both pi0 meson and recoil neutron from a liquid deuterium target were detected with a pair of Cerenkov counters combined with lead spark chambers and a hodoscope consisting of 16 modules of plastic scintillation counters. The experimental results were compared with the recent phenomenological partial-wave analysis, and indicate that the ratio of the isoscalar part to the isovector part of the resonant amplitude of B2_(N'(1520)(D13)) is only about 0.2, and that in the gamma + n --> pi0 + n reaction there is no remarkable enhancement due to the N'(1470)(P11) resonance.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2000
A detector called Drift Chamber Beta-ray Analyzer (DCBA) will provide momentum information of eac... more A detector called Drift Chamber Beta-ray Analyzer (DCBA) will provide momentum information of each -ray in double beta decay. The DCBA is expected to have good capabilities for particle identi"cation, detection e$ciency, background elimination and decay-source integration. Under the assumption of mass mechanism dominance in neutrinoless double beta decay, a simulation study shows that a combination method using both sum and single-energy distributions of double beta decay events can separate 0 -and 2 -events down to 0.05 eV of the e!ective neutrino mass with the help of a calculated nuclear matrix element, even though the DCBA has relatively poor energy resolution.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1995
The detection inefficiency of a 10 mm thick plastic scintillation counter for charged particles (... more The detection inefficiency of a 10 mm thick plastic scintillation counter for charged particles (1 GeV/c e *, ?T * and protons) was examined in a test experiment at the Tl line of the KEK 12 GeV Proton Synchrotron. The inefficiencies for e+ and C were obtained to be (3.2 i 0.9) X 10-j and (6.0 i 0.6) X lo-'; those for n+ and e-were obtained as the upper limits of 1.6 X 10m5 and 1.3 X 10-j in the case that the energy deposit was required to be more than 1 MeV in the scintillator. For protons, the inefficiency was obtained to be (5.0 k 1.6) X lop5 in the case that the energy deposit was required to be more than 1.9 MeV in the scintillator. For e *, the ADC spectra of the output signals as well as the obtained inefficiencies were well reproduced by calculations using the EGS4 code.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2011
ABSTRACT The aim of the DCBA (Drift Chamber Beta-ray Analyzer) experiment is to search for neutri... more ABSTRACT The aim of the DCBA (Drift Chamber Beta-ray Analyzer) experiment is to search for neutrinoless double beta decay (0νββ). The half-life of 0νββ is expected to give us the information of Majorana nature and the absolute mass scale of neutrinos. A prototype test apparatus DCBA-T2 has the energy resolution of about 150keV (FWHM) around 1MeV. In order to check the detector performance, engineering runs detecting double beta decay of 100Mo started in May 2009 using natural Mo, which contains 9.6% of 100Mo. Ten candidates of the double beta decay (ββ) have been detected so far. It has been found that the background events due to 214Bi decay are distinguishable from the double beta decays by detecting α-particles from 214Po.
Proceedings of 1994 IEEE Nuclear Science Symposium - NSS'94, 1995
We have constructed endcap photon detectors with undoped Cesium Iodide (CsI) crystals for a K+→π+... more We have constructed endcap photon detectors with undoped Cesium Iodide (CsI) crystals for a K+→π+νν¯ experiment E787 at Brookhaven National Laboratory (BNL). To reject backgrounds it is essential to have a photon detection system with high efficiency. Good resolution for timing and energy is critical for reducing accidental vetoes. The endcap detectors are located in a magnetic field of 1 T. Fine-mesh photomultiplier tubes are attached directly to the crystals for efficient light collection, and the fast-decay component of CsI light output is selected by optical filters. The tube gains are monitored with the light from a xenon flash lamp and from light pulsers. The pulse shapes are recorded by transient digitizers based on charged coupled devices (CCDs), which enable precise determination of timing of photons. The construction and performance of the detectors are described
Physical Review D - PHYS REV D, 1989
We report on the present status of a search for the rare decays K0L-->mue and K0L-->ee at t... more We report on the present status of a search for the rare decays K0L-->mue and K0L-->ee at the KEK 12-GeV Proton Synchrotron. We found no K0L-->mue or K0L-->ee events and found 54 K0L-->mumu events. The upper limits of the K0L-->mue and K0L-->ee branching ratios are B(K0L-->mue)<4.3×10-10 and B(K0L-->ee)<5.6×10-10 at 90% confidence level. The 54 K0L-->mumu events correspond to an absolute branching ratio of (8.4+/-1.1)×10-9.
The Astrophysical Journal, 2002
Using the Super-Kamiokande neutrino observatory, a search was conducted for neutrinos produced in... more Using the Super-Kamiokande neutrino observatory, a search was conducted for neutrinos produced in coincidence with gamma-ray bursts observed by the BATSE detector. Super-Kamiokande data in the neutrino energy range of 7 MeV ∼ 100 TeV were analyzed. For gamma-ray bursts that occurred between 1996 April and 2000 May, no statistically significant signal in excess of the background levels was detected. Implied upper limits on associated GRB neutrino production are presented.
Physical Review D - PHYS REV D, 2006
The first dedicated experiment for the rare kaon decay K{sub L}°âÏ°νν has been performed by t... more The first dedicated experiment for the rare kaon decay K{sub L}°âÏ°νν has been performed by the E391a Collaboration at the KEK 12-GeV proton synchrotron. A new upper limit of 2.1x10â»â· at the 90% confidence level was set for the branching ratio of the decay K{sub L}°âÏ°νν using about 10% of the data collected during the first period of data taking.
Physics Letters B, 2001
The KEK to Kamioka long-baseline neutrino experiment (K2K) has begun its investigation of neutrin... more The KEK to Kamioka long-baseline neutrino experiment (K2K) has begun its investigation of neutrino oscillations suggested by atmospheric neutrino observations. Twenty-eight neutrino events have been detected in coincidence with the expected arrival time of the beam in the 22.5 kt fiducial volume of Super-Kamiokande, the far detector at 250 km distance. The expectation is 37.8 +3.5 −3.8 , derived using measurements of neutrino interactions in a near detector and extrapolation using a beam simulation validated by a measurement of pion kinematics after production and focusing. The background is of order 10 −3 events.
Physics Letters B, 1992
A high-statistics experiment on the reaction n-p--,n +n-n°n at 8.06 GeV/c has been performed usin... more A high-statistics experiment on the reaction n-p--,n +n-n°n at 8.06 GeV/c has been performed using a spectrometer detecting both charged particles and gamma rays. A partial-wave analysis based on the isobar model has been carried out for ~+x-Tr ° data in the mass range between 0.86 and 1.50 GeV for four t' regions: 0.0-0.1, 0.1-0.25, 0.25-0.45 and 0.45-0.95 (GeV/c2). Two axial-vector resonances, a~ (1260) and h~ , were observed in the analysis. The masses and widths of a~ and h t were determined to be M(a~ ) = 1121 + 8 MeV, F(a, ) = 239 + 11 MeV, M( h~ ) = 1168 + 4 MeV and F( hi ) = 345 + 6 MeV, respectively, by fitting the Breit-Wigner formula to the partial wave amplitude. A fit including the Deck type background was also tried in each t' region. The results showed a small effect on these resonance parameters and were consistent with those obtained by the simple Breit-Wigner fitting.
Physics Letters B, 2005
Neutral current single π 0 production induced by neutrinos with a mean energy of 1.3 GeV is measu... more Neutral current single π 0 production induced by neutrinos with a mean energy of 1.3 GeV is measured using a 1000 ton water Cherenkov detector in the K2K long baseline neutrino experiment. The cross section for this process relative to the total charged current cross section is measured to be 0.064 ± 0.001(stat.) ± 0.007(sys.). The momentum distribution of neutral current π 0 s from a water target is measured with high statistics for the first time.
Physical Review Letters, 2000
We report the first measurement of a structure dependent component in the decay K + → µ + ν µ γ. ... more We report the first measurement of a structure dependent component in the decay K + → µ + ν µ γ. Using the kinematic region where the muon kinetic energy is greater than 137 MeV and the photon energy is greater than 90 MeV, we find that the absolute value of the sum of the vector and axialvector form factors is |F V + F A | = 0.165 ± 0.007 ± 0.011. This corresponds to a branching ratio of BR(SD + ) = (1.33 ± 0.12 ± 0.18) × 10 −5 . We also set the limit −0.04 < F V − F A < 0.24 at 90% c.l.
Physical Review Letters, 2004
Physical Review D, 2004
... E.; Stone, JL; Sulak, LR; Walter, CW; Wang, W.; Goldhaber, M.; Barszczak, T.; Casper, D.; Cra... more ... E.; Stone, JL; Sulak, LR; Walter, CW; Wang, W.; Goldhaber, M.; Barszczak, T.; Casper, D.; Cravens, JP; Gajewski, W.; Kropp, WR; Mine, S.; Liu ... K.; Shibata, T.; Kajiyama, Y.; Nagashima, Y.; Takita, M.; Yoshida, M.; Kim, HI; Kim, SB; Yoo, J.; Okazawa, H.; Ishizuka, T.; Choi, Y.; Seo ...
![Research paper thumbnail of Study of the K_{L}^{0}→π^{0}π^{0}νν[over ¯] decay](https://attachments.academia-assets.com/43966662/thumbnails/1.jpg)
](Physical Review D, 2011
We studied the rare decay K 0 L → π 0 π 0 νν with the E391a detector at the KEK 12-GeV proton syn... more We studied the rare decay K 0 L → π 0 π 0 νν with the E391a detector at the KEK 12-GeV proton synchrotron. With 9.4G K 0 L decays an upper limit on the branching fraction was set to be 8.1×10 −7 at the 90% confidence level (C.L.). We also set the limit on the process of K 0 L → π 0 π 0 X(X → invisible particles), which varied from 7.0×10 −7 to 4.0×10 −5 according to the mass of X from 50MeV/c 2 to 200MeV/c 2 .
![Research paper thumbnail of Experimental study of the decay K_{L}^{0}→π^{0}νν[over ¯]](https://attachments.academia-assets.com/43966694/thumbnails/1.jpg)
](Physical Review D, 2010
The first dedicated search for the rare neutral-kaon decay K 0 L → π 0 νν has been carried out in... more The first dedicated search for the rare neutral-kaon decay K 0 L → π 0 νν has been carried out in the E391a experiment at the KEK 12-GeV proton synchrotron. The final upper limit of 2.6 ×10 −8 at the 90% confidence level was set on the branching ratio for the decay.
Nuclear Physics B - Proceedings Supplements, 1991
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2002
The Publisher regrets the exchange of Figs. 15 and 17 on pp. 252-253 of the above paper. Fig. 15 ... more The Publisher regrets the exchange of Figs. 15 and 17 on pp. 252-253 of the above paper. Fig. 15 should be Fig. 17 and vice-versa. However, the captions of Figs. 15 and 17 are correct. $ PII of original article S0168-9002(01)01680-1
Journal of Physics: Conference Series, 2008
ABSTRACT Neutrinoless double beta decay experiment is the only realistic method to investigate th... more ABSTRACT Neutrinoless double beta decay experiment is the only realistic method to investigate the Majorana nature and the absolute mass scale of neutrinos. The DCBA (Drift Chamber Beta-ray Analyzer) experiment can separately detect electrons from other background particles in a uniform magnetic field. The kinetic energy of each electron is obtained from its momentum measurement. Therefore no energy calibration is required. The test prototype DCBA-T2 obtained the energy resolution of about 150 keV (FWHM) for 976 keV internal conversion electrons from 207Bi More improved prototype DCBA-T3 is now under construction. Its energy resolution is expected to be less than 100 keV (FWHM) according to the simulation study with Geant4. The future detector (temporarily called Magnetic Tracking Detector: MTD) enlarged from DCBA-T3 can investigate effective neutrino mass down to about 0.03 eV, if sufficient amount of 150Nd source is available.
Journal of Physics: Conference Series, 2008
Nuclear Physics B, 1973
ABSTRACT The differential cross sections for the reaction gamma + n --> pi0 + n have been ... more ABSTRACT The differential cross sections for the reaction gamma + n --> pi0 + n have been measured at pions angles of 45°, 60°, 105°, 120° and 140° in the c.m.s. for photon energies of 500-900 MeV. Both pi0 meson and recoil neutron from a liquid deuterium target were detected with a pair of Cerenkov counters combined with lead spark chambers and a hodoscope consisting of 16 modules of plastic scintillation counters. The experimental results were compared with the recent phenomenological partial-wave analysis, and indicate that the ratio of the isoscalar part to the isovector part of the resonant amplitude of B2_(N'(1520)(D13)) is only about 0.2, and that in the gamma + n --> pi0 + n reaction there is no remarkable enhancement due to the N'(1470)(P11) resonance.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2000
A detector called Drift Chamber Beta-ray Analyzer (DCBA) will provide momentum information of eac... more A detector called Drift Chamber Beta-ray Analyzer (DCBA) will provide momentum information of each -ray in double beta decay. The DCBA is expected to have good capabilities for particle identi"cation, detection e$ciency, background elimination and decay-source integration. Under the assumption of mass mechanism dominance in neutrinoless double beta decay, a simulation study shows that a combination method using both sum and single-energy distributions of double beta decay events can separate 0 -and 2 -events down to 0.05 eV of the e!ective neutrino mass with the help of a calculated nuclear matrix element, even though the DCBA has relatively poor energy resolution.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1995
The detection inefficiency of a 10 mm thick plastic scintillation counter for charged particles (... more The detection inefficiency of a 10 mm thick plastic scintillation counter for charged particles (1 GeV/c e *, ?T * and protons) was examined in a test experiment at the Tl line of the KEK 12 GeV Proton Synchrotron. The inefficiencies for e+ and C were obtained to be (3.2 i 0.9) X 10-j and (6.0 i 0.6) X lo-'; those for n+ and e-were obtained as the upper limits of 1.6 X 10m5 and 1.3 X 10-j in the case that the energy deposit was required to be more than 1 MeV in the scintillator. For protons, the inefficiency was obtained to be (5.0 k 1.6) X lop5 in the case that the energy deposit was required to be more than 1.9 MeV in the scintillator. For e *, the ADC spectra of the output signals as well as the obtained inefficiencies were well reproduced by calculations using the EGS4 code.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2011
ABSTRACT The aim of the DCBA (Drift Chamber Beta-ray Analyzer) experiment is to search for neutri... more ABSTRACT The aim of the DCBA (Drift Chamber Beta-ray Analyzer) experiment is to search for neutrinoless double beta decay (0νββ). The half-life of 0νββ is expected to give us the information of Majorana nature and the absolute mass scale of neutrinos. A prototype test apparatus DCBA-T2 has the energy resolution of about 150keV (FWHM) around 1MeV. In order to check the detector performance, engineering runs detecting double beta decay of 100Mo started in May 2009 using natural Mo, which contains 9.6% of 100Mo. Ten candidates of the double beta decay (ββ) have been detected so far. It has been found that the background events due to 214Bi decay are distinguishable from the double beta decays by detecting α-particles from 214Po.
Proceedings of 1994 IEEE Nuclear Science Symposium - NSS'94, 1995
We have constructed endcap photon detectors with undoped Cesium Iodide (CsI) crystals for a K+→π+... more We have constructed endcap photon detectors with undoped Cesium Iodide (CsI) crystals for a K+→π+νν¯ experiment E787 at Brookhaven National Laboratory (BNL). To reject backgrounds it is essential to have a photon detection system with high efficiency. Good resolution for timing and energy is critical for reducing accidental vetoes. The endcap detectors are located in a magnetic field of 1 T. Fine-mesh photomultiplier tubes are attached directly to the crystals for efficient light collection, and the fast-decay component of CsI light output is selected by optical filters. The tube gains are monitored with the light from a xenon flash lamp and from light pulsers. The pulse shapes are recorded by transient digitizers based on charged coupled devices (CCDs), which enable precise determination of timing of photons. The construction and performance of the detectors are described
Physical Review D - PHYS REV D, 1989
We report on the present status of a search for the rare decays K0L-->mue and K0L-->ee at t... more We report on the present status of a search for the rare decays K0L-->mue and K0L-->ee at the KEK 12-GeV Proton Synchrotron. We found no K0L-->mue or K0L-->ee events and found 54 K0L-->mumu events. The upper limits of the K0L-->mue and K0L-->ee branching ratios are B(K0L-->mue)<4.3×10-10 and B(K0L-->ee)<5.6×10-10 at 90% confidence level. The 54 K0L-->mumu events correspond to an absolute branching ratio of (8.4+/-1.1)×10-9.
The Astrophysical Journal, 2002
Using the Super-Kamiokande neutrino observatory, a search was conducted for neutrinos produced in... more Using the Super-Kamiokande neutrino observatory, a search was conducted for neutrinos produced in coincidence with gamma-ray bursts observed by the BATSE detector. Super-Kamiokande data in the neutrino energy range of 7 MeV ∼ 100 TeV were analyzed. For gamma-ray bursts that occurred between 1996 April and 2000 May, no statistically significant signal in excess of the background levels was detected. Implied upper limits on associated GRB neutrino production are presented.
Physical Review D - PHYS REV D, 2006
The first dedicated experiment for the rare kaon decay K{sub L}°âÏ°νν has been performed by t... more The first dedicated experiment for the rare kaon decay K{sub L}°âÏ°νν has been performed by the E391a Collaboration at the KEK 12-GeV proton synchrotron. A new upper limit of 2.1x10â»â· at the 90% confidence level was set for the branching ratio of the decay K{sub L}°âÏ°νν using about 10% of the data collected during the first period of data taking.
Physics Letters B, 2001
The KEK to Kamioka long-baseline neutrino experiment (K2K) has begun its investigation of neutrin... more The KEK to Kamioka long-baseline neutrino experiment (K2K) has begun its investigation of neutrino oscillations suggested by atmospheric neutrino observations. Twenty-eight neutrino events have been detected in coincidence with the expected arrival time of the beam in the 22.5 kt fiducial volume of Super-Kamiokande, the far detector at 250 km distance. The expectation is 37.8 +3.5 −3.8 , derived using measurements of neutrino interactions in a near detector and extrapolation using a beam simulation validated by a measurement of pion kinematics after production and focusing. The background is of order 10 −3 events.
Physics Letters B, 1992
A high-statistics experiment on the reaction n-p--,n +n-n°n at 8.06 GeV/c has been performed usin... more A high-statistics experiment on the reaction n-p--,n +n-n°n at 8.06 GeV/c has been performed using a spectrometer detecting both charged particles and gamma rays. A partial-wave analysis based on the isobar model has been carried out for ~+x-Tr ° data in the mass range between 0.86 and 1.50 GeV for four t' regions: 0.0-0.1, 0.1-0.25, 0.25-0.45 and 0.45-0.95 (GeV/c2). Two axial-vector resonances, a~ (1260) and h~ , were observed in the analysis. The masses and widths of a~ and h t were determined to be M(a~ ) = 1121 + 8 MeV, F(a, ) = 239 + 11 MeV, M( h~ ) = 1168 + 4 MeV and F( hi ) = 345 + 6 MeV, respectively, by fitting the Breit-Wigner formula to the partial wave amplitude. A fit including the Deck type background was also tried in each t' region. The results showed a small effect on these resonance parameters and were consistent with those obtained by the simple Breit-Wigner fitting.
Physics Letters B, 2005
Neutral current single π 0 production induced by neutrinos with a mean energy of 1.3 GeV is measu... more Neutral current single π 0 production induced by neutrinos with a mean energy of 1.3 GeV is measured using a 1000 ton water Cherenkov detector in the K2K long baseline neutrino experiment. The cross section for this process relative to the total charged current cross section is measured to be 0.064 ± 0.001(stat.) ± 0.007(sys.). The momentum distribution of neutral current π 0 s from a water target is measured with high statistics for the first time.
Physical Review Letters, 2000
We report the first measurement of a structure dependent component in the decay K + → µ + ν µ γ. ... more We report the first measurement of a structure dependent component in the decay K + → µ + ν µ γ. Using the kinematic region where the muon kinetic energy is greater than 137 MeV and the photon energy is greater than 90 MeV, we find that the absolute value of the sum of the vector and axialvector form factors is |F V + F A | = 0.165 ± 0.007 ± 0.011. This corresponds to a branching ratio of BR(SD + ) = (1.33 ± 0.12 ± 0.18) × 10 −5 . We also set the limit −0.04 < F V − F A < 0.24 at 90% c.l.
Physical Review Letters, 2004
Physical Review D, 2004
... E.; Stone, JL; Sulak, LR; Walter, CW; Wang, W.; Goldhaber, M.; Barszczak, T.; Casper, D.; Cra... more ... E.; Stone, JL; Sulak, LR; Walter, CW; Wang, W.; Goldhaber, M.; Barszczak, T.; Casper, D.; Cravens, JP; Gajewski, W.; Kropp, WR; Mine, S.; Liu ... K.; Shibata, T.; Kajiyama, Y.; Nagashima, Y.; Takita, M.; Yoshida, M.; Kim, HI; Kim, SB; Yoo, J.; Okazawa, H.; Ishizuka, T.; Choi, Y.; Seo ...
Physical Review D, 2011
We studied the rare decay K 0 L → π 0 π 0 νν with the E391a detector at the KEK 12-GeV proton syn... more We studied the rare decay K 0 L → π 0 π 0 νν with the E391a detector at the KEK 12-GeV proton synchrotron. With 9.4G K 0 L decays an upper limit on the branching fraction was set to be 8.1×10 −7 at the 90% confidence level (C.L.). We also set the limit on the process of K 0 L → π 0 π 0 X(X → invisible particles), which varied from 7.0×10 −7 to 4.0×10 −5 according to the mass of X from 50MeV/c 2 to 200MeV/c 2 .
Physical Review D, 2010
The first dedicated search for the rare neutral-kaon decay K 0 L → π 0 νν has been carried out in... more The first dedicated search for the rare neutral-kaon decay K 0 L → π 0 νν has been carried out in the E391a experiment at the KEK 12-GeV proton synchrotron. The final upper limit of 2.6 ×10 −8 at the 90% confidence level was set on the branching ratio for the decay.
Nuclear Physics B - Proceedings Supplements, 1991
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2002
The Publisher regrets the exchange of Figs. 15 and 17 on pp. 252-253 of the above paper. Fig. 15 ... more The Publisher regrets the exchange of Figs. 15 and 17 on pp. 252-253 of the above paper. Fig. 15 should be Fig. 17 and vice-versa. However, the captions of Figs. 15 and 17 are correct. $ PII of original article S0168-9002(01)01680-1
Journal of Physics: Conference Series, 2008
ABSTRACT Neutrinoless double beta decay experiment is the only realistic method to investigate th... more ABSTRACT Neutrinoless double beta decay experiment is the only realistic method to investigate the Majorana nature and the absolute mass scale of neutrinos. The DCBA (Drift Chamber Beta-ray Analyzer) experiment can separately detect electrons from other background particles in a uniform magnetic field. The kinetic energy of each electron is obtained from its momentum measurement. Therefore no energy calibration is required. The test prototype DCBA-T2 obtained the energy resolution of about 150 keV (FWHM) for 976 keV internal conversion electrons from 207Bi More improved prototype DCBA-T3 is now under construction. Its energy resolution is expected to be less than 100 keV (FWHM) according to the simulation study with Geant4. The future detector (temporarily called Magnetic Tracking Detector: MTD) enlarged from DCBA-T3 can investigate effective neutrino mass down to about 0.03 eV, if sufficient amount of 150Nd source is available.
Journal of Physics: Conference Series, 2008