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scattering length from 
photoproduction on the proton near the reaction thresholdIshikawa, Takatsugu*; Fujimura, Hisako*; Fukasawa, Hiroshi*; Hashimoto, Ryo*; He, Q.*; Honda, Yuki*; Hosaka, Atsushi; Iwata, Takahiro*; Kaida, Shun*; Kasagi, Jirota*; et al.
Physical Review C, 101(5), p.052201_1 - 052201_6, 2020/05
Times Cited Count：4 Percentile：45.12(Physics, Nuclear)Sako, Hiroyuki; Harada, Hiroyuki; Sakaguchi, Takao*; Chujo, Tatsuya*; Esumi, Shinichi*; Gunji, Taku*; Hasegawa, Shoichi; Hwang, S.; Ichikawa, Yudai; Imai, Kenichi; et al.
Nuclear Physics A, 956, p.850 - 853, 2016/12
Times Cited Count：12 Percentile：65.66(Physics, Nuclear)Sako, Hiroyuki; Sugimura, Hitoshi; Ahn, J. K.*; Han, Y.*; Hasegawa, Shoichi; Hwang, S. H.*; Ichikawa, Yudai; Imai, Kenichi; Kiuchi, Ryuta*; Ozawa, Kyoichiro; et al.
Nuclear Instruments and Methods in Physics Research A, 763, p.65 - 81, 2014/11
Times Cited Count：5 Percentile：38.03(Instruments & Instrumentation)We developed a prototype TPC for an H-dibaryon search experiment at J-PARC. To investigate its performance, we conducted tests with Ar-CH
(90:10) and Ar-CF (95:5), where the former is mainly used. The detection efficiency was measured to be 98% at the beam rate up to 
cps/cm
, and 90% at the rate of 
cps/cm. Based on the measured horizontal resolution of 0.19-0.46 mm at the drift length of 5-20 cm, the position resolution of better than 0.3 mm is estimated in 1 T magnetic field. The ion backflow fraction was measured to be 5% and reduced up to 3% at the gain of 
. The horizontal position distortion due to ion backflow in the gate operation was suppressed within 
mm at the beam rates up to cps/cm. On the other hand, the distortion with the gate open was measured to be 
mm. The distortion in the final experiment is estimated to be 
mm.
Sako, Hiroyuki; Chujo, Tatsuya*; Gunji, Taku*; Harada, Hiroyuki; Imai, Kenichi; Kaneta, Masashi*; Kinsho, Michikazu; Liu, Y.*; Nagamiya, Shoji; Nishio, Katsuhisa; et al.
Nuclear Physics A, 931, p.1158 - 1162, 2014/11
Times Cited Count：23 Percentile：80.23(Physics, Nuclear)Recently, a heavy-ion program as a future J-PARC project has been discussed. The main goals of the program are to explore the QCD phase diagram at highbaryon density with heavy ions up to uranium at the beam energies of around 10A GeV. We are planning to focus on the electron and muon measurements and rare probe search such asmulti-strangeness and charmed hadrons with high beam rates at J-PARC. A heavy-ionacceleration scheme has been considered with a new heavy-ion linac and a new booster ring, with the existing 3-GeV Rapid-Cycling Synchrotron, and the 30-GeV Main Ring synchrotron. An overview of the heavy-ion program and accelerator design, as well as physics goals and conceptual design of the experiments are presented.
collisions at 
= 200 and 62.4 GeVAdare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.
Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06
Times Cited Count：184 Percentile：99.44(Physics, Nuclear)Transverse momentum distributions and yields for 
, and 
in collisions at = 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different collisions. We also present the scaling properties such as 
and 
scaling and discuss the mechanism of the particle production in collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.
and Au+Au collisions at 
= 200 GeVAdare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Aramaki, Y.*; et al.
Physical Review C, 83(4), p.044912_1 - 044912_16, 2011/04
Times Cited Count：8 Percentile：49.7(Physics, Nuclear)Measurements of electrons from the decay of open-heavy-flavor mesons have shown that the yields are suppressed in Au+Au collisions compared to expectations from binary-scaled collisions. Here we extend these studies to two particle correlations where one particle is an electron from the decay of a heavy flavor meson and the other is a charged hadron from either the decay of the heavy meson or from jet fragmentation. These measurements provide more detailed information about the interaction between heavy quarks and the quark-gluon matter. We find the away-side-jet shape and yield to be modified in Au+Au collisions compared to collisions.
Sato, Susumu; Sako, Hiroyuki; Imai, Kenichi; Sugimura, Hitoshi; Adachi, Satoshi; Niiyama, Masayuki; Ozawa, Kyoichiro
no journal, ,
In the experimental study of hadron properties at J-PARC, especially for the study of hyperon (including production and decay properties), it is essential to measure decayed particles around the experimental target with larger solid angle. In this report, status of development of the 3-dimensional tracking detector is presented.
-spectrometerSato, Susumu; Sako, Hiroyuki; Imai, Kenichi; Sugimura, Hitoshi; Adachi, Satoshi; Kiuchi, Ryuta*; Tanida, Kiyoshi*; Miwa, Koji*; Ozawa, Kyoichiro*
no journal, ,
no abstracts in English
Sato, Susumu; Sako, Hiroyuki; Hasegawa, Shoichi; Sugimura, Hitoshi; Ichikawa, Yudai; Ozawa, Kyoichiro; Kiuchi, Ryuta*; Hwang, S. H.*; Imai, Kenichi
no journal, ,
no abstracts in English
Sako, Hiroyuki; Harada, Hiroyuki; Imai, Kenichi; Nagamiya, Shoji; Ozawa, Kyoichiro; Saha, P. K.; Nishio, Katsuhisa; Hwang, S.
no journal, ,
In heavy-ion collisions at 10 AGeV/c, the baryon density is expected to reach 10 times as high as the normal nucleus density. We are designing a spectrometer for a future heavy-ion experiment. We aim at observing directly the information on high baryon density in dilepton measurements. The spectrometer consists of a solenoid spectrometer which covers the backward acceptance at the polary angle larger than 30 degrees, and a dipole spectrometer which covers the polar angle less than 30 degrees. Hadrons will be identified by Time-of-flight counters, electrons will be identified by a Ring Imaging Cherencov Counters, photons will be identified by electromagnetic calorimeters, and muons will be measured by iron absorbers and trackers.
k
decay in p+A collisions at J-PARCSato, Susumu; Sako, Hiroyuki; Miake, Yasuo*; Inaba, Motoi*; Chujo, Tatsuya*; Ozawa, Kyoichiro*; Kyan, Shono*; Esumi, Shinichi*; Nonaka, Toshihiro*
no journal, ,
