Radiation Laboratory
Chief Scientist
Hideto EN' YO (D.Sci.)
Nucleons, such as protons and neutrons, are a bound state of constituent quarks glued together with gluons. The detail structure of nucleons, however, is not well understood yet. Especially the mechanism to build up the spin of proton, which is 1/2, is a major problem in physics of the strong force. The research goal of Radiation Laboratory is to solve this fundamental question using the world first polarized-proton collider, realized at RHIC in Brookhaven National Laboratory (BNL) in USA. RHIC stands for Relativistic Heavy Ion Collider, aiming also to create Quark Gluon Plasma, the state of Universe just after the Big Bang. RIKEN-BNL Research Center (RBRC) directed by N. Samios carries our core team at BNL for those exciting researches using the PHENIX detector. We have found that the proton spin carried by gluons is indeed small, which is a very striking finding beyond our expectations. Recently we successfully identified W boson in the electron/positron decay channel, with which we established the method to determine how much anti-quarks carry the proton spin. Other than the activities at RHIC we are preparing new experiments at SPring-8, J-PARC and Fermilab to study the nature of hadron. We are also performing technical developments such as novel ion sources, fine pitch pixel detectors and neutron optical devices.
- Spin physics with relativistic polarized-proton collisions at RHIC
- Study of nuclear matter at high temperature and/or at high density
- Technical developments on radiation detectors and accelerators
- RIKEN Nishina Center for Accelerator-Based Science Website_Laboratories Page
- Individual Website Laboratory Page
- October 30,2009
- Sifting out the sources of spin
THigh-energy proton collisions help solve the puzzle of what determines the proton's spin
- November 14,2008
- Gluons don't explain the spin surprise
The origins of the fundamental properties of particles in the core of atoms continue to puzzle scientists
- PHENIX Collaboration (A. Adare et al.):
"Measurements of Higher-Order Flow Harmonics in Au+Au Collisions at sqrt(sNN) = 200 GeV."
Phys. Rev. Lett. 107:252301(2011) - T. Nakamura, H. En'yo, T. Ichihara, Y. Watanabe, S. Yokkaichi,:
"Data oriented job submission scheme for the PHENIX user analysis in CCJ"
J. Phys. Conf. Ser.331:072025(2011) - PHENIX Collaboration (A. Adare et al.):
"Enhanced Production of Direct Photons in Au þ Au Collisions at sqrt(s_NN) = 200 GeV and Implications for the Initial Temperature"
Phys. Rev. Lett. 104, 132301 (2010) - PHENIX Collaboration (A. Adare et al.):
"Cross Section and Parity-Violating Spin Asymmetries of W Boson Production in Polarized p t p Collisions at sqrt(s)=500 GeV"
Phys. Rev. Lett. 106, 062001 (2011) - A. Bazilevsky et al.:
"Single Transverse-Spin Asymmetry in Very Forward and Very Backward Neutral Particle Production for Polarized Proton Collisions at s**(1/2) = 200-GeV."
Phys.Lett.B650:325-330 (2007) - PHENIX Collaboration (A. Adare et al.):
"Inclusive cross-section and double helicity asymmetry for pi0 production in p + p collisions at s**(1/2) = 200-GeV: Implications for the polarized gluon distribution in the proton"
Phys.Rev.D76:051106 (2007) - A. Bazilevsky et al.:
"Single Transverse-Spin Asymmetry in Very Forward and Very Backward Neutral Particle Production for Polarized Proton Collisions at s**(1/2) = 200-GeV."
Phys.Lett.B650:325-330 (2007) - PHENIX Collaboration (Stephen Scott Adler et al.):
"Measurement of direct photon production in p + p collisions at s**(1/2) = 200-GeV."
Phys.Rev.Lett.98:012002 (2007) - PHENIX Collaboration (Stephen Scott Adler et al.):
"Measurement of density correlations in pseudorapidity via charged particle multiplicity fluctuations in Au+Au collisions at s(NN)**(1/2) = 200-GeV."
Phys.Rev.C76:034903(2007) - KEK-PS-E325 Collaboration (R. Muto et al.):
"Evidence for in-medium modification of the phi meson at normal nuclear density."
Phys.Rev.Lett.98:042501 (2007)
Principal Investigator
- Hideto ENYO
- Chief Scientist
Staff Scientist
- Yasuyuki AKIBA
- Vice Chief Scientist
- Yasushi WATANABE
- Senior Research Scientist
- Yuji GOTO
- Senior Research Scientist
- Yoshie OTAKE
- Senior Research Scientist
- Hiroaki ONISHI
- Senior Research Scientist
- Itaru NAKAGAWA
- Senior Research Scientist
- Satoshi YOKKAICHI
- Senior Research Scientist
- Seidl RALF
- Research Scientist
Postdoctoral Fellow
- Kazuya AOKI
- Special Postdoctoral Researcher
- Yoshichika SEKI
- Special Postdoctoral Researcher
- Takashi HACHIYA
- Contract Researcher
- Yohei NAKATSUGAWA
- Contract Techinical Scientist
- Stephen Leslie BAUMGART
- Foreign Postdoctoral Researcher
- Kohei SHOJI
- Postdoctoral Researcher
- Yoki ARAMAKI
- Postdoctoral Researcher
- Tomonori TAKAHASHI
- Postdoctoral Researcher
- Yoshimitsu IMAZU
- Postdoctoral Researcher
- Yoshimasa IKEDA
- Postdoctoral Researcher
Student Trainee
- Dousatsu SAKATA
- Junior Research Associate
- Sunyoung RYU
- International Program Associate
- Masaya NIHASHI
- Junior Research Associate
- Hidemitsu ASANO
- Junior Research Associate
- Yusuke KOMATSU
- Junior Research Associate
- Shinichi MASUMOTO
- Junior Research Associate
- Takahito TODOROKI
- Junior Research Associate
- Megumi SEKINE
- Junior Research Associate