2nd Open Meeting for the Hyper-Kamiokande Project



The Hyper-Kamiokande project is being designed to be the next decade's flagship experiment for the study of neutrino oscillations, nucleon decays, and astrophysical neutrinos.

Following the successful format of the previous meeting, we will hold the 2nd International Open Working Group Meeting for Hyper-Kamiokande. The meeting will be open to all interested scientists and community members.

The slides for the first open meeting can be found here;

The goal of this meeting is to further discuss the physics potentials of Hyper-K, the design of the detector, and necessary R&D items including:
  • cavern excavation,
  • tank liner material and its design,
  • photo-sensors and their support structure,
  • DAQ electronics and computers,
  • calibration systems,
  • water purification systems,
  • software development,
  • neutrino beam-line,
  • near detector,
  • physics potentials of Hyper-K, and so on.

Participants are encouraged to submit abstracts for talks in which to present their individual interests in topics specifically related to Hyper-K, as well as discuss possible future contributions to the project.

If you would like to contact the relevant people in our group in advance to discuss the Hyper-K project and its development work, please click the contact information menu on the right side of this page to send an email to us.

We expect that those who are interested in joining the project will come to this meeting. However, the meeting will require prior registration to participate.  Due to capacity constraints at the meeting site we urge all interested parties to register at their earliest possible convenience.

We are looking forward to seeing you in Kashiwa,

Organizing Committee Members:
Yoshinari HAYATO (ICRR), Yusuke KOSHIO (ICRR), Neil MCCAULEY (Liverpool), Akihiro MINAMINO (Kyoto), Shun-ichi MINE (UCI), Makoto MIURA (ICRR), Tsuyoshi NAKAYA (Kyoto), Shoei NAKAYAMA (ICRR), Yasuhiro NISHIMURA (ICRR), Kimihiro OKUMURA (ICRR), Hiroyuki SEKIYA (ICRR), Masato SHIOZAWA (ICRR, chair), Yasuo TAKEUCHI (Kobe), Hidekazu TANAKA (ICRR), Hirohisa TANAKA (UBC), Mark VAGINS (Kavli IPMU), Roger Wendell (ICRR), Masashi YOKOYAMA (Tokyo)


Meeting photo
  • Akeo Misaki
  • Akihiro Minamino
  • Akimichi Taketa
  • Alexander Himmel
  • Atsumu Suzuki
  • Atsushi Takeda
  • Blair Jamieson
  • Bronner Christophe
  • Camillo Mariani
  • Carsten Rott
  • Chang Kee Jung
  • Chris Walter
  • Christopher Mauger
  • David Hadley
  • David Jaffe
  • David L Wark
  • Ed Kearns
  • Euan Richard
  • Fabrice Retiere
  • Francesca Di Lodovico
  • Giada Carminati
  • Giles Barr
  • Gus Sinnis
  • Hank Sobel
  • hgpwuly hgpwuly
  • Hide-Kazu TANAKA
  • Hiroaki Aihara
  • hirohisa a. tanaka
  • Hiroyuki Sekiya
  • Hiroyuki Tanaka
  • In Taek Lim
  • Itaru Shimizu
  • Jae Yool Kim
  • James Hill
  • James Stone
  • Jean-Michel Poutissou
  • Jennifer Raaf
  • Jia Liu
  • Jun Kameda
  • Kai Martens
  • Kate Scholberg
  • Keiji Tateishi
  • Kendall Mahn
  • Kenneth Ganezer
  • Kevin McFarland
  • Kimihiro Okumura
  • Kunxian Huang
  • Kyung Kwang Joo
  • Lluis Marti Magro
  • Luis Labarga
  • Makoto Miura
  • Marat Khabibullin
  • Mark Hartz
  • Mark Vagins
  • Masahiro Kuze
  • Masaki Ishitsuka
  • Masashi Yokoyama
  • Masato SHIOZAWA
  • Masayuki Nakahata
  • Michael Smy
  • Michael Wilking
  • Motoyasu Ikeda
  • Neil McCauley
  • Patrick de Perio
  • Peter Gumplinger
  • Ralitsa Sharankova
  • Robert Svoboda
  • Roger Wendell
  • Seiko Hirota
  • Shige Matsuno
  • Shigetaka Moriyama
  • Shimpei Tobayama
  • Shoei Nakayama
  • Shunichi Mine
  • Soo-Bong Kim
  • Sophie Berkman
  • Szymon Manecki
  • Takaaki Kajita
  • Takatomi Yano
  • Taku Ishida
  • Tarek Akiri
  • Taritree Wongjirad
  • Toru Iijima
  • Toshifumi Tsukamoto
  • Tsuyoshi NAKAYA
  • William R Kropp
  • Yasuhiro NISHIMURA
  • Yasuo Takeuchi
  • Yoichiro Suzuki
  • Yoshihiko Kawai
  • Yoshihisa Obayashi
  • Yoshinari Hayato
  • Yoshiyuki Fukuda
  • Yuekun Heng
  • Yuji Okajima
  • Yury Kudenko
  • Yusuke Koshio
  • Yusuke Suda
  • Monday, 14 January
    • 08:00 09:00
      • 08:00
        Registration 1h
    • 09:00 09:30
      Opening Session
      • 09:00
        Goals of Meeting 15m
        I will briefly explain discussion items of the meeting.
        Speaker: Prof. Masato SHIOZAWA (The University of Tokyo, Institute for Cosmic Ray Research, ICRR)
      • 09:15
        Steering Report 15m
        Steering Report
        Speaker: Prof. Tsuyoshi NAKAYA (Kyoto University)
    • 09:30 09:50
      J-PARC and Beamline
      • 09:30
        J-PARC and beam-line upgrade 20m
        J-PARC and beam-line upgrade
        Speaker: Dr Taku Ishida (KEK)
    • 09:50 11:45
      Physics Potential
      • 09:50
        CP study 20m
        An update of CP sensitivity study will be given.
        Speaker: Masashi Yokoyama (University of Tokyo)
      • 10:10
        Break 25m
      • 10:35
        Considerations for a Near Detector for the Tokai-to-HK experiment 20m
        I will discuss considerations for the design and desired capabilities for a near detector for the long-baseline component of the Hyper-Kamiokande physics program (Tokai-to-HK). My comments will focus mainly on potential incremental upgrades to the existing ND280 off-axis detector for T2K, but will include thoughts on more substantial upgrades.
        Speaker: Mr Hirohisa A. Tanaka (University of British Columbia/Institute of Particle Physics)
      • 10:55
        Off-Axis Detectors as Direct Measurements of Neutrino Energy Reconstruction 20m
        Uncertainties in neutrino energy reconstruction in quasi-elastic scattering due to nuclear effects may be a significant systematic uncertainty for oscillations measurements at Hyper-K. We investigate the possibility of directly measuring these misreconstructions in a model-independent way with a series of off-axis near detectors.
        Speakers: Prof. Kevin McFarland (University of Rochester) , Dr Mark Hartz (University of Toronto and York University)
      • 11:15
        Atmospheric Neutrino Sensitivity Studies 15m
        This talk will present an update of the expected sensitivity to neutrino oscillations at Hyper-K after corrections to the analysis method and updates of the global value of theta_13.
        Speaker: Roger Wendell (ICRR)
      • 11:30
        Muon charge identification with gadolinium-loaded water 15m
        A novel approach to muon charge-identification is described. The approach uses the neutron-capture signal available in the presence of gadolinium. Applications to atmospheric neutrino studies are discussed.
        Speaker: Dr Christopher Mauger (LANL)
    • 11:45 13:25
      Lunch 1h 40m
    • 13:25 15:50
      Physics Potential
      • 13:25
        Improvement of event selection of proton decay searches 15m
        This talk will present studies toward the improvement of proton decay event selection at HK using shape information from the signal and background distributions instead of pure counting methods used in proton decay searches at SK thus far. Emphasis will be on the p->e+pi0 mode.
        Speaker: Shunichi Mine (UCI)
      • 13:40
        Improvement of proton decay analysis in p-->nu-bar+K^+ 15m
        The proton decay mode, p--> nu-bar+K^+ is favored by SUSY-GUTs and it is an important analysis for Hyper-K. Recently, there have been several improvement in the alaysis. I will discuss how much sensitivity of Hyper-K will be improved by these improvements.
        Speaker: Dr Makoto Miura (Kamioka Observatory, ICRR, University of Tokyo)
      • 13:55
        Spallation background 20m
        An estimation of spallation background in HK will be reported.
        Speaker: Prof. Yasuo Takeuchi (Dept. of Physics, Grad. School of Science, Kobe Univ.)
      • 14:15
        Solar neutrinos and supernova burst neutrinos at Hyper-Kamiokande 20m
        The sensitivity of solar neutrinos is discussed in this presentation. The modification from the previous meeting will be updated back ground rate from spallation, therefore, the results will be more realistic. Another topics is supernova burst neutrinos. This will be more precise than the discussion in the previous meeting, especially, a correlation with another observation such as gravitational wave.
        Speaker: Dr Yusuke Koshio (Kamioka observatory, ICRR, Univ. of Tokyo)
      • 14:35
        SRN search with HK 20m
        In this presentation, SRN sensitivity at HK, with and without Gd option, will be discussed.
        Speaker: Dr Takatomi Yano (Okayama Univ.)
      • 14:55
        Break 25m
      • 15:20
        Neutrinographic imaging of the earth 30m
        Absorption neutrinography utilizes very high energy neutrinos with energies above 10 TeV to measure the nucleon density inside the earth whereas oscillation neutrinography measures the electron density by observing the MSW effect. Two independent physical quantities might provide new geophysical information, e.g., isotope ratio, to us. In this talk, a recent attempt to use atmospheric neutrinos for absorption neutrinography, based on a simulation of atmospheric neutrino events that can be collected with the IceCube neutrino detector, will be introduced as well as a possible oscillation neutrinography with Hyper-Kamiokande.
        Speaker: Akimichi Taketa (Earthquake Research Institute)
    • 15:50 17:10
      Cavity and Tank
      • 15:50
        Excavation of the Hyper-K cavern 30m
        I will show updates on studies related to the cavern stability, excavation method, waste rock disposal.
        Speaker: Prof. Masato SHIOZAWA (The University of Tokyo, Institute for Cosmic Ray Research, ICRR)
      • 16:20
        Hyper-K liner and PMT support design 30m
        Updates of Hyper-K liner and PMT support design will be discussed.
        Speaker: Dr Hide-Kazu TANAKA (ICRR, University of Tokyo)
      • 16:50
        Geomagnetic field compensation 20m
        I will present some results from studies on geomagnetic field compensation in the Hyper-K tank, especially an optimization of the compensation coil system.
        Speaker: Dr Shoei Nakayama (Kamioka Observatory, ICRR, University of Tokyo)
    • 17:10 17:35
      Break 25m
    • 17:35 18:35
      Water System
      • 17:35
        Water for Hyper-K 25m
        Plans of water source, pure water system, and water flow in the tank.
        Speaker: Dr Hiroyuki Sekiya (ICRR/IPMU)
      • 18:00
        Gadolinium for Hyper-K 20m
        Progress on the the design and pricing of the water system for the gadolinium option for Hyper-Kamiokande will be presented, as well as the current status of the EGADS gadolinium test project.
        Speaker: Prof. Mark Vagins (IPMU)
      • 18:20
        Preliminary results on water-based liquid scintillator in a proton beam 15m
        Samples of water-based liquid scintillator, liquid scintillator and water were exposed to proton beams of kinetic energy 210, 475 and 2000 MeV. Preliminary results on light yield will be presented. Implications for the scientific agenda of future large water Cherenkov detectors will be discussed.
        Speaker: David Jaffe (BNL)
  • Tuesday, 15 January
    • 10:00 11:20
      • 10:00
        Overview of the photodetector development 15m
        I will present a brief introduction of current activities in the photodetector sub-WG and the plan for the photodetector development.
        Speaker: Dr Shoei Nakayama (Kamioka Observatory, ICRR, University of Tokyo)
      • 10:15
        HPD development 20m
        Hybrid Photodetector (HPD) is being developed for Hyper-K and a proof test is planned using a 200-ton tank at Kamioka site. The development of an 8-inch HPD and a plan for the first proof test will be shown.
        Speaker: Dr Yasuhiro NISHIMURA (ICRR)
      • 10:35
        A new design of large area MCP-PMT for the next generation neutrino experiments 20m
        The next generation neutrino experiments call for significantly increasing the total detector volume. Inexpensive PMTs with large size and high efficiency photocathode are needed in order for these experiments to become reality. We have developed a conceptual design of large focusing type PMT aiming for improving the PMT photon detection efficiency. The transmission photocathode coated on the front hemisphere and the reflection photocathode coated on the rear hemisphere are assembled in the same glass envelope to form nearly 4π viewing angle to enhance the efficiency of the photoelectron detection. The two sets of small MCP units replace the traditional dynodes in the center of the big glass pulp. The photoelectrons from the 4π photocathode are collected and amplified by the two sets of MCP units. Some calculations about the photon-electron moving and collecting are introduced. And the prototypes of this kinds of PMT are being made in China.
        Speaker: Prof. Yuekun Heng (Experimental Physics Center, Institute of High Energy Physics)
      • 10:55
        Update on Photomultiplier Evaluation and Development in the U.S. 10m
        A summary of the evaluation of the Hamamatsu 12-inch PMT will be given, along with a status update on the development of an 11-inch ADIT PMT.
        Speaker: Robert Svoboda (UC Davis)
      • 11:05
        Photo-detector development for maximizing the overall photon detection efficiency 15m
        Photo-detector development for maximizing the overall photon detection efficiency The baseline Hyper-K concept relies on 99,000 20” photomultiplier tubes (PMTs) to provide 20% photo-coverage. We are investigating solutions that would enhance the photo-coverage without compromising either contrast or timing resolution. Contrast roughly quantifies the fraction of photons detected that retain the Cerenkov light directional information over the total number of photons detected including photons having scattered, been reflected or reemitted. Numerous observables, for example low energy neutrino would benefit from enhanced photo-coverage. A large fraction of the photons missing the PMTs could be detected by either using wavelength shifters to guide them towards either the primary PMT or additional PMTs or by using light concentrators to focus the light towards the primary PMTs. Wavelength shifters will worsen the contrast unless the reemitted light can be prevented from entering the active water volume. Dichroic mirrors may do just that by allowing the UV and blue light to be absorbed in the wavelength shifting material and then reflecting the reemitted green light. In general, we are planning to investigate possible applications of interference filters in Hyper-K whether they are used coupled to wavelength shifters, as broadband mirrors for the light collectors, or as anti-reflective films to maximize contrast. We will report our recent investigation of solutions that maximize the detection efficiency.
        Speaker: Dr Fabrice Retiere (TRIUMF)
    • 11:20 11:45
      DAQ and Electronics System
      • 11:20
        Baseline design of the DAQ and Electronics System 25m
        Present expected trigger rate from dark hits, low energy backgrounds and muons, data rate from those events assuming various photo-sensors' dark rates, low energy background rates and muon rates. Also, discuss the applicability of the simple majority trigger scheme for single/3/5 compartments in one detector. Referring to these estimation, baseline design will be presented assuming realistic configurations of the detector.
        Speaker: Dr Yoshinari Hayato (ICRR, Kamioka)
    • 11:45 13:05
      Lunch 1h 20m
    • 13:05 15:25
      • 13:05
        Overview of software development towards Hyper-K 10m
        Recently, we had several progresses in software development for Hyper-Kamiokande. In this talk, I will give a introduction about our activity.
        Speaker: Dr Makoto Miura (Kamioka Observatory, ICRR, University of Tokyo)
      • 13:15
        WCSim strategy and status 15m
        In this talk I will give an overview of the current use of WCSim for Hyper-K. I will explain our tuning and validation strategy, show current validation work by group members, and introduce the other talks in the session on geometry and calibration.
        Speaker: Prof. Chris Walter (Duke University)
      • 13:30
        Hyper-K Geometry for WCSim 10m
        This talk will describe the development of a parameterized geometry model of the Hyper-K detector for use in the WCSim simulation package. Both details of the geometry itself and the status of the implementation will be described.
        Speaker: Dr Peter Gumplinger (TRIUMF)
      • 13:40
        WCsim tuning 15m
        This talk will describe how we used comparisons between SKDetSim, the SuperK detector simulation, and a WCSim simulation of the SuperK geometry to tune the optical properties of the simulation, like reflectivity, scattering, and absorption. The goal was to tune the physical properties of the detector materials in order to improve the simulation accuracy in any geometry.
        Speaker: Dr Alex Himmel (Duke University)
      • 13:55
        High Energy reconstruction performance 15m
        This talk will show a comparison between the reconstruction performances of WCSim in its Super-K configuration and those of the actual Super-K simulation called SKDetSim. This comparison was done after the tuning of WCSim to SKDetSim. This talk will show many critical distributions as vertex, direction and momentum resolutions as well as the performances for a T2K-like set of cuts for the nue appearance analysis.
        Speaker: Dr Tarek Akiri (Duke University)
      • 14:10
        Recent Updates on fiTQun, a New Event Reconstruction Algorithm for Water Cherenkov Detectors 25m
        fiTQun is a new event reconstruction algorithm which has been developed for the Super-K detector. Using the charge and time information from the photomultiplier tubes in the detector, a likelihood function is constructed, which is then maximized to extract particle track parameters. The new algorithm has the potential to substantially improve particle identification performance as well as vertex and momentum resolutions compared to the existing Super-K reconstruction algorithm. Furthermore, the framework is naturally extendable to complex event topologies that are relevant to atmospheric neutrinos and proton decay. In this talk, an overview on the recent improvements of the fitter, its latest performance, and initial results of validation studies using Super-K controlled samples will be presented. The modularized nature of the new algorithm allows us to adopt the framework to Hyper-K, and the status and our plans for the implementation will also be discussed.
        Speaker: Mr Shimpei Tobayama (University of British Columbia)
      • 14:35
        Computing Strategy for Hyper-Kamiokande 15m
        A computing strategy that is capable of taking advantage of new technologies (such as Cloud technologies) with minimal impact is needed. The strategy needs to provide a scalable architecture that minimizes the operational overhead. Moreover, long-term data access and preservation are becoming a growing concern worldwide. It has become a requirement in the EU and the US. Incorporating long-term data management practices into the computing strategy from inception will guarantee data-reuse through the capture of sufficient tools and information to understand and reuse the data by a wider audience increasing the value of the data.
        Speaker: Prof. Francesca Di Lodovico (Queen Mary, University of London)
      • 14:50
        Break 25m
      • 15:15
        The Super-KAVE 10m
        This talk will describe the Super-KAVE, a 3D immersive and interactive event display developed using Duke University's DiVE (Duke immersive Virtual Environment) facility. This event display could easily be adapted to Hyper-K or other experiments, and could be ported to similar facilities elsewhere.
        Speaker: Prof. Kate Scholberg Scholberg (Duke University)
    • 15:25 17:00
      • 15:25
        HK calibration overview & PMT/electronics calibration 20m
        I will discuss PMT/electronics calibration and monitoring.
        Speaker: Dr Hide-Kazu TANAKA (ICRR, University of Tokyo)
      • 15:45
        Considerations for the calibration of water properties and reflection at HK 15m
        I will discuss considerations for the measurement of the optical properties of the water and reflection off the photosensors at Hyper-Kamiokande, including the necessary calibration devices and analysis methods . The talk will include a review of relevant techniques employed at Super-Kamiokande, SNO and MiniBooNE.
        Speaker: Mr Hirohisa A. Tanaka (University of British Columbia/Institute of Particle Physics)
      • 16:00
        Low energy calibration 15m
        The higher level calibration for low energy physics in Hyper-K is discussed. In Super-K, the precise calibration using LINAC, DT and nickel was crucial for make a results. Because of several limitation in Hyper-K, it may not be easy to do the same calibration as Super-K. In this presentation, what is needed for a low energy physics will be discussed.
        Speaker: Dr Yusuke Koshio (Kamioka observatory, ICRR, Univ. of Tokyo)
      • 16:15
        High energy calibration 15m
        The SK detector calibrations only related to the higher energy physics data analyses (atmospheric neutrino, proton decay, T2K-SK, etc.) will be summarized for the HK detector calibration.
        Speaker: Dr Shunichi Mine (UCI)
      • 16:30
        Outer detector calibration 10m
        The SK OD calibrations will be reviewed for the HK OD calibration.
        Speaker: Dr Shunichi Mine (UCI)
      • 16:40
        Calibration source deployment system 20m
        In this talk I will present a review of the calibration systems that were implemented in the detectors of SNO and Borexino experiments. I will cover the most important points of each of the systems that will be critical for the design of the Hyper-K source deployment apparatus and its new requirements. Some of the major points in the discussion will be dedicated to the Borexino style source positioning system with CCD cameras and current ideas on how to achieve an automatic and lightweight design.
        Speaker: Mr Szymon Manecki (VirginiaTech)
    • 17:00 17:25
      Break 25m
    • 17:25 18:25
      • 17:25
        Discussions 1h