4th 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 meetings, we will hold the 4th International Open Working Group Meeting for Hyper-Kamiokande. The meeting will be open to all interested scientists and community members.

The slides for the past open meetings can be found here;
(1st) http://indico.ipmu.jp/indico/conferenceTimeTable.py?confId=7#all.detailed
(2nd) http://indico.ipmu.jp/indico/conferenceTimeTable.py?confId=10#all.detailed
(3rd) http://indico.ipmu.jp/indico/conferenceTimeTable.py?confId=23#all.detailed

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:
Francesca DI LODOVICO (QMUL), Mark HARTZ (Kavli IPMU), Yoshinari HAYATO (ICRR), Yusuke KOSHIO (Okayama), 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), Chris WALTER (Duke), Roger WENDELL (ICRR), Masashi YOKOYAMA (Tokyo)


  • Akihiro Minamino
  • Akira Konaka
  • Alexander Himmel
  • Alexis Haesler
  • Arturo Fiorentini
  • Atsumu Suzuki
  • Benjamin Quilain
  • Blair Jamieson
  • Camillo Mariani
  • Carsten Rott
  • Chris Kachulis
  • Christophe Bronner
  • Costas Andreopoulos
  • Daisuke Fukuda
  • David Hadley
  • David Payne
  • Davide Sgalaberna
  • Debra Dewhurst
  • Ed Kearns
  • Elder Pinzon
  • Enrico Scantamburlo
  • Fabrice Retiere
  • Francesca Di Lodovico
  • Giada Carminati
  • Henry Sobel
  • Hide-Kazu TANAKA
  • hirohisa tanaka
  • Hiroyuki Sekiya
  • Hisakazu Minakata
  • Jae Yool Kim
  • Jean-Michel Poutissou
  • Jeanne Wilson
  • Jiae Kim
  • John Martin
  • Jonathan Perkin
  • Jun Kameda
  • kevin connolly
  • Kimihiro OKUMURA
  • Kirsty Duffy
  • Kunxian huang
  • Lee Thompson
  • Leïla Haegel
  • Linda Cremonesi
  • Lluis Marti Magro
  • M. Fatih Bay
  • Makoto Miura
  • Marat Khabibullin
  • Marc Bergevin
  • Mark Hartz
  • Mark Rayner
  • Mark Scott
  • Mark Vagins
  • Masahiro Kuze
  • Masashi Yokoyama
  • Masato SHIOZAWA
  • Masayuki Nakahata
  • Matthew Malek
  • Megan Friend
  • Miao Jiang
  • Michael Shaevitz
  • Michael Wilking
  • Michel Gonin
  • Motoyasu Ikeda
  • Neil McCauley
  • raj shah
  • Richard Calland
  • Richard Helmer
  • Robert Svoboda
  • Roberto Sacco
  • Roger Wendell
  • Ryan Terri
  • Sampa Bhadra
  • Seiko Hiota
  • Shao-Feng Ge
  • Shimpei Tobayama
  • Shoei Nakayama
  • Shunichi Mine
  • Silvestro di Luise
  • Sophie Berkman
  • Takaaki Kajita
  • Takatomi Yano
  • Takayuki OHMURA
  • Taku Ishida
  • Teppei Katori
  • Tetsuro Sekiguchi
  • Thomas Dealtry
  • Thomas Lindner
  • Tom Feusels
  • Tord Ekelof
  • Toru Iijima
  • Tsunayuki Matsubara
  • Tsuyoshi NAKAYA
  • Yasuhiro NISHIMURA
  • Yasuo Takeuchi
  • Yoshihiko Kawai
  • Yoshihisa Obayashi
  • Yoshinari Hayato
  • Yuichi Oyama
  • Yuji Okajima
  • Yuri KUDENKO
  • Yusuke Koshio
  • Yusuke Suda
  • Monday, 27 January
    • 08:30 09:00
      • 08:30
        Registration 30m
    • 09:00 09:30
      Opening Session
      • 09:00
        Opening remark 15m
        Opening remark
        Speaker: Prof. Masato Shiozawa (Kamioka Observatory, ICRR, The University of Tokyo)
      • 09:15
        Steering group report 15m
        Steering group report
        Speaker: Prof. Tsuyoshi Nakaya (Kyoto University)
    • 09:30 10:20
      J-PARC and Beamline
      • 09:30
        Status of the J-PARC accelerators / neutrino facility and their upgrade plans 30m
        Status of the J-PARC accelerators / neutrino facility and their upgrade plans
        Speaker: Dr Taku Ishida (KEK)
      • 10:00
        The ESSnuSB project 20m
        We are making a Design Study of a neutrino Super Beam long base line (500 km) experiment ESSnuSB based on the use of the European Spallation Source (ESS) 5 MW, 2 GeV proton linac and a Megaton water Cherenkov detector to discover leptonic CP violation, performing measurements at the second oscillation maximum, where the sensitivity to CP violation is significantly higher than at the first maximum and thereby making the CP angle measurement significantly less sensitive to systematic errors. Operation at the second maximum is made possible by the very high intensity of the ESS proton linac (1.6exp16 protons on target per year). An account is given of how the high intensity neutrino beam is generated using the ESS linac, of the properties of deep mines around 500 km from ESS that are possible sites for the neutrino detector and of the performance of the experiment for leptonic CP violation discovery.
        Speaker: Prof. Tord Ekelof (Uppsala University)
    • 10:20 10:45
      Coffee Break 25m
    • 10:45 11:45
      Physics Potential and Near Detectors
      • 10:45
        Introduction 10m
        Introduction to the "Physics Potential and Near Detectors" session
        Speaker: Prof. Masashi Yokoyama (University of Tokyo)
      • 10:55
        Sensitivity studies for Tokai to Hyper Kamiokande 30m
        We will describe sensitivity studies done after the Hyper-Kamiokande LOI by adapting the code used for sensitivity studies in T2K, first to reproduce the results of this LOI and later study the effect of using the fiTQun pi-zero rejection cut and including the muon neutrino sample, as well as requirements for the near detectors constraints.
        Speakers: Dr Christophe Bronner (Kyoto University), Ms Linda Cremonesi (Queen Mary University of London)
      • 11:25
        HyperK sensitivity study using the VALOR T2K joint 3-flavour analysis 20m
        Will present initial results from a HyperK sensitivity study using the well-established VALOR joint 3-flavour oscillation analysis. This analysis performs simultaneous fits of the HyperK single muon-like ring and single electron-like ring event reconstructed energy distributions in a framework of 3 active neutrino oscillations including matter effects. Near detector constraints from the 2013 T2K analysis are included and ~80 flux, cross-section, final state re-interaction and efficiency systematics are fully taken into account in the fit. The analysis is performed with the current T2K systematics and with HyperK-era error projection scenarios.
        Speaker: Mr Shah Raj (Oxford University)
    • 11:45 13:05
      Lunch 1h 20m
    • 13:05 14:40
      Physics Potential and Near Detectors
      • 13:05
        Flux Extrapolation Uncertainties from Tokai to Hyper-K 20m
        Preliminary sensitivity studies for a CP violation measurement with a Tokai-to-HyperK neutrino beam suggest that 2% systematic errors are required to remain statistics limited. We investigate the uncertainty on the flux extrapolation from potential near detector sites in Tokai, including the current ND280 site and potential sites out to 2 km from the neutrino beam production point. We evaluate the neutrino flux uncertainties using current uncertainties on hadron production data from NA61/SHINE used by T2K, and using the expected ultimate uncertainties from NA61/SHINE data. We compare the results to the 2% systematic error requirement and consider the suitability of existing or potential near detector sites.
        Speaker: Prof. Mark Hartz (Kavli IPMU (WPI), University of Tokyo/TRIUMF)
      • 13:25
        A New Near Detector at Intermediate Disastance for Hyper-Kamiokande 20m
        A description of the studies on a new near detector at intermediate distances (around 2km or so) for Hyper-Kamiokande is presented, along with a description of the possible benefits and design.
        Speaker: Prof. Francesca Di Lodovico (Queen Mary, University of London)
      • 13:45
        The nuPRISM Near Detector: Constraining Neutrino Energy Using Multiple Off-Axis Angles 20m
        At the previous Hyper-K meeting, the idea for a long water Cherenkov detector that spans multiple off-axis angles was presented. Using this configuration, it is possible to constrain the relationship between lepton kinematics and neutrino energy from the neutrino beam information, rather than relying solely on model-dependent neutrino generator extrapolations. Several details of this detector concept will be presented, such as potential near detector sites and event pileup considerations.
        Speaker: Dr Michael Wilking (TRIUMF)
      • 14:05
        LoI to J-PARC PAC 15m
        Goals and schedule for the Letter of Intent to be submitted to J-PARC PAC will be discussed.
        Speaker: Masashi Yokoyama (University of Tokyo)
      • 14:20
        The DAEdALUS at Hyper-K Experiment: Searching for CP Violation 20m
        DAEdALUS is a phased program leading to a high-sensitivity search for CP violation. The experiment uses a set of high-intensity 800 MeV cyclotrons to produce pion decay-at-rest neutrino sources at several locations (with baselines of 1.5km, 8km, and 20km) going to the Hyper-K ultra-large, underground detector. The Hyper-K detector would be used to isolate and measure a very large sample of inverse-beta-decay events separately from each of the three sources. The DAEdALUS experiment will provide a high-statistics antineutrino data set with no matter effects that can be combined with the Hyper-K long-baseline data to provide greatly enhanced sensitivity for CP violation measurements.
        Speaker: Prof. Michael Shaevitz (Columbia University)
    • 14:40 15:05
      Coffee Break 25m
    • 15:05 15:30
      Physics Potential and Near Detectors
      • 15:05
        Supernova Relic Neutrino search with Hyper-Kamiokande 25m
        The sensitivity of SRN in HK is reported for several cosmic ray intensity case. The cosmic muon flux in HK is also reported.
        Speaker: Dr Takatomi Yano (Okayama Univ.)
    • 15:30 16:40
      Cavities and Tanks
      • 15:30
        Hyper-K site and cavern 30m
        This talk will discuss current status and plan of geological survey at Mozumi site, and also cover status of technical design document for HK cavern construction.
        Speaker: Dr Hide-Kazu TANAKA (ICRR)
      • 16:00
        Hyper-K tank 30m
        This talk will discuss current status and plan of Hyper-K tank design, and also cover status of technical design document for the tank design.
        Speaker: Dr Shoei Nakayama (Kamioka Observatory, ICRR, The University of Tokyo)
      • 16:30
        Summary 10m
        Speaker: Prof. Masato Shiozawa (Kamioka Observatory, ICRR, The University of Tokyo)
    • 16:40 17:40
      Institute Representative Meeting
      • 16:40
        Institute Representative Meeting 1h
    • 17:40 18:40
      Sub-WG Meetings
      • 17:40
        Software Group 1h Room-A


      • 17:40
        Sub-WG Meetings 1h
  • Tuesday, 28 January
    • 09:00 10:15
      • 09:00
        Overview of the photodetector development 10m
        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, The University of Tokyo)
      • 09:10
        Measurement of large-aperture photodetectors in a water tank 30m
        New large aperture photodetectors for Hyper-Kamiokande are under development and these usability is tested. For the first proof test, high-QE photomultiplier tubes (51 cm Φ) and hybrid photodetectors (20 cm Φ) have been measured in a 200-ton water tank in Kamioka, Japan. These installation, calibration and performance evaluation, and development status of other new photodetectors will be presented.
        Speaker: Dr Yasuhiro NISHIMURA (ICRR)
      • 09:40
        Status of Texas PMTs 15m
        Current status of development of 11 inch HQE PMTs from ADIT/ETEL. Schedule for delivery of prototypes and planned testing. Possible use in WATCHMAN.
        Speaker: Robert Svoboda (UC Davis)
      • 09:55
        Enhanced light collection with photon trap 20m
        We investigate the performance of photon traps for enhancing the light collection efficiency within the Hyper-Kamokiokande detector. Cerenkov photons enter the trap by going through a dichroic mirror transmitting UV and blue light and reflecting green light. Some Cerenkov photons are detected directly by a PMT while the others are absorbed in a wavelength shifting plate that reemit green photons. Green photons are confined within a box by the dichroic mirror and regular broad band mirrors covering the other walls. A large fraction of the green photons eventually hit the PMT are detected. Our simulations show that the overall detection efficiency of a 1x1m2 trap with a 12" PMT in the center exceeds the detection efficiency of a 20" PMT. However, the timing resolution is very significantly impaired. We will show the performances of the trap and discuss how it could be used in the context of Hyper-Kamiokande.
        Speaker: Dr Jean-Michel Poutissou (TRIUMF)
    • 10:15 10:40
      Coffee Break 25m
    • 10:40 11:35
      DAQ and Electronics System
      • 10:40
        DAQ session ~ Introduction 15m
        Conveners' summary
        Speaker: Dr Yoshinari Hayato (Kamioka obs., ICRR, Univ. of Tokyo)
      • 10:55
        HK FADC Digitization and Communication Work 20m
        We report on two separate research projects related to HK electronics. First, we are exploring the idea of using Flash ADCs (FADCs) for digitizing the HK PMT signals (rather than ADC/TDC digitization). We have done simple tests at TRIUMF of the timing resolution achievable with FADCs. We are also thinking about how to quantify the benefits of FADCs. Second, we are investigating a solution for redundant communication between front end boards based on the RapidIO protocol. A prototype system is being developed based on a Altera Cyclone 5 evaluation board by Terasic.
        Speaker: Dr Thomas Lindner (Triumf)
      • 11:15
        DAQ plans for HK 20m
        Several UK institutions will participate in the development of Data Acquisition Systems (DAQ) for the prototype and full-scale detectors. We present an overview of considerations towards a conceptual design for a DAQ system and UK interests in this area.
        Speaker: Francesca Di Lodovico (Queen Mary, University of London)
    • 11:35 13:00
      Lunch 1h 25m
    • 12:00 13:00
      T2HK discussion (Flux/ND inputs to the J-PARC LOI) Balcony A (the 4th floor)

      Balcony A (the 4th floor)

      • 12:00
        T2HK discussion (Flux/ND inputs to the J-PARC LOI) 1h
    • 13:00 14:30
      • 13:00
        Introduction of Software session 5m
        A review of the status of software at the previous meeting and what we will discuss in this session will be presented.
        Speaker: Dr Makoto Miura (Kamioka Observatory, ICRR, University of Tokyo)
      • 13:05
        Development of WCSim 25m
        WCSim is a simulator for water cherenkv detectors and we have developed it for Hyper-K detector simulation. We have compared WCSim with skdetsim which is used in Super-K. To determine a detector configuration of Hyper-K, simulations of HPD are going to install on WCSim. Also an event display for WCSim will be discussed here.
        Speakers: Dr Alex Himmel (Duke University), Mr Yuji Okajima (Tokyo Institute of Technology)
      • 13:30
        Development of event reconstruction software for Hyper-K 30m
        fiTQun is a event reconstruction software based on maximum likelihood method and it can determine physics variables (vertex, direction, number of rings, momentum, PID) at once. It was originally developed for Super-K analysis and it could be event reconstruction software also for Hyper-K. Here we will report about status of fiTQun for Hyper-K,
        Speakers: Dr Blair Jamieson (University of Winnipeg), Dr Michael Wilking (TRIUMF)
      • 14:00
        Computing Model for Hyper-Kamiokande 20m
        A description of the current computing model strategy for Hyper-Kamiokande is provided. The results from the current simulation production are presented and plans for the simulation production for the LoI shown.
        Speaker: Prof. Francesca Di Lodovico (Queen Mary, University of London)
      • 14:20
        Summary and toward determination of detector configuration 10m
        I will summarize the status of software and discuss plan, especially strategy to determine detector configuration of Hyper-K.
        Speaker: Dr Makoto Miura (Kamioka Observatory, ICRR, University of Tokyo)
    • 14:30 14:55
      Coffee Break 25m
    • 14:55 15:20
      Water System
      • 14:55
        Water Status 15m
        HK water system and tank water flow design updates
        Speaker: Dr Hiroyuki Sekiya (ICRR/IPMU)
      • 15:10
        Gd Status 10m
        The current status of gadolinium-in-water R&D studies, particularly the ongoing EGADS project, will be discussed.
        Speaker: Prof. Mark Vagins (IPMU)
    • 15:20 16:15
      Detector Calibrations
      • 15:20
        Overview and plan 10m
        This talk will overview HK calibration WG status and plan, and give a brief introduction to HK calibration R&D programs.
        Speaker: Dr Hide-Kazu TANAKA (ICRR, University of Tokyo)
      • 15:30
        New source inserting system for SK as an R&D of HK calibration 15m
        Current SK calibration is done by inserting sevarel calibration sources from the holes at the top of the tank manually in the dark. So we, Kobe group, are planning to set the source inserting system using a winch with a wire eoncoder controlled by PC. This is also the first step of R&D of the HK calibration system. The target position precision of the system is less than 1cm. By using a gate valve, we can change the sources even under the light. The installation and practical use will be done by the end of FY2015. At this stage, we can move the sources only in z (vertical) direction. At the next stage, we are thinking of testing the calibration system which is movable in all (x, y, and z) deirections in the HK prototype.
        Speaker: Dr Atsumu Suzuki (Kobe University)
      • 15:45
        Pulsed LEDs as a light source for calibration 15m
        Pulsed LEDs provide an alternative light source for calibration and have been used in other experiments. I will present information on previous LED pulers and discuss their potential application for calibration in hyper-kamiokande.
        Speaker: Dr Neil McCauley (University of Liverpool)
      • 16:00
        Neutron Generators for Calibration 15m
        This talk will present neutron generators as calibration sources in water Cherenkov detectors. Discussion will include a description of existing sources as well as present ideas for a future compact neutron generator.
        Speaker: Roger Wendell (ICRR)
    • 16:15 16:45
      • 16:15
        Discussion 30m
    • 16:45 17:45
      J-PARC LOI Meeting
      • 16:45
        J-PARC LOI Meeting 1h
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