＜＜＜「@」を「__AT__」に置き換えています＞＞＞
Date: Thu, 16 Apr 2026 12:42:22 +0900
To: sg-l__AT__ml.yukawa.kyoto-u.ac.jp
Subject: [Sg-l:10287] KEK素核研 金茶会(4月24日)のご案内
From: Toru Kojo (Sg-l 経由)
皆様、（重複して受け取られる方はご容赦ください）
(See below for English translation.)
KEK素核研では月に１回程度、金曜日の夕方から物理やそれ以外の広いテーマに
ついて語り合う、インフォーマルな交流会＋講演会「金茶会」を今年度も開催します。
どなたでもご参加いただけます。
次回の講演は、4月２4日（金）の１６：３０から開催予定です。(直前のご連絡になり申し訳ありません。）
講演後の１７：３０から講演会場にて交流会があります。多少の茶菓子等を準備してありますので、是非会場にお越し下さい。
KEK外からのリモート接続 (zoom) を希望する方は、以下から登録をお願いいたします。
KEK内部からの接続はご遠慮ください。（ぜひ、会場にお越しください。）
https://kek-jp.zoom.us/j/95138580454?pwd=BdqSwd5psZfTahTWyuGYhu21Z7xvK8.1
=============================================================
第２５回金茶会案内：
日時：２０２６年4月２4 日（金）午後４時半から６時（講演は４時半から）
場所：つくば 研究本館１階 小林ホール
(リモート会場：東海キャンパス => JRB２階大会議室、和光キャンパス => 仁科
記念棟１０６室)
講演者：Gordon Baym (University of Illinois, Urbana-Champaign)
[ wikipedia: https://en.wikipedia.org/wiki/Gordon_Baym ]
タイトル：The puzzle of angular momentum conservation in beta decay and related processes
要旨：We ask the question of how angular momentum is conserved in a number of related processes, from elastic scattering of a circularly polarized photon by an atom, where the scattered photon has a different spin direction than the original photon; to scattering of a fully relativistic spin-1/2 particle by a central potential; to inverse beta decay in which an electron is emitted following the capture of a neutrino on a nucleus, where the final spin is in a different direction than that of the neutrino – an apparent change of angular momentum.
The seeming non-conservation of angular momentum arises, in fact, in the quantum measurement process in which the measuring apparatus does not have an initially well-defined angular momentum, but is localized in direction in the outside world. We generalize the discussion to massive neutrinos and electrons, and examine nuclear beta decay and electron-positron annihilation processes through the same lens, enabling physical insights into angular and helicity distributions in these reactions.
=============================================================
ご質問などはこちらまで：ipns-kincha__AT__ml.post.kek.jp
多くの皆様の参加をお待ちしております。
上岡修星、古賀太一朗、古城徹、齊藤直人、山我拓巳、
長谷川雅也、本多良太郎、森野雄平、フレンド メーガン（世話人一同)
##############################################################
Dear All, (Please apologize if you receive this multiple times.)
The KEK Institute of Particle and Nuclear Studies (IPNS) will continue to host "Kin-cha-kai" this fiscal year.
This is an informal gathering and lecture series held about once a month on Friday evenings, covering a wide range of topics in physics and beyond. Anyone is welcome to attend.
The next lecture is scheduled for Friday, April 24th, starting at 16:30. (We apologize for the short notice.)
Following the lecture, a social gathering will be held at the same venue from 17:30. Light refreshments and snacks will be served, so please feel free to join us at the hall.
For those outside KEK who wish to join remotely via Zoom, please register using the link below. We ask that those inside KEK attend in person at the venue rather than connecting remotely.
https://kek-jp.zoom.us/j/95138580454?pwd=BdqSwd5psZfTahTWyuGYhu21Z7xvK8.1
=============================================================
The 25th Kin-cha-kai Announcement:
Date & Time: Friday, April 24, 2026, from 16:30 to 18:00 (Lecture starts at 16:30)
Main Venue: Kobayashi Hall, 1st Floor, Kenkyu-Honkan, Tsukuba Campus
(Remote Venues: Tokai Campus => JRB 2nd Floor Conference Room; Wako Campus => Nishina Memorial Building, Room 106)
Speaker: Gordon Baym (University of Illinois, Urbana-Champaign) [Wikipedia: https://en.wikipedia.org/wiki/Gordon_Baym ]
Title: The puzzle of angular momentum conservation in beta decay and related processes
Abstract：We ask the question of how angular momentum is conserved in a number of related processes, from elastic scattering of a circularly polarized photon by an atom, where the scattered photon has a different spin direction than the original photon; to scattering of a fully relativistic spin-1/2 particle by a central potential; to inverse beta decay in which an electron is emitted following the capture of a neutrino on a nucleus, where the final spin is in a different direction than that of the neutrino – an apparent change of angular momentum.
The seeming non-conservation of angular momentum arises, in fact, in the quantum measurement process in which the measuring apparatus does not have an initially well-defined angular momentum, but is localized in direction in the outside world. We generalize the discussion to massive neutrinos and electrons, and examine nuclear beta decay and electron-positron annihilation processes through the same lens, enabling physical insights into angular and helicity distributions in these reactions.
=============================================================
For any inquiries, please contact: ipns-kincha__AT__ml.post.kek.jp
We look forward to seeing many of you there.
Shusei Kamioka, Taichiro Koga, Toru Kojo, Naohito Saito,
Takumi Yamaga, Masaya Hasegawa, Ryotaro Honda, Yuhei Morino, and Megan Friend
(Organizers)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Date: Tue, 30 Jun 2026 18:01:40 +0900
To: sg-l__AT__ml.yukawa.kyoto-u.ac.jp
Subject: [Sg-l:10483] KEK素核研 金茶会(７月１７日)のご案内：福山寛氏 (東大/KEK) 「超低エネルギー物理学の魅力 −量子凝縮系を中心に−」
From: Toru Kojo (Sg-l 経由)
皆様、（重複して受け取られる方はご容赦ください）
(See below for English translation.)
KEK素核研では月に１回程度、金曜日の夕方から物理やそれ以外の広いテーマに
ついて語り合う、インフォーマルな交流会＋講演会「金茶会」を今年度も開催します。どなたでもご参加いただけます。
次回の講演は、７月１７日（金）の１６：３０から開催予定です。
講演後の１７：３０から講演会場にて交流会があります。多少の茶菓子等を準
備してありますので、是非会場にお越し下さい。
KEK外からのリモート接続 (zoom) を希望する方は、以下から登録をお願いい
たします。
KEK内部からの接続はご遠慮ください。（ぜひ、会場にお越しください。）
https://kek-jp.zoom.us/j/95138580454?pwd=BdqSwd5psZfTahTWyuGYhu21Z7xvK8.1
=============================================================
第２７回金茶会案内：
日時：２０２６年７月１７ 日（金）午後４時半から６時（講演は４時半から）
場所：つくば 研究本館１階会議室１
(リモート会場：東海キャンパス => JRB２階大会議室、和光キャンパス => 仁科
記念棟１０６室)
講演者：福山 寛 (東大低温科学研究センター/KEK QUP)
タイトル： 超低エネルギー物理学の魅力 −量子凝縮系を中心に−
言語：日本語
要旨： 原子質量が小さく原子間相互作用の弱い4He（複合ボース粒子）と3He（複合フェルミ粒子）は、全ての原子・分子系の中で最も量子効果が強く、各種の空間次元や圧力のもとで数K以下に冷却すると、量子液体、量子固体、量子液晶（？）などさまざまな量子凝縮系を形成する。これらをさらなる超低温に冷却すると（4Heの場合〜100 mKまで、3Heの場合〜100μKまで）、超流動、量子スピン液体、核強磁性など多彩な性質をもつ低温相が、特徴的な素励起（フォノン、ロトン、準粒子、マヨラナ粒子？）やトポロジカル欠陥（量子渦、秩序変数のテクスチャー）を伴って出現する。その出現の仕方つまり相転移も一次、二次、ラムダ型、Berezinskii-Kosterlitz-Thouless型など多彩である。また、自発的対称性の破れ、Kibble-Zurek機構、マヨラナ粒子など、高エネルギー・宇宙物理学分野との接点も少なくない。量子液体固体（QFS）研究と呼ばれるこの分野の魅力をいくつかの事例をあげて紹介したい。
=============================================================
今回は、日本語の講演です。英語の通訳がつきます。
https://kds.kek.jp/event/59858/
ご質問などはこちらまで：ipns-kincha__AT__ml.post.kek.jp
多くの皆様の参加をお待ちしております。
上岡修星、古賀太一朗、古城徹、齊藤直人、山我拓巳、
長谷川雅也、本多良太郎、森野雄平、フレンド メーガン（世話人一同)
##############################################################
Dear all,
(We apologize if you receive this message more than once.)
At KEK IPNS, we hold an informal gathering and lecture series called “Kincha-kai” about once a month on Friday evenings.
The topics range widely from physics to various other fields. Everyone is welcome to participate.
The next lecture is scheduled for Friday, July 17, starting at 16:30.
A social gathering will be held at the lecture venue from 17:30 after the talk.
Light refreshments will be provided, so please join us at the venue.
If you would like to join remotely from outside KEK (via Zoom), please register using the link below.
Please refrain from connecting remotely from within KEK (we encourage you to attend in person).
https://kek-jp.zoom.us/j/95138580454?pwd=BdqSwd5psZfTahTWyuGYhu21Z7xvK8.1
Please note that the venue in Tsukuba is different from before: Main
Research Building 1F, Conference Room 1 (the glass-walled room in front of Kobayashi Hall).
=============================================================
Announcement of the 27th Kincha-kai:
Date: Friday, July 17, 2026, 16:30–18:00 (talk begins at 16:30)
Venue (Tsukuba): Main Research Building, 1F, Conference Room 1
(Remote Tokai: JRB 2F conference room, Tokai Campus)
(Remote Wako: Nishina Bldg. #106)
Speaker: Dr. Hiroshi Fukuyama (UTokyo CRC/KEK QUP)
Title: The Fascination of Ultra-Low-Energy Physics: Focusing on Quantum Condensed Matter Systems
Abstract:
The helium isotopes 4^{4}4He, a bosonic composite particle, and 3^{3}3He, a fermionic composite particle, possess the strongest quantum character among all atomic and molecular systems owing to their small atomic masses and weak interatomic interactions. When cooled below a few kelvin under various dimensionalities and pressures, they form a wide variety of quantum condensed phases, including quantum liquids, quantum solids, and quantum liquid crystals.
Upon further cooling to ultralow temperatures (down to ∼100\sim100∼100 mK for 4^{4}4He and ∼100\sim100∼100 μK for 3^{3}3He), these systems exhibit diverse low-temperature phases such as superfluidity, quantum spin liquids, and nuclear ferromagnetism. These phases are accompanied by characteristic elementary excitations—including phonons, rotons, quasiparticles, and Majorana quasiparticles—as well as topological defects such as quantized vortices and order-parameter textures. The associated phase transitions are equally rich, encompassing first-order, second-order, lambda-type, and Berezinskii–Kosterlitz–Thouless transitions.
Quantum fluids and solids also provide fertile ground for concepts shared with high-energy and astrophysics, including spontaneous symmetry breaking, the Kibble–Zurek mechanism, and Majorana particles. In this lecture, I will highlight several examples illustrating the fascination and broad scientific significance of the field known as Quantum Fluids and Solids (QFS) research.
=============================================================
This talk will be given in Japanese with English interpretation.
https://kds.kek.jp/event/59858/
For inquiries, please contact: ipns-kincha__AT__ml.post.kek.jp
We look forward to your participation.
Shusei Kamioka, Taichiro Koga, Toru Kojo, Naoto Saito, Takumi Yamaga,
Masaya Hasegawa, Ryotaro Honda, Yuhei Morino, Megan Friend
(on behalf of the organizing committee)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Date: Wed, 15 Jul 2026 14:59:25 +0900
To: sg-l__AT__ml.yukawa.kyoto-u.ac.jp
Subject: [Sg-l:10520] KEK金茶会 7/17, 4:30pm-, zoomリンクの変更 [Kincha-kai, July 17, 4:30pm-, zoom link updated]
From: Toru Kojo (Sg-l 経由)
皆様
（重複して受け取られる方はご容赦ください）
先にご案内した第27回 KEK金茶会（7/17, 4:30pm-)について、Zoom情報が変更になりました。
リモートで参加される方は、以下の新しいZoom情報をご利用ください。
開催日時、会場、講演内容等に変更はありません。
Zoom URL:
https://kek-jp.zoom.us/j/96121879959?pwd=Nnu5TjFAQbwO6y4yhzaDxAWC2vMahv.1
Meeting ID: 961 2187 9959
Passcode: 682785
講演者：福山 寛 (東大低温科学研究センター/KEK QUP)
タイトル： 超低エネルギー物理学の魅力 −量子凝縮系を中心に−
言語：日本語
要旨： 原子質量が小さく原子間相互作用の弱い4He（複合ボース粒子）と3He（複合フェルミ粒子）は、全ての原子・分子系の中で最も量子効果が強く、各種の空間次元や圧力のもとで数K以下に冷却すると、量子液体、量子固体、量子液晶（？）などさまざまな量子凝縮系を形成する。これらをさらなる超低温に冷却すると（4Heの場合〜100 mKまで、3Heの場合〜100μKまで）、超流動、量子スピン液体、核強磁性など多彩な性質をもつ低温相が、特徴的な素励起（フォノン、ロトン、準粒子、マヨラナ粒子？）やトポロジカル欠陥（量子渦、秩序変数のテクスチャー）を伴って出現する。その出現の仕方つまり相転移も一次、二次、ラムダ型、Berezinskii-Kosterlitz-Thouless型など多彩である。また、自発的対称性の破れ、Kibble-Zurek機構、マヨラナ粒子など、高エネルギー・宇宙物理学分野との接点も少なくない。量子液体固体（QFS）研究と呼ばれるこの分野の魅力をいくつかの事例をあげて紹介したい。
どうぞよろしくお願いいたします。
金茶会世話人一同
================================================================
Dear all,
(We apologize if you receive this message more than once.)
Please note that the Zoom information for the 27th Kincha-kai (July. 17, 4:30pm-) announced previously has been changed.
If you plan to participate remotely, please use the new Zoom information below.
There are no changes to the date, venue, or lecture details.
Zoom URL:
https://kek-jp.zoom.us/j/96121879959?pwd=Nnu5TjFAQbwO6y4yhzaDxAWC2vMahv.1
Meeting ID: 961 2187 9959
Passcode: 682785
Speaker: Hiroshi Fukuyama (University of Tokyo Cryogenic Research Center / KEK QUP)
Title: The Fascination of Ultra-Low-Energy Physics: Focusing on Quantum Condensed Matter Systems
The helium isotopes 4^{4}4He, a bosonic composite particle, and 3^{3}3He, a fermionic composite particle, possess the strongest quantum character among all atomic and molecular systems owing to their small atomic masses and weak interatomic interactions. When cooled below a few kelvin under various dimensionalities and pressures, they form a wide variety of quantum condensed phases, including quantum liquids, quantum solids, and quantum liquid crystals.Upon further cooling to ultralow temperatures (down to ∼100\sim100∼100 mK for 4^{4}4He and ∼100sim100∼100 μK for 3^{3}3He), these systems exhibit diverse low-temperature phases such as superfluidity, quantum spin liquids, and nuclear ferromagnetism. These phases are accompanied by characteristic elementary excitations—including phonons, rotons, quasiparticles, and Majorana quasiparticles—as well as topological defects such as quantized vortices and order-parameter textures. The associated phase transitions are equally rich, encompassing first-order, second-order, lambda-type, and Berezinskii–Kosterlitz–Thouless transitions.Quantum fluids and solids also provide fertile ground for concepts shared with high-energy and astrophysics, including spontaneous symmetry breaking, the Kibble–Zurek mechanism, and Majorana particles. In this lecture, I will highlight several examples illustrating the fascination and broad scientific significance of the field known as Quantum Fluids and Solids (QFS) research.
Best regards,
The Kincha-kai Organizing Committee