Toshihide Maskawa

{{Short description|Japanese theoretical physicist (1940–2021)}}

{{Use dmy dates|date=April 2025}}

{{Infobox scientist

| name = Toshihide Maskawa

| native_name = 益川 敏英

| image = Toshihide Masukawa-press conference Dec 07th, 2008-2.jpg

| caption = Maskawa in 2008

| birth_date = {{birth date|1940|2|7|df=y}}

| birth_place = Nagoya, Japan

| death_date = {{death date and age|2021|7|23|1940|2|7|df=y}}

| death_place = Kyoto, Japan

| nationality = Japanese

| spouse = Akiko Takahashi

| children = 2

| fields = High energy physics (theory)

| workplaces = Nagoya University
Kyoto University
Kyoto Sangyo University

| alma_mater = Nagoya University

| doctoral_advisor = Shoichi Sakata

| thesis_title = 粒子と共鳴準位の混合効果について.

| thesis_year = 1967

| thesis_url = http://www.worldcat.org/oclc/653092215

| known_for = Work on CP violation
CKM matrix

| awards = Sakurai Prize (1985)
Japan Academy Prize (1985)
Asahi Prize (1994)
Nobel Prize in Physics (2008)

| signature =

}}

{{Standard model of particle physics}}

{{nihongo|Toshihide Maskawa (or Masukawa)|益川 敏英|Masukawa Toshihide|7 February 1940 – 23 July 2021}} was a Japanese theoretical physicist known for his work on CP-violation who was awarded one quarter of the 2008 Nobel Prize in Physics "for the discovery of the origin of the broken symmetry which predicts the existence of at least three families of quarks in nature."

{{cite web

| title = The Nobel Prize in Physics 2008

| url = http://nobelprize.org/nobel_prizes/physics/laureates/2008/index.html

| publisher = The Nobel Foundation

| access-date = 17 October 2009

}}

Early life and education

Maskawa was born in Nagoya, Japan. After World War II ended, the Maskawa family operated as a sugar wholesaler. A native of Aichi Prefecture, Toshihide Maskawa graduated from Nagoya University in 1962 and received a Ph.D. degree in particle physics from the same university in 1967. His doctoral advisor was the physicist Shoichi Sakata.

{{cite web

|title=Toshihide Maskawa - Biographical

|url=https://www.nobelprize.org/nobel_prizes/physics/laureates/2008/maskawa-bio.html

|website=www.nobelprize.org

}}

{{cite web

|title=Nagoya University World Class Researchers

|url=http://en.nagoya-u.ac.jp/people/nobel/toshihide_maskawa/index.html

|publisher=Nagoya University

|language=en

}}

{{cite web

|title=Toshihide Maskawa

|url=http://www.kyoto-u.ac.jp/static/en/research/forefronts/archives/maskawa.html

|publisher=Kyoto University

}}

From early life Maskawa liked trivia, also studied mathematics, chemistry, linguistics and various books. In high school, he loved novels, especially detective and mystery stories and novels by Ryūnosuke Akutagawa.

Career

At Kyoto University in the early 1970s, he collaborated with Makoto Kobayashi on explaining broken symmetry (the CP violation) within the Standard Model of particle physics. Maskawa and Kobayashi's theory required that there be at least three generations of quarks, a prediction that was confirmed experimentally four years later by the discovery of the bottom quark.

Maskawa and Kobayashi's 1973 article, "CP Violation in the Renormalizable Theory of Weak Interaction",

{{cite journal

|author=M. Kobayashi, T. Maskawa

|year=1973

|title=CP-Violation in the Renormalizable Theory of Weak Interaction

|journal=Progress of Theoretical Physics

|volume=49 |issue=2 |pages=652–657

|bibcode = 1973PThPh..49..652K

|doi=10.1143/PTP.49.652

|doi-access=free

|hdl=2433/66179

|hdl-access=free

}} is the fourth most cited high energy physics paper of all time as of 2010.

{{cite web

|year=2009

|url=http://www.slac.stanford.edu/spires/topcites/2010/alltime.shtml

|title=Top Cited Articles of All Time (2010 edition)

|publisher=SLAC

|access-date=21 June 2014

}} The Cabibbo–Kobayashi–Maskawa matrix, which defines the mixing parameters between quarks was the result of this work. Kobayashi and Maskawa were jointly awarded half of the 2008 Nobel Prize in Physics for this work, with the other half going to Yoichiro Nambu.

Maskawa was director of the Yukawa Institute for Theoretical Physics from 1997 to 2003.

{{cite web

|url=http://www.yukawa.kyoto-u.ac.jp/english/contents/about_us/history.html

|title=History of YITP

|date=23 February 2017

|publisher=Yukawa Institute for Theoretical Physics

}} He was special professor and director general of Kobayashi-Maskawa Institute for the Origin of Particles and the Universe at Nagoya University,{{cite web |url=http://www.kmi.nagoya-u.ac.jp/eng/message/index.html |title=Message from Director | Nagoya University: Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI) |website=www.kmi.nagoya-u.ac.jp |access-date=12 January 2022 |archive-url=https://web.archive.org/web/20110722073210/http://www.kmi.nagoya-u.ac.jp/eng/message/index.html |archive-date=22 July 2011 |url-status=dead}} director of Maskawa Institute for Science and Culture at Kyoto Sangyo University[http://www.cc.kyoto-su.ac.jp/project/MISC/MISC_home-smpl.html]{{Dead link|date=July 2018|bot=InternetArchiveBot|fix-attempted=no}} and professor emeritus at Kyoto University.

Nobel lecture

On 8 December 2008, after Maskawa told the audience "Sorry, I cannot speak English", he delivered his Nobel lecture on “What Did CP Violation Tell Us?” in Japanese language, at Stockholm University. The audience followed the subtitles on the screen behind him.[https://www.nobelprize.org/nobel_prizes/physics/laureates/2008/maskawa-lecture.html Toshihide Maskawa - Nobel Lecture: What Does CP Violation Tell Us?]

Personal life

Maskawa married Akiko Takahashi in 1967. The couple have two children, Kazuki and Tokifuji.

Death

On 23 July 2021 at the same day as the opening ceremony of Tokyo Summer Olympic Games, Maskawa died of oral cancer at his home in Kyoto at the age of 81.{{Cite news|url=https://www.nytimes.com/2021/08/10/science/space/toshihide-maskawa-dead.html|title = Toshihide Maskawa, a Nobel Prize-Winning Physicist, Who Helped Unlock a Cosmic Mystery, Dies of Oral Cancer at 81|newspaper = The New York Times|date = 10 August 2021|last1 = McClain|first1 = Dylan Loeb}}[https://www3.nhk.or.jp/news/html/20210729/k10013168691000.html ノーベル物理学賞受賞 益川敏英さん死去 81歳] {{in lang|ja}} Although his death was unrelated to triple disaster and COVID-19 infection. He was cremated in October 2021 after the private funeral.

Professional record

Recognition

File:Krugman-Tsien-Chalfie-Shimomura-Kobayashi-Masukawa-press conference Dec 07th, 2008-1.jpg, Roger Tsien, Martin Chalfie, Osamu Shimomura, Makoto Kobayashi and Toshihide Masukawa, Nobel Prize Laureates 2008, at a press conference at the Swedish Academy of Science in Stockholm]]

Political proposition

File:Toshihide Maskawa's slide rule at the Nobel Museum (51963).jpg on display at the Nobel Prize Museum]]

In 2013, Maskawa and chemistry Nobel laureate Hideki Shirakawa issued a statement against the Japanese State Secrecy Law.[https://www.science.org/content/article/updated-over-scientists-objections-japan-adopts-state-secrets-law Updated: Over Scientists' Objections, Japan Adopts State Secrets Law | Science | AAAS]" The following is Maskawa's main political proposition:

  • Support for Article 9 of the Japanese Constitution[http://www.9-jo-kagaku.jp/event/message.html 「九条科学者の会」呼びかけ人メッセージ (2005.3.13)]
  • Criticizing Japanese politician visits to the Yasukuni Shrine"[http://www.chosunonline.com/site/data/html_dir/2013/07/14/2013071400036.html 益川敏英博士「日本の平和憲法は改悪の危機」]". 朝鮮日報/朝鮮日報日本語版 (2013/07/14 01:31)。
  • Support for selective couple surname system

See also

References

{{reflist}}