View source for 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]], [[Empire of Japan|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]]<br />[[Kyoto University]]<br />[[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]]<br />[[Cabibbo–Kobayashi–Maskawa matrix|CKM matrix]]
| awards            = [[Sakurai Prize]] (1985)<br />[[Japan Academy Prize (academics)|Japan Academy Prize]] (1985)<br />[[Asahi Prize]] (1994)<br />[[Nobel Prize in Physics]] (2008)
| signature         = <!--(filename only)-->
}}
{{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 people|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 [[Spontaneous symmetry breaking|broken symmetry]] which predicts the existence of at least three families of [[quark]]s in nature."<ref name="nobelcitation">
{{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
}}</ref>

==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 [[Doctor of Philosophy|Ph.D.]] degree in particle physics from the same university in 1967. His doctoral advisor was the physicist [[Shoichi Sakata]].<ref name="Nobel Biographical">
{{cite web
 |title=Toshihide Maskawa - Biographical
 |url=https://www.nobelprize.org/nobel_prizes/physics/laureates/2008/maskawa-bio.html
 |website=www.nobelprize.org
}}</ref><ref name="Nagoya University Researcher">
{{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
}}</ref><ref name="Kyoto University's bibliography">
{{cite web
 |title=Toshihide Maskawa
 |url=http://www.kyoto-u.ac.jp/static/en/research/forefronts/archives/maskawa.html
 |publisher=Kyoto University
}}</ref>

From early life Maskawa liked [[trivia]], also studied [[mathematics]], [[chemistry]], [[linguistics]] and various books. In high school, he loved [[novel]]s, especially detective and mystery stories and novels by [[Ryūnosuke Akutagawa]].<ref name="Nobel Biographical"/>

==Career==
At [[Kyoto University]] in the early 1970s, he collaborated with [[Makoto Kobayashi (physicist)|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 [[generation (physics)|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",<ref>
{{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
 }}</ref> is the fourth most cited high energy physics paper of all time as of 2010.<ref>
{{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
}}</ref> The [[Cabibbo–Kobayashi–Maskawa matrix]], which defines the [[Cabbibo angle|mixing parameters]] between [[quark]]s 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]].<ref name="nobelcitation" />

Maskawa was director of the [[Yukawa Institute for Theoretical Physics]] from 1997 to 2003.<ref>
{{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]]
}}</ref>  He was special professor and director general of Kobayashi-Maskawa Institute for the Origin of Particles and the Universe at [[Nagoya University]],<ref>{{cite web |url=http://www.kmi.nagoya-u.ac.jp/eng/message/index.html |title=Message from Director &#124; 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}}</ref> director of Maskawa Institute for Science and Culture at [[Kyoto Sangyo University]]<ref>[http://www.cc.kyoto-su.ac.jp/project/MISC/MISC_home-smpl.html]{{Dead link|date=July 2018|bot=InternetArchiveBot|fix-attempted=no}}</ref> 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.<ref>[https://www.nobelprize.org/nobel_prizes/physics/laureates/2008/maskawa-lecture.html Toshihide Maskawa - Nobel Lecture: What Does CP Violation Tell Us?]</ref>

==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 [[2020 Summer Olympics opening ceremony|opening ceremony]] of [[Tokyo]] [[2020 Summer Olympics|Summer Olympic Games]], Maskawa died of [[oral cancer]] at his home in [[Kyoto]] at the age of 81.<ref>{{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}}</ref><ref>[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}}</ref> Although his death was unrelated to triple disaster and COVID-19 infection. He was [[Cremation|cremated]] in October 2021 after the private funeral.

==Professional record==
*July 1967 – Research Associate of the Faculty of Science, [[Nagoya University]]
*May 1970 – Research Associate of the Faculty of Science, [[Kyoto University]]
*April 1976 – Associate Professor of the Institute for Nuclear Study, [[University of Tokyo]]
*April 1980 – Professor of the Research Institute for Fundamental Physics (present [[Yukawa Institute for Theoretical Physics]]), [[Kyoto University]]
*November 1990 – Professor of the Faculty of Science, [[Kyoto University]]
* 1995 – Councilor, [[Kyoto University]]
* 1997
** January – Professor of Yukawa Institute for Theoretical Physics, [[Kyoto University]]
** April – Director of Yukawa Institute for Theoretical Physics, [[Kyoto University]]
* 2003
** April – Professor Emeritus of [[Kyoto University]]
** April – Professor of [[Kyoto Sangyo University]] (till May 2009)
* October 2004 – Director of the Research Institute, [[Kyoto Sangyo University]]
* October 2007 – Distinguished Invited University Professor of [[Nagoya University]]
* 2009
** February – Trustee of [[Kyoto Sangyo University]] 
** March – University Professor of [[Nagoya University]]
** June – Head of Maskawa Juku and Professor, [[Kyoto Sangyo University]] (till March 2019)
* 2010
** April – Director of the Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI) at [[Nagoya University]]
** December – Member of the [[Japan Academy]]
* 2018
** April – Director Emeritus of KMI at [[Nagoya University]]
* April 2019 – Professor Emeritus of [[Kyoto Sangyo University]]

==Recognition==
[[File:Krugman-Tsien-Chalfie-Shimomura-Kobayashi-Masukawa-press conference Dec 07th, 2008-1.jpg|thumb|[[Paul Krugman]], [[Roger Tsien]], [[Martin Chalfie]], [[Osamu Shimomura]], [[Makoto Kobayashi (physicist)|Makoto Kobayashi]] and Toshihide Masukawa, Nobel Prize Laureates 2008, at a press conference at the [[Swedish Academy of Science]] in Stockholm]]
*1979 – [[Nishina Memorial Prize]]
*1985 – [[Sakurai Prize]]
*1985 – [[Japan Academy Prize (academics)|Japan Academy Prize]]
*1995 – [[Chunichi Culture Award]]
*1995 – [[Asahi Prize]]
*2007 – High Energy and Particle Physics Prize by [[European Physical Society]]
*2008 – [[Nobel Prize in Physics]]
*2008 – [[File:JPN Bunka-kunsho BAR.svg|45px|ribbon bar]][[Order of Culture]]
*2010 – Member of [[Japan Academy]]

==Political proposition==
[[File:Toshihide Maskawa's slide rule at the Nobel Museum (51963).jpg|thumb|Maskawa's [[slide rule]] 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]].<ref>[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]</ref>" The following is Maskawa's main political proposition:

*Support for [[Article 9 of the Japanese Constitution]]<ref>[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)]</ref>
*Criticizing Japanese politician visits to the [[Yasukuni Shrine]]<ref>"[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)。</ref>
*Support for selective couple surname system

==See also==
* ''[[Progress of Theoretical Physics]]''
* [[List of Japanese Nobel laureates]]
* [[List of Nobel laureates affiliated with Kyoto University]]

==References==
{{reflist}}

==External links==
*[http://www.kmi.nagoya-u.ac.jp/eng/ Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI), Nagoya University]
* {{Nobelprize}}

{{Commons category|Toshihide Masukawa}}
{{2008 Nobel Prize winners}}
{{Nobel Prize in Physics Laureates 2001-2025}}
{{Japanese Nobel laureates}}

{{Authority control}}

{{DEFAULTSORT:Maskawa, Toshihide}}
[[Category:1940 births]]
[[Category:2021 deaths]]
[[Category:Scientists from Nagoya]]
[[Category:Japanese Nobel laureates]]
[[Category:Japanese physicists]]
[[Category:Nobel laureates in Physics]]
[[Category:Recipients of the Order of Culture]]
[[Category:Japanese theoretical physicists]]
[[Category:J. J. Sakurai Prize for Theoretical Particle Physics recipients]]
[[Category:Particle physicists]]
[[Category:Nagoya University alumni]]
[[Category:Academic staff of Nagoya University]]
[[Category:Academic staff of the University of Tokyo]]