1185

˙ ஊ࿩ࣨ͝஫จ͸৽ཻࢠͰ͔͢?

— LHC 750 GeV ೋޫࢠΞϊϚϦʔహ຤‫— ه‬
KIAS (‫ߴࠃؖ‬౳ՊֶӃ)੢࿬ ݈ೋnishiken@kias.re.kr
2016 ೥ (ฏ੒ 28 ೥) 11 ݄ 7 ೔1ॳΊʹૉཻࢠ࣮‫ݱͼٴݧ‬৅࿦ͷ‫͍͓ͯʹڀݚ‬ɼ࠷΋ॏཁͳ͜ͱͷҰͭ͸ɼ‫ཱ֬͞ʹط‬Εͨཧ࿦Ͱ͸આ໌Ͱ͖ͳ͍‫ݱ‬৅͕ൃ‫͞ݟ‬ΕͨࡍʹͲ͏͢Δ͔Ͱ͋Δɻಛʹ‫ݱ‬৅࿦Λ‫ڀݚ‬
͢Δਓؒʹͱͬͯɼ΋͠‫؍‬ଌ͞Εͨࣄ৅͕ਅʹ৽͍͠෺ཧͷଘࡏΛ͍ࣔͯ͠ΔͳΒɼ͜ͷࣄ৅Λઆ໌͢Δ͜ͱ͸ૉཻࢠͷඪ४໛‫ܕ‬Λ௒͑ͨཧ࿦Λߏங͢Δࡍͷࢦಋ‫ݪ‬ཧͱͳΔͷͰɼඇৗʹେ͖ͳҙຯΛ࣋ͭɻ΋ͪΖΜɼൃ‫͞ݟ‬Εͨ‫ݱ‬৅ͷಛੑʹΑΓɼͲͷΑ͏ͳ৽͍͠෺ཧ͕๬·͍͔͠͸େ͖͘ҟͳͬͯ͘Δ͕ɼ2015 ೥ 12 ݄ʹ ATLASɼ

CMS ࣮྆‫ݧ‬άϧʔϓʹΑΓൃද͞Εͨɼ
ʮ750 GeV ۙลʹ‫ݱ‬Εͨೋͭͷޫࢠ͔Βߏ੒͞ΕΔෆม࣭ྔͷϐʔΫͷଘࡏʯ [1, 2, 3] ͸ɼҎԼͷೋͭͷཧ༝Ͱଟ͘ͷ‫ݱ‬৅࿦‫ऀڀݚ‬ͷؔ৺Λ‫ݺ‬ΜͩɻҰͭ͸ɼಛఆͷੑ࣭Λ࣋ͭ৽ཻࢠΛಋೖ͢Ε͹ɼൺֱత༰қʹແໃ६ͳઆ໌͕Մೳͳ͜
ͱɼ΋͏Ұͭ͸ɼࠓ·Ͱ‫͞ڀݚ‬Ε͖ͯͨଟ͘ͷ‫ݱ‬৅࿦໛‫ܕ‬ͷηοτΞοϓʹ (ඞཁͳΒ໛‫ܕ‬Λ֦ுͯ͠) ຒΊࠐΊΔ͜ͱͰ͋ΔɻຊߘͰ͸ɼ2015 ೥ 12 ݄த०͔Β 2016 ೥ 8 ݄ॳ०ʹ͔͚ͯɼ࣮྆‫ݧ‬άϧʔϓ͔Βެࣜʹ൱ఆత‫ݟ‬ղΛग़͞ΕΔ·Ͱଓ͍ͨɼ࠷ऴతʹ 400 ຊҎ্ͷ࿦จ͕ൃද͞ΕΔ
݁Ռͱͳͬͨɼૉཻࢠ‫ݱ‬৅࿦ʹ͓͚Δ “͓ࡇΓ” ‫ݱ‬৅ʹؔͯ͠ৼΓฦͬͯΈ͍ͨ 1 ɻຊߘͷߏ੒͸ҎԼͷ༷ʹͳ͍ͬͯΔɻ·ͣ 2 ষͰ

750 GeV ͷϐʔΫʹ·ͭΘΔ෺ཧͷ‫ج‬ຊతࣄ߲Λɼଓ͘
3 ষͰ࠷΋୯७͔ͭແໃ६ͳઆ໌ͷํ๏Λղઆ͢Δɻͦͷ‫ʹޙ‬ɼ4 ষͰ‫ݱ‬৅࿦‫“ ʹ͔͍͕ऀڀݚ‬ΑΓྑ͍” આ໌Λ໛ࡧ͍ͯͬͨ͠ͷ͔Λ۩ମྫΛத৺ʹղઆͨ͠‫ʹޙ‬ɼ

5 ষͰ౰࣌ͷঢ়‫گ‬Λɼߟ࡯Λަ͑ͳ͕ΒৼΓฦΔɻ࠷‫ޙ‬
ʹ 6 ষͰɼ͜ͷҰ࿈ͷహ຤͔Βɼզʑ͕ԿΛֶͿ͜ͱ͕
Ͱ͖Δ͔ʹؔͯ͠؆୯ʹίϝϯτ͍ͤͯͨͩ͘͞ɻ

2৽ཻࢠͱͯ͠ͷղऍ

2.1

ཻࢠͷ‫ج‬ຊੑ࣭

750 GeV ۙลʹग़‫ͨ͠ݱ‬ೋͭͷޫࢠ͔Βߏ੒͞ΕΔ
ෆม࣭ྔͷϐʔΫͷղऍͱͯ͠࠷΋ૉ๿͔ͭࣗવͳ΋ͷ͸ɼ
ʮ࣭ྔ 750 GeV ఔ౓ͷཻࢠ͕ଘࡏ͠ɼ͜Ε͕ޫࢠରʹ่յͨ͠ʯͱߟ͑Δ͜ͱͰ͋Δɻ2012 ೥ 7 ݄ 4 ೔ʹ࣭ྔ (͓Αͦ)125 GeV ͷώοάεཻࢠͷଘࡏ͕ ATLAS‫ ͼٴ‬CMS ࣮‫ʹݧ‬ΑΓཱ֬ͨ͜͠ͱʹΑΓɼඪ४໛‫ʹܕ‬͸ະൃ‫ݟ‬ͷཻࢠ͕‫·ؚ‬Εͳ͘ͳͬͨͷͰɼ͜ͷΑ͏ͳཻࢠͷग़‫ݱ‬͸ɼ΄΅ඞવతʹඪ४໛‫ܕ‬Λ௒͑ͨ෺ཧͷଘࡏΛ͍ࣔࠦͯ͠Δ͜ͱʹͳΔɻ
͜͜Ͱɼ͜ͷཻࢠͷ࣋ͭεϐϯͷ஋ʹؔͯ͠ߟ࡯ͯ͠
ΈΑ͏ɻεϐϯ 1/2 ͷϑΣϧϛΦϯ͸ϑΣϧϛ౷‫ܭ‬ੑ͔Β໌Β͔ʹໃ६͠ɼεϐϯ 1 ͷཻࢠ͸ޫࢠରʹ่յͰ͖ͳ͍ͱ͍͏ Landau-Yang ͷఆཧͷଘࡏΛ೦಄ʹஔ͘ͱ൱ఆ͞ΕΔɻ͜͜Ͱɼ࢒Δεϐϯ 0(εΧϥʔཻࢠɼώοάεཻࢠ͕Ұྫ) ΍εϐϯ 2(ςϯιϧཻࢠɼॏྗࢠ [ະൃ‫͕ ]ݟ‬Ұྫ) ͳͲͷϘιϯ͕ީิʹͳΔ͕ɼҎԼͰ͸ಋೖ͕؆୯ͳɼεΧϥʔཻࢠΛީิʹߟ͑Δ͜ͱʹ͢Δɻ
ޫࢠ͸ిՙΛཻ࣋ͬͨࢠͱ݁߹Ͱ͖Δ͕ɼޫࢠࣗ਎͸ిՙΛ͍࣋ͬͯͳ͍ɻҰํͰɼిՙͷอଘଇʹΑΓɼ‫ݩ‬
ͷ 750 GeV ͷཻࢠ͸ిՙతʹதੑͰͳ͚Ε͹ͳΒͳ͍ࣄ͕෼͔ΔɻΑͬͯɼ750 GeV ͷ৽ཻࢠ͸ޫࢠͱ௚઀
݁߹͢Δ͜ͱ͸Ͱ͖ͳ͍ɻ͔͠͠ɼ͜ͷ͜ͱ͸ɼ͜ͷεΧϥʔཻࢠ͕ޫࢠରͱ݁߹Ͱ͖ͳ͍͜ͱΛҙຯ͢ΔΘ͚Ͱ͸ͳ͍ɻԾʹ͜ͷཻࢠ͕ɼԿ͔ిՙΛཻ࣋ͬͨࢠͱ݁
߹͢ΔͳΒɼਤ 1 ͷΑ͏ʹ 1 ϧʔϓͷաఔΛ௨่ͯ͠յ͕Մೳͩɻ่յલͷੜ੒աఔʹؔͯ͠΋ಉ༷ʹɼεΧϥʔཻࢠ͕ΫΥʔΫͷ༷ʹΧϥʔՙΛཻ࣋ͭࢠͱ݁߹͢
ΔͳΒɼάϧʔΦϯରͱਤ 1 ͱಉ༷ͷμΠΞάϥϜΛ௨ͯ݁͠߹Ͱ͖ΔɻάϧʔΦϯ͸ཅࢠ಺෦ʹԾ૝తʹଘࡏ
͍ͯ͠Δ͔ΒɼҎ্ͷࣄฑ͕࣮‫͍ͯ͠ݱ‬Ε͹ɼ750 GeV

1 ؔ࿈࿦จͷ΄΅‫׬‬શͳϦετ͸ɼҎԼͷϦϯΫ͔ΒೖखՄೳ [4]ɻͷεΧϥʔ͸ LHC ʹ͓͚Δཅࢠ-ཅࢠিಥաఔ͔Βੜ੒2186

͞Εɼͦͷ‫ࢠޫޙ‬ରʹ่յՄೳͱ݁࿦Ͱ͖Δɻ

ཚஅ໘ੵ͸ 5 fb ఔ౓Ͱ͋Δͱ‫؍‬ଌ͞Ε͍ͯΔ [12]ɻ͜
ͷࢄཚஅ໘ੵʹ͓͚Δޫࢠରͱ W ɼZ Ϙιϯରͷൺ཰γfʹൺ΂ͯେ͖ա͗ΔͨΊɼ͜ͷΑ͏ͳՄೳੑ͸‫غ‬٫͞Εf

Sf(∼ 5/250) ͸ɼ্ड़ͷ่յ཰ʹର͢Δൺ཰ (∼ 10−7 /0.6)
Δ3 ɻҎ্͔Βɼީิͱͯ͠ద౰ͳεΧϥʔཻࢠ͸ɼW ɼZ

γϘιϯͱ௚઀݁߹Ͱ͖ͳ͍ɼ
ʮϋΠύʔిՙΛ࣋ͨͳ͍ɼ
ήʔδ‫ ܈‬SU (2)L ͷҰॏ߲ʯͷ༷ʹৼΔ෣͏΋ͷͱͳΔɻਤ 1: 750 GeV εΧϥʔཻࢠ (S) ͕ೋͭͷޫࢠ (γ) ʹɼిՙΛ࣋ͬͨϑΣϧϛΦϯ (f ) Λ௨่ͯ͠յ͢Δաఔ
ͷྫɻ

2.3

‫ ఺ͳົح‬2: શ่յ෯͸޿͍?

ೋޫࢠରͷ༷ͳ៉ྷͳΠϕϯτͰෆม࣭ྔʹϐʔΫ͕ൃ‫͞ݟ‬ΕΕ͹ɼͦͷԣ෯͔Βཻࢠͷશ่յ෯ (Γ) ͷ

2.2‫ ఺ͳົح‬1: Կ‫ނ‬ଞͷνϟϯωϧ͕ແ͍ͷ͔?

લड़ͷաఔ͸ώοάεཻࢠͷൃ‫ݟ‬ͷࡍʹ΋ٞ࿦͞ΕͨͷͰɼ͝ଘ஌ͷํ΋ଟ͍ͷͰ͸ͳ͍ͩΖ͏͔ɻ͔͠
͠ɼࠓճͷ৔߹ͱώοάεཻࢠͷ৔߹Ͱ͸ɼܾఆతʹҧ͏఺͕͋ΔɻͦΕ͸ɼʮޫࢠରʹߦ͘աఔҎ֎͔Β͸ɼ

750 GeV ۙลʹϐʔΫ͕‫͍ͳ͍͔ͯͬͭݟ‬ʯ͜ͱͰ͋

৘ใΛಘΔ͜ͱ͕ՄೳͰ͋ΔɻATLAS ͸ 2015 ೥ 12 ݄ͷஈ֊͔Βɼ࣭ྔ m ͕ 750 GeV ఔ౓ͷࡍʹɼൺ Γ/mͷ 13 TeV ͷӡసͰಘΒΕͨσʔλͰͷ࠷֬஋Λ͓Αͦ

6% (Γ ∼ 45 GeV) [1, 14]ɼ‫ ʹޙ‬CMS ͸ 2016 ೥ 3 ݄ʹ
1.4% (Γ ∼ 11 GeV) ͱൃදͨ͠ [12]ɻͳ͓ CMS ͸ಉ࣌ʹɼ8 TeV ͷσʔλ΋ߟྀʹೖΕͨ৔߹ͷ࠷֬஋΋ެද͓ͯ͠Γɼ͜ͷ৔߹͸ 1.4 × 10−2 % (Γ ∼ 100 MeV) ͱͳ͍ͬͯΔ [12]ɻ

Δɻ͜ͷ͜ͱ͸ɼ͜ͷཻࢠͷ‫ݯى‬Λߟ͑Δ্Ͱॏཁͳώ͜͜Ͱઌఔͱಉ༷ʹɼඪ४໛‫ܕ‬తͳ 750 GeV εΧϥʔϯτͱͳΔɻҰൠʹ෺࣭ͷήʔδ૬‫༻࡞ޓ‬ͷ‫ܗ‬͸ɼରԠཻࢠͷ৔߹Λ࠶౓ߟ࡯ͯ͠ΈΑ͏ɻ͜ͷ৔߹ɼશ่յ෯

͢Δήʔδม‫׵‬ͷԼͰͷม‫׵‬ੑ (ήʔδ‫܈‬ͷද‫ )ݱ‬Λܾ

͸ 247 GeV ͱେ͖͍͕ɼޫࢠର΁ͷ่յ෯͸ 1 ϧʔϓΊΕ͹ܾఆ͞ΕΔɻԾʹɼ͜ͷεΧϥʔ͕ඪ४໛‫ͱܕ‬ಉաఔ΁ͷ཈੍ޮՌ͕ޮ͍ͯΘ͔ͣ 0.04 MeVɻάϧʔΦ͡ϋΠύʔిՙ 1/2 Λ࣋ͭήʔδ‫ ܈‬SU (2)L ͷೋॏ߲Λϯର΁ͷ่յ෯΋ɼରԠ͢Δ่յ཰͕ 2.55 × 10−2 % ͔‫͢ͱݯى‬ΔͱɼW ‫ ͼٴ‬Z Ϙιϯͱ௚઀݁߹Λ࣋ͭ͜ͱΒ 63 MeV ͱࢉग़Ͱ͖Δ [5]ɻ΋ͪΖΜɼ͜ͷ 750 GeVʹͳΔɻͦͯͦ͠ͷ݁߹ͷ‫͞ڧ‬͸ɼిՙతʹதੑͳཻࢠ

εΧϥʔ͕ɼώοάεཻࢠͱτοϓΫΥʔΫͱͷ౬઒݁ͷ৔߹ɼҰൠʹઁಈͷߴ࣍Ͱ͋Δ 1 ϧʔϓ͔Β͔࣮͠‫ݱ‬߹ (େ͖͞͸େମ 1 ఔ౓) ΑΓ΋ɼང͔ʹ‫͘ڧ‬ϧʔϓΛͰ͖ͳ͍ޫࢠରͱͷ݁߹ΑΓ‫ͱ͍ڧ‬༧૝͞ΕΔɻ

ճΔϑΣϧϛΦϯͱ૬‫͍ͯ͠༻࡞ޓ‬Δ৔߹΋ߟ͑ΒΕΔ

ྫ͑͹ɼ750 GeV εΧϥʔͱඪ४໛‫·ؚʹܕ‬ΕΔΫ͕ɼઁಈͷ༗ޮੑΑΓ݁߹ͷେ͖͞ʹ͸্‫͔͔͕ݶ‬Δ͜

ΥʔΫ΍Ϩϓτϯͱͷ౬઒݁߹͕ඪ४໛‫ͱܕ‬ಉ͡Ͱ͋Δ

ͱ͔ΒɼͦΕͰ΋ (গͳ͘ͱ΋)ATLAS ͷ 45 GeV ͱ͍ͱ૝ఆ͢Δͱɼ750 GeV εΧϥʔͷ W Ϙιϯର΁ͷ่͏஋͸ɼඇৗʹେ͖͍Α͏ʹ‫͑ݟ‬Δɻյ཰͸ 58.6%ɼZ Ϙιϯର΁͸ 29.0%ɼޫࢠରʹରͯ͠
͸ 1.79 × 10−5 % ͱͳΔ [5]ɻ͜͜Ͱɼ750 GeV εΧϥʔ͕ώοάεཻࢠରʹ่յ͢Δաఔ͸ͳ͍΋ͷͱͨ͠ɻҰ
ํɼ2015 ೥౓ʹ͓͚Δ 13 TeV Ͱͷ࣮‫ ͕ࢠཻ৽Ͱݧ‬W
ϘιϯରɼZ Ϙιϯରʹߦ͘ஹީ͕Կ΋ͳ͔ͬͨ͜ͱ͔
Βɼ750 GeV ͷϘιϯཻࢠ͕ LHC Ͱੜ੒͞ΕɼW W‫ ͼٴ‬ZZ ͷ่յաఔΛͨͲΔ৔߹ͷࢄཚஅ໘ੵ͸‫͘ڧ‬੍‫͞ݶ‬Ε͓ͯΓɼͦΕͧΕॱʹ 95% ͷ৴པ౓Ͱ͓Αͦ

257 fb [6]ɼ221 fb [7] ҎԼͰͳ͍ͱ͍͚ͳ͍͜ͱ͕ղੳ
݁Ռ͔Βཁ‫͞ٻ‬ΕΔ (͜ΕΒ͸ 13 TeV ATLAS ࣮‫ݧ‬ͷ݁Ռ)2 ɻҰํͰɼ750 GeV ʹϐʔΫͷ͋Δޫࢠରͷࢄ
2 ࣮ࡍʹ͸ɼΑΓ‫ࢄ͍ڧ‬ཚஅ໘ੵ΁ͷ੍‫ ͕ݶ‬8 TeV ͷ࣮‫݁ݧ‬Ռ͔Β՝͞ΕΔɻATLAS ͕ 8 TeV ͷ࣮‫ݧ‬σʔλ͔Βಘͨ۩ମతͳ (8 TeV Ͱͷ) ࢄཚஅ໘ੵ΁ͷ্‫ݶ‬ͷେ͖͞͸ɼ35 fb(W W ) [8]ɼ12 fb(ZZ) [9]Ͱ͋Δɻ[10] ͷҰൠ࿦ΑΓɼཅࢠ಺෦ͷάϧʔΦϯͱͷ݁߹ʹΑΓ
750 GeV εΧϥʔ͕ੜ੒͞ΕΔ৔߹ɼ13 TeV Ͱͷࢄཚஅ໘ੵͷେ͖͞͸ɼରԠ͢Δ 8 TeV ͷେ͖͞ͷ໿ 4.7 ഒʹ૿෯͞ΕΔ͕ɼ্ͷ

3࠷খ໛‫ܕ‬ͷߏங࣮͸ઌͷٞ࿦Ͱࣔࠦͨ͠ʮϋΠύʔిՙΛ࣋ͨͳ͍ɼ

ήʔδ‫ ܈‬SU (2)L ͷҰॏ߲ʯεΧϥʔཻࢠΛՃ͑Δ໛‫ܕ‬͸ɼඪ४໛‫ʹܕ‬୯ʹ͜ͷεΧϥʔཻࢠΛՃ͑Δ͚ͩͰ͸࿩͸ऴΒͳ͍ɻͱ͍͏ͷ΋ɼલষͰड़΂ͨ௨Γɼ750 GeVͷཻࢠʹରͯ͠ޫࢠͱάϧʔΦϯͱͷ݁߹ʹ͸ͦΕͧΕిՙɼΧϥʔՙΛཻ࣋ͭࢠΛഔհ͢Δඞཁ͕͋Γɼඪ४
13 TeV Ͱͷσʔλͷ੍‫ݶ‬͸ɼ8 TeV ͷ੍‫ݶ‬ͷ 4.7 ഒΑΓऑ͍ (஋ͱͯ͠͸େ͖͍)ɻ͜ͷ͜ͱ͸ɼओʹղੳʹ࢖༻͍ͯ͠Δσʔλྔ͕େ෯ʹ 8 TeV ͷ৔߹ͷํ͕ଟ͍͜ͱʹ‫ى‬Ҽ͢Δ [8 TeV: 20.3 fb−1 ɼ
13 TeV: 3.2 fb−1 ]ɻߋʹิ଍͢Δͱɼ࠷΋‫ݦ‬ஶͳ੍‫ݶ‬͸ Zγ ΁ͷ่յաఔ͔ΒདྷΔ (8 TeV Ͱ 4.0 fb) [11]ɻ
3 ্Ͱࣔͨ͠ޫࢠରաఔͷࢄཚஅ໘ੵͷ໨ඪ஋͸ CMS ࣮‫ݧ‬ͷެࣜ‫ݟ‬ղͰ͋Δ͕ɼ͜Ε͕ൃද͞Εͨͷ͸ 2016 ೥ 3 ݄Ͱ͋ΔɻͦΕҎલͷ‫ʹڀݚ‬͸ɼATLAS, CMS ඇެࣜͷ global fit ͰಘΒΕͨ஋ͳͲ͕
໨ඪ஋Ͱ࢖༻͞Ε͍ͯͨ (ྫ͑͹ [13])ɻ

3187

໛‫ܕ‬ͷൣғ಺Ͱ͸ΫΥʔΫͱϨϓτϯ͕ީิʹͳΔɻ͠

ੳͷ݁Ռͨ·ͨ·େ͖͘‫͍ͯ͑ݟ‬ΔͷͩʯͱͷղऍΛͱ͔͠ͳ͕Βɼώοάεཻࢠͷ৔߹ͱ͸ҟͳΓɼSU (2)LΓɼΑΓখ͞ͳશ่յ෯ͷ஋Λλʔήοτʹͨ͠΋ͷ͕Ұॏ߲εΧϥʔ͸ɼඪ४໛‫ܕ‬ͷϑΣϧϛΦϯͱ౬઒݁߹

ଟ͍͜ͱΛิ଍͍ͤͯͨͩ͘͞5 ɻΛ࣋ͭ͜ͱ͕ҎԼͷཧ༝ͰෆՄೳ͔ͩΒͩɻҰൠʹ౬઒݁߹ͷߏ੒ʹ͸ɼΧΠϥϦςΟͷࠨ‫͖ר‬੒෼ͱӈ‫͖ר‬੒෼ͷ྆ํ͕ඞཁʹͳΔ͕ɼඪ४໛‫ܕ‬͸ࠨ‫ͱ͖ר‬ӈ‫͕͖ר‬ͦΕͧΕ SU (2)L ͷҧ͏ද‫ʹݱ‬ଐ͍ͯ͠Δ (ࠨ‫͖ר‬: ೋॏ߲ɼӈ‫͖ר‬: Ұॏ߲) ͨΊɼSU (2)L ήʔδม‫׵‬ͷԼͰෆมͳ‫ߏ͕߲Ͱܗ‬੒Ͱ͖ͳ͍ͱ݁࿦͞ΕΔ (ώοάεཻࢠ͸ SU (2)L ͷೋॏ߲ʹଐ͢ΔͨΊɼήʔδෆมͳ‫ܗ‬Ͱ౬઒݁߹͕ߏ੒Մೳ)ɻ
ैͬͯɼ໛‫ܕ‬Λߟ͑Δࡍʹ͸ɼඪ४໛‫ʹܕ‬͸ଘࡏ͠ͳ͍ిՙɼΧϥʔՙΛཻ࣋ͭࢠΛ໛‫ʹܕ‬ಋೖ͢Δ͜ͱ͕ཁ‫͞ٻ‬ΕΔɻ͜͜Ͱ࠷΋୯७ͳՄೳੑ͸ɼӈ‫͖ר‬ɼࠨ‫ר‬͖ͱ΋ʹɼಉ͡ SU (2)L ͷද‫ݱ‬ɼಉ͡ϋΠύʔిՙͷ஋Λ࣋ͭ৽छͷΫΥʔΫɼߋʹ͸ϨϓτϯΛಋೖ͢ΔࣄͰ
͋Δ4 ɻ͜ͷ৔߹ͳΒҰॏ߲εΧϥʔͱ΋ແໃ६ʹ౬઒૬‫༻࡞ޓ‬Λߏ੒Ͱ͖ͯɼޫࢠରͷෆม࣭ྔʹൃ‫͞ݟ‬Εͨ

750 GeV ϐʔΫΛઆ໌͢Δҝͷ४උ͕੔ͬͨ͜ͱʹͳ
Δɻਤ 2 ʹɼࠓͷ൓ԠશମΛද͢໛ࣜਤΛࡌ͓ͤͯ͘ɻ

p

γ

4

࠷খ໛‫ܕ‬Λ௒͑Δʹ͸ͯ͞લষʹ͓͍ͯɼ࣮‫݁ݧ‬ՌΛແໃ६ʹઆ໌͢ΔͨΊͷॲํᝦΛ͕ࣔͨ͠ɼ͜Ε͕ඇৗʹਓ޻తʹ‫ํͨ͑ݟ‬΋ଟ͍ͷͰ͸ͳ͍ͩΖ͏͔ɻͦͷ‫ݪ‬Ҽͷ΄ͱΜͲ͸ɼ࠷খ໛‫͍͓ͯʹܕ‬ɼ750 GeV ͷεΧϥʔཻࢠɼ৽͍͠ΫΥʔΫɼϨϓτϯ‫ʹڞ‬ɼ୯ʹ‫ݱ‬৅Λઆ໌͢ΔͨΊʹ࠷΋౎߹ͷྑ͍഑ҐΛ͖͍࣋ͬͯͯΔ͚ͩͩͱ‫͡ײ‬ΒΕΔ఺Ͱ͋
Ζ͏ɻ͔͠͠ɼ‫ݱ‬৅࿦ͷ໛‫ʹܕ‬ཁ‫͞ٻ‬ΕΔ࠷ॏཁ՝୊͸ɼ“‫؍‬ଌ͞Εͨਅ࣮” Λ‫ه‬ड़͢Δ͜ͱͰ͋Δɻ೗Կʹ “ਓ޻త” ʹ‫͑ݟ‬Α͏ͱ΋ɼ͜ͷൃ‫͕ݟ‬ਅ࣮Ͱ͋ΔՄೳੑ͕͋
ΔҎ্ɼແໃ६͔ͭ࠷খ‫౓ݶ‬ͷઆ໌Λߟ࡯͢Δ͜ͱ͸ɼ‫ݱ‬৅࿦తߟ࡯ͷୈҰาͱͯ͠ඇৗʹॏཁͱߟ͑ΒΕΔɻ
ͱ͸͍͑ɼͦͷୈҰาͷ‫ʹޙ‬͸ɼ‫ݱ‬৅࿦‫ऀڀݚ‬͸ΑΓྑ͍ཧ࿦Λߏங͢ΔΑ͏౒ΊΔඞཁ͕͋Δɻ“ΑΓྑ͍”ͷ࣋ͭҙຯ߹͍ʹؔͯ͠͸ɼ

1. 750 GeV εΧϥʔͷ‫د‬༩Ͱɼ750 GeV ͷϐʔΫҎ֎ͷࣄ৅Λ΋ಉ࣌ʹઆ໌Ͱ͖Δ΋ͷɼS

2. 750 GeV ۙ๣ʹ‫ݱ‬ΕͨϐʔΫͷઆ໌ͱͯ͠ɼࠓ·Ͱʹແ͔ͬͨࢹ఺Λఏএͯ͘͠ΕΔ΋ͷɼpγ

3. 750 GeV ͷϐʔΫ͕આ໌Ͱ͖ͳ͍͜ͱҎ֎ͷඪ४ਤ 2: ࠷খ໛‫Ͱܕ‬ͷ 750 GeV εΧϥʔཻࢠ (S) ͷੜ੒໛‫͚͓ʹܕ‬Δ “໰୊఺” ʹ΋ޫΛ౰ͯΔ΋ͷɼͷ໛ࣜਤɻࠨͷ‫ؙ‬ҹͰ S ͸ཅࢠ (p) ಺ͷάϧʔΦϯରͱͳͲ৭ʑͳߟ͑ํ͕͋Δͱࢥ͏͕ɼຊߘͰ͸্‫ ه‬1, 2 ͷ৽͍͠ΫΥʔΫΛ௨ͯ͠ɼӈͷ‫ؙ‬ҹͰ S ͸่յઌͷޫࢠ(γ) ରͱ৽͍͠ΫΥʔΫ‫ͼٴ‬ϨϓτϯΛ௨ͯ͠૬‫༻࡞ޓ‬͢Δɻ৽͍͠ΫΥʔΫɼϨϓτϯ‫ ʹڞ‬SU (2)L Ұॏ߲ͱ͢Δͷ͕Ұ൪୯७ͳ৔߹ͷҰͭͰ͋Δɻ͜ͷ୯७ͳ৔߹Ͱ΋ɼ౬઒݁߹ͷઁಈ͕ΪϦΪϦ༗ޮͳ஋ (4π) ΛऔΔ৔߹ʹɼ࣮‫݁ݧ‬ՌΛແໃ६ʹઆ໌Ͱ͖ΔύϥϝʔλྖҬ (‫ط‬ଘͷ৽छͷΫΥʔΫɼϨϓτϯ୳ࡧͷ݁Ռ͔ΒདྷΔ੍‫ͱݶ‬΋ແໃ६ͳྖҬ) ͕ଘࡏ͢Δ͜ͱ͕ࣔ͞Ε͍ͯΔ [15]ɻͨ
ͩ͠ɼATLAS ࣮‫ݧ‬ͷ෼ղೳ͔Βਪఆ͞ΕΔશ่յ෯ͷ

5.3 GeV ఔ౓Λ࣮‫͢ݱ‬Δ͜ͱ͸Ͱ͖ͯ΋ɼ45 GeV Λࠓͷ໛‫Ͱܕ‬ໃ६ͳ͘આ໌͢Δ͜ͱ͸ඇৗʹ೉͍͠Α͏Ͱ͋
Δɻ͜͜Ͱؔ࿈ͯ͠ɼ‫ݱ‬৅࿦‫ʹऀڀݚ‬ΑΓఏҊ͞Εͨ਺ଟ͘ͷ໛‫Ͱܕ‬͸ɼʮATLAS ͷ 45 GeV ͷશ่յ෯ͷ஋͸࣮ࡍʹ͸΋ͬͱখ͍͞͸ͣͰɼ‫ݶ‬ΒΕͨσʔλྔͰͷղ
4 ͜ΕΒ݁߹ͷಋೖͷͨΊͷཻࢠ͸ɼ‫ݪ‬ཧతʹ͸εΧϥʔཻࢠͰ΋ྑ͍ɻ·ͨɼ৽ͨͳΫΥʔΫ͚ͩಋೖͯ͠΋ 750 GeV εΧϥʔͷޫࢠͱάϧʔΦϯͱͷ݁߹͸ੜ੒Մೳ͕ͩɼϨϓτϯ΋ಉ࣌ʹಋೖ͢Δ
ͱೋͭͷ݁߹Λผʑʹૢ࡞͢Δ͜ͱ͕Ͱ͖ΔͷͰɼΑΓ‫؍‬ଌ݁Ռʹ߹ΘͤΔ͜ͱ͕༰қʹͳΔɻ

ೋͭͷࢹ఺ΛऔΓ্͛ͯ࿩ΛਐΊΔ͜ͱʹ͢Δɻ͜͜Ͱํ޲ੑ 3 ʹͦͬͨ‫Ͱڀݚ‬͸ɼࠓ·Ͱ༷ʑͳϞνϕʔγϣϯͰ‫͞ڀݚ‬Ε͖ͯͨ “ඪ४໛‫ܕ‬Λ௒͑Δૉཻࢠ໛‫ྫ(”ܕ‬:௒ରশੑ໛‫ )ܕ‬ͷ࿮಺ͰɼͲͷ༷ʹ͜ͷϐʔΫͷଘࡏΛ
આ໌͢Δ͔ͱ͍͏఺͕௥‫͞ٻ‬Ε͍ͯΔ͜ͱΛิ଍ͤͯ͞
͍ͨͩ͘ɻͦΕͰ͸ҎԼͰɼ‫ݱ‬৅࿦‫͕ऀڀݚ‬೗Կʹ໛‫ܕ‬Λ “վྑ” ͍͔ͯ͘͠Λɼ֤߲໨ͷ۩ମྫͷղઆΛ௨ͯ͠‫͠ʹͱ͍ͩͨͯ͘͜ݟ‬Α͏ɻ‫ ఺؍‬1 ͷཱ৔ͰΑΓྑ͍ཧ࿦Λߏங͢Δ্Ͱͷཁ఺͸ɼ750 GeV εΧϥʔΛଞͷͲͷ෺ཧͷઆ໌ʹ࢖༻͢Δ͔ʹ‫ؼ‬ண͞ΕΔɻҎԼͰ͸Ұྫͱͯ͠ɼ[17] ͷٞ࿦ΛऔΓ্͛ΔɻॳΊʹɼ750 GeV εΧϥʔ͸ϐʔΫͷઆ໌ͷͨΊɼిՙɼΧϥʔՙΛཻ࣋ͬͨࢠͱ݁߹͍ͯ͠Δ͜ͱ͕ཁ‫͞ٻ‬Εɼ͜ΕΒ͸‫ݪ‬ཧతʹ͸εΧϥʔཻࢠͰ΋ྑ͍͜ͱʹ໨Λ޲͚
5 750 GeV εΧϥʔ͕҉ࠇ෺࣭ͷରʹେ͖ͳ่յ෯Ͱ่յ͍ͯ͠
ΔΑ͏ͳঢ়‫گ‬Λߟ͑Δͱɼશ่յ෯ͷ஋Λ্͔͛͞Ͱ͖Δ ɻ͔͜͠͠Ε͸ɼ͜ͷεΧϥʔ͕ޫࢠରʹߦ͘ൺ཰͕‫ݮ‬গ͢Δ͜ͱ΋ҙຯ͢Δ
ͷͰɼ๬·͍͠ޫࢠରͷੜ੒அ໘ੵͱ 45 GeV ͷ่յ෯Λಉ࣌ʹ࣮‫ͤ͞ݱ‬Δͷ͸ͦΕఔ୯७Ͱ͸ͳ͍ (ྫ͑͹ [16])ɻ

4
188

⟨S⟩

750GeVスカラーの真空期待値

荷電スカラーgγ
γ

750GeVスカラーη

スカラーレプトクォーク

σLQ+1/3φ+
LQ+4/3
νL

eL eR
⟨H⟩

dR dL
⟨H⟩

ヒッグスの真空期待値

g

η
軽い
スカラー

γ

(d)

νL

γ

ਤ 4: “ॖୀͨ͠ޫࢠ” ʹΑΔ “ೋޫࢠ” ΠϕϯτΛද͢μΠΞάϥϜɻg ͸ೖࣹཅࢠ಺ʹԾ૝తʹଘࡏ͢Δάϧʔγ

レプトクォーク・スカラー

ਤ 3: [17] Ͱߟ࡯͞Εͨ 2 ϧʔϓͰग़‫͢ݱ‬ΔχϡʔτϦϊ (ν) ͷϚϤϥφ࣭ྔ߲ͷ໛ࣜਤɻe ͸ిՙ −1 ͷՙిϨϓτϯɼd ͸ిՙ −1/3 ͷΫΥʔΫɼL/R ͸ΧΠϥϦ
ςΟͷࠨ‫͖ר‬/ӈ‫͖ר‬Λද͢ɻϑΣϧϛΦϯͷੈ୅ʹؔͯ͠͸ɼॻ͘͜ͱΛলུͨ͠ɻ
Α͏ɻ͜͜Ͱిՙ 1, 4/3, 1/3 ͷࡾͭͷ SU (2)L Ұॏ߲ͷεΧϥʔཻࢠΛಋೖ͠ɼ‫ऀޙ‬ೋͭ͸ΫΥʔΫͱಉ༷ʹΧϥʔՙ΋࣋ͭͱ͠Α͏ɻ͜ͷ༷ͳిՙͱΧϥʔՙΛ࣋ͭεΧϥʔཻࢠΛɼ(εΧϥʔ) ϨϓτΫΥʔΫͱ‫Ϳݺ‬ɻ໘ന͍͜ͱʹɼ͜ΕΒͷిՙɼΧϥʔՙΛ࣋ͭ SU (2)LҰॏ߲εΧϥʔ͸ɼΫΥʔΫɼϨϓτϯͱ݁߹Ͱ͖Δɻ
͢Δͱਤ 3 ͷ༷ʹɼ2 ϧʔϓͷஈ֊ͰɼχϡʔτϦϊͱ൓χϡʔτϦϊ͕ 750 GeV εΧϥʔ͕ग़‫͢ݱ‬Δཻࢠ S
Λ௨ͯ݁͠߹͠ɼS ͕ώοάεཻࢠͷ༷ʹਅۭ‫ظ‬଴஋Λ࣋ͭͳΒɼ͜Ε͸ඪ४໛‫Ͱܕ‬͸࣮‫͍ͳ͖Ͱݱ‬χϡʔτϦϊʹ࣭ྔΛ༩͑ΔϚϤϥφ࣭ྔ߲͕ྔࢠޮՌͰੜ੒͞ΕͨࣄΛҙຯ͢Δɻ౎߹ͷྑ͍͜ͱʹɼ͜ͷ࣭ྔ߲ͷେ͖͞͸ 2 ϧʔϓͰ཈੍͞ΕΔͨΊɼ֤छ݁߹ͷେ͖͞Λ‫ۃ‬୺ʹখ͘͞͠ͳͯ͘΋ඍখͳχϡʔτϦϊ࣭ྔͷ஋Λແໃ६ʹઆ໌͢Δ͜ͱ͕ՄೳͰ͋Δɻ͜ͷ໛‫ܕ‬͸ɼϐʔΫͷಛੑ͔Βཁ‫͞ٻ‬ΕΔঢ়‫ͱگ‬ɼʮεΧϥʔ͸ਅۭ‫ظ‬଴஋Λ࣋ͯΔʯͱ͍͏εΧϥʔཻࢠ࠷େͷಛੑΛ͏·͘૊Έ߹Θͤɼ750 GeV ͷϐʔΫͷઆ໌ͱಉ࣌ʹɼ‫؍‬ଌ͞Ε͍ͯΔχϡʔτϦϊͷ഑ҐΛઆ໌Մೳͱ͍͏఺Ͱɼ࠷খ
໛‫ܕ‬Λ௒͑ͨ໛‫͍ͯͬͳͱܕ‬Δࣄ͕෼͔Δɻ࣍ʹ‫ ఺؍‬2 ͷཱ৔͔Βઆ໌Λ࠶ߟͯ͠ΈΑ͏ɻҰͭͷॏཁͳࢹ఺͸ɼཧ࿦ʹΑΓ‫ه‬ड़͞ΕΔࢄཚ൓Ԡͷૉաఔ͕ɼͦͷ··Ճ଎‫͑ݟͰث‬Δͱ͸‫ݶ‬Βͳ͍͜ͱͩɻ
໘ന͍ҰͭͷՄೳੑͱͯ͠ɼਤ 4 Ͱඳ͔ΕͨૉաఔΛ‫ͯݟ‬ΈΑ͏ [18]ɻ͜͜Ͱ σ ͕ 750 GeV ͷεΧϥʔͰɼη ͸ O(1) GeV ҎԼͷ͍ܰεΧϥʔཻࢠͰ͋Δͱ͠ɼͦfΦϯΛࣔ͠ɼεΧϥʔ͸ɼάϧʔΦϯ‫ͱࢠޫͼٴ‬ɼϧʔf (੨‫ )ؙ‬Λ࣋ͭͱ͢Δɻ੺ϓաఔ౳Λ௨ͯ͠༗ޮ૬‫༻࡞ޓ‬
荷電ヒッグス఺ઢͷίʔϯ͸ɼLHC ࣮‫Ͱݧ‬͸ۙ઀ͨ͠ೋͭͷޫࢠ (γ)γ͸ɼҰͭʹ‫͑ݟ‬Δ͜ͱΛද‫͍ͯ͠ݱ‬Δɻ
ʹཻࢠ͕ (ೋମ) ่յ͢Δࡍʹ͸ɼࣗ෼ͷ࣭ྔͷ൒෼ΑΓॏ͍ಉछཻࢠରʹ͸่յ͕ෆՄೳͳͷͰɼ͜ͷ৔߹ɼη ͔Β W ΍ Z Ϙιϯରʹߦ͘Α͏ͳաఔ͸ࣗવʹ‫ࢭې‬͞ΕΔɻ·ͨɼσ ͕ 2 ͭͷ η ͱ‫͍ͯ͠߹݁͘ڧ‬Ε͹ɼ҆શʹࢄཚஅ໘ੵͷ஋ΛՔ͙͜ͱ΋Մೳͩɻ͜ͷ༷ͳ࢓ࣄ͸ɼʮૉաఔ͕࠷΋୯७ͳղऍ͔Β཭ΕΔʯͱ͍͏࿦఺ͦ
Εࣗମ͕ܹࢗతͰ໘ന͍͕ɼ͞Βʹ৽ͨͳΔղऍͷఏ‫ڙ‬͸‫ݱ‬৅࿦ͷՄೳੑΛ޿͛Δͱ͍͏ҙຯͰ‫ۃ‬Ίͯॏཁͱߟ
͑ΒΕΔ6 7 ɻଞͷ‫ڵ‬ຯਂ͍աఔͱͯ͠ɼ750 GeV εΧϥʔཻࢠͷੜ੒աఔ΋ೋͭͷޫࢠͱͷ݁߹͔Βൃੜͨ͠ͱ͢ΔՄೳ
ੑ͕͋Δɻ͜ͷ৔߹ɼਤ 2 ͔Β෼͔Δ௨Γɼ࢝ঢ়ଶͷೋͭͷޫࢠ͸ (άϧʔΦϯͷ৔߹ͱಉ͘͡)ɼೋͭͷՃ଎͞Εͨཅࢠ಺෦ʹͦΕͧΕԾ૝తʹଘࡏ͢ΔཻࢠͱͳΔɻ௨ৗͷ৔߹ɼΧϥʔ૬‫༻࡞ޓ‬͸ి࣓૬‫ͱ༻࡞ޓ‬ൺֱͯ͠ང͔ʹ‫͍ͨڧ‬Ίɼޫࢠ͕࢝ঢ়ଶͷࢄཚաఔ͸ཻࢠͷੜ੒அ໘ੵʹຆͲ‫د‬༩͠ͳ͍ɻ͔͜͜͠͠ͰɼάϧʔΦϯͱ

750 GeV εΧϥʔͱΛഔհ͢ΔΧϥʔՙΛཻ࣋ͭࢠ͕
ଘࡏͤͣɼଞํͰ 750 GeV εΧϥʔ͕ޫࢠରͱ͸Կ͕͔͠ͷՙిཻࢠΛհͯ͠‫͍ͯ͠߹݁͘ڧ‬Δঢ়‫گ‬Λߟ͑ͯΈΑ͏ɻ͜ͷ༷ͳ৔߹͸ɼޫࢠ͕࢝ঢ়ଶͷੜ੒൓Ԡ͕ओ
ཁੜ੒աఔʹͳΓɼ·ͨͦͷੜ੒அ໘ੵ΋ͦΕͳΓͷେ͖͞ʹͳͬͯ΋͓͔͘͠͸ͳ͍ɻ[23] ʹΑΔͱɼ͜ͷ৔߹ͷऴঢ়ଶ͕ೋޫࢠର΁ͷࢄཚஅ໘ੵ͸"!
ΓS
× Br2 (S → 2γ)
9.1 fb ×
100 MeV(1)ΕͧΕ͕ೋͭͷޫࢠʹ่յ͢Δͱ͢ΔɻϙΠϯτʹͳΔ

ఔ౓ͱͳΔɻ͜͜Ͱ ΓS ͸ 750 GeV εΧϥʔ S ͷશ่ͷ͸ɼॏཻ͍ͨࢠͷ่յ͔Βग़‫ͨ͜͠ݱ‬ͷ༷ͳཻ͍ܰࢠ

յ෯ɼBr(S → 2γ) ͸ S ͷೋޫࢠର΁ͷ่յ෼‫ذ‬ൺΛද͸ඇৗʹߴ͍ӡಈྔΛ࣋ͭͨΊɼ࣍ͷ่յաఔͰੜ·ΕΔೋͭͷޫࢠ͸‫ʹ͍ޓ‬ඇৗʹۙ઀͠ɼՃ଎‫Ͱث‬ͷࣝผ͕೉͘͠ͳΔ͜ͱͩɻ݁Ռͱͯ͠ɼ͜ͷΑ͏ͳೋͭॏͳͬ
ͨޫࢠ͸ɼҰͭͷޫࢠͱ࣮ͯ͠‫Ͱݧ‬͸‫؍‬ଌ͞ΕΔɻҰൠ͢ɻ஫໨͢΂͖఺͸ɼྫ͑͹΋͠ Br(S → 2γ) ∼ 60%
6 ͜ͷํ޲ੑͷ࢓ࣄͱͯ͠ɼଞʹ΋ྫ͑͹ [19, 20, 21] ͕͋Δɻ

7 ۩ମతͳ໛‫Ͱܕ‬ͷྫΛ‫͛ڍ‬Δͱɼྫ͑͹࣍࠷খ௒ରশඪ४໛‫ܕ‬(NMSSM) ͷಛఆͷύϥϝʔλྖҬͰɼ͜ͷՄೳੑ͸࣮‫͖Ͱݱ‬Δ (ྫͱͯ͠ [22])ɻ

5
189

ఔ౓ɼΓS ∼ 100 MeV Λ࣮‫͖Ͱݱ‬Ε͹ɼઆ໌ʹඞཁͳ∼ 5 fb ͷࢄཚஅ໘ੵ͸े෼ʹՔ͛Δ͜ͱͩɻ͜ͷ‫ڀݚ‬΋ɼঢ়‫ʹگ‬ଈͨ͠৽͍͠Մೳੑͷ൶Λ։͘ͱ͍͏఺Ͱඇ
8ৗʹ໘ന͍ ɻ·ͷ΋ͷͷ਺΋ଟ͔͕ͬͨɼଞํͰ 4 ষͰ‫ࣔ͠ྫ͔ͭز‬ͨɼ࠷খ໛‫ܕ‬Λ௒͑Δ “ΑΓྑ͍” ํ޲ੑͷୈҰใͷ਺ଟ͕͘ɼ2015 ೥ 12 ݄ͷ಺ʹఏҊ͞Εͨࣄ΋‫ڵ‬ຯਂ͍ࣄ࣮Ͱ͋Δɻ࠷‫ʹޙ‬εϖʔεͷؔ܎্ɼ͜͜Ͱ͸ൃද͞Εͨ࿦จͷҰํ͜ͷྲྀߦʹ͸ɼϏδωεϥΠΫͳଆ໘΋͔֬ʹ͘͝Ұ෦͔͠औΓ্͍͛ͯͳ͍͜ͱΛਃ͠ఴ͑ΔɻΑΓ͋ͬͨͱࢥΘΕΔɻͦͷཧ༝͸ɼ‫ݱ‬৅࿦త‫͔఺؍‬Βૉ๿ৄࡉͳঢ়‫ڵʹگ‬ຯͷ༗Δํ͸ɼϨϏϡʔ [25, 26, 27] Λʹߟ͑Δͱɼ͜ͷ࣮‫݁ݧ‬Ռʹ͸ҎԼͷ༷ͳٙΘ͍͔ͭ͠͝ཡ௖͖͍ͨɻ

೰·͍͠఺͕ଘࡏ͢Δͱߟ͑ΒΕΔ͔ΒͰ͋Δɻ• ઁಈͷߴ࣍ (ϧʔϓաఔ) ͔Β͔͠௨ৗੜ͡ͳ่͍

スカラーの5真空期待値ࠓৼΓฦͬͯΈΔͱյաఔ͕ඇৗʹ૿෯͞ΕΔΑ͏ͳঢ়‫گ‬͸ਓҝతͰɼ(ଞͷ෺ཧͱͷབྷΈΛߟ͑ΒΕΔʹͯ͠΋) ෆࣗવલষ·Ͱͷ‫ه‬ड़Ͱɼզʑ͸ؔ࿈͢Δ෺ཧͷ‫ج‬ຊࣄ߲ͷʹ‫͑ݟ‬Δ͜ͱɼղઆΛަ͑ͳ͕Βɼ‫ݱ‬৅࿦‫ ͕ऀڀݚ‬750 GeV ۙ๣ʹޫ• ౷‫͕ྔܭ‬গͳ͍ஈ֊Ͱ͸౷‫ܭ‬ΏΒ͕͗େ͖͘ɼِͷࢠରͷෆม࣭ྔʹ‫ݱ‬ΕͨϐʔΫͷଘࡏΛ࣮ࣔ͢‫݁ݧ‬Ռ͕ϐʔΫ͕‫ͱ͜͏·ͯ͑͠ݟ‬͸େ͍ʹ͋ΓಘΔ͜ͱɻൃද͞ΕͨࡍʹɼͲͷ༷ʹߟ࡯͠࢓ࣄΛਐΊ͍ͯͬͨͷ͔Λɼ۩ମྫΛ௨͠ͳ͕Β‫͖ͨͯݟ‬ɻ͜ͷষͰ͸ɼͦͷ͜ͷࣄ͔Βɼ͜ͷϐʔΫͷଘࡏΛ৴པੑ͕ߴ͍΋ͷͩͱ౰࣌ͷঢ়‫گ‬ΛৼΓฦͬͯΈ͍ͨɻߟ͍͑ͯͨؔ܎ऀͷ਺͸ɼ‫ݶ‬ΒΕ͍ͯͨͱ૝૾͞ΕΔɻ

2015 ೥ 12 ݄ 15 ೔ɼάϦχοδඪ४࣌Ͱ‫ޙޕ‬ೋ͔࣌Β͔͠͠ɼࣗવ͸ਓ͕ؒૉ௚ʹ “ࣗવ” ͱࢥ͑ΔΑ͏ͳੈ‫ Ͱ·࢛࣌ޙޕ‬CERN Ͱ։࠵͞ΕͨɼATLAS ‫ ͼٴ‬CMS

քΛߏஙͨ͠ͱ͸ඞͣ͠΋ߟ͑ΒΕͳ͍͠ɼԿΑΓԾʹ࣮‫ݧ‬άϧʔϓʹΑΔ 750 GeV ϐʔΫͷଘࡏΛࠂ͛Δηϛ࣮‫݁ݧ‬Ռ͕ਅ࣮Λ͍ࣔͯͨ͠৔߹ͷϝϦοτΛࢥ͑͹ɼ

φʔͷऴྃͱͱ΋ʹɼຊτϐοΫεͷ‫ݱ‬৅࿦త‫ڀݚ‬ͷ։ࢀՃোนͷ௿͔͞Βߟ͑ͯ΋ɼʮࢀՃ͠ͳ͍ཧ༝͕ͳ͍ͱ

࢝Λࠂ͛Δΰϯά͸ਖ਼ࣜʹ໐Γ‫͕͍ͨڹ‬ɼঢ়‫گ‬͸౰ॳ͔͍͏ཧ༝ͰࢀՃ͢Δʯͱ͍͏ͷ͸ɼଧࢉతͳଆ໘΋͋Δ

Βੌ·͍༷͡૬Λఄ͍ͯͨ͠ɻৄࡉ͸ [28] ʹৄ͍͕͠ɼ

ʹ͠Ζɼ‫ेͯ͠ͱऀڀݚ‬෼߹ཧతͳ൑அͩͱࢥΘΕΔɻࣄલʹӟΛฉ͖͚ͭͯ४උ͍ͯͨ͠άϧʔϓ౳ʹΑΔσʔλ͕஝ੵ͞Εͯղੳ͞ΕΔ·Ͱɼຊ౰ͷࣄ͸୭ʹ΋ؔ࿈࿦จ͕ɼηϛφʔ౰೔ͷ‫Ͱ·࣌۝ޙޕ‬ͷؒʹ 10 ຊɼΘ͔Βͳ͍ͷ͔ͩΒɻ͔ͯ͘͠ɼ਺ଟ͘ͷ‫ݱ‬৅࿦ؔ܎ऀ

ཌ೔ʹ΋ 8 ຊ΋ͷ਺ϓϨϓϦϯταʔό (arXiv.org) ʹ͕զઌʹͱ‫ڀݚ‬ΛःೋແೋਐΊɼ݁Ռͱͯ͠ 400 ຊҎ্౤ߘ͞Εͨɻ࿦จ౤ߘͷ੎͍͸ͦͷ‫ޙ‬΋ࢭ·Βͣɼ2015ͷ࿦จ͕ൃද͞ΕΔ͜ͱͱ૬੒ͬͨͷͰ͋Δ9 ɻ೥಺͚ͩͰ౤ߘ͞Εͨ࿦จ૯਺͸ 120 ຊҎ্ʹ΋‫ͼٴ‬ɼ࠷ऴతʹ͸ 400 ຊΛ௒͑Δ‫ൃ͕ߘݪ‬ද͞Εͨɻิ଍ͱ͠
ͯɼൃද࿦จ਺ͷਪҠͷঢ়‫[ ͕گ‬29] ʹ͓͍ͯɼ[30] ʹ‫ج‬ͮ͘ൃද࿦จͷ༧ଌ‫ۂ‬ઢͱ‫ެʹڞ‬։͞Ε͍ͯΔ͜ͱɼߋʹ [31] Ͱɼؔ࿈࿦จͷ૯Ҿ༻਺ɼ૯ຊ਺͝ͱͷ‫ऀڀݚ‬ϥϯΩϯά (্Ґࡾਓ) ͕࡞੒͞Ε͍ͯΔ͜ͱΛड़΂͍ͤͯͨͩ͘͞ɻ
͜ͷੌ·͍͡࿦จϥογϡͷେ͖ͳ‫ݪ‬ҼΛೋͭ‫͛ڍ‬Δ
ͱ͢Δͱɼ

6

݁ͼ
ࠓ·Ͱ‫ࡇ͓“ ͖ͨͯݟ‬Γ૽͗” ΋ɼ2016 ೥ 8 ্݄०ʹ͋ͬ͞ΓͱͦͷນΛԼΖͨ͠ [32, 33]ɻγΧΰͰ։࠵͞Εͨੈքతͳࠃࡍձٞ ICHEP2016 ʹͯɼ2016 ೥౓ʹ࣮ࢪ͞Εͨ 13 TeV ͷ࣮‫ݧ‬σʔλΛՃຯͯ͠࠶ղੳΛߦͬ
ͨ݁Ռɼ750 GeV ෇ۙͷ‫ݦ‬ஶͳϐʔΫ͕ফ͑ͨͱͷใࠂ͕ ATLASɼCMS ࣮‫ݧ‬άϧʔϓ‫͔ڞ‬Βͳ͞ΕͨͷͰ

• 2011 ೥ʹ 125 GeV ώοάεཻࢠͷஹީ͕‫࢝͑ݟ‬Ί

͋Δɻ͔ͯ͘͠ɼࢁͷ༷ʹॻ͔Εͨ࿦จͷɼ౰ॳͷҙٛͨࡍʹ΋ೋޫࢠ΁ͷ่յϓϩηεʹඪ४໛‫ܕ‬ͷ༧‫ݴ‬͸‫׬‬શʹࣦΘΕͯ͠·ͬͨɻ͔͜͠͠ΕΒͷ‫ڀݚ‬աఔͰ஋͔Βͷ௒ա͕ใࠂ͞ΕɼࣅͨΑ͏ͳٞ࿦͕‫਺ʹط‬ಘΒΕͨɼಛʹ 4 ষͷ‫ ఺؍‬2 Ͱٞ࿦͞ΕͨΑ͏ͳɼ৽͠

ଟ͘ͳ͞Ε͍ͯͨ͜ͱɼ

͍΋ͷͷ‫ํݟ‬Λఏ‫͢ڙ‬ΔΑ͏ͳ‫݁ڀݚ‬Ռ͸ɼͦͷશ͕ͯ• ϐʔΫͷઆ໌ʹཁ‫͞ٻ‬ΕΔηοτΞοϓ͕ಛʹࠔ೉ͳ΋ͷͰ͸ͳ͘ɼ༷ʑͳ໛‫͕࡯ߟͰܕ‬Մೳͩͬͨ
͜ͱɼ͕‫͛ڍ‬ΒΕΔɻ۩ମతͳ໛‫ʹܕ‬ଈͯ͠ͷ‫ڀݚ‬͸ɼ750 GeVϐʔΫͷઆ໌ͱͯ͠͸‫ج‬ຊతʹ “࠷খ໛‫ ”ܕ‬ͷߟ͑ͷ·8 ଞํͰ͜ͷ༷ʹ 750 GeV εΧϥʔ͕ɼ۩ମతͳ໛‫ࢠޫͰܕ‬ରͱແໃ६ʹ‫͖Ͱ߹݁͘ڧ‬Δͷ͔ͱ͍͏ٙ໰΋࢒Δɻࢲ͸‫ڞ‬ಉ‫͜ͱऀڀݚ‬ͷ࿦఺ΛਂΊͯ࿦จʹ·ͱΊͨ [24]ɻ

ແବʹࣦΘΕΔΘ͚Ͱ͸ͳ͘ɼকདྷʹ͓͍ͯ༗ޮ‫Ͱ༻׆‬
͖Δͱ৴͍ͯ͡Δɻࠓ‫ޙ‬΋ɼྫ͑ࠓճͷ༷ʹ “՚ʑ͍͠” ΋ͷͰ͸ͳͯ͘΋ɼ৽͍͠෺ཧΛද͢ͱղऍͰ͖Δ࣮‫݁ݧ‬Ռ͕ग़Δ౓ʹɼ
9 ಛʹઌऔ‫ݖ‬૪͍ͷܹ͔ͬͨ࢝͠Ίͷ಺͸ɼன໷໰Θͣ໠྽ʹ࢓ࣄΛਐΊ͍ͯͨάϧʔϓ͕ଟ਺͋ͬͨͱࢥΘΕΔɻ͔͍͘͏ࢲ΋ɼ2015೥ 12 ݄தʹ‫ߘݪ‬Λ‫׬‬੒ͤ͞ΔͨΊ࠷‫ޙ‬ͷํ͸΄΅ప໷Ͱ࢓ࣄΛଓ͚ɼ݁Ռతʹ೥຤ʹ೔ຊͷ࣮Ոʹ‫ؼ‬Δඈߦ‫ػ‬Λ৸ա͝͠·ͨ͠ɾɾɾͨͩɼग़ͨ͹͔Γͷ࣮‫݁ݧ‬Ռʹଈ࠲ʹ൓Ԡ͢ΔλΠϓͷ‫ڀݚ‬Λͨ͠ͷ͸ࢲʹͱͬͯॳΊͯͷ‫Ͱݧܦ‬ɼͱͯ΋ܹࢗతͰָ͘͠΋͋Γ·ͨ͠ɻ6190ྫ͑ͦͷσʔλ͕ଟগٙΘ͘͠‫͑ݟ‬Δͱͯ͠΋ɼಉ͡Α͏ͳ “ήʔϜ” ͸‫܁‬Γฦ͞ΕΔͱߟ͑ΒΕΔɻͦͯͦ͠
Ε͸ɼ‫ݱ‬৅࿦ͷ‫͍͓ͯʹڀݚ‬͸Ұͭͷਖ਼͍͠ํ޲ੑͳͷͩɻͳͥͳΒɼਅ࣮Λ‫ه‬ड़͢Δཧ࿦Λ “௥‫͢ ”ٻ‬Δ͜ͱͦ͜‫ݱ‬৅࿦‫͚͓ʹڀݚ‬Δ࠷େͷ໋୊Ͱ͋Γɼͦͷ௚઀తͳख͕͔Γ͸࣮‫݁ݧ‬Ռ͔Β͔͠ಘΒΕͳ͍͔ΒͰ͋Δɻँࣙ͜ͷ༷ͳ‫و‬ॏͳ‫ػ‬ձΛࢲʹ༩͑ͯ௖͍ͨߴΤωϧΪʔχϡʔεͷฤूҕһͷօ༷ɼಛʹ‫ࣥߘݪ‬චʹؔͯ͠਺ʑ
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Ճ଎‫ߏػڀݚث‬।‫ڭ‬त)ɼ͞ΒʹɼຊߘΛॻ͔ͤͯ௖͘
͖͔͚ͬͱͳͬͨߨԋʹࢲΛߨԋऀͱͯ͠ਪનͯͩ͘͠

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