500118

˙ ‫঺ڀݚ‬հ

LHC–ALICE ࣮‫ݧ‬ͷ࠷৽ঢ়‫گ‬ஜ೾େֶ਺ཧ෺࣭‫ܥ‬෺ཧֶҬதᑍ ୡ໵chujo.tatsuya.fw@u.tsukuba.ac.jpஜ೾େֶେֶӃ਺ཧ෺࣭Պֶ‫ڀݚ‬Պԣࢁ ޿थhiroki.yokoyama@cern.ch
2017 ೥ (ฏ੒ 29 ೥) 12 ݄ 6 ೔

1

͸͡Ίʹ

1.1

ALICE ࣮‫ݧ‬2015 ೥ͷ CERN LHC Ճ଎‫ث‬ͷୈ̎෺ཧӡస (Run-ɹ ALICE ࣮‫( ݧ‬ਤ 1, 2) ͸ɼ2017 ೥ 12 ݄‫ࡏݱ‬ɼ422) ͷ։࢝ʹ߹Θͤͯɼզʑ͕ࢀՃ͍ͯ͠Δ ALICE ࣮Χࠃɼ176 ‫ؔػڀݚ‬ɼ1,800 ໊ͷ‫͔ऀڀݚ‬ΒͳΔେ‫ࠃܕ‬‫[ ݧ‬1, 2] Ͱ͸ɼੈք࠷ߴΤωϧΪʔʹΑΔॏΠΦϯিಥࡍ‫ڞ‬ಉ࣮‫͋Ͱݧ‬Δɻ೔ຊ͔Β͸ɼਖ਼‫ͯ͠ͱؔػن‬ɼஜ೾࣮‫ݧ‬ͷୈೋນ্͕͕ͬͨɻߴΤωϧΪʔॏΠΦϯিಥ࣮େֶɼ౦‫ژ‬େֶɼ௕࡚૯߹Պֶେֶɼಸྑঁࢠେֶɼ޿

‫ݧ‬ͷΤωϧΪʔϑϩϯςΟΞͰ͋Δ ALICE ࣮‫ݧ‬͸ɼॏౡେֶͷ 5 ‫ࢀ͕ؔػ‬Ճ͠ɼ·ͨ४ਖ਼‫ͯ͠ͱؔػن‬ɼ೔ຊΠΦϯিಥʹΑΓੜ੒͞ΕΔ௒ߴԹ෺࣭ʮΫΥʔΫɾά‫ڀݚྗࢠݪ‬։ൃ‫ߏػ‬ɼཧԽֶ‫ॴڀݚ‬ͷ 2 ‫ࢀ͕ؔػ‬Ճͯ͠ϧʔΦϯɾϓϥζϚ (QGP)ʯΛੜ੒͠ɼͦͷ෺ੑղ໌͍Δɻ‫Ͱ఺࣌ݱ‬ɼελοϑ 13 ໊ɼେֶӃੜ 24 ໊ (಺ 10Λ࠷େͷ໨తͱ͍ͯ͠Δɻͦ͜Ͱ͸ɼϋυϩϯͷด͡ࠐ໊͕ത࢜‫ظޙ‬՝ఔֶੜ)ɼ߹‫ ܭ‬37 ໊ʹΑΓ ALICE-J άΊ͔Βղ์͞ΕͨΫΥʔΫͱάϧʔΦϯͷࣗ༝౓͕ൃ‫ݱ‬ϧʔϓ [4] Λ૊৫͍ͯ͠Δɻ

͠ɼੈք࠷ߴԹ౓Ͱੜ੒͞ΕΔ QGP ‫͕ڀݚ‬ՄೳͱͳΔɻ

ALICE ࣮‫ݧ‬ͷ Run-2 σʔλऩूʹ͓͍ͯ͸ɼ‫·ࡏݱ‬Ͱʹཅࢠɾཅࢠ 13 TeV, 5.02 TeV σʔλʹՃ͑ͯɼ֩
ࢠ͋ͨΓͷॏ৺িಥ‫ܥ‬ΤωϧΪʔ 5.02 TeV ͷԖɾԖিಥ࣮‫ݧ‬ɼ5.02 TeV, 8 TeV ͷཅࢠɾԖিಥ࣮‫ݧ‬Λߦ͍ɼ·
ͨ Run-2 ࠷‫ޙ‬ͷ೥ͱͳΔ 2018 ೥ 11 ݄ʹ͸ɼߴ౷‫ܭ‬ͷ
ԖɾԖ 5.02 TeV িಥ࣮‫ߦ͕ݧ‬ΘΕΔ༧ఆͰ͋ΔɻRun-2
ͷσʔλऩूͷ໨ඪ஋͸ɼԖɾԖ 5.02 TeV িಥ࣮‫Ͱݧ‬ɼ

1 nb−1 (250 M ϛχϚϜόΠΞεࣄ৅, 200 M ߴଟॏ౓ࣄ৅) Ͱ͋Δɻ͜ͷ‫঺ڀݚ‬հͰ͸ɼALICE ࣮‫͚͓ʹݧ‬Δ Run-2 ͷσʔλɼ‫ ͼٴ‬ୈ̍෺ཧӡస (Run-1) ͷσʔλ͔Βɼ৽͘͠෼͔ͬͨ͜ͱΛத৺ʹใࠂ͢Δɻ·ͨɼ೔ຊάϧʔϓ͕த৺ͱͳΓ Run-2 ʹ޲͚ͯ৽ͨʹఏҊɼ‫ݐ‬ઃɾઃஔɼ෺ཧӡసΛ࢝Ίͨ‫ݕ‬ग़‫ث‬ʮμΠδΣοτΧϩϦϝʔλ‫ݕ‬ग़‫( ث‬Di-jet Calorimeter; DCal) ʯΛ঺հ͠ɼͦͷӡసঢ়‫ͱگ‬ੑೳʹ͍ͭͯड़΂Δɻ࠷‫ͱ·ʹޙ‬Ίͱࠓ‫ޙ‬ͷকདྷల๬Λ֓‫͢؍‬ΔɻLHC ୈ̍Քಇ‫ظ‬ͷॳ‫݁ظ‬Ռʹ͍ͭͯ͸ [3] Λࢀরͷ͜ͱɻਤ 1: ALICE ίϥϘϨʔγϣϯɻALICE ࣮‫ݧ‬ΤϦΞ

(Point-2) લʹͯࡱӨ [5]ɻALICE ࣮‫ݧ‬͸ɼLHC ࣮‫ݧ‬ͷதͰ‫֩ࢠݪ‬িಥͷ෺ཧʹಛԽͨ͠།Ұͷ࣮‫͋Ͱݧ‬Γɼओͳ໨త͸ɼߴΤωϧΪʔॏΠΦϯিಥʹ͓͍ͯɼΫΥʔΫɾάϧʔΦϯɾϓϥζϚ (QGP) ૬Λੜ੒͠ɼͦͷߴԹΫΥʔΫ૬ͷ෺ੑ‫ڀݚ‬ɼ‫ݶۃ‬ঢ়ଶͷྔࢠ৭ྗֶɼΧΠϥϧରশੑͷࣗൃత

501
119

ഁΕʹ൐͏ϋυϩϯ࣭ྔൃ‫ߏػݱ‬ͷղ໌ʹ͋ΔɻͦΕʹϥϝʔλΛ෼෍Λඳ͍ͨ΋ͷͰ͋Δɻύϥϝʔλͷ̍ΑΓɼӉ஦ϏοΫόϯ͔Β໿ 10 µsec ͷؒʹଘࡏͨ͠ͱ

ͭ͸ɼޫ଎ c Λ‫ج‬४ͱͨ͠ฏ‫ۉ‬ͷ‫ܥ‬ͷ๲ு଎౓Λද͢͞ΕΔ QGP ঢ়ଶΛ஍্Ͱ࠶‫͠ݱ‬ɼͦͷঢ়ଶΛௐ΂Δɻ< βT >ɼ΋͏̍ͭ͸ɼϋυϩϯ͕‫͔ܥ‬Βӡಈֶతʹ཭ΕถࠃɾϒϧοΫϔϒϯࠃཱ‫ Ͱॴڀݚ‬2000 ೥ʹՔಇ։࢝ͨ (ӡಈΤωϧΪʔ͕‫ݻ‬ఆ͞Εͨ) ࣌ͷԹ౓ Tkin Ͱ͋Δɻͨ͠ RHIC Ճ଎‫ʹث‬ΑͬͯɼQGP ૬ͷੜ੒͕͔֬ΊΒਤ 3 ͸ɼԣӡಈྔ෼෍ͷϑΟοτ͔ΒಘΒΕΔ < βT >

Ε [6, 7, 8]ɼ·ͨ‫׬‬શྲྀମʹ͍ۙੑ࣭Λ࣋ͭ͜ͱ͕෼

ͱ Tkin Λɼ༷ʑͳিಥ‫ܥ‬ɼத৺িಥ౓ɼিಥΤωϧΪʔ

͔ͬͨɻLHC Ͱ͸ɼRHIC Ҏ্ʹߴԹͷ QGP ૬Λ҆ఆͰଌఆͨ͠΋ͷͰ͋Δɻத৺িಥ౓ͱ͸, ‫֩ࢠݪ‬ɾ‫ࢠݪ‬͔ͭେྔʹੜ੒͠ɼΑΓৄࡉͳ QGP ෺ੑ‫ڀݚ‬Λߦ͏ɻ֩িಥʹ͓͚Δিಥ‫ ਺ܘ‬impact parameter ʹ૬౰͢Δ

ߴ͍ΤωϧΪʔྖҬͰ͸༰қʹੜ੒ՄೳͳɼδΣοτ΍

ྔͰ͋Γɼ0 %ʹ͍ۙ΄Ͳத৺িಥͰ͋Δ͜ͱΛࣔ͠,௚઀ޫࢠɼνϟʔϜ΍ϘτϜͱ͍ͬͨॏΫΥʔΫΛ࢖͏

100 %ʹ͍ۙ΄ͲपลিಥͰ͋Δ͜ͱΛࣔ͢ɻ͜͜Ͱ͸͜ͱʹΑΓɼͦͷ෺ੑΛৄࡉʹܾΊΔ͜ͱ͕Ͱ͖Δɻ

ཻࢠଟॏ౓ (dN/dη, η ͸ٖϥϐσΟςΟ) ͷେখͰ৭෼͚͍ͯ͠ΔɻRun-2 Ͱଌఆ͞Εͨ < βT > ͸ɼޫ଎ͷ
໿ 0.65 ഒʹ΋ୡ͠ɼ·ͨେ͖ͳ๲ு଎౓ͷͨΊɼϋυϩϯͷӡಈֶత์ग़Թ౓΋ͦΕʹ൐ͬͯ௿͘ͳ͍ͬͯΔ
͜ͱ͕Θ͔Δɻ͜ͷ๲ு଎౓͸ɼLHC 5.02 TeV ʹ͓͚
ΔԖɾԖத৺িಥͰ࠷΋େ͖͍ɻ͜ͷେ͖ͳूஂӡಈ͸ɼ

LHC ͰͷॏΠΦϯিಥͷॏཁͳಛ௃ͷ̍ͭͰ͋Δɻ໘
ന͍͜ͱʹɼখ͞ͳ‫͋Ͱܥ‬ΔཅࢠɾཅࢠɼཅࢠɾԖ‫ࢠݪ‬֩িಥʹ͓͍ͯ΋ɼཻࢠଟॏ౓্͕͕ΔʹͭΕͯɼॏΠΦϯিಥͱಉ༷ʹେ͖ͳूஂ๲ு଎౓Λ΋ͭ͜ͱ͕Θ͔
Δɻখ͞ͳ‫Ͱܥ‬ͷৼΔ෣͍ʹ͍ͭͯ͸ɼ͜ͷ‫ৄͨ·Ͱޙ‬ਤ 2: Run-2 ʹ͓͚Δ ALICE ‫ݕ‬ग़‫ث‬ɻ͘͠ड़΂Δ͜ͱʹ͢Δɻಉ͡ଟॏ౓Ͱ΋ɼখ͞ͳ‫Ͱܥ‬ͷ๲ு଎౓ͷํ͕ɼԖɾԖিಥͷͦΕͱൺ΂ͯେ͖͍݁Ռ

0.2
0.18

ch

0.16

|η |< 0.5

〈dN /dη 〉ALICE ࣮‫͚͓ʹݧ‬Δ Run-2 ॏΠΦϯ෺ཧͷϋΠϥΠτ

2

T kin (GeV)

͕ग़͍ͯΔ͜ͱ΋‫ڵ‬ຯਂ͍ɻ

LHC Run-2 ͕࢝·Γɼ͜Ε·Ͱͷ֩ࢠ͋ͨΓͷॏ৺√িಥΤωϧΪʔ ԖɾԖ sN N =2.76 TeV ͔Β໿ 2 ഒ

0.1410ͱͳΔ 5.02 TeV Ͱͷ‫֩ࢠݪ‬িಥ࣮‫ͨͬ·͕࢝ݧ‬ɻ͜͜

0.16

Ͱ͸ɼ͜Ε·Ͱʹ෼͔͖ͬͯͨ Run-2 ͷϋΠϥΠτΛɼ

0.085

Run-1 ͷ݁Ռͱ߹Θͤͯ঺հ͢Δɻ

0.063

9

40

0.128

35

7

30

Global Blast-Wave fit toπ (0.5-1 GeV/ c) , K (0.2-1.5 GeV/c) , p (0.3-3.0 GeV/c)

4
2

0.04

2.1

ߴԹΫΥʔΫ෺࣭ͷόϧΫͳੑ࣭ (େ͖ͳूஂ๲ுͱ೤౷‫ܭ‬Ϟσϧͷ༧‫)ྗݴ‬·ͣɼԖɾԖিಥ࣮‫ݟͰݧ‬ΒΕͨόϧΫͳੑ࣭Λ‫ͯݟ‬ΈΑ͏ɻόϧΫͳੑ࣭ͷ୅දྫͱͯ͠͸ɼ‫֩ࢠݪ‬িಥͰੜ͡Δϋυϩϯੜ੒ྔ (ཻࢠଟॏ౓)ɼूஂతͳӡಈ (౳ํత๲ு΍ɼཻࢠͷํҐ֯ҟํੑ)ɼԹ౓ɼϋυϩϯੜ੒‫ݯ‬ͷαΠζ (HBT ൒‫͛ڍ͕Ͳͳ )ܘ‬ΒΕΔɻ͜͜Ͱ͸·ͣɼ౳ํతͳूஂӡಈΛද͢ྔͰ͋Δɼ‫ܥ‬ͷ๲ு଎౓ (radial flow) ͱ, ͦͷͱ͖ͷԹ౓ (ӡಈֶతϋυϩϯౚ݁Թ౓; kinetic freeze-out temperature) ʹண໨͢Δɻ
ਤ 3 ͸ɼཻࢠࣝผ͞Εͨ π ± , K ± , ཅࢠɼ൓ཅࢠͷԣӡಈྔ෼෍Λɼ๲ுϞσϧͷ̍ͭͰ͋Δ Boltzmann-Gibbs

Blast-Wave Ϟσϧ [9] ͰϑΟοτ͠ɼಘΒΕΔ̎ͭͷύ

1

0.020
0

25
20

ALICE Preliminary, pp, s = 7 TeV
ALICE, p-Pb, s = 5.02 TeV
ALICE, Pb-Pb, sNN = 2.76 TeV
ALICE Preliminary, Pb-Pb, sNN = 5.02 TeV
5

ALI-PREL-122516

150.110 0.2

20
0.3

25
0.4

30 0.5 35

15
10
5

0.640

45
0.7
〈β 〉
T

ਤ 3: π ± ɼK ± ɼཅࢠɼ൓ཅࢠͷԣӡಈྔ෼෍Λ࢖ͬͨ

Blast-Wave ϞσϧͰͷϑΟοτ݁ՌɻϑΟοτʹΑͬͯಘΒΕΔύϥϝʔλ < βT > −Tkin ͷཻࢠଟॏ౓ґଘੑɻਤ 4ʹࣔͨ͠ͷ͸ɼ2.76 TeV ͰͷԖɾԖিಥʹ͓͚
Δཻࢠࣝผ͞Ε༷ͨʑͳϋυϩϯͷੜ੒ྔ (dN/dy, y͸ϥϐσΟςΟ) Ͱ͋Δɻ͜Ε΋ߴΤωϧΪʔॏΠΦϯিಥΛද͢όϧΫͳଌఆྔͷ୅දྫͰ͋Δ͕ɼ͜ΕΒͷσʔλ͸ɼ౷‫ܭ‬తαʔϚϧϞσϧ (statistical thermal

model) [10] Λ࢖ͬͯɼ‫ج‬ຊతʹ̎ͭͷύϥϝʔλͷΈͰɼશͯͷϋυϩϯͷऩྔΛඇৗʹΑ͘‫ه‬ड़͢Δ͜ͱ͕
Ͱ͖Δɻ̎ͭͷύϥϝʔλͱ͸ɼϋυϩϯͷԽֶతౚ݁

502
120

Թ౓ Tch (chemical freeze-out temperature) ͱɼόϦΦ

͜͜ͰɼNcoll ͸‫֩ࢠݪ‬িಥʹ͓͚Δ֩ࢠؒೋମিಥ

ϯԽֶϙςϯγϟϧ (µB ) Ͱ͋ΔɻLHC ͷΤωϧΪʔͰ

਺Ͱ͋Δɻͭ·ΓɼRAA ͸ɼ֩ࢠରিಥ͋ͨΓͷ‫֩ࢠݪ‬͸ɼཅࢠͱ൓ཅࢠͷੜ੒ൺ͕΄΅ 1 Ͱ͋Δ͜ͱ͔Β΋෼িಥͱ p+p িಥͰͷऩྔൺͰ͋Δɻ΋͠ A+A িಥ͕͔ΔΑ͏ʹɼµB ≈ 0 ͱͯ͠Α͘ɼ֤ʑͷϋυϩϯͷऩp+p িಥͷॏͶ߹ΘͤͰද͞ΕΔͱ͢ΔͱɼRAA = 1ྔ͸΄΅ Tch ͷΈͰܾఆ͞ΕΔɻܾఆ͞Εͨ Tch ͸ɼ͜ͱͳΓɼऩྔʹ཈੍͕͋Δͱ RAA < 1 ͱͳΔɻͷ৔߹ɼ155 MeV Ͱ͋Δɻ͜ͷԹ౓͸ RHIC Ͱͷ݁ՌͰ΋ಉ༷Ͱ͋Δ͕ɼ֨ࢠ QCD ‫͕ࢉܭ‬༧‫͢ݴ‬Δϋυϩϯ

ਤ 5 ʹ‫ݟ‬ΒΕΔ༷ʹɼ௿͍ӡಈྔྖҬͰ͸૿Ճ (RAA >1) ͕ɼߴ͍ӡಈྔྖҬͰ͸཈੍ (RAA < 1) ͞Ε͍ͯΔ

૬ͱ QGP ૬ͷΫϩεΦʔόʔ૬సҠԹ౓ͱ΄΅ಉ͡஋͜ͱ͕෼͔Δɻ͜ͷσʔλͷղऍͱͯ͠͸ɼQGP தͰΛͱΔɻͷ cc̄ ͷ͏ͪɼҐ૬ۭؒͷ͍ۙ cc̄ ͕࠶݁߹͠ɼJ/ψ ͕ύʔτϯಉ࢜ͷॳ‫ظ‬িಥͰੜ੒͞Εͨ΋ͷΑΓ΋ଟ͘ੜdN /dy

π++π2

K++K
2

-

K*+K*
2

0

KS

p+p
2

φ

Ω +Ω+
2

Ξ +Ξ+
2

-

-

Λ

103

d

3
3
Λ H+ Λ H

2

3

He੒͞ΕͯΔͱ͍͏‫͕ํݟ‬༗ྗͰ͋ΔɻҰํͰɼߴ͍ӡಈྔྖҬͰ͸ɼRHIC ΤωϧΪʔͱಉ༷ɼ‫͍ڧ‬཈੍͕‫ݟ‬Β

ALICE Preliminary
Pb-Pb sNN = 2.76 TeV, 0-10%102ΕΔɻ͜ͷ௿͍ӡಈྔྖҬͰͷ J/ψ ੜ੒૿େ͸ɼLHC

10
1

ͷॏΠΦϯσʔλͷΈͰ‫ݟ‬ΒΕΔେ͖ͳಛ௃Ͱ͋Δɻcc̄

Not in fit
Extrapolated

Model

T (MeV)χ2/NDF

10−3

THERMUS 2.3

155 ± 224.5/9GSI-Heidelberg

156 ± 2

18.4/9

10−4

SHARE 3156 ± 315.1/9(mod.-data)/ σdata (mod.-data)/mod.

10−1
10−2

࠶݁߹Λࣔࠦ͢Δ΋͏Ұͭͷσʔλ͸ɼJ/ψ ཻࢠͷେ͖ͳํҐ֯ҟํੑͰ͋ΔɻํҐ֯ҟํੑͱ͸ɼ‫֩ࢠݪ‬ಉ࢜ͷඇத৺িಥ൓Ԡʹ͓͍ͯɼিಥ‫਺ܘ‬ϕΫτϧ ⃗b ͕ுΔ

BR = 25%0.50ฏ໘ (൓Ԡฏ໘ Ψ) ʹରͯ͠ɼཻࢠͷ์ग़֯౓ΛํҐ֯

−0.5

2
41
2
0
−2
−4
1
2
ALI−PREL−94600

3

4

5

6

7

8

9

10

11

12

13

3

4

5

6

7

8

9

10

11

12

13

ͷ̎࣍ͷϑʔϦΤ੒෼ͷ͜ͱͰ͋Δɻ۩ମతʹ͸ɼ࣍ࣜͰද͞ΕΔྔͰ͋Γɼ̎࣍ͷϑʔϦΤ੒෼ͷ͜ͱΛ v2

Ͱද͢ɻ

ਤ 4: ϋυϩϯͷऩྔͱ౷‫ܭ‬తαʔϚϧϞσϧɻ2.2

φ ͰଌͬͨࡍɼdN/d(Ψ − φ) ͰཻࢠͷऩྔΛଌఆ͠ɼͦ

dN= A · (1 + 2v2 cos(2(Ψ − φ)))d(Ψ − φ)J/ψ ཻࢠͰ‫ݟ‬ΒΕͨνϟʔϜΫΥʔΫ࠶݁߹

(2)

ਤ 6 ʹ͋Δ༷ʹɼJ/ψ ͷํҐ֯ҟํੑ v2 ͸େ͖͘ɼ·࣍ʹɼLHC σʔλͰΈΒΕͨϢχʔΫͳಛ௃ͷ̍ͭͨͦͷେ͖͞͸ɼଞͷ (u, d, s ΫΥʔΫΛ‫ؚ‬Ή) ͍ܰϋυ

Ͱ͋Δ J/ψ ͷੜ੒ʹ͍ͭͯ‫ͯݟ‬ΈΑ͏ɻߴΤωϧΪʔϩϯͱಉ༷ͷେ͖͞Λ࣋ͭ͜ͱ͕Θ͔ͬͨɻϞσϧͱͷൺॏΠΦϯ൓Ԡʹ͓͍ͯɼJ/ψ ཻࢠ͸ಛผͳҙຯΛ΋ͭɻֱͰ͸ɼେ͖ͳ v2 ͷ‫د‬༩͸ɼॳ‫ظ‬ੜ੒‫( ݯى‬Primordial)

1980 ೥୅ɼQGP தͰͷΧϥʔσόΠःณޮՌʹΑΔͷ΋ͷΑΓɼ࠶݁߹ (Inclusive) ͔Β͖͍ͯΔ͜ͱ΋෼J/ψ(cc̄) ੜ੒ͷ཈੍͕ɼদҪɾSatz ΒʹΑͬͯఏএ͞

͔͖ͬͯͨ (ਤ 7)ɻ·ͨɼνϟʔϜΫΥʔΫΛ‫ؚ‬Ή D த

Ε [11]ɼͦͷ‫ޙ‬΋ QGP ੜ੒ͷ༗ྗͳϓϩʔϒͱͯ͠ੜؒࢠͷ v2 ΋ɼେ͖ͳ஋Λ‫؍‬ଌ͍ͯ͠Δʢਤ 6ʣɻ͖࢒ͬͨɻ1990 ೥୅ͷ SPS Ճ଎‫Ͱث‬ͷॏΠΦϯ൓ԠͰ͸ͦͷ཈੍ͷஹީ͕ɼ·ͨ 2000 ೥୅ʹೖΓ RHIC ࣮‫ݧ‬খ͞ͳিಥ‫ Ͱܥ‬QGP ੜ੒ʁ

͕࢝·ΓɼJ/ψ ੜ੒ͷ཈੍ޮՌ͕֬ೝ͞ΕΔʹࢸͬͨɻ

2.3

ҰํɼLHC Ͱ͸Ͳ͏ͩΖ͏͔ɻLHC ͷ࣮‫݁ݧ‬Ռ͔ΒΘۙ೥ಛʹ஫໨Λཋͼ͍ͯΔͷ͸ɼখ͞ͳিಥ‫( ܥ‬Small
System) ͰͷूஂӡಈతͳৼΔ෣͍Ͱ͋ΔɻSmall Sys-͔ͬͨ͜ͱ͸ɼ‫ʹͱ͖͜΂͘ڻ‬ɼJ/ψ ͷ཈੍Ͱ͸ͳ͘ɼͦͷ൓ରͷ૿େ‫ݱ‬৅Ͱ͋ͬͨɻ
ਤ 5 ʹࣔͨ͠ͷ͸ɼJ/ψ ͷ RAA (‫֩ࢠݪ‬཈੍Ҽࢠ 1 )Λԣ࣠ pT (ԣӡಈྔ) Ͱϓϩοτͨ͠΋ͷͰ͋Δɻ‫ࢠݪ‬֩཈੍Ҽࢠ RAA ͸ɼ‫֩ࢠݪ‬িಥʹ͓͚ΔޮՌΛද͢ྔͱͯ͠ɼҎԼͷࣜͰఆٛ͞ΕΔɻ

RAA (pT ) =d2 NAA /dpT dy⟨Ncoll ⟩ × d2 Npp /dpT dy

tem ͱ͸ɼ2 ֩ࢠ‫͋Ͱܥ‬Δཅࢠɾཅࢠিಥɼ·ͨ͸Ұํ͸ཅࢠ͕ͩɼ΋͏Ұํ͸‫͑ྫ( ֩ࢠݪ‬͹ p+P b ΍ p+Au ি√ಥ) ͳͲͷিಥ‫ܥ‬Λࢦ͢ɻLHC Ճ଎‫͕ث‬Քಇ͠ɼ sN N

= 7 TeV Ͱͷཅࢠɾཅࢠিಥσʔλ͕ग़࢝Ίͯ·΋ͳ͘ͷ 2010 ೥ 9 ݄ɼCMS ࣮‫ʹݧ‬ΑΓɼඇৗʹߴཻ͍ࢠଟॏ౓ͷΠϕϯτΛબͿͱɼ͔͋ͨ΋ॏΠΦϯিಥͰΈ

(1)ΒΕ༷ͨͳ‫ݱ‬৅͕‫؍‬ଌ͞Εͨͱͷใࠂ͕͋ͬͨ [12]ɻͦ
ͷ‫ޙ‬ɼLHC Ͱͷ࣮‫ݧ‬ͷΈͳΒͣɼRHIC ʹ͓͍ͯ΋ಉ༷ͷղੳ͕ͳ͞Εɼ‫Ͱࡏݱ‬΋༷ʑͳϓϩʔϒΛ༻͍ͯ͜

1 nuclear modification factorͷখ͞ͳ‫ܥ‬ͷ‫͕ڀݚ‬ਐΜͰ͍Δɻ

503

2

v2 {EP}

R AA

121

ALICE, Pb−Pb sNN = 5.02 TeV, 0-20%

1.8
1.6

0.25
ALICE 20 - 40% Pb-Pb, sNN = 5.02 TeV
0.2-

J/ ψ → µ µ 2.5 < y < 4, (PLB 766 (2017), 212)0.15

J/ ψ → e+e- |y| < 0.9 (Preliminary)

1.4
1.2

Inclusive J/ψ

e+e , |y | < 0.9, v 2{EP, ∆ η = 0}µ+µ-, 2.5 < y < 4, v 2{EP, ∆ η = 1.1}
- global syst : 1%

+ -

0.1

1
0.05

0.8
0.6

0
−0.05

0.2
0

K. Zhou et al. (2.5 < y < 4)
Inclusive J/ ψ w non-collective
Inclusive J/ ψ w/o non-collective
Primordial J/ ψ

X. Du et al.

0.4

0

2

4

6

8

10
12
p (GeV/c)T

ALI-PREL-132236

ਤ 5: J/ψ ཻࢠͷ‫֩ࢠݪ‬཈੍Ҽࢠ (ԖɾԖ

√

−0.1
0

Inclusive J/ ψ , |y | < 0.9
Inclusive J/ ψ , 2.5 < y < 4
Primordial J/ ψ , 2.5 < y < 4

2

4

8

10

12

p (GeV/ c )ALI−PUB−138833

sN N =

6Tਤ 7: J/ψ தؒࢠͷํҐ֯ҟํੑ (v2) ͱϞσϧͱͷൺֱɻ

5.02 TeV,0-20 %த৺িಥ)ɻத৺ϥϐσΟςΟʔྖҬͰଌΒΕͨ J/ψ → e+ e− (੺֯)ɼલํํ޲ͰଌΒΕͨ࠶‫͕ݱ‬೉͍͜͠ͱ΋Θ͔͍ͬͯΔɻʮετϨϯδωε૿ऩྔ‫֨ن‬Խʹ‫ى‬Ҽ͢Δ‫ܥ‬౷తෆ͔֬͞ɻ

Ε [13]ɼ͜Ε·ͰॏΠΦϯিಥಛ༗ͷ΋ͷͩͱࢥΘΕͯ

v2 {EP}

J/ψ → µ+ µ− (੨‫ )ؙ‬ͷσʔλɻRAA =1ɼӈଆͷόʔ͸ɼେʯ‫ݱ‬৅͸ɼ͔ͭͯ͸ QGP ͷγάωνϟͱͯ͠ఏএ͞
͖ͨ‫ݱ‬৅͕ɼ࣮͸ߴཻ͍ࢠଟॏ౓ͷখ͞ͳিಥ‫͍͓ʹܥ‬

0.25
ALICE Pb-Pb, sNN = 5.02 TeV

global syst : ± 1%ͯ΋ɼ‫ݦ‬ஶʹʮετϨϯδωε૿େʯ͕͋Δ͜ͱ͕ॳΊ0.2

ͯ໌Β͔ʹͳͬͨ [14]ɻ
Ͱ͸ɼখ͍͞িಥ‫Ͱܥ‬ͷूஂతͳӡಈ͸Ͳ͏Ͱ͋Ζ͏

0.15

͔ɻਤ 9 ͸ɼԣ͕࣠ԣӡಈྔɼॎ͕࣠લग़ͷํҐ֯ҟํ√
ੑ v2 Ͱ͋Δɻিಥ‫ܥ‬͸ཅࢠɾԖিಥ sN N = 5.02 TeV

0.1
0.05
0
−0.05
−0.1
0

Ͱɼߴཻ͍ࢠଟॏ౓ࣄ৅ΛબΜͰ͍Δɻσʔλ͸ओʹཻInclusive J/ψ → µ+µ−,v 2{EP, ∆η = 1.1}, 2.5 < y < 4

Prompt D0, D+, D*+ average,v 2{EP, ⎜∆η⎜= 0.9}, ⎜y ⎜< 0.8

5-20% 40-60%
20-40%

30-50%, arXiv:1707.01005

2

4

6

8

ALI−PUB−138837

ࢠࣝผ͞ΕͨϋυϩϯͰ͋ΔɻॏΠΦϯিಥͰ΋ΈΒΕͨେ͖ͳ v2 ͕ɼখ͞ͳ‫͋Ͱܥ‬ΔཅࢠɾԖͰ΋‫͍ͯ͑ݟ‬Δ͜ͱ͕෼͔ͬͨɻ
12ͦΕͰ͸ɼQGP ੜ੒ͷূ‫ڌ‬ͷ̍ͭͰ͋ΔδΣοτ཈p (GeV/ c )੍͸খ͞ͳিಥ‫ͨ͑ݟͰܥ‬ͷͩΖ͏͔ɻਤ 10 ʹࣔ͢

10Tਤ 6: J/ψ ͱ D தؒࢠͷํҐ֯ҟํੑ (v2)ɻD தؒࢠ͸ɼD0ɼD+ ɼD− ͷଌఆΛฏ‫ۉ‬Խ͍ͯ͠Δɻখ͞ͳ‫Ͱܥ‬ͷଟॏཻࢠੜ੒Πϕϯτʹ͓͍ͯɼQGP͸ੜ੒͞ΕͨͷͰ͋Ζ͏͔ʁ·ͣɼ͜Ε·Ͱ ALICE ͰΈΒΕͨɼখ͞ͳ‫Ͱܥ‬ͷ݁ՌΛ‫ͯݟ‬ΈΔ͜ͱʹ͢Δɻ
ਤ 8 ͸ɼԣཻ͕࣠ࢠͷଟॏ౓ (dN/dη) Ͱɼॎ͕࣠εΛɼΞɼΩ) ͷऩྔ
τϨϯδωεΛ‫ؚ‬Ή༷ʑͳϋυϩϯ (Ks0ɼͱɼՙి π தؒࢠͷऩྔͷൺΛͱͬͨ΋ͷͰ͋Δɻϓϩοτ͍ͯ͠Δিಥ‫ܥ‬͸ɼ7 TeV ͷཅࢠɾཅࢠɼ5.02 TeVͷཅࢠɾԖɼ2.76 TeV ͷԖɾԖͰ͋Δɻཅࢠɾཅࢠɼཅ
ࢠɾԖͷཻࢠଟॏ౓͕ͦΕͧΕ্͕ΔʹͭΕͯɼετϨϯδωεɾϋυϩϯͷऩྔ΋૿Ճ͠ɼ΄΅̍ͭͷϥΠϯΛ‫ܗ‬੒͍ͯ͠Δ͜ͱ͕Θ͔Δɻ·ͨཅࢠɾԖͰͷ࠷΋ߴཻ͍ࢠଟॏ౓ͷ఺͸ɼԖɾԖσʔλͷपลিಥͷσʔλͱྑ͘Ұக͍ͯ͠Δɻਤʹ͸Ϟσϧ‫ࢉܭ‬ͷ஋΋͓ࣔͯ͠ΓɼPYTHIA ͳͲͷैདྷͷΠϕϯτδΣωϨʔλʔ(soft ͳ QCD Ϟσϧ) Ͱ͸࠶‫͖ͣͰݱ‬ɼϚϧνύʔτϯ૬‫༻࡞ޓ‬Λ‫ؚ‬ΉϞσϧ (DIPSYɼEPOS) ͳͲͰͳ͍ͱ

ͷ͸ɼཻࢠࣝผ͞Ε༷ͨʑͳཻࢠͷ‫֩ࢠݪ‬཈੍ҼࢠΛ√ཅࢠɾԖিಥ‫ ܥ‬sN N = 5.02 TeV Ͱ‫ͨݟ‬΋ͷͰ͋Δɻ
ߴ͍ԣӡಈྔྖҬ (8 GeV/ c Ҏ্) ͷϋυϩϯ͸ɼͦͷੜ੒‫ݯى‬Λॳ‫ظ‬ύʔτϯͷߗࢄཚ (hard scattering) ʹ΋ͭɻͦΕΒ͸δΣοτͱͳͬͯऴঢ়ଶͰ‫؍‬ଌ͞ΕΔɻ
ਤ 10 ͷ੺֯ͷσʔλ (த৺ϥϐσΟςΟʔྖҬ |y| <0.9 ɼJ/ψ → ɹ e+ e− ) ʹ‫ݟ‬ΒΕΔΑ͏ʹɼ8 GeV/ c Ҏ্ͷԣӡಈྔͷ‫֩ࢠݪ‬཈੍Ҽࢠ RpP b ͸Ͳͷཻࢠछ΋ 1෇ۙʹ͋ΓɼδΣοτ཈੍ޮՌ͕খ͞ͳিಥ‫Ͱܥ‬͸‫ݟ‬ΒΕ͍ͯͳ͍ɻ͜ͷਤ͸த৺িಥ౓Λ෼͚͍ͯͳ͍͕ɼ෼
͚ͨ৔߹Ͱ΋δΣοτ཈੍ޮՌ͸‫ݟ‬ΒΕͳ͔ͬͨɻ
খ͞ͳিಥ‫ஂूͰܥ‬ӡಈ΍ετϨϯδωε૿େ͕‫ݟ‬ΒΕͨͷʹ΋ؔΘΒͣɼδΣοτ཈੍͕‫ݟ‬ΒΕ͍ͯͳ͍͜ͱͷղऍͱͯ͠ɼQGP తͳ΋ͷ͕࡞ΒΕͨͱͯ͠΋ɼͦͷαΠζ͕খ͍͞ҝʹे෼ͳύʔτϯͷΤωϧΪʔଛࣦ͕ੜ͡ͳ͍Ͱɼ‫ܥ‬ͷ֎ʹग़͖ͯͯ͠·ͬͨͱͷ‫ํݟ‬΋͋Δɻͨͩ͜ͷখ͍͞িಥ‫Ͱܥ‬ͷूஂӡಈͷ‫͕ݯى‬Ϛϧνύʔτϯ૬‫͔༻࡞ޓ‬Βੜ͡Δྲྀମ‫ݱ‬৅ͱͯ͠ղऍͰ͖
Δͷ͔ɼ͋Δ͍͸ɼিಥॳ‫ظ‬ͷ৚݅ͱͯ͠ߟ͑ΒΕ͍ͯ

504v unsub{2,|∆η|>0.8}
2

122

0.3
ALICE Preliminary

0-20% (V0A)|η| < 0.8
without non-flow subtraction

p-Pb sNN = 5.02 TeV

0.25

h±
0

KS

0.2

φ
Λ (Λ )

0.15

PLB 726 (2013) 164

0.1

errors: stat.+syst.

π±
K±
p(p)

0.05
0

1

2

3

4

5

6

p (GeV/ c )T

ALI−PREL−134117

ਤ 9: ཅࢠɾԖিಥ

√sN N = 5.02 TeV ͷߴཻࢠଟॏ౓

ࣄ৅ʹ͓͚Δཻࢠࣝผ͞ΕͨϋυϩϯͷํҐ֯ҟํੑR pPb(v2 )ɻ
3
-

+

-

+

Ξ +Ξ

-0.5 < y CMS < 0Ω +Ω -0.5 < y CMS < 02.52π++π-0.5 < y< 0 for p < 2.0 GeV/ c
CMS
T-0.3 < y< 0.3 for p > 2.0 GeV/ c
T
- CMS
+
K +K
-0.5 < y< 0 for p < 2.8 GeV/ c
CMS
T-0.3 < y< 0.3 for p > 2.8 GeV/ c
CMS
T
p+p
-0.5 < y< 0 for p < 3.0 GeV/ c
CMS
T-0.3 < y< 0.3 for p > 3.0 GeV/ c
CMS

T

1.5
1
ALICE Preliminary
NSD, p-Pb sNN = 5.02 TeV

0.5
ALI-PUB-106878

Uncertainties: stat. (bars), sys. (boxes)ਤ 8: ετϨϯδωεΛ‫ؚ‬Ήϋυϩϯͱ π தؒࢠͷऩྔൺͷཻࢠଟॏ౓‫ͼٴ‬িಥ‫ܥ‬ґଘੑɻ

0
0

2

4

ਤ 10: ཅࢠɾԖিಥ
ΔάϧʔΦϯ๞࿨‫ݱ‬৅ (CGC, Color Glass Condensate)

6

8

10

12
14
p (GeV/ c)T

ALI−PREL−107381√

sN N = 5.02 TeV ͷཻࢠࣝผ͞

Εͨϋυϩϯͷ‫֩ࢠݪ‬཈੍Ҽࢠɻʹ‫ݯى‬Λ΋ͭ΋ͷͳͷ͔·ͩ෼͔͓ͬͯΒͣɼࠓ‫ޙ‬ͷॏཁͳ‫ڀݚ‬՝୊ͷ 1 ͭͱͯ͠࢒͞Ε͍ͯΔɻ

΁ͱͭͳ͕Δɻ͜ΕΛɼδΣοτ཈੍ޮՌ2 ͱ‫Ϳݺ‬ɻ͜͜Ͱ͸ɼδΣοτ཈੍ޮՌͱύʔτϯͷΤωϧΪʔଛࣦʹ

2.4δΣοτͰ୳ΔύʔτϯͷΤωϧΪʔଛࣦ‫ߏػ‬ؔ͢Δ࠷৽ͷ࣮‫݁ݧ‬ՌΛใࠂ͢Δɻલड़ͷ௨ΓɼδΣοτ͸ߴԣӡಈྔͷϋυϩϯͷଋͰ͋ΔͨΊɼߴԣӡಈྔϋυϩϯऩྔΛଌఆ͢Δ͜ͱʹΑΓɼଛࣦ‫ߏػ‬ͷ୳ࡧʹ͓͍ͯɼিಥॳ‫ʹظ‬ੜ͡ΔߗࢄཚύʔδΣοτ཈੍ޮՌΛؒ઀తʹௐ΂Δ͜ͱ͕Ͱ͖Δɻਤ 11√
͸ɼALICE ʹ͓͍ͯଌఆ͞Εͨ sNN = 2.76 TeVɼ‫ٴ‬τϯ͸ɼඇৗʹ༗ޮͳϓϩʔϒͱͳΔɻͳͥͳΒɼͦͷͼɼ5.02 TeV ͷԖɾԖিಥʹ͓͚Δՙిཻࢠͷ RAA Ͱ༷ͳύʔτϯ͸ɼߴΤωϧΪʔॏΠΦϯিಥͰੜ੒͞

͋Δɻ‫֩ࢠݪ‬ͷத৺িಥ (0 ∼ 5 %) Ͱ͸ɼδΣοτ‫ى‬Ҽ

QGP ͷ༌ૹಛੑ΍ QGP தͰͷύʔτϯͷΤωϧΪʔ

ΕΔ෺࣭Λ௨ա͢Δࡍʹɼͦͷ෺ੑΛ൓өͨ͠Ө‫ڹ‬Λड͚Δ͔ΒͰ͋Δɻཧ࿦తʹ͸ɼύʔτϯ͕ QGP தΛͷཻࢠ͕༏ҐͱͳΔߴӡಈྔྖҬʹ͓͍ͯɼ‫͍ڧ‬ऩྔ཈੍͕ଌఆ͞Εɼ‫ʹٯ‬ɼपลিಥ (60 ∼ 80 %) Ͱ͸ɼͦͷ௨ա͢Δ࣌ɼओʹάϧʔΦϯ์ࣹʹΑΓɼQGP தͷάޮՌ͕ऑ͍͜ͱ͕Θ͔Δɻ͜ͷҧ͍͸ɼத৺িಥʹ͓͍ϧʔΦϯີ౓ (dNg /dy) ‫ͼٴ‬ɼ௨ա‫ʹ཭ڑ‬Ԡͨ͡Τωϧ

ͯɼQGP தͰͷߗࢄཚύʔτϯͷฏ‫ۉ‬௨ա‫͕཭ڑ‬௕͍ΪʔΛࣦ͏ͱߟ͑ΒΕ͍ͯΔɻ࣮‫͍͓ͯʹݧ‬ɼ͜ΕΒͷύʔτϯͷଟ͘͸ߴ͍ԣӡಈྔ (pT ) Λ࣋ͭϋυϩϯͷଋ (δΣοτ) ͱͯ͠‫؍‬ଌ͞ΕΔɻ͕ͨͬͯ͠ɼύʔτϯҝͰ͋Δͱߟ͑ΒΕΔɻ

LHC ͰͷॏΠΦϯিಥͰ͸ɼੜ੒͞ΕΔߴΤωϧΪʔύʔτϯ෺࣭தͰͷΤωϧΪʔଛࣦͱൺ΂ɼॆ෼େ͖ͳ

ͷΤωϧΪʔଛࣦ͸ɼߴΤωϧΪʔδΣοτͷऩྔ‫ݮ‬গ
2 jet quenching eﬀect

505
123

ALI-PREL-114186√
ਤ 12: ԖɾԖিಥʹ͓͚ΔՙిཻࢠδΣοτ ( sNN =√5.02 TeV)ɼ‫ͼٴ‬ՙి+தੑཻࢠδΣοτ ( sNN =2.76 TeV) ͷ‫֩ࢠݪ‬཈੍Ҽࢠ RAA [15]ɻ

3.1

ΧϩϦϝʔλ‫܈‬ͷΞοϓάϨʔυ

LHC ͷΤωϧΪʔྖҬͰ͸ɼRHIC ͱൺֱͯ͠ଟ͘
ALI-PREL-107300

ਤ 11:

√

sNN = 2.76 TeVɼ‫ͼٴ‬ɼ5.02 TeV Pb+Pb িಥʹ͓͚Δՙిཻࢠͷ‫֩ࢠݪ‬཈੍Ҽࢠ RAA ɻͷߴΤωϧΪʔδΣοτ͕ੜ੒͞ΕɼδΣοτͷ௚઀ଌఆʹΑΔύʔτϯͷΤωϧΪʔଛࣦͷ‫͕ڀݚ‬ՄೳͱͳΔɻδΣοτ͸ύʔτϯͷೋରࢄཚΛ‫ݯى‬Λ࣋ͭͨΊɼδΣοτࣄ৅͸ํҐ֯ํ޲ʹ૬ରͨ͠δΣοτର (Di -ΤωϧΪʔΛ࣋ͭଟ਺ͷߗࢄཚύʔτϯ͕ੜ੒͞ΕΔɻjet)ɼ·ͨ͸ޫࢠ - δΣοτର (γ - jet) ͱͯ͠‫؍‬ଌ͞ΕͦͷͨΊɼδΣοτ࠶ߏ੒Λ༻͍ͨδΣοτͷ௚઀ଌఆ͕
√Մೳͱͳͬͨɻਤ 12 ʹɼԖɾԖিಥ sNN = 5.02 TeV ʹ

ΔɻDCal ϓϩδΣΫτ͸ɼ‫ط‬ଘͷେཱମ֯ి࣓ΧϩϦϝʔλ “EMCal5 ” ͷ൓ରଆʹ৽ͨͳి࣓ΧϩϦϝʔλ͓͍ͯଌఆ͞ΕͨՙిཻࢠδΣοτͷ RAA Λࣔ͢ [15]ɻ

Λઃஔ͠ɼDi - jetɾγ - jet ΛߴΤωϧΪʔ෼ղೳͰଌఆ

લઅͰࣔͨ͠ՙిཻࢠͷ RAA ͱಉఔ౓ͷ‫͍ڧ‬ऩྔ཈੍√͕ଌఆ͞Εͨ 3 ɻ·ͨɼಉਤதͷ sNN = 2.76 TeV Ͱ͢Δ͜ͱΛ໨తͱ͍ͯ͠Δ (ਤ 13 ࢀর)ɻEMCal, DCalͷՙిཻࢠͱதੑཻࢠʹΑͬͯ࠶ߏ੒͞ΕͨδΣοτͷ

ϯϓϦϯά‫࣓ిܕ‬ΧϩϦϝʔλͰ͋ΓɼγϟγϦΫߏ଄݁Ռͱͷൺֱ͢ΔͱɼՙిδΣοτ཈੍ͱಉఔ౓ͷδΣο

WLS ϑΝΠόʔʹͯγϟϫʔ‫ݯى‬ͷޫΛूޫ͠ɼAPD(Avalanche Photo Diode) Ͱޫ‫ݕ‬ग़ͯ͠ಡΈग़͢ɻΤω√ϧΪʔ෼ղೳ͸ ∆E/E ≈ 8 %/ E + 2 % Ͱ͋Δɻτ཈੍͕ੜ͍ͯ͡Δ͜ͱ͕෼͔ͬͨɻ

3

ALICE ి࣓ΧϩϦϝʔλALICE ࣮‫ݧ‬͸ 2013∼2015 ೥ͷ LHC ӡసఀࢭ‫ؒظ‬த(LS1) ʹ͍͔ͭ͘ͷ‫ݕ‬ग़‫ث‬ΞοϓάϨʔυΛߦͬͨɻ͜
͜Ͱ͸ɼ೔ຊάϧʔϓ͕ࢀը͠େ͖ͳ໾ׂΛՌͨͨ͠ɼ

(1) δΣοτରଌఆ༻ి࣓ΧϩϦϝʔλ “DCal4 ” ͷ৽ઃͱɼ(2) ి࣓ΧϩϦϝʔλΛ‫ͨ͠༻׆‬δΣοτ‫ߴͼٴ‬ΤωϧΪʔޫࢠτϦΨͷ։ൃʹ͍ͭͯ঺հ͢Δɻͷ‫ݕ‬ग़‫ث‬σβΠϯ͸ಉ͡Ͱ͋ΓɼԖɾγϯνϨʔλͷαຊϓϩδΣΫτ͸ 2008 ೥ʹ೔ถ෹ҏதͷ 5 Χࠃ‫ڞ‬ಉʹ্ཱͯͪ͛ΒΕɼஜ೾େֶ͸ओʹɼDCal ಋೖʹΑΔ෺
ཧͷ༗༻ੑͷධՁɼ‫ݕ‬ग़‫ث‬੡࡞ɼLevel-1 τϦΨΞϧΰ
ϦζϜͷ։ൃʹ‫ܞ‬Θͬͨɻશ෦Ͱ 8 εʔύʔϞδϡʔϧɼ

1,344 ϞδϡʔϧΛ Run-2 ʹ޲͚ͯ৽ͨʹಋೖ͠ɼ2014೥ʹશͯͷϞδϡʔϧͷΠϯετʔϧΛ‫( ྃ׬‬ਤ 14)ɼ2015 ೥ͷ Run-2 ΑΓ෺ཧଌఆΛ։࢝ͨ͠ɻRun-2 ͷ
Pb+Pb িಥʹͯಘΒΕͨμΠδΣοτީิΛ‫ؚ‬ΉΠϕϯτσΟεϓϨΠ (ਤ 15) Λࣔ͢ɻDCal ͷσʔλ͕ਖ਼ৗʹऔಘͰ͖͍ͯΔ͜ͱ͕Θ͔Δɻ

3 ‫ڞ‬ஶऀͷԣࢁ޿थ͸ɼຊσʔλղੳ‫ޙͼٴ‬ड़ͷΧϩϦϝʔλ‫ݕ‬ग़‫ث‬ͷ Level-1 τϦΨͷ։ൃʹΑΓɼୈ̎ճɹ TYL-FJPPL Young
Investigator Award Λड৆ͨ͠ (2017 ೥ 5 ݄)ɻ
4 Di - jet CALorimeter

5 ElectroMagnetic CALorimeter

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ਤ 13:

ALICE ʹ͓͚ΔΧϩϦϝʔλ‫ݕ‬ग़‫܈ث‬ɻࠨ

্:EMCal, ӈԼ:DCal ‫ݕ‬ग़‫ث‬ɻӈԼͷ஡৭தԝͷ‫ݕ‬ग़‫ث‬͸ PHOSɻਤ 15: Run-2√
sNN = 5.02 TeV ԖɾԖিಥ࣮‫͓ʹݧ‬͚ΔμΠδΣοτΠϕϯτީิͷΠϕϯτσΟεϓϨΠ
(ӈ্ɿEMCalɼࠨԼɿDCal)ɻ(plot: ࡉ઒཯໵)άϨʔυͰ͸ɼޮ཰Α͘ߴΤωϧΪʔδΣοτΛ‫ؚ‬ΉΠϕϯτΛબͼͩͨ͢ΊɼҎԼͷ఺Λ՝୊ͱ͠ɼτϦΨΞϧΰϦζϜͷมߋ͕ߦΘΕͨɻ

1. ΠϕϯτόοΫάϥ΢ϯυͷ‫ੵݟ‬΋Γਤ 14: DCal εʔύʔϞδϡʔϧͷΠϯετʔϧલͷࣸਅ (ALICE point-2 ʹͯ)ɻ2013 ೥ 9 ݄ࡱӨɻ

2. ॲཧ࣌ؒͷ୹ॖ
՝୊ 1 ͷղܾͷͨΊʹɼALICE ࣮‫ʹݧ‬Πϯετʔϧ͞Ε͍ͯΔ 3 छͷΧϩϦϝʔλɼEMCal, DCal, PHOS Λ

3.2τϦΨγεςϜͷΞοϓάϨʔυ౷߹ͨ͠৽ͨͳτϦΨΞϧΰϦζϜΛ࠾༻ͨ͠ (ਤ 16)ɻ͜͜Ͱ͸ɼॏΠΦϯিಥͷಛ௃Ͱ͋Δେ͖ͳόοΫάϥ

ߴΤωϧΪʔॏΠΦϯিಥ͸‫ۃ‬Ίͯෳࡶͳࣄ৅Ͱ͋Γɼ

1 ౓ͷিಥʹ 2 ສ‫ݸ‬΋ͷଟ਺ͷཻࢠ͕ੜ੒͞ΕΔɻͦͷͨΊɼޮ཰ྑ͘ߴΤωϧΪʔδΣοτΛ‫ؚ‬ΉΠϕϯτΛ
நग़͢ΔͨΊͷΦϯϥΠϯτϦΨγεςϜ͕ඞਢͱͳ
ΔɻδΣοτ‫ߴͼٴ‬ΤωϧΪʔޫࢠͷτϦΨͱͯ͠ɼಡ
ग़͠଎౓ͷൺֱతߴ଎ͳΧϩϦϝʔλͷ࢖༻͕༗ޮͰ͋
ΔɻALICE ࣮‫Ͱݧ‬͸ɼLS1 ‫͍͓ͯʹؒظ‬ΧϩϦϝʔλΛ༻͍ͨτϦΨγεςϜͷΞοϓάϨʔυ͕ߦΘΕͨɻΧϩϦϝʔλͷτϦΨ͸ɼਤ 16 ͷΑ͏ʹ਺ஈͷϞδϡʔϧΛ௨ͯ͠࡞੒͞ΕΔɻͦͷதͷ࠷ऴஈͰ͋Δτ
ϦΨ૷ஔ “STU6 ”(ਤ 17) Ͱ͸ɼԼҐϞδϡʔϧ͕౷߹͞ΕɼτϦΨΞϧΰϦζϜ͕࣮ߦ͞ΕΔɻࠓճͷΞοϓ
6 Summary Trigger Unit΢ϯυΛ EMCal ͱ DCal+PHOS ͰͦΕͧΕ‫ੵݟ‬΋ΓɼͦΕΛ૬ର͢Δ‫ݕ‬ग़‫͋Ͱث‬Δ DCal+PHOS ͱ EMCalͷฏ‫ۉ‬όοΫάϥ΢ϯυͱͯ͠औΓѻ͏͜ͱʹΑΓɼࣗ‫ݾ‬όΠΞεͷ‫ݮ‬গΛਤͬͨɻҰํɼ՝୊ 2 ʹؔͯ͠͸ɼτϦΨϞδϡʔϧؒͷσʔλ௨৴தʹՄೳͳ‫ݶ‬ΓॲཧΛਐΊɼ௨৴࣌ؒΛ‫ؚ‬Ίͨॲཧ࣌ؒͷ࠷దԽΛߦͬͨɻ݁ՌɼALICE ͷཁ‫Ͱ༷࢓ٻ‬͋Δ 7µs Ҏ಺ͱ͍͏୹࣌ؒͰશॲཧΛ‫ͤྃ͞׬‬Δ͜ͱʹ੒ޭͨ͠ɻ͜ͷ৽͍͠τϦΨγεςϜ͸ɼ2015 ೥ͷԖɾԖিಥ࣮
‫ݧ‬ΑΓӡ༻͕։࢝͞Εɼͦͷ‫ޙ‬ͷ Run-2 ͷσʔλऩूʹ͓͍ͯ҆ఆͨ͠τϦΨੑೳΛ࣮‫͍ͯ͠ݱ‬Δɻσʔλऔಘ‫ޙ‬ɼઃఆᮢ஋ʹ͓͚ΔδΣοτͷϦδΣΫγϣϯೳྗɼ

507

T

1/NEvents dNcluster/dp cluster

102

kINT7

10
1

10− 1

DJ1

10− 2

Ratio (DJ1 / kINT7)

125

3

10

102

−3

10

10
10− 4
−5

10

−6

10

1
0

20

40

60

80

100

120

140

1

Cluster Energy (GeV)

10

102

Cluster Energy (GeV)ਤ 18: DCal ‫ݕ‬ग़‫Ͱث‬ಘΒΕͨδΣοττϦΨσʔλɻਤ 16: ALICE ࣮‫͚͓ʹݧ‬ΔΧϩϦϝʔλτϦΨͷσʔࠨɿΫϥελʔΤωϧΪʔ෼෍ɻӈɿϦδΣΫγϣϯೳλϑϩʔ֓ཁɻࠨ͔Β FEE (Front End Electronics),

ྗ (plot: ΩϜ Ϗϣϯνϣϧ)ɻ

TRU (Trigger Region Unit), STU (Summary Trigger
Unit), CTP (Central Trigger Processor)ɻ

4·ͱΊͱల๬
Ҏ্ɼ͜Ε·ͰಘΒΕͨ ALICE ͷ࣮‫݁ݧ‬ՌϋΠϥΠτɼ‫ͼٴ‬ɼRun-2 Ͱ೔ຊάϧʔϓΒ͕৽͘͠ಋೖͨ͠

DCal ‫ݕ‬ग़‫ث‬ͷ঺հΛߦͬͨɻ2018 ೥͸ Run-2 ࠷‫ޙ‬ͷ೥Ͱ͋Γɼ11 ݄ʹ͸࠶౓ͷԖɾԖ 5.02 TeV ͷߴ౷‫ܭ‬σʔλऩू͕ߦΘΕΔ༧ఆͰ͋Δɻࠓ‫ޙ‬͸ɼະղ໌ͷখ͞ͳিಥ‫ݟͰܥ‬ΒΕͨॏΠΦϯతͳৼΔ෣͍ͷཧղΛ༷ʑͳϓϩʔϒΛ࢖ͬͯ୳ࠪ͢Δ͜ͱʹͳΔͩΖ͏ɻྫ͑͹ɼখ͞ͳ‫Ͱܥ‬ͷ೤తޫࢠ୳ࠪɼ͋Δ͍͸δΣοτ΍ॏΫΥʔΫΛ࢖ͬͨখ͞ͳিಥ‫ܥ‬ͷ෺ཧɼͦͷੜ੒‫͍ͯͭʹݯى‬ͷ‫͋Ͱڀݚ‬ΔɻͦͷΑ͏ͳ෺ཧʹ͓͍ͯɼզʑ͕ઃஔ͠
ͨ DCal ͳͲΛ‫ؚ‬ΉΧϩϦϝʔλ‫ݕ‬ग़‫܈ث‬͸େ͖ͳҖྗΛൃ‫͢ش‬Δ͜ͱ͕‫ظ‬଴͞Ε͍ͯΔɻ͞Βʹ͸ɼδΣοτਤ 17: ΧϩϦϝʔλ‫ݕ‬ग़‫༻ث‬ɼLevel-1 τϦΨ૷ஔ STU(Summary Trigger Unit)ɻ
τϦΨޮ཰౳ͷධՁΛߦ͍ɼτϦΨγεςϜ͕ਖ਼ৗɾ҆ఆʹಈ࡞͢Δ͜ͱΛ֬ೝͨ͠ɻ
ਤ 18 ͸ɼ2015 ೥ͷԖɾԖিಥ࣮‫͚͓ʹݧ‬Δ DCal ‫ݕ‬ग़‫Ͱث‬ಘΒΕͨδΣοττϦΨσʔλͰ͋Δɻࠨଆ͸ DCal‫ݕ‬ग़‫Ͱث‬ͷΫϥελʔΤωϧΪʔ෼෍ΛϛχϚϜόΠΞ
ετϦΨ (kINT7) ͱδΣοττϦΨ (DJ1) ͰಘΒΕͨ΋ͷΛॏͶͯϓϩοτ͍ͯ͠Δɻͦͷ྆ऀͷൺ͕ӈଆͷਤͰ͋ΓɼϛχϚϜόΠΞετϦΨʹର͢ΔϦδΣΫγϣ
ϯೳྗ͕͓Αͦ 200ɼ·ͨઃఆͨ͠ᮢ஋͔Βͷ্ཱ͕ͪΓɼ໿ 30 GeV ʹͯฏୱͳ෼෍ʹͳ͓ͬͯΓɼͦΕΑΓߴ͍ΤωϧΪʔྖҬͰ͸τϦΨޮ཰͕΄΅ 100 %ʹୡ͍ͯ͠Δ͜ͱ͕ࣔ͞Ε͍ͯΔɻ

ͱ QGP ഔ࣭ͱͷ૬‫༻࡞ޓ‬ɾԠ౴ (medium response)ɼ
͓Αͼ c, b ΫΥʔΫΛ‫ؚ‬ΉॏΫΥʔΫϋυϩϯͷ෺ཧͷ৽ల։΋‫ظ‬଴͞ΕΔɻ͞Βʹɼ2019೥͔Β͸ LHC ͷୈ 2 ‫ظ‬௕‫ظ‬γϟοτμ΢ϯ (LS2) ͕ߦΘΕɼALICE ͷେ‫ن‬໛ͳΞοϓάϨʔυ͕ߦΘΕΔɻ1 ͭ͸ GEM Λ࢖ͬͨ TPC ΞοϓάϨʔυɼ΋͏Ұͭ͸ MAPS ‫ݕ‬ग़‫ٕث‬ज़Λ࢖ͬͨ ITS (γϦίϯ‫ݕ‬ग़‫ )ث‬ΞοϓάϨʔυͰ͋ΔɻͦΕΒʹΑΓɼ50 kHz ϛχϚϜόΠΞεࣄ৅ͷ࿈ଓಡΈग़͠Λ࣮‫͠ݱ‬ɼ͜Ε·Ͱͷ 100 ഒͷσʔλಡΈग़͠Λߦ͍ɼτϦΨ͕೉͍͠ࣄ৅

(ྫ͑͹νϟʔϜϋυϩϯͷ่յ) ͳͲΛ༨͢͜ͱͳ͘‫ه‬࿥͠ɼղੳΛߦ͏͜ͱ͕ՄೳͱͳΔɻ͜ͷߴ଎ಡΈग़͠ͷΞοϓάϨʔυ͕ɼO2 ϓϩδΣΫτ (Online-Oﬄine

computing) Ͱ͋ΔɻՃ͑ͯɼલํϛϡʔཻࢠରଌఆʹ͓͍࣭ͯྔ෼෍ΛΑΓਖ਼֬ʹଌఆ͢Δ͜ͱΛ໨తͱͨ͠

MFT(Muon Forward Tracker) ϓϩδΣΫτ΋ਐߦதͰ͋ΓɼRun-2 ͷ‫ؒظ‬தʹΞοϓάϨʔυΛߦ͏ɻTPCɼ
ITSɼMFTɼO2 ͷΞοϓάϨʔυʹΑΓɼϨϓτϯର(Ծ૝೤తޫࢠɼ೤తిࢠରɼΫΥʔίχΞ) ͷߴਫ਼౓ଌఆ͕ՄೳͱͳΔɻ͞Βʹɼ௒લํͷ௚઀ޫࢠɼϋυϩϯɼ

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δΣοτΛଊ͑ɼલํͷ෺ཧΛ৽‫ن‬։୓͢Δ৽͍͠ϓϩδΣΫτ FoCal(Forward Calorimeter) ΋࢝ಈதͰ͋Γɼ[12] The CMS collaboration, Observation of longrange, near-side angular correlations in proton-೔ຊάϧʔϓͷ‫د‬༩΋େ͖͍ɻߴԹ QGP ෺ੑͱͦͷੜ

proton collisions at the LHC, JHEP 09 (2010) 091.

੒‫ݯى‬ղ໌ʹ޲͚ͯɼզʑ ALICE ೔ຊάϧʔϓ͸ɼࠓ‫ ޙ‬ALICE ࣮‫΁ݧ‬ͷߩ‫ݙ‬Λ͞ΒʹߴΊɼ৽͍͠෺ཧΛਪਐͯ͠Ώ͘ɻ

ࢀߟจ‫ݙ‬

Production in the Quark-Gluon Plasma, Phys.
Rev. Lett. 48, 1066, Published 19 April 1982; Erratum Phys. Rev. Lett. 56, 2334 (1986).
[14] ALICE Collaboration, Enhanced production ofmulti-strange hadrons in high-multiplicity protonproton collisions, Nature Physics 13, 535-539[1] http://aliweb.cern.ch/.
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3, S08002 (2008).
[3] ࢤ֞‫ݡ‬ଠ, தᑍୡ໵, ‫ ୎࢘܊‬ʮLHC-ALICE ࣮‫ݧ‬ͷॳ‫ظ‬੒ՌʯߴΤωϧΪʔχϡʔε 32-1,6 (2013).

[4] http://alice-j.org/.

(2017), DOI: 10.1038/NPHYS4111[15] H. Yokoyama (for the ALICE Collaboration), Measurement of Inclusive Charged
Jet Production in pp and Pb-Pb colli√
sions atsN N =5.02 TeV with ALICE,
Nucl.Part.Phys.Proc. 289-290 (2017) 109-112,
DOI: 10.1016/j.nuclphysbps.2017.05.021[5] Courtesy of ALICE Collaboration.
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PHENIX collaboration, Nucl.Phys. A757 (2005)
184-283, DOI: 10.1016/j.nuclphysa.2005.03.086[7] STAR Collaboration, Experimental and theoretical challenges in the search for the quark
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10.1016/j.nuclphysa.2005.02.130[13] Johann Rafelski and Berndt Müller, Strangeness

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