197■談話室CERN Summer Student Programme 2016
Ã¼èØÝØÝƳ ņÝŖšŝì » Ę űkawaguchi@hepl.phys.nagoya-u.ac.jp
2016 ò 10 Ě 24 ē Lq ǆ Lg )ľß*ĝƁ=<#

1 はじめに' COMPASS$*ǆàÛexclusive(ŇĄ<;Deeply Ŝ*6Ě27ē 99Ě2ē)10ƥưǆCERN Summer Student

Virtual Compton Scattering (DVCS)ƨş$; µp → µpγ

Programme 2016 (¶«ğhxLto$*ǆÀ£Ƭ$

ǄÍ1ǅ>ň#Generalised Parton Distribu-ķƛ;|ĸ)Ŗšŵ(8;Ƒų>º:ǆCERN$Ɓ=tions(GPDs)(AKUTǆ Lq >ľß;%>ŏĉ#<#;łß)àǂLv{h(ąé#ę©Ů)Ŗš(Č=;%$3ǆĩ'Î

9ƶ3!ŧ300);GPDs*d{]y)ůƧ®ƭ%)d{]y)ůƧ
®ƭ(ÑŐ'ƹ(;Ű)őƱ>

;5ǆ Lq )ÝŇ%ĸ>;%$ǆ×)ƕƫ'ǂ>ù;%Ɖţ>½ŷ(;COMPASS$*Ħnr{Gye{o$ğhxLto$)Ňķ7ķ®â(" #~(%ĻĴŨW{NZ]>ňǆ µp → µpγ )û£đƹŠÓÅ;

>ľß#; µp → µpγ ·ý(*DVCSƨş%*¦(Bethe-HeitlerƨşÜÏ;ǄÍ1ǅĦnr{Gy2 活動内容

e{o>ň2.1$<>ľß;%$GPDs0)AKUT½ŷ(Lectures / Visit hxLto©³)Ĝư)6Ě27ē

98Ě5ē)ư(*ǆ²©(Ƒų!)â*ǆŨťÛņƐ)Òř

;%$DVCSƨş("#)Ƽ)4>Ć¢';9Ú

3:ǆĥ¢É7«ƣÉ)Ū4ǆ]uI{7Rnrw{Rsy)ĒĶ'&ǆ%#6ñó

£Ƭ>Hc{ǆàƵ(CERN$Ŗš# ;ŅÔ)Ŗšŵ )žƎ(8;Ƒų!
 3ǆhxLtoĜư(ATLAS)Oy]x{vv{o7CERN)¥ı)«ƣÉ$;Synchrocyclotron'&)ƅÝ
Í 1 𝜇𝜇𝜇𝜇 → 𝜇𝜇𝜇𝜇𝜇𝜇 )·ýí DVCS ƨşǆ¾ Bethe-Heitler ƨ

6Ɓ=<ǆ<96àâ$!

ş>Ś#;



2.2

研究活動

 Ŝ*CERN)hwz@ZPyÐ°(;Super Proton
Synchrotron (SPS)>ňCommon Muon and Proton Ap-paratus for Structure and Spectroscopy (COMPASS)àǂ[1](¶«
2.2.1 COMPASS COMPASSàǂ$*DVCSƨş)ľß)5(2012ò(e{o>ňĥ¢É)®ĥƋ>Ɓ2016ò9Łņ)5)\{W¸ƶ>ƯÚ2016ò)COMPASS)àǂ
UZ]AZh*Í2)8$;COMPASSàǂ$*ǆSPS

$450 GeV3$«ƣƴÛ>´500 mm)iuuDo
W{NZ](ƂŢ;%(8!#ŇĄ;160 GeV)
Ħnr{Gye{o>ň  ĤÛĈ")Tfy*ĤÛ)ĨƤ8:ǆ;<>´2.5 m)ĻĴŨ

W{NZ](ƂŢǆ àǂ>Ɓ!#1 1= ΔΣ + ΔG + Lq + Lg
2 2;W{NZ])}ĸ(*ǆk^TO{h(8;e{oƧ®ƭ£ġŦ:ǆ%ƃ%$;$ ΔΣ % ΔG *ǆ<<~ĸ(*TjK]xp{W{ƸŘŕǆƿƘľßÉŲǆRICH

KF{K%Lv{Gy)Tfy)ä$; Lq ǆ Lg

(8;ťÛƒ¦ǆƸŘ8-b^xyHxup{W{%*ǆKF{K%Lv{Gy)ƜƩƇƧ®ƭ>ƃTfy

nr{Gyĥ¢É>

ı)TjK]xp{W{

KtCRT%#Ŕ9<;8;

(ǆ1988ò)EuropeanMuon Collaborationàǂ$KF{K)Tfy)äā
<#8:æ%ŬĢ[2]Çƾ%'!#;

198#3$Ŝ*W{NZ])}ĸ(ƊŰ#;SciFiǄÍ2)SI01, SI02, SI03, FI01, FI15, FI02ǅ$9<e{o[wTO{h9ù9<;\{W>ň#ǆe{o)W{NZ]ƪ( ;üŰ>ĵ5;%()ŬĢ>Í4(Śy [cm]y versus x (beamtracks) random trigger
xypEntries
198100Mean x− 0.2515
Mean y− 0.1329
Std Dev x0.794
Std Dev y 0.7602

43211008060

040−1−220−3−4−4−3−2−101234x [cm]0Í 4 W{NZ]ƪ)e{oŰ£ïÍ 2 2016 ò) COMPASS )UZ]AZh}Ǉ}ĸƪ£ǆ~Ǉ )£ï> x Ɲ("#IDTƱĎ$gBZ[ByL#ĵ5e{o)üŰ* x = −0.24 cm $!<~ĸƪ£)Í$:ǆƮ* 50 m 2&(';

8:ǆe{o)üŰ%W{NZ])üŰŋ';

%=;ÓÅǆe{oƝ> x ĒÄ( x = 0.44 cm Ş®;%#e{o('!)ƈġ(8!#e{o)Ű>čÈ;% )$Ŝ*2016ò)\{W¸ƶįƁ=<#&>ŗ

5;5(ǆù9<\{W>ňŰ)AtCpy]%ǆnr{Gy}ĸ)RyYw{Rsyg@Cc{ĥ¢ÉǄSciFiǅ>ƢƨĖ¨>ŗƍĥ¢É)®ŗƍ)5(¹ù2012ò)\{W>ň

$
2.2.
 Ĭ(Ŝ*nr{GyW{NZ])}ĸ(;SciFi>Ƣ

ŬĢ%Ĳƞ;%$2016ò)\{W¹ù)Ńăŗƍ
$

2.2.2

ƨĖ¨>.")ĒĶ$ĵ5,%"ŏ)ĒĶ*~ĸ(;k^TO{h(8;]uI{)WCnyL 9nr{
GySciFi>ƢƨĖ¨>ċľ;ĒĶǆ."ŏ*SciFi Ŝ**5(ǆW{NZ])}ĸ%~ĸ(y)ƿƘ)Ŀ'ƹ(!)$ǆ)%>COMPASS)n{[ByL$;nr{G9W{NZ])ƪ$)e{oƝ(ÑŐy [cm]XYVertex
Entries
64538
Mean x− 0.2266
Mean y− 0.103
Std Dev x0.8224
Std Dev y0.7452

23525

020−115−210−35−3−2−1Í 3 e{oƝ(ÑŐ'ƹ(012ǆ]uI{(!

Ɣ)ÔÁ*tyXo'|ĩ£ï%';)ƈġ$*ǆVg

4030

1−4−4('!¿)ÔÁ)nr{Gy%*¦)nr{GySciFi(§ĠŶė

Vertex x-y distribution
38!#ĵ5Ė¨)î*Í5)8Ė¨)î)£ï* 0 ns (f{K>Ĉ

;e{o)ëÕĿ)£ï>ĵ5 (Í3)
4>ƢƨĖ¨>ľß;ĒĶ$;).")ĒĶ(34x [cm]]DEA( ;ƿƘĨĄ)ñ> −5 ns

9 5 ns %#;5ǆÍ5$* −5 ns

9 5 ns )ư(ŶėƔ)£ïó;2016ò)ŬĢ%2012ò)ŬĢ>Ĳƞ;%£ï)f{K)ñ2012ò8:62016ò)Ēó!#;%=;

0;e{o)ëÕĿ)£ïÍ3) x = −1.8 cm Ɵ)Ciy]Ď×ƪ£*ǆĻĴ

ŨW{NZ])kvX{)Ű%|Ź#;W{NZ])  ü (x ,y) = (0.2cm,− 0.1cm) ( å  # í  ) 4 ( W {NZ])kvX{ƅ# ;% 9ǆe{o)üŰW{NZ])üŰ 9í(<# ;%= ;
e{o)üŰW{NZ])üŰ9<#;%ǆ1#)e{o>ě¬(ň$' 5ĥ¢¬ńƀ

Í 5 ]uI{%ĥ¢É$ľß<Ėư)î)£ïí 2012ò)ŬĢǆ¾ 2016 ò)ŬĢ199ēğ)ď¯(źÆ>Ĉ!# )µË>ŢĮ5;5(ǆŜ*ǆSciFi)ÀYqya

Ǝ>­õ# ;%v("Ǝ$ƌ#)Ėưî)£ï>ƏģǄÍ6ǅTime [ns]hFI02Ychan
Entries
3231091
Mean x
53.32
Mean y− 0.1596
Std Dev x
17.48
Std Dev y
3.334

1510

1600
1400
1200

5
1000
0800
−5400

−15
P

:ǆ|ŭ(BBQ>Ɓ!:#×)Ėư

>|ŭ(ƨ$ǆPm{TYr{\y] )ŠĦĀ(*ô6ǃ<¥åƹ$6ƚƙ'ƌ #;$*'ǆŸ£)źÆ;%(Ʊ;ĩ'Ciy]>Ÿ£ $ŉ#àƁ#  ǂ200020406080

ũ=!#;YqyavŊ¿%Ėưî)ƱÍ6(ǆ ";8)f{KŰ2)$Ý?ŠĦĀ7÷9%Ť

0100Channel

Í 6 ; SciFi (9=9<;%:ǆ%#6ǃm{TYr{\y]%Ɵ)Srtê(bCJyL(¢

×600−10−20Pm{TYr{\y]6 #ǆēğ3ǆē(6÷9%Ɓ®;%×ǆ)8

Mean time distribution vs channel number (FI02)
20;6×ǆ(*ēğ96Ø¤(#Ʊ>)hxLto%Ă)Yqyav$Ėưî£ï)Yqyav(Ĳ1#<#;)8 'Yqyav*SciFi)(2 (6ÜÏ# 
<*SciFi)AtCpy]

3!#'%µË$;½ŷĀ;İþ'9ğhxLto)ũ=:
Ġ#3!5ǆ)%("'#ļơĵ;%$!ǆ)ƈġ(8!#SciFi)AtCpy](Ʊ;ƓƐÚ3!

Í 7 2)Pm{TYr{\y]

%ƥĞ( CERN )Ɵ)

 T{d{cCQ{7COMPASS)ƈġLv{h)pyc{Srtê(bCJyL(Ɓ!%)¡Œ%|"|"ƓƐ'9Ŗš>Ʀ5;%$)*%

に#6ƕƫ'ūǂ('! ğhxLto(¶«#Ý?|ŊØ'%*ŠĦō活(®%)ƫƄĀ$;<3$)Ÿ£(" Ƒų);©³)Ĝư$*ǆ²©*2)Pm{T%ǆn{[ByL'&$£9'#Ŵ;%!#6ǆƌ>

Yr{\y] %Ƒų>ºǆĕǀø(<<)ŖšÔ

#ą(Ş®ǆ19Ėƻ3$Ŗš>3ǆƑų)'œư(*Ĭ)ƓƐÚ3!# #ǆĺ¯Ž(';%ç)Ĝư(*ǆ²©ø³9<<)ŖšÔą$Ŗš>Ɓ!

;ƌũ

''

9ŗƍ8%Ŵ

#5ǆĬ)!<(Ĳ1#ǆCERN $¢!

()5ǆĜư>Ƣ#4;%COMPASS)pyc{*ǆŌÇ(Ă9(ƖÇ;ŠĦĀ;5ǆn{%ƨĖư|Ŋ×'!

[ByL7Ŗš(ķĳŇ3<ǆOnr`M{Rsy6±£

 COMPASS*ǆATLAS7CMS'&(Ĳ1ǆæƆĪ'à(¹<# ;8 (Ă$Ý?ŠĦĀ>ø)Ÿ

ǂ$ǆ¶«Pm{TYr{\y]63%ç'ǆ)£)Ŗš$6Ň£×)COMPASSpyc{%ļƱ=;%$ Ŝ*ǆ)ī>Ƣ#×)%>Ý/%$Ê*Ŝ(%!#ĹÖ$Ŗš>;¥5#)ī!)$ǆĠòƲ6ǆòÂĩ(ǆÝŇ()hxLto(¶«;

CERN(Ġ;©*Þ×ī>!ǆCOMPASSpyc{*#ĭ#%ÿ!#%ÿ!#;

;#ǆ×)ÝŇƌ #<;+ :$ǆŸ£$ćö# ;ĥ

)hxLto>ǂ#Ÿ£)$Ý?$ĭ%ÿ

¢É(" ęø(':3ǆ×)Ē)$)#)Un_{>ƽŊ(Ư#<;'&ǆĔ;ªĽ)ƷÌĳ)$ħÝ/%$3ǆŖšø(pyhxLto(¶«;%$ǆàē>ƨc{$BBQ>:ǆT{d{cCQ{)á$k{od{%$3)Ô>[B{>;%6!

#ƺ3

Ŗšũ=!#ãŻ(ð!##9)Ėư*Pm{TYr{\y] %)ĸ)Ėư$ǆ)Î)Đņ>Ÿ£$!#|ŭ(ǀ1;%6×ǆŜÙ4ŀ>

!#Ċż!:ǆHvl_{t7ſ>ǁƗ('!::#ǆŎĩ(úś>Ơ1

[1] P. Abbon, et al., Nucl.Instrum.Meth. A 577 (2007) 455[2] J. Ashman et al., Phys. Lett. B206 , 364 (1989)