about starting the LHC

Transcription

1 about starting the LHC 1

2 Starting LHC (rather slowly) Expand experimental reach significantly Cutting into TeV scale first time. Last chance to solve naturalness problem. We have solid observational evidences on the existence of DM in our Universe. A new particle! future experimental projects are now tied up with LHC discovery, ILC, Super B factory, DM searches...huge responsibility to provide correct scientific results quickly. 2

3 Accelarators are state-of-art technology that human have ever had.!"!#$%&'(%&$)*+,-.-/ Example: an electron flies for 3 hous at KEKB =3,000,000,000Km (! 3 ) Uranus 89 :; <;!"# r0= 2,870,990,000Km...and hitting 2 μm targets each 3 Km! =>?/234567@ABCD-µE$FGAHI=JKLM compare with voyager, which is at 15,480,000,000Km from the sun s )*+,NOPQRS$T;UVWXYZ[\ seeing Heliopause ]^K_`abc?deJfg>h 3

4 LHC experiment 2008 a ２７Km ring for pp collision beam energy 7000GeV X７from Tevatorn Place: CERN (Swiss and France) 1) very clean, very high tech machine over 27Km. Inside must be vacuum. 2) a beam energy corresponds to 100Kg TNT. 3) beam size 16 micron, collide every 25 ns. 4) components comes from all over the world. People from differnt culture must work together 4

5 The incident on Sep 19 original plan 900 GeV collision 10TeV commissioning-> 14 TeV(2009) a failer of electrical connector, He leak (and quenches?). Decided to go into commissioning directly spring at 14TeV(beam earliest in May 2009?) Need investigation and review so that this never happen again. Security first. web.cern.ch/hcc/file/images/magnets_sector34_smaller.png 5

6 What we should avoid (Tevatron example) a year This will be crucial year for LHC. They need support. 6

7 VERY Basics about collider experiments processes, detectors and the aim 7

8 basic process jets Final state radiation Initial state radiation proton proton 8

9 Coordinates 20 degree degree degree 3.1 particle momentum "! interaction point beam direction ( η = ln tan θ ) 2 Transverse momentum is most basic quantity at hadron collider. only parton participate hard process, therefore, the momentum of the beam direction is not known. 9

10 Parton distribution, cross section PDF ---quark and gluon energy distribution as seen by hard collisions. cross section is given as... σ tot = dx 1 dx 2 f i (x 1 )f j (x 2 )σ ij X (x 1 x 2 Q 2 ) X=E_i/ Ebeam x=0.1~1.4 TeV at LHC. parton distribution and cross sections are largest at the threshold of the particle. σ for TeV particle discovery u >d > g for 100 GeV particles g>> u>d new particles will be boosted to one of the beam direction in general. 1/s 2m s 10

11 particles Silicon visible Pixels Detector stable e γ, p, n long lived K (3.7m K0 (2.5cm,15.5m π (7.8m μ(685m) short but vertex visible. ｂ(0.5mm τ(87μｍ charm (...) Vertex detector R=4cm, 11cm 20cm(ATLAS) Pixel detector Support Structure vertex resolution 100μm, essential for flavor physics. Silicon Pixels Detector Barrel η <1.7: radius 4, 10, 13cm σ in r = 12, z = 66 (μm) End-cap 1.7< η <2.5: z cm σbarrel in r η <1.7: = 12, r = 77 (μm) Support Structure 11

12 Poor theorists detector Muon tracker Muon ECAL λ=10g/cm^2 Vertex Detector 12

13 CMS 13

14 detector size to relect the relative number of segmentations (not exact) Tracking Vertex Detector Atras detector commissioning!"#$%&'&(')*+,+-./01+ 2)0$3)* /23&#) ) 689) A256 A) 68A)?;%"#/'(") B%C/%'(")?;%-D3;) E8F256 F) 9) G8H8)>%&(;/.3$3;) 58I5256 F) +%C;("/-) >%&(;/.3$3;) 56 J) 685) M(;L%;C)NO;) EF66) 689) P%;;3&)HQ(") 7256 F) 68F) G"CR-%<)HQ(") E89256 F) 6869) O?NO:! The others Human figure to reflect the relative space of our body parts occuly on the cortex. lips, hands, feet have more sensory neurons

15 A ToroidaL ApparatuS rrently in the final stages of installation and commissioning. Struggling Lari Talk in IPMU 15 15

16 !"#"$#%&! '()'*! +,*!!"#$%&'()*%+,! -.(/0+%$0*,(( L+%'=207"#$%&'( M"+02*7%=%2! Y",20$*'(( M"+02*7%=%2! /*+*'0$(A*B%+CD(/=2*EC((1(.<.(!FE.( G(HBIJ 59 E.( "(JKJI! AN(1(O*PKQ2(Q''02,*0$(!FL(G(IJRFSL("(JKJJT! )%1C'*$&++"=02(F(M>1O*PKQ2(8IJZ;(!FL(G(HJRFSL("(JKJX!!>0$!!FE.( G(-R\HJ]%^(=0(IJR\I.%^( 8_`1!/;! 9.(/0+%$0*,(( /*+*'0$(A*B%+CD(/=2*EC(!FE.( G(IKHBIJ 59 E.( "(JKJJH! ANUV 9 (M2WC="+C(!FL(G(XRFSL("(JKJJX! 32"CC1C'*$&++"=02(8TZ(1('"='[%2;(!FL(G(IJJRFSL("(JKJH!!FE.( G(IR\HJ]%^(=0(IJR\I.%^( 8`.FM/M1.2"'@%2;!.2*##%2! OI(1(<0_5N"C%,(YO.(8O-1L);! OI(1(YO.(8O-(1(OX;! 16 "#! 16

17 Being Hadron collider :A Example. 10 fb^-1 year %. - %/ %. - %/ 4 event /bunch crossing b tag=60% %. - %/ %. - %/ 50% 20%? 20 event/bunch crossing 200event /bunch crossing! ""# µµ$$ $%$&'#(#)*+$#,)#$%$&'-#./0#1*..$0$&'#+,2*&/-*'*$-# 17

18 Numerical study Comphep, Madgraph, ALPGEN,... sherpa CTEQ,... Hard Process LHA parton level momenta Theorists PDF's LHA LHA Herwig, Pythia Hard Process PS and hadronizatios AcerDET, PGS lepton, hadron momenta Fast detector simulation jets, isolated leptons Detector/ Experimental design Simulation of the Interactions of particles with detector Experimentalists GIANT 18

19 about the aim of the LHC 19

20 Direct connection to astrophysics Black hole? A very short lived black hole state at LHC is predicted in extradimension models concern occurred in public side-- gonna eat us? Safety report appear in 2003 and re-evaluated recently. Conclusion: long lived black hole is not consistent with astrophysical observations. The collisions at the LHC energy are not special at all in out universe. (please go to CERN page for detail) Example that all Science is connected. Important example that particle and astrophysics can be connected. 20

21 Maybe Germans are not worried such unrealistic things anyway but... Science and technology development can destroy human, society, etc if it is mis-used. however it does not destroy the earth nor the solar systems. Our big expectation+ vague words to public (like huge accelerator, very high energy beams, something unexpected to happen cause this problem. Be open, precise, scientific to face true mystery of nature. 21