夸克子、奇异星、及夸克物质Quarks, Quark Matter and Strange Stars

Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,夸克子、奇異星、及夸克物質,Quarks,Quark Matter and Strange Stars,朱明中,香港中文大學物理系,夸克子,(quarks),與,強作用力,(strong force),夸克子之,禁閉,(confinement),發現夸克子,:,高能電子,-,核粒子散射實驗,(deep inelastic electron-nucleon scattering),夸克物質,(quark matter):,重塑宇宙之初！,奇異星,(strange stars),中大相關研究,夸克子,與,強作用力,Quarks and strong force,夸克子,與,強作用力,強作用力,(strong force):,四種基本力之一,主控核粒子,nucleons,（及所有強子,hadrons,）之相互作用 如質子,protons,，中子,neutrons,介子,mesons,，,K,介子，粒子,Ref.:,Serway,Moses,Moyer,Modern Physics(Saunders College Publishing,1996),D.H.Perkins,Introduction to High Energy Physics(Addison-Wesley,1982),短程,(10,-1,5,m),，,強（重,弱 電磁2,mc,2,q,q,漸近自由,Asymptotic freedom,強荷隨夸克距離而改變,(running coupling constant),長距離時強荷強,相互作用大,禁閉,夸克,/,膠子短距離,(m),相互作用微弱,自由夸克,/,膠子,D.Gross,H.D.,Politzer,F.,Wilczek,於一九七三年發現,高能電子,-,核粒子散射實驗,deep-inelastic electron-nucleon scattering,盧瑟福散射,(Rutherford Scattering),以高能粒子撞擊目標，從散射情況得知目標結構,盧瑟福以高能,(20000m/s),粒子撞擊金箔，發現有少數,(1/20,000),粒子被大角度散射，得知原子內有細小而堅固的原子核,盧瑟福並已推測中子,(neutrons),之存在,http:/www.physics.brown.edu/Studies/Demo/modern/demo/7d5010.htm,Geiger,Marsden,Rutherford 1910-14,盧瑟福散射,(Rutherford Scattering),查德威,(Chadwick),用更高能撞擊把原子核打破，釋出中子及質子，證明中子之存在,(1932),原子核半徑,10,-14,m,，核粒子半徑,10,-15,m,，皆遠小於光波長，必需用高能粒子,鈹箔,核子偵測器,中子,氮核子,高能電子散射,粒子愈高能，愈能感應微細結構,更高解像度,(resolution),研究核粒子結搆,用更高能電子（沒有強作用）,SLAC-MIT,研究組於,1966-1978,利用幾十億電子伏特,(20GeV),能量之電子撞擊核粒子,發現大角度散射遵從盧瑟福散射,費曼,(R.Feynman):,核粒子內有質點,(point particles)=,“部份子,(,partons,)”,夸克子,史丹福線性粒子加速器,Stanford Linear Accelerator,SLAC,Photos Courtesy Stanford Linear Accelerator Center.,www.slac.stanford.edu,/,3km,R.Taylor,J.Friedman,H.Kendall,Nobel Prize in Physics 1990,“for their pioneering investigations concerning deep inelastic scattering of electrons on protons and bound neutrons,which have been of essential importance for the development of the quark model in particle physics.”,Photo courtesy SLAC,http:/www2.slac.stanford.edu/vvc/nobel/1990nobel.html,自由夸克何處尋,?,夸克物質,(Quark matter),高能重離子碰撞,Ultra-relativistic Heavy-ion collisions,QCD,理論預測高溫或高密度時強荷變弱,至高溫或高密時可釋放夸克,:,相變,(,phase transition,),如液態水,蒸氣,T,核子物質,夸克物質,T,c,T,c,140,MeV,10,12,K!,Figures courtesy Brookhaven National Lab,http:/,www.bnl.gov,/RHIC/,R,elativistic,H,eavy,I,on,C,ollider,Brookhaven National Lab,NY,實驗於,2000,年開始,重離子（至鈾）加速至,200GeV/n(,v,=0.99995,c,),對撞，於極短時間達至,10,12,K,，重塑宇宙初開狀況。,1km,Figures courtesy Brookhaven National Lab,http:/,www.bnl.gov,/RHIC/,粒子加速管道,其中之一個粒子探測器,STAR,Photo downloaded from,http:/www.star.bnl.gov/,Photo downloaded from,http:/www.bnl.gov/rhic/fascinating.htm,Au on Au,Downloaded from Brookhaven National Lab webpage,http:/www.bnl.gov/rhic/fascinating.htm,A real event in one of the detectors,Downloaded from Brookhaven National Lab webpage,http:/www.bnl.gov/rhic/full_en_images.htm,製造夸克物質,高能重離子對撞,高溫火球,夸克,膠子漿,(,Quark-gluon Plasma,)?,火球急速膨脹、降溫，夸克物質只維持約,10,-23,s,夸克,膠子漿冷卻至,T,3,M,o,),死亡時必經,超新星,爆炸,(,supernova,),恆星大部份物質拋出太空，剩下核心形成致密星,(1.5,M,o,R,10-100 km),超新星爆炸,Animation courtesy Bryan Preston(,STScI,/AVL),SN1987A,超新星,1987A,Photo courtesy Anglo-Australian Observatory,M1,蟹狀星雲,Crab Nebula,Photo courtesy NOAO,Animation courtesy NASA/CXC/ASU/J.Hester,et al,.,downloaded from,http:/chandra.nasa.gov/,Chandra X-ray,HST,Pulsar/compact star,蟹狀星雲,M1,M1,之脈沖,拍於中大,傳統理論,:,致密星,=,急促自轉中子星,neutron star,http:/www.fourmilab.ch/earthview/vplanet.html,50km Photo credit:NASA,尋找奇異星,(strange stars),奇異星,=u,d,s,夸克組成的星體,理論上高溫高密時比中子星穩定,?,?,若穩定，可以比中子星更細小,(,R,7 km),，而且冷卻極快。,4/2002:3C58,及,RXJ 1856.5-3754,可能是奇異星！,RXJ 1856.5-3754,可見光,Credit:European Southern Observatory Very Large Telescope,Photos courtesy NASA/CXC/SAO,downloaded from,http:/chandra.harvard.edu/press/kits/strangematter/index.html,X-ray,Chandra/NASA,R,11.3 km,太小,!,http:/www1.msfc.nasa.gov/NEWSROOM/news/releases/2002/02-082.html,3C58,Photo courtesy NASA/CXC/SAO,Chandra X-ray,SN1181,遺下之致密星,表面溫度,10,6,K,太冷,!,中大的相關研究,中大的相關研究,在高溫度時強作用物質之性質,強子的夸克結構,(Klaus,Colanero,PhD),奇異星之相變,(,黃嘉華,MPhil,),夸克,強子相變對宇宙膨脹之影響,(,陳文豪、林江，,MPhil,),奇異星 在中大,人,黃嘉華,研究,初步,結論,超新星可以製造奇異星,奇異星急速冷卻變回中子星,相變釋放大量能量,(,潛熱,)10,53,ergs,兩次中微子爆發,中微子望遠鏡觀測,伽瑪線爆發,GRB,源？,夸克子,(quarks),與,強作用力,(strong force),夸克子之,禁閉,(confinement),發現夸克子,:,高能電子,-,核粒子散射實驗,(deep inelastic electron-nucleon scattering),夸克物質,(quark matter):,重塑宇宙之初！,奇異星,(strange stars),夸克子、奇異星、及夸克物質,醒啦！,