HIAF上EIC物理综述

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Transcript HIAF上EIC物理综述

HIAF上EIC物理综述
陈旭荣
中科院 近代物理研究所
EIC物理研讨会,威海 July 28 – 30, 2013
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提纲
• 引言
• [email protected]物理目标综述
• [email protected]模拟和探测器
• 结论
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什么是EIC
极化电子
p
极化质子
ee+
极化正电子
重离子(Au)
极化轻离子D, 3He
① 当与质子对撞时,点状电子像一个小的探头,对质子内部进行扫描
② 更具体地讲,电子穿透质子,碰到质子的一个组成部分-夸克。夸克从
质子中撞出,变成一个新的粒子喷注,这些新的粒子沿着电子和质子
的碎片向所有方向散射
③ 这些粒子在探测器中留下的轨迹使物理学家们就质子内部发生了什么
变化得出结论
④ 这可视为“超级电子显微镜”,它提供世界上质子内部最清楚的图像
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Theory @ EIC
Lattice
Gauge Theory
Condensed
Matter Physics
(B-E Condensates,
Spin Glasses
Graphene)
High Energy
Physics
(LHC,LHeC
Cosmic Rays)
EIC计划
 目前,国际核物理界几乎已形成共识:电子重离子对撞
机EIC将是研究核子、原子核内夸克胶子分布的最有效
设备
 美国、西欧都建议建造此对撞机
 EIC将是世界高能物理和核物理学界研究强子物理和核
子结构下一代最主要的加速器装置
 十二五大科学装置-强流重离子加速器装置(HIAF)预计于
2019年建成,中科院近代物理所在此基础提出了建设中
国EIC的计划
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世界上主要EIC实验-分布图
[email protected]
LHC  LHeC
RHIC  eRHIC
CEBAF  MEIC/EIC
HERA
FAIR  ENC
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Lepton-Nucleon Facilities
[email protected]: e(2.4 GeV) +p(12 GeV), both polarized, L = 4 x 1032cm2/s
HIAF
[email protected] Kinematic Coverage Comparison with JLab 12 GeV

e(2.4 GeV) +p(12 GeV), both polarized, L = 4 x 1032cm2/s
[email protected]:
study sea quarks (x > 0.01)
deep exclusive scattering at
 Q2 > 5-10
higher Q2 in valance region
[email protected]的实验比JLab的动力
学范围更广
在较大的x范围内,不但可以给我
们价夸克的分布函数的信息,还能
给我们提供海夸克,以及胶子的分
布函数的信息
能更有效地验证各种夸克模型,
帮助手征微扰论确定其低能常数,
最终给我们揭示更全面的核子的内
部结构
[email protected]特性
 [email protected] 第一期(3GeV e X 12 GeV p) x主要区间为
[0.01,0.1],这个区域胶子还没完全掩盖住海夸克, 是研究
海夸克的最佳窗口。EIC的实验不仅能能给我们提供价夸克
对核子性质的贡献,也能给我们提供海夸克和胶子的贡献
 在核子结构方面,它的主要优势在于能够给我们很多PDF
,GPD和TMD的信息
 With the parameters (energy, luminosity and polarization)
of this machine, it will be the best machine in the world for
hadron physics before the full EIC. EIC may very well
have good advantage over any existing facilities:
1. The energy reach of the [email protected] is higher than JLab
12GeV but lower than the full EIC being considered in US
(at about the lower end)
2. The main theme for JLab 12 GeV is the study of the
valance quark structure (and confinement)
3. The main theme for full EIC is to understand the glue
4. HERA只有ep,没有eA;无极化,亮度低(1031)
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J P Chen
HIAF上EIC(I)可实现的物理目标
实验条件:e(3GeV) +p(12GeV) ,双极化, 亮度:1032~33cm2/s
 核子结构
① 部分子味分布和自旋分布(一维)
② 核子三维结构 (TMD,GPD)
 核效应
 eA散射过程中的强子产生
 其他?
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Spin-Flavor Study at [email protected]
 Unique opportunity for Δs
 JLab12 GeV energy not high enough to have clean Ds
measurements
But, [email protected], combination of energy and luminosity:
 By semi-inclusive DIS, in particular, for Kaons , will help to
identify strange quark helicity
TMD Study at [email protected]
 Unique opportunity for TMD in “sea quark” region
 reach x ~ 0.01 (JLab12 mainly valence quark region, reach
x ~ 0.1)
 Semi-inclusive DIS, for charged hadrons, to measure TMD
sea quark distributions
 Charm-pair production to measure TMD gluon distributions
 Significant increase in Q2 range for valence region
energy reach Q2 ~40 GeV2 at x ~ 0.4 (JLab12, Q2 < 10)
GPD Study at [email protected]
 Significant increase in range for DVCS
 Extend the kinematics covered by JLab
 Unique opportunity for Deeply virtual meson production
(DVMP) (pion/Kaon)
 flavor decomposition needs DVMP energy reach Q2 > 510 GeV2
 JLab12 energy not high enough to have clean light meson
deep exclusive process
 which is the case for [email protected] design
Golden Measurements at [email protected]
1. To measure strange quark polarization in kaon Semiinclusive DIS production
2. TMD Sivers function in Semi-inclusive DIS, Q2 evolution, etc.
3. DVCS/DVMP, to measure quark orbital angular momentum
4. Quark propagation in medium to compare with heavy ion
collisions
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[email protected] meeting
 The 2nd International workshop on QCD and Hadron
Physics, March 30-April 3, 2013, Lanzhou
 QCD and hadron physics
 EIC Physics
 [email protected]
[email protected] meeting
• The 2nd International workshop on QCD and Hadron
Physics, March 30-April 3, 2013, Lanzhou
• Not only the previous four experiments were re-affirmed
as good candidates for golden measurements, but also
two more ones were added
• Adjustability of beam energy is needed for flavor
separation of GPD study (which is the case for [email protected]
design)
• We decided to do simulation and whitepaper at once, and
should be done before July 2013
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Two More Golden Measurements
 Craig Roberts:
 Pointed out the importance of higher Q2 [email protected]
will provide (comparing to JLab12), which are
essential for clean measurement in the valence
quark region
 Suggests: (5) the pion and kaon structure
function measurment, which can be a benchmark
experiment to test non-perturbative QCD
calculations
 Eli: (6): EMC-SRC measurement:
which will be a high impact experiment
if [email protected] can make precision
measurement
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[email protected]强子物理
 在[email protected]上可开展强子物理研究
 [email protected]的能区可以产生某些粒子,和其他实验相比,
由于产生道的不同,能够加深对其性质的认识
 可以与目前我国正在运行的正负电子对撞机形成互补
 在EIC上我们可以开展以下研究:




奇特轻介子态
粲夸克偶素和类粲夸克偶素 (XYZ)
粲介子
核子及重子共振态
隐粲核子共振态:在电子与核子碰撞过程中,通过交换一
个光子可以在核子中拉出一个粲夸克对,从而形成一个隐
粲核子共振态,因此EIC是研究隐粲核子共振态的理想装置
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EIC模拟
JLab/RHIC等已经开发了很多EIC模拟软件
 物理过程模拟
e+p collisions:PYTHIA6, HERWIG, LEPTO, PEPSI,
RAPGAP, ARIADNE , CASCADE , SHERPA
eA collisions:DPMJET (DIS过程)
 EIC探测器模拟
eic-smear A package for apply very fast detector
smearing to Monte Carlo events.
ESIM: An eRHIC detector simulation using GEANT3.
Geant4: C++ detector simulation
FLUKA: Fortran-based transport code, including a
graphical interface (Flair)
Jlab/RHIC EIC模拟已经很成熟
Simulation Progress
 Xiaodong Jiang's group (Los Alamos) is doing the sea-quark
polarization simulation and it has been done
 The TMD simulation is done by Haiyan's group (Duke). The
plot is being finalized.
 The GPD group (Saclay/ODU/JLab) is doing the GPD
(DVMP with pi/K) simulation, they are trying to produce
results
 Paul Reimer (Argonne) is doing the pion structure function
simulation. Craig has produced first draft of a write-up
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The TMD simulation: Projections for SIDIS Asymmetry π+
By Haiyan’s group
[email protected] may reach the same precision with SoLID
Exploration of the sea quark Sivers function will provide, for the first time,
the unique information on the spin-orbital correlation in the small-x region
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Simulated errors for pi structure function
measurement
By Paul E. Reimer
• Simulated errors for DIS events using a 3 GeV electron
beam on a 12 GeV proton beam with a luminosity of 5 x
1032 cm−2 s−1 and 106 s of running. A precise result could be
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obtained on the domain x <= 0.9
EIC探测器设计考虑
 EIC探测器的设计应当根据物理目标来决定。针对不同的物理目标,
进行全举、半全举和单举测量。需要探测的粒子包括光子、中子、电
子、质子和π介子等。
 根据[email protected]的物理目标,要求谱议满足以下条件:粒子辨别(PID)
(e/π/K/p);测量散射电子的能量和角度;测量强子末态;高动量分
辨率;粒子测量和光子测量等
 [email protected]应当根据自身的物理目标和要求,开发相应的探测器。我
们将开展国内外合作,不断优化谱议设计
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[email protected]子探测器和电子学
1.
2.
3.
4.
5.
6.
7.
8.
时间飞行器(TOF)
电磁量能器(e,γ能量;位置)
切伦科夫(e, π ,K鉴别)
Tracking (GEM)(所有带电粒子径迹位置、动量)
漂移室(顶点位置)
超导磁铁
μ子探测器
电子学
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当前计划
1. 陈剑平正在组织[email protected]的六个”golden measurements”
物理模拟工作,即将完成
2. 下一步是探测器模拟
3. 陈剑平,邱健伟和袁锋等人正在撰写[email protected] 英文版白
皮书。第一版本很快完成
4. 参考英文版,国内专家撰写中文版的白皮书
5. 需要整个国际高能物理学界,特别是中国高能物理学会和
国内外华人共同努力,推动[email protected] 项目,以及模拟和
白皮书撰写工作
6. 定期召开EIC研讨会,以及理论进展,模拟,加速器和探测
器设计等方面的讨论会
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HERA模式” 的国际合作:如何解决经费问题?
 建造HERA是一个大型的国际合作,共有11个国家参加了建造,在粒子
研究历史上属于首次
 以前,在国际合作的框架下建造大型探测器很普遍,建造加速器本体则
是本研究所自己的责任
 但是,国际上对HERA的兴趣非常之大,法国、意大利、以色列、加拿
大、荷兰和美国的研究所提供了装置的主要部件和为主要部件支付费用
,或进行重要的测试。英国、波兰、捷克斯洛伐克、中国和前德意志民
主共和国及德意志联邦共和国的研究所派专家协助工作。有不少于45个
国外研究所和320家公司(合同金额超过25,000欧元)参加了这一工
程的建造
 HERA加速器所须经费20%以上来自国外,HERA实验约60%的经费也
来自国外
 这种“HERA模式”的国际合作非常奏效,现在已成为大型国际研究项
目的榜样
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结论
 EIC将是世界高能物理和核物理学界研究强子物理和核子
结构下一代最主要的加速器装置
 EIC可被视为“超级电子显微镜”,它将提供世界上核子
内部最清楚的图像
 [email protected]为我们研究和理解核子结构,特别是海夸克,
开辟了一个新的窗口
 [email protected]装置将使中国对宇宙中可见物质的深层结构和
形成的研究走在世界前列(预期10年内世界领先)
 中国物理学家,尤其是理论物理学家已在这方面做出了大
量的工作, [email protected]将是实验物理学家大好机会
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谢谢大家!