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High Intensity Electron Positron Accelerator Facility
(HIEPAF)Zhengguo Zhao
On behalf of Steering Committee
Collaborative Innovation Center for Particle Physics and Interaction University of Science and Technology of China
Institute of High Energy Physics, CASInstitute of Theoretical Physics, CAS Tsinghua UniversityUniversity of Chinese Academy of Sciences Shangdong University Shanghai Jiaotong UniversityPeking UniversityNanjing University Nankai UniversityWuhan University Hua Zhong Normal University
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Outline
• What project are we proposing ?• What is HIEPAF? • Why do we propose HIEPAF? • Current status
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What Project Are We Proposing?
High Intensity Electron Positron Accelerator Facility (HIEPAF)
• Providing peak luminosity about 1x1035 cm-2s-1 at 4 GeV for physics at tau charm sector, covering Ecm = 2-7 GeV.
• Being a 3rd/4th generation SRF (synchrotron radiation facility).
• Reserving the potential for FEL( free electron laser) study with the long LINAC.
Possible Schematic Layout
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Features of the t-c Energy Region Rich of resonances, charmonium and charmed mesons. Threshold characteristics (pairs of , D, Ds, charmed baryons…). Transition between smooth and resonances, perturbative and
non-perturbative QCD. Mass location of the exotic hadrons, gluonic matter and hybrid.
5t+t- DsDs LcLc
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Physics at t-c Energy Region
_
• Precision DQED, am, charm quark mass extraction. • Hadron form factor(nucleon, , ).L p
R scan
R=s(
e+ e-
hadr
on)/
s(e
+ e-
m+ m
- )
• Hadron form factors• Y(2175) resonance• Mutltiquark states
with s quark, Zs• MLLA/LPHD and QCD
sum rule predictions
• Light hadron spectroscopy• Gluonic and exotic states• Process of LFV and CPV• Rare and forbidden decays• Physics with t lepton
• XYZ particles• Physics with D
mesons• fD and fDs
• D0-D0 mixing• Charm baryons
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Highlighted Physics Program
• Search for new forms of hadron and study their properties.
• The nucleon/hadron electromagnetic form factors (NEFFs) and QCD study in none perturbative region.
• Search for new physics beyond the SM.
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Key science question: Is there any new forms of hadron exist ?
• Exotic hadrons: made of quarks and possibly gluon, but do not have the same quark content as ordinary hadrons. They are not predicted by the simple quark model.
• After several decades’ effort, XYZ particles, such as X(3872), Y(4260) and Zc(3900) discovered by Belle, Babar and BESIII experiments.
• To reach conclusive evidence of an exotic hadron, an e+e- collider in the t-c sector, which is able to provide much higher statistical data and cover broader energy range is essential.
Standard hadrons Exotic hadrons
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Exotic Hadrons(possible combination of quark and glue)
Pentaquar
Hybrid
S=+1 Baryon Tightly bound diquark-diantiquark
Tightly bound 6-quark state
Loosely bound meson-antimeson
Color-single multi-glue bound state
qq glue hybrid_
Pentaquark H-diBaryon Tentraquark
Meson molecule Glueball
g
gg
XYZ Particles: Candidate of Exotic HadronsY(4660)Y(4630)
Y(4008)
BELLE: PRL99, 142002
BESIII: Primary
BESIII: PRL(2013) 252001
Zc+-(3900)p+-J/y
e+e- X(3872)
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Zc(3900) Observed at BESIIII and Belle
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• M = 3894.56.64.5 MeV• = 632426 MeV• 159 49 events• >5.2
• M = 3899.03.64.9 MeV• = 461020 MeV• 307 48 events• >8
BESIII at 4.260 GeV: PRL110, 2520010.525 fb-1 in one month running time
Belle with ISR: PRL110, 252002967 fb-1 in 10 years running time
重要科学媒体报道 Zc(3900)
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2013 年物理重要进展之首!
SLAC Inspire : 101 次引用
Cristina Morales
Space-like:FF real
Time-like:FF complex
, Λ Λ
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Nucleon Electromagnetic Form Factors(NEFFs) Spatial distributions of electric charge and current inside the nucleon
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Nucleon Electromagnetic Form Factors (NEFFs)
• Key science question: why do quarks forms colourless hadrons with only two stable configurations, proton and neutron?
• NEFFs are among the most basic observables of the nucleon, and intimately related to its internal structure.
• Nucleons are the building blocks of almost all-ordinary matter in the universe. The challenge of understanding the nucleon's structure and dynamics has occupied a central place in particle physics.
• The fundamental understanding of the NEFFs and HEFF (hadron form factor) in terms of QCD is one of the outstanding problems in particle physics.
Cristina Morales16
The Measurement of Proton FF—Space-likeThere have been many measurements of the proton form factors in the space-like region. At Jlab, the proton factor ratio was measured precisely with an uncertainty of ~1%, based on which the proton electronic and magnetic radii could be extracted.
JLab
JLab
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Proton Form Factor: IGEI/IGMI
time-like
Complete picture of the nucleon structure requires space-like and time-like measurements!
10-24% precision from B factory
Only 2 measurements, but results are contradict
QCD predict
Babar: 469 fb-1 10-24% precisionBESIII: 0.4 fb-1 ~10% precision (expected)
first time extraction without any assumption.
δ|REM
|/|REM
| ~ 9% - 35%
δ|GM|/|G
M| ~ 3% - 9%
δ|GE|/|G
E| ~ 9% - 35%
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Measurement of Proton FFs with BESIII
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Measurement of Proton FFs at HIEPAFExample @ 2.23 GeV
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Nsig REM/REM / Luminosity (pb-1)
comment
614±24 24% 3.9% 2.631 BESIII test run3881±62 9.5% 1.6% 16.630 BESIII expected156253±395 1.5% 0.25% 669.533 HIEPAF reach 1389898±624 0.96% 0.16% 1670.69 HIEPAF reach 2
HIEPAF reach 1 HIEPAF reach 2
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New Physics• The discovery of the Higgs particle completes the list of the
particles in the SM. • Physics beyond the SM due to phenomena that cannot be
explained within the SM framework: - SM does not explain gravity - SM does not supply any fundamental particles that are good dark matter candidates, nor be able to explain dark energy - No mechanism in the SM sufficient to explain asymmetry of matter and anti-matter. • No evidence of new physics been found at high energy frontier,
it is important to search for new physics both directly and indirectly in the precision frontier.
Lepton Flavour Violating (LFV)
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CLFV processes sensitive to New Physics (NP)
through lepton-lepton coupling
m, t anomalous decays m e conversion
Anomalous magnetic moment
PSI Mu2e
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• The process e+e-+-, dominant background source at (4S), does
not contribute below 2E 4m/3 4.1 GeV.
• The favorable kinematical condition and the use of polarization can allow an UL(STCF in 1-2 years) ≤ UL(SuperBelle@Y in 12-15 yrs).
E
10.6 GeV
E
4.0 GeV
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MDC
PXD/SSD
PID-barrel PID-endcap
EMC
Superconducting magnet(0.7-1 T)
York/Muon
York/Muon
IP3~6 cm
10 cm15 cm
85 cm
105 cm
135 cm
185 cm
245 cm
120 cm
140 cm
190 cm
240 cm
300 cm
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Detector
MDC
• sxy=130 mm
• dE/dx<7%, sp/p =0.5% at 1 GeV
PXD• Material budget
~0.15%X0 / layer
• sxy=50 mm
PID• /K (and K/p) 3-4
separation up to 2GeV/c
EMC Energy range: 0.02-2GeVAt 1 GeV sE (%)
Barrel(Cs(I): 2 Endcap (Cs): 4
MUD• / suppression power
>10
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OrganizationHIEPAF
Physics&Software Detector
VertexTracker
EMCALPID
MUDSCM
Collectivity
Electronics
Trigger
DAQ
Theory
Generator simulation
CalibrationReconstruction
Infrastructure
Civilengineering
Technical supporting
Computing network
data service
SafetyEnvironment
Accelerator
Injector
Ring
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Activities
http://wcm.ustc.edu.cn/pub/CICPI2011/futureplans/
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HEPAF Study Time Line2013 2014 2015 2016 2017
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Kick-offcollaboration forming
WorkshopsFeasibility study
Review
CDR, R&D TDR?
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Forthcoming Discoveries in Particle PhysicsTopic Crucial measurement Significance
WIMP Existence Dark Mater
Higgs boson M ~125 GeV Confirm spontaneous symmetry breaking in gauge theory
Super-symmetric particles Existence, M > 1 TeV Hope of understanding gravity
Technicolour particles Existence, M > TeV? Dynamic symmetry breaking, Composite Higgs
Gravitational waves (Gravitons)
Existence Support general relativity
Magnetic monopole Existence, mass, electric charge Electric and magnetic charge symmetry predicted by Dirac. Structure of gauge field
configuration
Free quarks Existence, fractional charge Would confuse all current prejudice
Neutrino mass and oscillation
M < 1 eV Structure of GUTs. Eventual fate of the universe
Exotic hadronGlueball
Mg = 1-2 GeV, Mexotic, c~4 GeVExistence
Understand QCD
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Summary
• HIEPAF is one of the possible options for high energy physics in China.
- Have interesting physics relating to key science questions - Have challenges in terms of key technologies - Reasonable scale and cost. - One stone, two birds. (STCF + SRF)
• Working groups are formed and are making progress with regular weekly meeting and workshops.
• Welcome to join the effort.
• Next workshop: June, Dec.
Produce >1000 different isotopes
1959, 678 m
1969
450 GeV
25 GeV
LEP: 1988-2000Ecm(e+e-) = 200-209 GeV
Discover W, Z
2007
LHC: Construction 1998-2007 Commission 2007 E(p+p) = 14 TeV
nt–n m
Over 50 years!
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Heavy Ion Accelerator Facility (HIAF)
(BR+SR+CR): high quality & intensity pulsed RIBs, b beam
high accuracy RIA, astrophysics, application… (BR+SR+CR): high power compressed U beam HED… (BR+SR+CR+ER): polarized e & p beams EIC
U+U, RIB+RIB… Merging Experiments…
10’s MW Spallation Target
Integrate with HIAF:
Power In Flight and
ISOL for RIB & b Beam
中科院:詹文龙Oct. 18. 2013
Could be an accelerator complex in China electron, proton, heavy ionNeutrino beam
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Extra Slides
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Data Sample at Resonances for 1 ab-1
BESIII 109 108 107 106 106 106
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Web Page
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Requirement To The Detector
Efficient event triggering, exclusive state reconstruction and tagging – high efficiency and resolutions for charged and neutral particles
• Best possible solid angle coverage• High resolution for charged particles: [0.05, 1.6] GeV• Good PID: [0.05, 2] GeV• Good e, g detection eff. and energy resolution: [0.02,2.5]
GeV • Good vertex detection: 50 mm
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Forthcoming Discoveries in Particle PhysicsTopic Crucial measurement Significance
WIMP Existence Dark Mater
GlueballExotic matter
M = 1-2 GeVExistence
Understand QCD
Higgs boson M ~125 GeV Confirm spontaneous symmetry breaking in gauge theory
Neutrino mass and oscillation
M < 1 eV Structure of GUTs. Eventual fate of the universe
Proton decay t > 4x1032 years Evidence for validity of GUTs
Magnetic monopole Existence, mass, electric charge Electric and magnetic charge symmetry predicted by Dirac. Structure of gauge field
configuration
Free quarks Existence, fractional charge Would confuse all current prejudice
Super-symmetric particles Existence, M > 1 TeV Hope of understanding gravity
Technicolour particles Existence, M > TeV? Dynamic symmetry breaking, Composite Higgs
Gravitational waves (Gravitons)
Existence Support general relativity
Beam Parameters
Beam energy (GeV)3.0
Revolution frequency (MHz) 0.302
Circumference (m) 992.8 Harmonic number 1656Coupling factor
0.005 βx, y @ IP (mm)1000,
1.0Emittance (nm.rad) 10 Beam-beam parameter 0.06Bunch length (mm) 10 Number of bunch 540
Momentum compaction 0.001 Bunch current (mA) 5.0SR energy loss/turn
(MeV) 0.716 Beam current (A) 2.7Synchrotron tune 0.0128 SR power (MW) 1.93RF voltage (MV) 2.0 Energy spread 8.12E-4
RF frequency (MHz) 500.06 Luminosity (cm-2s-1) 1.05E35
(Lattice and other related AP studies are under way)
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Precision EW
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Mike Roney, Dec 2012
See: https://agenda.infn.it/getFile.py/access?contribId=241&sessionId=64&resId=0&materialId=slides&confId=4442
Vus
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Emilie Passemar τ decays could provide a competitive measurement of Vus+ many other topics covered
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• The process e+e-+-, dominant background source at (4S), does
not contribute below 2E 4m/3 4.1 GeV.
• The favorable kinematical condition and the use of polarization can allow an UL(SuperB near threshold in 1-2 years) ≤ UL (SuperB@Y(4s) in 5-6 yrs). It will take 12-15 yrs to SuperBELLE).
E E E
10.6 GeV 4.25 GeV 4.0 GeV
Facilities for Particle Physics in China
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Cosmic RayObservatory
?
?
?
?
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• M = 388551 MeV• = 34124 MeV• 81 20 events 6.1
Confirmed with CLEOc data!
BESIII
Belle
CLEOc data at 4.17 GeV:
arXiv:1304.3036, PLB727, 366 (2013)
发现带电类粲偶素粒子Zc(3900)
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6 月 17 日,发现 Zc(3900) 的论文在《物理评论快报》发表,杂志编辑推荐,并特别
配发题为“新粒子暗示存在四夸克物质”的评论;《自然》杂志发表了题为“夸克
‘四重奏’开启物质世界新视野”的研究热点报道。
2013 年 3 月 26 日, BESIII 合作组宣布发现 Zc(3900) ; 3 月 30 日 Belle 合作
组提交 Zc(3900) 论文。因其衰变产生
和 J/ 介子,组成中含有粲夸克和反粲夸克
且带有和电子相同或相反的电荷,提示其
中至少含有四个夸克,可能是科学家长期
寻找的一种奇特强子。
BESIII: PRL110, 252002(2013)
BESIII Detector
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Muon counterResistive plate chamber Barrel: 9 layersEndcaps: 8 layerssspatial: 1.48 cm
Time-of-flight (TOF)Plastic scintillator sT(barrel): 105 pssT(endcap): 125 ps
Drift chamber (MDC)Small cell, 43 layerGas He/C3H8=40/60sxy=130 mm, dE/dx~6%sp/p = 0.6% at 1 GeV
ECAL calorimeter CsI(Tl): L=28 cm (15X0)Energy range: 0.02-2GeVAt 1 GeV sE (%) sl(mm)Barrel: 2.5 6.1Endcap: 5 9
1 T Super conducting magnet
Data acquisition Event rate: 4 kHzData size: 50 MB/s
Grid computingCPU: 3200 core Storage: 2.2 pB
RO channels: 104
Cost: 200 M RMB
5.1
m
5.6 m
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Discovery of X, Y and Z Particles
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• Fundamental properties of the nucleon– Connected to charge, magnetization distribution– Crucial testing ground for models of the nucleon
internal structure– Necessary input for experiments probing nuclear
structure, or trying to understand modification of nucleon structure in nuclear medium
• Driving renewed activity on theory side– Models trying to explain all four electromagnetic
form factors– Trying to explain data at both low and high Q2
– Progress in QCD based calculations
Nucleon Form Factors
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QCD predict
限于统计量,大多数实验假设 GE=GM:
B-factory 的测量精度在 10% ~ 24%.
只有两个实验组测量了 |GE/GM|, 但结果显然是不一致的。
质子形状因子测量:类时过程e+e-p:
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中子数据更稀缺,长期以来只有 Fenice 结果 (74 个 e+e- → 事例 , 0.4 pb-
1).
Assuming GE=0
现有数据表明中子的形状因子是质子的 2 倍,需要实验验证 !
中子电磁形状因子测量
意大利曾计划对 DANE/FINUDA 做重大专门改进来测量核子形状因子。提高中子形状因子的测量精度在实验和理论方面都具有重要意义!
预期精度~ 10%,略好于 BaBar,但远不如 JLab(~ 1%)
first time extraction without any assumption.δ|R
EM|/|R
EM| ~ 9% - 35%
δ|GM|/|G
M| ~ 3% - 9%
δ|GE|/|G
E| ~ 9% - 35%
15%15%
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在 BESIII 上测量质子形状因子
Assuming STCF has a luminosity 100 times higher than that of BEPCII, MC study shows a precision comparable to JLab can be achieved. Example @ 2.23 GeV:
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在 STCF 上测量质子形状因子
Nsig REM/REM / Luminosity (pb-1)
comment
614±24 24% 3.9% 2.631 BESIII test run
3881±62 9.5% 1.6% 16.630 BESIII expected
156253±395 1.5% 0.25%
669.533 STCF reach 1
389898±624 0.96% 0.16%
1670.69 STCF reach 2
STCF reach 1 STCF reach 2
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Diptimoy Ghosh
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Diptimoy Ghosh
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Charmonium• Reasonably well understood below open charm. However,
information about decays of low-lying states is very incomplete (e.g. only 40% of hadronic decays of J/y is known).
• Many unknown above the open charm.
Not well understood
Reasonably well understood
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Precision Measurement• Precision measurement of probabilities for transition
between low-lying levels of charmonium, their masses, total and leptonic or two-photon widthsCompare with the predictions from potential quark models, LQCD
• Measure probabilities of rare, not yet discovered electric/magnetic dipole transitions Electric - hc(2S)ghc 2.5x10-3
- y(3770)gcc0 2x10-4 Magnetic - y(2S)ghc(2S) 5x10-4
- hc(2S)gJ/y 3x10-5
- hcgcc0 10-6
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XYZ-like Particles
• High statistics data at y(4040), y(4160) y(4200?) y(4400) gccJ(2P)
• Direct production of Y(4260), Y(4360), Y(4660) -scan from 3.8 to 5.0 GeV 100 fb-1
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Search for Weak Charmonium Decays
csW+ ~10-8
• Semileptonic: J/yDs(D*s) ln
• Hadronic decay: J/yDs+r-, Ds
*+p-
DS=0 process (SM suppressed) - 10-11
• J/yD0p0, D0r0
ccss (with W exchange, C parity violating)• J/y ff 10-8
10-9
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Search for CPV, LFV Processes
One of physical effects BSM is the existence of the non-zero electric dipole moment (EDM) of quarks or leptons leading to CPV
• J/ygff c quark EDM at 10-15 e-cm level
• J/yLL set limit ~10-19 e-cm for EDM of L (two order of magnitude more stringent)
Lepton flavor violation• J/yll’ (l,l’=e, m, ) < t 10-9
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Light Hadron Spectroscopy• Systematically study spectroscopy of states of light
quarks.
• Search for bound states of two gluons, glueballs, and hybrid states, qqg, multi-quark states. Glueball: J/y radiotive decay, two-photon meson production Hybrid: p1(1400), p1(1600)
- Exotic(JPC= 1-+): search for S-wave decay cc1pp1, P-wave
decay J/yrp1 - Noe-exotic(JPC= 0-+): cc0pp1, y decays
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Physics with D Mesons
Advantage as compared to SBF• Low multiplicity—low background• Threshold effect• Produce in a quantum-coherent state, with - JPC=1-- for e+e-DD - JPC=0++ for e+e-gDD
SCTF• 109 pairs of charge and neutral D mesons• 107 pairs of Ds mesons
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The D-meson States and Their Transition
• Experimental information is incomplete. • The quantum numbers for most of them are not established. • Almost no information about their decay modes. • The masses of the DsJ mesons lie well below the predictions of the quark model hypotheses for six-quark or molecular DsJ structure.
Production• 4.3-5 GeV:
• 5-6 GeV - DsJ(2632), DsJ(2708), DsJ(2860) - New states
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Charmed Meson Decays
• Precision measur. of leptonic, semi-leptonic decays of D and Ds• Measure fD, fDs to better than 0.5% • The difference between the experiment and the SM calculation
may indicate physics BSM.
CLEOC
SM gives:
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D0-D0 MixingEigenstates of the mass matrix: Two non-dimensional parameters:
Results from BF
With 10 ab-1 data at SCTF, a precision of measuring mixing parameters can compete with that from SBF.
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Search for CPV • Search for CPV in D decay—one of the most interesting
project at SCTF• SM predict a very small CP asymmetry in charm sector—10-3 is
expected in the Cabibbo-suppressed (CS) D decays. • Observation of a CP asymmetry in CF and DCS decays at any
level or an asymmetry higher than 10-3 in CS decays will clearly indicate the presence of new physics BSM.
Current values of CP asymmetry measured in D decays
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D Meson Rare Decays• Rare decays of D mesons are a tool for a search for
new physics BSM.• Most suitable for: - flavor-changing neutral current (FCNC) decays via the weak neutral current, providing the transition between c and u quarks. SM suppressed - lepton-flavor-violating (LFV) decays - lepton-number-violating (LV) decays SM forbidden
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Rare Decays of D• 10-8 for transition of cul+l- and cug. Increased to
10-5 considering large distance dynamics.
Experimental upper limit on rare D and Ds decays in unite of 10-6
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Charmed Baryons• First observed in 1970s• Observed mass range: 2.3-2.7 GeV • Evidence of doubly charmed meson Xcc at 3.52 GeV
from SELEX • Predicted triply charmed baryon Wccc, but not yet
observed.• There is practically no experimental information
about the quantum numbers of baryons and absolute branching fractions of their decays.
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Parameters of the S-wave Charmed Baryons
• Mainly from BF, 107 LcLc
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Physics with t Leptons• e+e-t+t- near threshold -- low and controlled background• Precision measurements of as, ms, Vus
• Lepton universality: mt, tp+nt and tK+nt
• Lorentz structure of the amplitude for tlnlnt
• Search for LFV processes: tl , g lll’, lh – sensitive to new physics (10-7-10-8 from BF)• Search for CPV: ACP = (G(tf+) - G(tf-)) / (G(tf+) + G(tf-)) Most promising processes tKp0nt, rpnt, wpnt, a1pnt Observation of CP asymmetry would be an explicit indication of physics BSM.• Competition from SBF, but threshold effect is important for
controlling and understanding background• Longitudinal polarization of the initial beams will significantly
increase sensitivity in searches for CPV in lepton decays.
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R-values and QCD • R (1%), s and mc
• Quark and glue fragmentation functions
• Form factors: p, ……p
• Important test of QCD: Modified Leading Log
Approximation/Local parton-hadron duality (MLLA/LPHD)
- distribution (=-ln(2p/s), parameter L &
KLPHD
- Multiplicity, 2nd binomial moment R2
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HIEPAF: Accelerator • Peak luminosity: 1 x 1035 cm-2s-1 at Ecm=4 GeV
• Energy range: Ecm=2–7 GeV • Polarization available on one beam?• Symmetric machine with low currents and crab
waist solution for the interaction region • Interdisciplinary mode for - ring: compatible with synchrotron radiation facility (SRF) - linac: free electron laser (FEL)