Meeting on e e- physics perspectives - PowerPoint PPT Presentation

About This Presentation
Title:

Meeting on e e- physics perspectives

Description:

Meeting on e e- physics perspectives (non-K-decays) at LNF. Frascati 19-20 Jan. 2006 ... GM| ' 1/q4 ) d o ' 1/q10 ] Accept / reject event according to d ... – PowerPoint PPT presentation

Number of Views:9
Avg rating:3.0/5.0
Slides: 24
Provided by: Mar5332
Category:

less

Transcript and Presenter's Notes

Title: Meeting on e e- physics perspectives


1
Meeting on ee- physics perspectives (non-K-decays
) at LNF
Frascati 19-20 Jan. 2006
Simulation of time-like form factor measurements
at DAFNE-2
Marco Radici INFN - Pavia
  • with
  • Bianconi (Brescia)
  • B. Pasquini (Pavia)

2
Outline
  • Review master formulae
  • Gakh Tomasi-Gustafsson hep-ph/0511240
  • describe setup of Monte Carlo simulation
  • q2 -, ? distributions of unpolarized cross
    section
  • extraction of GM, GE
  • q2 -, ? distributions of Ay
  • extraction of phases

4. explore sensitivity to 2? mechanisms
3
  1. Born and 2? amplitudes
  2. Unpolarized cross section
  3. Normal polarization
  4. Details of simulation
  5. Input parametrizations of FF
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

R angular asymmetry
q2lt0 Rosenbluth plot change E, ?e at fixed q2 )
linear plot in ?
q2gt0 measure ? at fixed q2 ) get R cos2?
typical of Born diagram
non cos2 ? ) explore 2? mechanisms
4
  1. Born and 2? amplitudes
  2. Unpolarized cross section
  3. Normal polarization
  4. Details of simulation
  5. Input parametrizations of FF
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

5
  1. Born and 2? amplitudes
  2. Unpolarized cross section
  3. Normal polarization
  4. Details of simulation
  5. Input parametrizations of FF
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects
  • Sort events distributed as 1/q10 in 4m2 lt q2 lt
    50 GeV2
  • GM 1/q4 ) d?o 1/q10
  • Accept / reject event according to d?o
  • each event is a n-tuple of 6 elements
    q2,?,?,Px,Py,Pz
  1. Sample of 270 000 events
  • DAFNE-2 L1032 cm-2s-1 ? (ee- ! ppbar) 1nB
  • ) rate 0.1 Hz collect sample in 1 month
  • DAFNE-2 range (m?)2 lt q2 lt (2.4)2 GeV2
  • simulation for 4m23.52 lt q2 lt 5.76 GeV2

6
  1. Born and 2? amplitudes
  2. Unpolarized cross section
  3. Normal polarization
  4. Details of simulation
  5. Input parametrizations of FF
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

Which form factors provide to Monte Carlo ?
DAFNE-2
Brodsky et al. P.R. D69 (04) 054022
7
  1. Born and 2? amplitudes
  2. Unpolarized cross section
  3. Normal polarization
  4. Details of simulation
  5. Input parametrizations of FF
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

Iachello Iachello et al.
P.L. B43 (73) 191 P.R.C69 (04)
055204 (dipole core)x(?,?,? poles)
VMD
Lomon Lomon P.R. C66 (02)
045501 (double dipole)x(?,?,?,?,?)
VMD
8
  1. Lomon fit to Born cross section
  2. Iachello fit to Born cross section
  3. Statistical comparison of two fits
  4. Fits to total Born cross section
  5. Summary
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

P1
P2
9
  1. Lomon fit to Born cross section
  2. Iachello fit to Born cross section
  3. Statistical comparison of two fits
  4. Fits to total Born cross section
  5. Summary
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

P1
P2
10
  1. Lomon fit to Born cross section
  2. Iachello fit to Born cross section
  3. Statistical comparison of two fits
  4. Fits to total Born cross section
  5. Summary
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

11
  1. Lomon fit to Born cross section
  2. Iachello fit to Born cross section
  3. Statistical comparison of two fits
  4. Fits to total Born cross section
  5. Summary
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

12
  1. Lomon fit to Born cross section
  2. Iachello fit to Born cross section
  3. Statistical comparison of two fits
  4. Fits to total Born cross section
  5. Summary
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

13
  1. Lomon fit to Born cross section
  2. Iachello fit to Born cross section
  3. Statistical comparison of two fits
  4. Fits to total Born cross section
  5. Summary
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

Need good coverage over whole range in ?
q2 close to threshold ! more events, better
statistics q2 close to upper bound ! low
statistics, no selective power
14
  1. Lomon angular fit to Born Ay
  2. Iachello angular fit to Born Ay
  3. Statistical relevance of Lomon fit
  4. Statistical comparison of fits for Ay(45o)
  5. Summary
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

P3
15
  1. Lomon angular fit to Born Ay
  2. Iachello angular fit to Born Ay
  3. Statistical relevance of Lomon fit
  4. Statistical comparison of fits for Ay(45o)
  5. Summary
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

P3
16
  1. Lomon angular fit to Born Ay
  2. Iachello angular fit to Born Ay
  3. Statistical relevance of Lomon fit
  4. Statistical comparison of fits for Ay(45o)
  5. Summary
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

17
  1. Lomon angular fit to Born Ay
  2. Iachello angular fit to Born Ay
  3. Statistical relevance of Lomon fit
  4. Statistical comparison of fits for Ay(45o)
  5. Summary
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

18
  1. Lomon angular fit to Born Ay
  2. Iachello angular fit to Born Ay
  3. Statistical relevance of Lomon fit
  4. Statistical comparison of fits for Ay(45o)
  5. Summary
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

19
  1. Lomon angular fit to Born Ay
  2. Iachello angular fit to Born Ay
  3. Statistical relevance of Lomon fit
  4. Statistical comparison of fits for Ay(45o)
  5. Summary
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects
  • in 4m2ltq2lt5.76 GeV2 Ay is small
  • ) extraction of phases via Im GMGE is
    difficult

2. study Ay(q2) at specific ? enhances
statistical noise ) look at angular
distribution
  • 3. angular fit is problematic, but the sin2? Born
    trend is
  • visible ) extracting Im GMGE is it possible
    ?
  • ) again need full coverage of ?

20
  1. Born and 2? amplitudes
  2. Unpolarized cross section
  3. Normal polarization
  4. Details of simulation
  5. Input parametrizations of FF
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

21
  1. Test functions for A(q2,t)
  2. Angular fits for unpol. cross section
  3. Statistical comparisons of fits
  4. Statistical comparisons of fits for Ay(90o)
  5. Summary
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

try C 0.02 ! see nothing try C 0.2 ! see
something
22
  1. Test functions for A(q2,t)
  2. Angular fits for unpol. cross section
  3. Statistical comparisons of fits
  4. Statistical comparisons of fits for Ay(90o)
  5. Summary
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

23
  1. Test functions for A(q2,t)
  2. Angular fits for unpol. cross section
  3. Statistical comparisons of fits
  4. Statistical comparisons of fits for Ay(90o)
  5. Summary
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

P1
P2
P3
C 0.02
24
  1. Test functions for A(q2,t)
  2. Angular fits for unpol. cross section
  3. Statistical comparisons of fits
  4. Statistical comparisons of fits for Ay(90o)
  5. Summary
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

P1
P2
P3
C 0.2
Re(A)Im(A)
25
  1. Test functions for A(q2,t)
  2. Angular fits for unpol. cross section
  3. Statistical comparisons of fits
  4. Statistical comparisons of fits for Ay(90o)
  5. Summary
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

C 0.2
Re(A) -Im(A)
26
  1. Test functions for A(q2,t)
  2. Angular fits for unpol. cross section
  3. Statistical comparisons of fits
  4. Statistical comparisons of fits for Ay(90o)
  5. Summary
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

C 0.2
Re(A) -Im(A)
Re(A) Im(A)
27
  1. Test functions for A(q2,t)
  2. Angular fits for unpol. cross section
  3. Statistical comparisons of fits
  4. Statistical comparisons of fits for Ay(90o)
  5. Summary
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

28
  1. Test functions for A(q2,t)
  2. Angular fits for unpol. cross section
  3. Statistical comparisons of fits
  4. Statistical comparisons of fits for Ay(90o)
  5. Summary
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects
  • Modelling 2? diagram is very difficult !
    approximations
  • ?GE ?GM 0 A(q2,?) ¼ A(q2)
  • if non-Born dependence cos? ) boundary ? are
    important

2. Counting rules ) asymptotically ReA(q2) /
ReGE(q2) ImA ReA ) test interference
ReGE/M ImGE/M angular separation possible
3. Ay(q2) at ??/2 only from 2? but too few
events ) statistical noise, no selectivity )
again full ? coverage important
29
Backup slides
30
  1. Born and 2? amplitudes
  2. Unpolarized cross section
  3. Normal polarization
  4. Details of simulation
  1. Monte Carlo
  2. Extraction of moduli
  3. Extraction of phases
  4. 2? effects

polarized cross section for
Ax, Az require polarization of the electron beam
Pe ? 0
31
  1. Questions in SL region
  2. Surprise in SL TL
  3. Few and poor TL data
  4. Better constrain models
  1. Why TL FF ?
  2. What do we learn ?
  3. Which measurements ?
  4. Available data and models ?

JLab Hall A Qattan et al.
P.R.L. 94 (05) 142301
Blunden et al. nucl-th/0506039
2? ?
32
  1. Questions in SL region
  2. Surprise in SL TL
  3. Few and poor TL data
  4. Better constrain models
  1. Why TL FF ?
  2. What do we learn ?
  3. Which measurements ?
  4. Available data and models ?

SpaceLike
TimeLike
analytic continuation by Dispersion Relations
(DR)
But
fit to pQCD TimeLike
fit to pQCD SpaceLike
33
  1. Questions in SL region
  2. Surprise in SL TL
  3. Few and poor TL data
  4. Better constrain models
  1. Why TL FF ?
  2. What do we learn ?
  3. Which measurements ?
  4. Available data and models ?

pQCD analyticity
But
fit to GMp
34
  1. Questions in SL region
  2. Surprise in SL TL
  3. Few and poor TL data
  4. Better constrain models
  1. Why TL FF ?
  2. What do we learn ?
  3. Which measurements ?
  4. Available data and models ?

poor statistic
integrate d? over wide angular range
all data assume
its true only at
where steep rise is observed
35
  1. Form factors are complex
  2. FF from unpol. cross section
  3. Phases from polarization
  4. Unphysical region
  1. Why TL FF ?
  2. What do we learn ?
  3. Which measurements ?
  4. Available data and models ?

phases of FF from Final-State Interactions (FSI)
of final baryon system interference of
channels with different phases ( Im (GEGM) )
pQCD FSI ! 0 for Q2 ! 1 ) test transition
to scaling and Color Transparency (CT)
FSI ! T-odd mechanisms are allowed
generates
GE F1 ? F2 GE ei ?E GM F1 F2
GM ei ?M
not possible in elastic scattering
Im (GEGM) (? -1) Im F2F1 threshold t14M2 !
Im( )0 consistent with GEGM from GT1(t1)0
ambiguity ? ? - ? solved by
36
  1. Form factors are complex
  2. FF from unpol. cross section
  3. Phases from polarization
  4. Unphysical region
  1. Why TL FF ?
  2. What do we learn ?
  3. Which measurements ?
  4. Available data and models ?

discriminate among models that are close in SL
region
IJL
CQM
pQCD improved
37
  1. data proton
  2. models
  1. Why TL FF ?
  2. What do we learn ?
  3. Which measurements ?
  4. Available data and models ?

ADONE Q2 4.4 GeV (1973)
CERN Q2 3.6 (1977)
Orsay-DM1 Q2 3.75-4.56 (1979)
Orsay-DM2 Q2 4-5 (1983)
LEAR Q2 3.5-4.2 (1994)
E760 Q2 8.9-13 (1993)
FENICE Q2 3.7-6 (1994)
E835 Q2 8.8-18.4 (1999)
11.6-18.2 (2003)
CLEO Q2 11-12 (2005)
BES Q2 4-9 (2005)
BaBar Q2 2-20 (2005)
38
  1. data neutron
  2. models
  1. Why TL FF ?
  2. What do we learn ?
  3. Which measurements ?
  4. Available data and models ?

FENICE Q2 3.7-6 (1994)
but always assumed GEN GMN Np,n
39
  1. data
  2. models
  1. Why TL FF ?
  2. What do we learn ?
  3. Which measurements ?
  4. Available data and models ?
  • Dispersion Relations (DR)
  • analyticityunitarityVector Mesons
    (VM) (Drechsel, Meissner,

  • Hammer,
    Hoehler,..)

  • input exp. data (Baldini, Pacetti, )
  • VM Dominance (VMD) based models (Iachello,
    Bijker, Lomon, )
  • Soliton (Holzwarth)
  • CQM Light Front Form (Pace, Salmè, Simula,
    )
  • \pi
    cloud (Miller, Jennings, .. )
  • Point Form (Pavia Graz
    collaboration)
  • Diquark (Ma, )
  • pQCD inspired (Brodsky, Ji, Belitski, Yuan,
    ..)
  • reviews Brodsky et al. P.R. D69 (04) 054022
  • Tomasi-Gustafsson et al.
    E.P.J. A24 (05) 419

40
Possible logo ?
(from Pacetti talk at Nucleon05)
Write a Comment
User Comments (0)
About PowerShow.com
Home About Us Terms and Conditions Privacy Policy Presentation Removal Request Contact Us
Copyright 2024 CrystalGraphics, Inc. — All rights Reserved. PowerShow.com is a trademark of CrystalGraphics, Inc.
The PowerPoint PPT presentation: "Meeting on e e- physics perspectives" is the property of its rightful owner.
Do you have PowerPoint slides to share? If so, share your PPT presentation slides online with PowerShow.com. It's FREE!