Results from the Alghero Workshop on e e in the 12 GeV range

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Results from the Alghero Workshop on ee- in the
1-2 GeV range

• C. Biscari
• LNF, INFN

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The aim of the Workshop is to discuss the physics
issues and to address the strategies and the
problems towards higher luminosities in the
energy range between 1 and 2 GeV. Particular
attention will be devoted to possible future
upgrades of DAFNE.Physics topics will include
precision measurements of nucleon form factors,
low energy spectroscopy, physics of hypernuclei,
tests of fundamental symmetries through rare kaon
decays, gamma-gamma interactions.
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Lim Youb KEK Llanes Estrada Felipe Univ.
Complutense Lubicz Vittorio Università Roma
Tre Mangano Michelangelo CERN Mazzitelli Giovanni
INFN-LoNF Milardi Catia INFN-LNF Mirazita Marco
INFN-LNF Miscetti Stefano INFN-LNF Morra Ombretta
INFN-CNR Torino Moulson Matthew
INFN-LNF Muccifora Valeria INFN-LNF Mueller
Stefan Uni Karlsruhe Napolitano Marco Univ.
INFN-Napoli Nappi Aniello Università Perugia Outa
Haruhiko IPNS, KEK Pacetti Simone Università
Perugia INFN Palutan Matteo INFN-LNF Passalacqua
Luca INFN-LNF Passeri Antonio INFN-Roma3 Patera
Vincenzo INFN-LNF Paticchio Vincenzo
INFN-Bari Pennington Michael University of
Durham Petrascu Catalina INFN-LNF Placidi Massimo
LBNL Preger Miro Andrea INFN-LNF Raimondi
Pantaleo INFN-LNF Ricci Ruggero INFN-LNF Ripani
Marco INFN-Genova Rubin David Cornell
University Ruggiero Francesco CERN Salmè Giovanni
INFN-Roma1 Serci Sergio INFN-Cagliari Serio
Mario INFN-LNF Shatunov Yuri BINP
Agnello Michelangelo Politecnico di
Torino Alberico Wanda Maria Univ. Torino
INFN- Antonelli Antonella INFN-LNF Antonelli
Mario INFN-LNF Baldini Ferroli Rinaldo
INFN-LNF Battaglieri Marco INFN-Genova Bencivenni
Giovanni INFN-LNF Benedetti Gabriele
INFN-LNF Bertani Monica INFN-LNF Bertolucci Sergi
INFN-LNF Biagini Maria Enrica INFN-LNF Biscari
Caterina INFN-LNF Bloise Caterina INFN-LNF Boni
Roberto INFN-LNF Boscolo Manuela INFN-LNF Bossi
Fabio INFN-LNF Botta Elena INFN-Torino Bottigli
Ubaldo Università Sassari Bramon Albert Univ.
Autonoma de Barcelona Branchini Paolo
INFN-Roma3 Bressani Tullio INFN-Torino Brodsky
Stanley SLAC Busso Luigi INFN-Università Torino
Calvetti Mario Università Firenze
INFN-Firenze Campana Pierluigi INFN-LNF Capon
Giorgio INFN-LNF Ceccucci Augusto CERN Cenci
Patrizia INFN-Perugia Chiavassa Emilio Università
INFN Torino Cimino Roberto INFN-LNF Clozza
Alberto INFN-LNF Conetti Sergio University of
Virginia Corcoran Marjorie Rice University Czyz
Henryk Inst. of Physics, Univ. of Silesia
D'Ambrosio Giancarlo INFN-Napoli Dal Piaz Piero
Università INFN-Ferrara De Falco Alessandro
INFN-Cagliari de Rafael Eduardo
CPT-CNRS-Marseille De Sanctis Enzo INFN-LNF De
Simone Patrizia INFN-LNF Dell'Agnello Simone
INFN-LNF Denig Achim Universitaet Karlsruhe /
IEKP Di Domenico Antonio Univ. Roma1 Di Donato
Camilla INFN-Napoli Diemoz Marcella
INFN-Roma1 Dosselli Umberto INFN-Padova Drago
Alessandro INFN-LNF Dubnicka Stanislav Inst. of
Physics SAS Feliciello Alessandro
INFN-Torino Ferretti Dal Piaz Paola
INFN-Ferrara Ferroni Fernando Università Roma "La
Sapienza" Filippi Alessandra INFN-Torino Fox John
SLAC Franzini Paolo Università Roma La
Sapienza Gallo Alessandro INFN-LNF Gauzzi Paolo
Università Roma 1 INFN Ghigo Andrea
INFN-LNF Giannini Mauro Università
INFN-Genova Giovannella Simona INFN-LNF Greco
Mario Univ. Roma III Guiducci Susanna
INFN-LNF Iacopini Enrico INFN-Firenze Ikeda
Hitomi KEK Isidori Gino INFN-LNF Jaffe David
Brookhaven National Laboratory Lanfranchi Gaia
INFN-LNF Lee-Franzini Juliet Università Roma 1
LNF Ligi Carlo INFN-LNF
Sibidanov Aleksej BINP Solodov Evgeni BINP Sozzi
Marco CERN Spadaro Tommaso INFN-LNF Temnykh
Alexander Cornell University Teytelman Dmitry
SLAC Tomassini Sandro INFN-LNF Valente Paolo
INFN-LNF Vescovi Mario INFN-LNF Zenoni Aldo
Università Brescia Zhang Chuang Institute of High
Energy Physics Zobov Mikhail INFN-LNF
114 participants of which
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Benedetti Gabriele INFN-LNF Biagini Maria Enrica
INFN-LNF Biscari Caterina INFN-LNF Boni Roberto
INFN-LNF Boscolo Manuela INFN-LNF Cimino Roberto
INFN-LNF Clozza Alberto INFN-LNF Drago Alessandro
INFN-LNF Fox John SLAC Gallo Alessandro
INFN-LNF Ghigo Andrea INFN-LNF Guiducci Susanna
INFN-LNF Ikeda Hitomi KEK Ligi Carlo
INFN-LNF Mazzitelli Giovanni INFN-LNF Milardi
Catia INFN-LNF Placidi Massimo LBNL Preger Miro
Andrea INFN-LNF Raimondi Pantaleo INFN-LNF Ricci
Ruggero INFN-LNF Rubin David Cornell
University Ruggiero Francesco CERN Serio Mario
INFN-LNF Shatunov Yuri BINP Temnykh Alexander
Cornell University Teytelman Dmitry SLAC Vescovi
Mario INFN-LNF Zhang Chuang Institute of High
Energy Physics Zobov Mikhail INFN-LNF
30 for ACCELERATORS
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SOME PHYSICS ITEMS around 2 GeV
Neutron time-like Form Factors Measured only
once (at ADONE) 100 events Unexpected s( e
e- -gt n n) gt s( e e- -gt p p) Very difficult by
means of Initial State Radiation L time-like
Form Factors Measured only once (at DCI) 4
events Very difficult by means of ISR Proton
time-like Electric Form Factor and Phase Never
measured Difficult by means of ISR Looking for
non qq states in multihadronic production Exotic
Isoscalars expected cross sections lt 1 nb Very
difficult by means of ISR Total cross section
measurement High accuracy lt 1
PEP-N Program
R. Baldini
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NUCLEON FORM FACTORS

• CONCLUSIONS
• A measurement that is of intrinsic importance
  since is relevant to an observable that any
  theory must be able to predict
• DAFNE2 is the only place where such a measurement
  can be performed
• Simulations with FINUDA show that precision of
  some even at threshold may be obtained with L
  1032 cm-2s1. proton and neutron F.F. in the
  time-like region can quite easily be measured
• The measurement of the polarization of the
  neutron seems also possible in FINUDA (C sheets
  used for antineutron converters and neutron
  polarization analyzers)

T. Bressani
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G. Isidori
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G. Isidori
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PAST, PRESENT AND FUTURE
SUPER FACTORIES
STATUS REPORT on
COLLIDERS
FACTORIES
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VEPP-2000
DAFNE
Beam ? end of 2004
Restarting now from a long stutdown
BEPC-II
CESR-c
Commissioning with wigglers
1st beam 2006 - full operation 2008
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• Basic concept
• Luminosity is generally higher for high energy
  rings for several reasons, some of the more
  beneficial are
• 1) Tune shifts scales with 1/Energy (E) leading
  to a fundamental linear increase of the
  luminosity vs Energy
• 2) Radiation damping-time decrease with 1/E3
  leading to higher limits for tune-shifts
• 3) Touschek effect decrease with 1/E3
• 4) Natural bunch length shorter
• 5) Beam stiffer, single and multi bunch
  instabilities decrease with 1/E
• 2) and 3) lead to smaller Design horizontal
  emittance for higher Energy colliders

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CESR-c Energy dependence

• Radiation damping
• In CESR at 5.3 GeV, an electron radiates
  1MeV/turn
• gt ? 5300 turns (or about 25ms)
• SR Power E2B2 E4/?2 at fixed bending radius
• 1/? P/E E3
• so at 1.9GeV, ? 500ms
• Longer damping time
• Reduced beam-beam limit
• Less tolerance to long range beam-beam effects
• Multibunch effects, etc.
• Lower injection rate

D. Rubin
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CESR-c Energy dependence

• Damping and emittance control with wigglers

D. Rubin
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Simulation

• -Machine model includes
• Wiggler nonlinearities
• Beam beam interactions
• (parasitic and at IP)
• -Synchrotron motion
• -Radiation excitation and
• damping
• -Weak beam
• -200 particles
• - initial distribution is gaussian
• in x,y,z
• - track 10000 turns

D. Rubin
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Tune plane appearancebeam-beam interaction
VEPP 4
Particle loss rate from positron beam
Vertical beam size from luminosity (r.u.)
I 6.2mA, I- 10.2mAxx 0.015, xy 0.060
A. Temnick
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Beam based characterization Nov 2002, one
wiggler optics, wiggler1 (7p)
3) 2D tune scan vertical beam versus tune,
evaluation with wiggler field
Bmax 0
1.9T
2.1T
Oct. 14 2002, Optics 1843MeV_1WIG_R3_OT, fs
25kHz Observed resonances Wiggler OFF -fhfv
0, -fhfh-fs0, fh2fv fs 2f0, Pmax 3
Wiggler ON -3fhfv -f0, fhfv-3fsf0, 3fv2f0,
fh2fv2fs2f0, 4fhfv3f0, 2fhfv2fs2f0,
2fh-2fsf0 and -3fhfvfs-f0, Pmax 5
A. Temnick
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Frascati colliders e e-
FUTURE
x 100
x 2
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DAFNE2 Energy x 2
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DAFNE2
Specifications Upgrade of DAFNE from the present
energy of 1.02 GeV c.m. up to and above the
neutron-antineutron threshold, 2-2.4 GeV c.m.,
using the existing systems and structures. Lumino
sity 1032 cm-2 s-1 Compatibility with present
operation at F
D. Rubin
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WHAT CAN BE USED FROM DAFNE

• DAFNE2 can exploit DAFNE hardware
• vacuum chamber
• all quads and sexts
• RF cavity
• Feedback, vacuum system...
• But needs new
• stronger bending dipoles
• 4 SC quads in IR2

G. Benedetti
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IR2 BETA FUNCTIONS

• bx 2.5 m and by 2.5 cm, already achieved at
  DAFNE
• FF DFFD FF quad sequence

G. Benedetti
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Superconducting IR Quadrupoles

Requirements

Tunable 510MeV -gt 1.2GeV Solenoid
compensation Superimposed skew quad
windings
CESR IR
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DESIGNPARAMETERS

• Luminosity requirements not critical for DAFNE2
• horizontal crossing angle at IP2 ?x 15 mrad
  Piwinsky angle f ?x sL/sx 0.22 already
  exceeded in existing factories
• linear tune shift is xx / xy 0.014 / 0.024,
  below the limit achieved in DAFNE
• 30 bunches we can inject out of collision and
  collide with a fast RF phase jump
• L 11032 s-1 cm-2 is straightforward to achieve
  with a total current of 0.45 A

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Super DAFNE Luminosity x 100
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Ideas for Luminosity increase
Some will be tested in near future
Others

• collisions with neutralized beams
• (four beams) feedback system
• ring against linac
• Monochromators
• Collisions with large crossing angle
• Ecm 2Ebeamcos(qc/2),
• e.g. qc/2 60,Ebeam1GeV

• Crab cavities (KEK-B)
• Collisions with round beams (VEPP2000)
• Negative aC (KEK-B, DAFNE)

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Large crossing angle
If we want to collide at the F-pole, we could
increase the ring Energy by greatly increasing
the crossing angle 2a, such as Ecm
2Ebeamcos(a)
detector
Ecm 1 GeV
E 1 GeV
E - 1 GeV
For example a60 corresponds to Ebeam1GeV
Raimondi
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Large crossing angle
If we want to collide at the F-pole, we could
increase the ring Energy by greatly increasing
the crossing angle 2a, such as Ecm
2Ebeamcos(a)
detector
Ecm 1 GeV
E 1 GeV
E - 1 GeV
For example a60 corresponds to Ebeam1GeV
Raimondi
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Detector concepts conventional
4 m
1.8 m
2 m
fiducial volume
0.5 m
0.4 m
not to scale
0.4 m
tagger
Scalo ? 25 p m2
calorimeter
acc. ? 27
F. Bossi
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Detector concepts forward
10 m
Ebeam 1 GeV
fiducial volume
beam hole
8 m
4 m
0.4 m
tagger
1 m
calorimeter
not to scale
Scalo ? 25 p m2
acc. ? 23
F. Bossi
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Conclusions
Physics Machine
The search for KL??0?? is probably the most
exciting goal and solid motivation for the high
luminosity option of DA?NE 2 (see Ginos talk
yesterday)
It requires however luminosities of order
1035 cm-2s-1
The large x-ing angle option, although
fascinating, seems to present some major
disadvantage in terms of tagging wrt to the
conventional one
Beam related backgounds have to be kept under
control
F. Bossi
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Main guidelines for the designL gt 10 34 at F
energy

• Powerful damping
• Short bunch at IP
• Negative momentum compaction

Which kind of collider is possible at
Frascati using present infrastructures?
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Damping time on magnetic field
For C 100 m E 510 MeV
Factor 2 on tuneshift by factor 10 on damping
time
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Beam Dynamics with ac lt 0

• Bunch is shorter with a more regular shape
• Longitudinal beam-beam effects are less dangerous
• Microwave instability threshold is higher (?)
• Sextupoles can be relaxed since head-tail
  disappears

M. ZOBOV
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Negative alfa tests at KEKB
Ikeda, KEKb
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• It is worthwhile to try a collider operation with
  a negative momentum compaction factor since this
  can provide several advantages in beam dynamics
• Simulations indicate that by shifting the working
  point close to the integers and applying a
  lattice with the negative momentum compaction we
  have a possibility to push DAFNE luminosity to
  1033 cm-2s-1 level

M. ZOBOV
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Strong RF Focusing for Luminosity Increase
A. Gallo, P. Raimondi, M.Zobov
See Gallos talk tomorrow
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Varying bunch length along the ring by large
longitudinal phase advance
Drift Space
RF Cavity long. thin lens
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Varying bunch length along the ring
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HIGH and NEGATIVE MOMENTUM COMPACTION strong
RADIATION emission
Sf
Sd
Sf
Qf Qd
Qd Qf
Alternating positive and negative bending
dipoles (proposed by Raimondi)
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ZOOM OF THE RINGS SECTION
QUADRUPOLES
SEXTUPOLES
1m
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Layout similar to present DAFNE rings
One IR Second crossing for injection, rf,
diagnostics Short inner arc and long outer arc
with the condition of equal longitudinal phase
advance between cavity and IP in both directions
rf
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ARCS to IR Dispersion suppressors
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ARCS to Injection and rf section, with D
suppressor
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BIAGINI
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Dynamic aperture
First evaluation by E.Levichev, P.Piminov) BINP,
Lavrentiev 13, Novosibirsk 630090, Russia
ACCELERATICUM computer code Symplectic 6-D
tracking for transversely and longitudinally
coupled magnetic lattice
Tracking code ACCELERATICUM, VEPP-4M Internal
Note, BINP, Novosibirsk, 2003.
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Adding the longitudinal phase plane3D
resonances
Choice of the working point
Tune footprint in 2D - transverse
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----- no synchr oscill ----- Dp/p 0 ----- Dp/p
0.1 ----- Dp/p 0.5
V 300 kV Qs 0.059
V 3 MV Qs 0.2
Strong dependence on V but specially on Qs gt
Resonances in 3D
V 5 MV Qs 0.3
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Feedback systemsFirst analysisby J.Fox, D.
TeitelmannSLAC
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Beam lifetime

• Touschek lifetime has been calculated with a
  preliminary set of longitudinal parameters. A
  further optimization is possible.
• Anyway
• At L 1034
• lifetimes are of the order of 10 minutes
• continous injection is needed

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Background
High current Short beam lifetime High rate of
particle losses Continuos injection Dominated by
Touschek lost particles IR design together with
detector design
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Dipole parameters
Cost evaluated 1600 k
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DAFNE HALL
KLOE
F. Sgamma
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• Injection system
• upgrade
• The proposed transfer lines pass in existing
  controlled area
• Additional shielding needed in the area between
  the accumulator and DAFNE buildings

new e- line
new e line
A. Ghigo
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Crossing point section schematic layout
SC RF Cavities
FB kickers
correctors
TOP VIEW
kicker
quadrupoles
injection septa
vertically separated vacuum chambers
SIDE VIEW
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Luminosity 1034set of consistent parameters
new
challenges
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Tests foreseen in collaboration with other
machines
We are considering the possibility of testing
the strong RF focusing in PEP2, KEK-B, CESR,
ALS,
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10 33 Optimistic extrapolation of present
knowledge and technologies 10 34 Very
challenging design based on new ideas Proofs of
principle and validation needed 10 35
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DAFNE status and outlook

• Adiabatic changes on DAFNE approaching to an
  end.
• DAFNE performances expected to reach the
  original design goals (L 5 10 32), within the
  next 2 years.
• 3- 4 years of physics program fully booked with
  current ( or slightly upgraded) detectors.
• After that, only radical changes possible

S. Bertolucci, closing Alghero workshop
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Next steps

• Keep going!
• Interim status report at the DAFNE conference in
  spring 2004 and at the CERN October 2004 meeting.
• Repeat this workshop !
• Start the RD and test measurements on
  accelerator and detectors.

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Conclusions

• Physics measurement in the 1-2 GeV range
  competitive in next decade
• Overview of ee- colliders in the low energy
  range
• Evolution of already assessed principles
  (BEPCII, CESRc, DAFNE)
• Expectation for round colliding beams at
  VEPP2000
• New ideas for increasing L, i.e. negative a,
  strong rf
  focusing,
• Need of collaboration between institutes