Super c/ factory

Budker INP, Novosibirsk

Bondar A.

ECFA, 12 March, 2011, Vienna

Physics at -charm factory• Precision charm physics

– Precision charm precision CKM (strong phases, fD, fDs ,form-factors…)

– Unique source of coherent D0/D0bar states (D0 mixing, CPV in mixing, strong phases for 3 measurements at SuperB and LHC)

• Precision -physics with polarized beams– Lepton universality, Lorentz structure of -decay…– CP and T-violation in and c decays– LFV decays ()– Second class currents (with kinematical constraints at

threshold)

• High statistic spectroscopy and search for exotics– Charm and charmonium spectroscopy– Spectroscopy of the highly exited Charmonium states

(complimentary to Botomonium)– Light hadron spectroscopy in charmonium decays

Advantages of near threshold production

• Particle multiplicity at 3.77 GeV is about two times lower than at 10.6 GeV•Close to threshold the additional kinematical constraints can suppress combinatorial background ( useful for second class currents studies)• Two body production e+e-DD. This allows to use double tag method:

• fully reconstruct one D • then either fully reconstruct the other D (absolute branching ratios)• or look for events with one missing particle (leptonic, semileptonic decays)

• Coherent production of D pairs allows to use quantum correlations for D-meson mixing and CP violation studies

Polarization

•Michel parameters

•CP-violation in -decays and/or C• CP-violation new physics, charged Higgs• Two amplitudes with different weak and strong

phases • Observables

– Rate asymmetry: (+f+)-(-f)~sin sin– Triple product asymmetry (T-odd) (p1p2)

T+-T-~cos sin• For complete description of matrix element ,

polarization and direction of should be known– Polarization may increase sensitivity by several

times

If even one beam polarized, almost 100% longitudinally polarized near the threshold

LFV decaysSuper-B, 75 ab-1

71010 -pairs

• decay •Current limit: ~ 310-8 by Belle with 7108 •At Y(4S):

ISR background e+e-+-Upper Limit 1/L

• tau-charm factory with 1010 will have better sensitivity

ISR Spectrum At near threshold

– E for ee background cannot be as high as E for .

– Background from ee will become more important. good MUID is essential.

s =10.58GeV s =5.0GeV

s =4.25GeV s =4.0GeV

E (CMS) from and ISR()

(4s)

maximum

H.Hayahii 2008

Backgrounds

•Combinatorial background from +- events

•QED processes •Continuum background•Charm•Anything else?

()(0)

()()

2E=3.77GeV

Level of the sensitivity c/ factory to Br(->)<10-9

Quantum correlated DD state decay is a instrument for strong phase measurement in the hadronic D-meson decays

D mixing contribution to the KSπ+π– Dalitz plot distributions for even and odd DD states is different. It can be used for CPV and Mixing parameters measurement in the time integrated mode !

Quantum correlated DDbar states

Pure DD final state (ED(*) = Ebeam)

Equal to cross-section of DDLow particle multiplicity ~6 charged

part’s/eventGood coverage to reconstruct in

semileptonic decaysPure JPC = 1- - initial state - Flavor tags (K-+ ,K-+ 0,K-+ -+), Semileptonic (Xe)

e+ e

*0D

0D

+

e/+

K

KS

D mixing in time integrated mode at c/

Factory

e+e- -> KSπ+π– + K+ – (CLEO-c)

(yD)=0.9 10-3

(xD)=1.3 10-3 (CP)=2.3 o

(|q/p|)=3.6 10-2

)()(

)()(

asymi

asymi

asymi

symi

iKK

KKf

MC Sensitivity (KSπ+π–+ K+l – ) 1ab-

1

If sensitivity of other states is comparablethe total statistical uncertainty should be 2-3 times better.

SuperB sensitivity

Ryan Mitchell @ CHARM2010

Signal of Y(4260)→hc+- ?

Search for hb in (5S) data

Rate of Yb→hb+- is high?

CLEOc Observation of e+e- -> hc+-

13

2S

1S

3S

1S

Preliminary

121.4 fb-1

CLEOc observation motivated Belle for hb search at Y(5S)

• Beam energy from 1.0 to 2.5 GeV • Peak luminosity is 1035 cm-2s-1 at 2 GeV• Electrons are polarized longitudinally at IP• On-line energy monitoring (~5÷1010-5)

• Two rings with Crab Waist collision scheme and single interaction point

• Sub-mm beta-y at IP• Preserving of damping parameters (by 4 SC

wigglers) through the whole energy range to optimize the luminosity

• 5 Siberian snakes to obtain the longitudinally polarized electrons for the whole energy range

• Highly effective positron source (50 Hz top-up injection)

• Polarized electron source• 2.5 GeV full energy linac

Technical specifications for Super c/ factory

Main features of the Super c/ factory design

Main ring schematically

Polarization degree vs energy

Luminosity betatron tune scan

CW advantage:

BB coupling resonances are suppressed

is feasible

Wide red area corresponds to 1035 cm-2s-1

Horizontal tune

Ve

rtic

al tu

ne

Super factories accelerator challenges

Similar (Nanobeam/CW) approaches yield similar problems in accelerator designAll problems typical for Crab Waist/Nanobeam machines could be solved in collaborative manner by accelerator physicists

SB-INFN

Detector

PID

PIDCDC

TPC

ECL

Photon Detectors

SiPM

Aerogel Tiles

•Ultimate Hermeticity •PID e///K separation up to 2GeV/c•Momentum resolution•Low pT track efficiency•ECL energy resolution•Low energy (~20MeV) photons efficiency

momentum range in ->

Artistic view of future machine

• Accelerator Complex 200 MEuro

• Detector 80 MEuro

• Buildings Construction and Site Utilities 50 MEuro

Project status and plans

•CDR –in progress (to be ready in November 2011)

•Collaboration is growing (now 10 Institutes from Russia and 9 Institutes from other countries) •Design of the buildings –in progress (funded)

•Injection complex - beginning of commissioning

•Funding decision – end of 2012 ?

•Construction 2012-2017?