Round table Physics at Super- -c factory 1 Super- -c factory, BINP, Sep 2008 Some starting points...

Round table Physics at Super--c factory 1 Super--c factory, BINP, Sep 2008

Some starting pointsfor discussion

Physics @ Super--c factory


Generalities

Production cross-sect., lumin.:

cc prod. cross-sect. at (4S): ~1.3 nb; prod. of D*+ → D0+: 4x107 D0’s/100 fb-1;

prod. of D0’s at (3770): 6x107 D0’s/100 fb-1;

Super-B: ~8-10 ab-1/year (107 s); Super--c: ~1 ab-1/year; BES-III: ~10 fb-1/year;

Time schedule? end of 2011: BES-III 30 fb-1

Super-Belle start in ~10 years(?): Super-B Super--c


List of possible topics

Questions: - motivationanswers: high/medium/low

- what precission is needed/can be achieved (compared to Super-B/BES-III/LHCb)answers: feasible/not feasible/not useful


List of possible topicsPhysics topics -



Physics topics - charm • leptonic decays (decay constants)• semileptonic decays (form factors)• rare decays (NP search/identification)• D0 mixing, CPV t-dependent/t-independent CPV, so far unused methods at B-factories (T-odd observables, advantages of polariz. - cc)• Spectroscopy “exotic” (X,Y,Z); X(3872) 1++ (B decays) ;

Y family 1-- (ISR produced from (4S)); Z+(4430) (B decays); production, CMS energy, scan? (D(*)D(*)) @ s~4.5 GeV (inclusive/exclusive)

Other (, ...)



Machine & detector topics

need for asymmetric energy machine? (asymmetry factor?) CMS energy, scan?

Long. polarization - energy interval? Transverse polariz.?Need for equal polariz. of opposite helicity?Need for polarized e+ beam?

, /K, /e PID performance needed? Vertex detector?Beam pipe issues?Momentum resol.? EM calorim. angular & energy resol.? KL, range system? polarization measurement?Hermeticity?

MC (background) simulation


1. Ds leptonic decaysDs → Average of absolute meas.;

huge improvement in LQCD accuracy;

to do list:confirm LQCD uncertainty;reduce exp. uncertainty;

Ds →e

0.4% non-scaling syst. (#tags) BES-III: (fDs)~1%; from ealone with 100 fb-1 (fDs)~0.5% (not considering more tagging modes)

230 240 250 260 270 280 290 300 MeV

e

aver.

Belle, PRL100, 241801 (2008), 548fb-1

Cleo-c, PRL99, 071802 (2007), 314pb-1

Cleo-c, PRL100, 161801 (2008), 298pb-1

MILC, PRL95, 122002 (2005)

LQCDHPQCD, UKQCD, PRL100, 062002 (2008)

3.3 discrepancy

274 ±10 MeV

241 ±3 MeV

Cleo-c, PRL100, 161801 (2008), 298pb-1

Round table Physics at Super--c factory 10

Super--c factory, BINP, Sep 2008

2. Semileptonic decays

Vub

exclusive measurements, B → l |Vub|f+(0) |Vub|=(3.6 ± 0.5)x10-3

comparable accuracy to incl. measurements f+(0) th. uncertainty (LQCD) ±12%

need: improvement in th. accuracy & tests of LQCD f.f. calculations in charm sector

D →Pe, P=K, ; untagged meas., p from pmiss; q2 dependence ((q2)~0.01 GeV2); sys. due to simulation ±1.7% on Br; total error ±4.8% on Br;

with 1 ab-1 uncertainty on |Vcd|f+D(0) dominated by syst. error, ~ 0.5%;

Cleo-c, PRD77, 112005 (2008) 281 pb-1

D0 →e



~40%, Br(mee<0.7 GeV)~10-7,

background? (negligible in )

3. Rare decays

D±→ ±l+l-

need sensitivity to ~10% of Br at high/low mee;

Cleo-c, PRL95, 221802 (2005) 281 pb-1

c

W±

d,s,b

Z0, l+

l-

u, d

u

u, d

c g

Z0,

uc~ u~

~

mee[GeV]

17 5.010125~01.02

1~)(

%10~)(2

11)(2

abBr

DDN

DDBrNNBr

DDN

NBr

Br



4. D0 mixing

D →K*(p1,1)K*(p2,2)T(pi,i) = -pi,i;

but AT ~ sin(): weak phase: strong phase;

)0)(()0)((

)0)(()0)((

211211

211211

pNpN

pNpNAT

:2

T

TTCPT

A

AAA

asymmetry of conjugated process

ATCP ~ sincos

n.b.: ACPdir ~ sinsin



4. D0 mixing

CPV c →

angular distrib. diff. between c and anti-c;

(e+e- →c X) at (4S) ~ 0.2 nb at threshold ~0.5 nb

p

c

rest frame



MD+MD*

c’

J/c

c0c1c2

’”

hc

c”

hc’

c1’

c2

2 3

5. Spectroscopy

X(3872) JPC=1++, 2-+; DD* mode larger than J/ 1++ favoured; not easy to produce; (4040), (4160) decays?

Y family Y(4260), Y(4360), Y(4660); produced in ISR from (4S), 1--; @4.2 GeV eff. lumin. ~O(100 pb-1) hybrid, DD1(D*) decay mode?

MeVMeVM X

3.25.02.3871)3872(



Backup



Super-KEKB bckup

KEK roadmapA. Suzuki, KEK Director General, Inaugural meeting of Super Belle



Ds leptonic decays bckupDs → Average of absolute meas.;

huge improvement in LQCD accuracy;

agreement for fD+: LQCD: 208 ± 4 MeV exp.: 223 ±17 MeV (but exp. error larger than for fDs)

230 240 250 260 270 280 290 300 MeV

e

aver.

Belle, PRL100, 241801 (2008), 548fb-1

Cleo-c, PRL99, 071802 (2007), 314pb-1

Cleo-c, PRL100, 161801 (2008), 298pb-1

MILC, PRL95, 122002 (2005)

LQCDHPQCD, UKQCD, PRL100, 062002 (2008)

3.3 discrepancy

274 ±10 MeV

241 ±3 MeV

to do list:confirm LQCD uncertainty;reduce exp. uncertainty;



Ds leptonic decays bckup

Ds →

signal shape checked with fully recon. events (with one Ds discarded);

5% syst. on Br from #tags; out of this ~3% from unknown bkg. shape & bias in #tags in , compared to generic events 1.5% non-scaling system. on fDs; total 5.4% error on fDs;

tags Ds →KK, MM*2 from Ds

tag,

Cleo-c, PRL99, 071802 (2007), 314pb-1

Cleo-c, hep-ex/0607074, 200pb-1




Ds →e

sideband subtraction for #tags; syst. on Br from #tags 0.8%;

peaking bkg. from KLe; estimated from data using KSe; 0.4% non-scaling system. on fDs; total 6.6% error on fDs;

BES-III: (fDs)~1% from ealone with 100 fb-1 (fDs)~0.5% (not considering more tagging modes)

energy in calorim. from Ds*Ds

(signal from Ds*)

Cleo-c, PRL100, 161801 (2008), 298pb-1

tags




Ds →l NP

M: NP mass

B.A. Dobrescu, A.S. Kronfeld,, PRL100, 241802 (2008)

type II two Higgs doublets models: destructive interference



Semileptonic decays bckup

Vub

exclusive measurements, B → l |Vub|f+(0) |Vub|=(3.6 ± 0.5)x10-3

comparable accuracy to incl. measurements f+(0) th. uncertainty (LQCD) ±12%

need: improvement in th. accuracy & tests of LQCD f.f. calculations in charm sector

D →Pe, P=K, ; untagged meas., p from pmiss; q2 dependence ((q2)~0.01 GeV2); shape of f.f. determined in data;

Cleo-c, PRD77, 112005 (2008) 281 pb-1

D0 →e



Semileptonic decays bckup

Vub

absolute measurement of Br, need N(DD); sys. error due to N(DD) scales with lumin.; sys. due to simulation ±1.7% on Br; total error ±4.8% on Br; Br(D0 →e)=(0.299±0.011±0.009)%

with 1 ab-1 uncertainty on |Vcd|f+D(0) dominated

by syst. error, ~ 0.5%;

method of absolute Br measurement developed also by Belle; with 5 ab-1 uncertainty on |Vcd|f+

D(0) ~1%

Cleo-c, PRD77, 112005 (2008) 281 pb-1

D. Asner, ICHEP’08



Rare decays bckup

D±→ ±l+l-

need sensitivity to ~10% of Br at high/low mee;

Cleo-c, PRL95, 221802 (2005) 281 pb-1

c

W±

d,s,b

Z0, l+

l-

u, d

u

u, d

c g

Z0,

uc~ u~

~

mee[GeV]

90% C.L. UL on total Br ~ 7.4x10-6

for e+e- mode, excluding resonant contrib.



Rare decays bckup

D±→ ±l+l-

~40%, Br(mee>1.1 GeV)~10-7,

background? (negligible in )

17 5.010125~01.02

1~)(

%10~)(2

11)(2

abBr

DDN

DDBrNNBr

DDN

NBr

Br

Cleo-c, PRL95, 221802 (2005) 281 pb-1

Round table Physics at Super- -c factory 1 Super- -c factory, BINP, Sep 2008 Some starting points...

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