Physics @ Super- t -c factory
description
Transcript of Physics @ Super- t -c factory
Round table Physics at Super--c factory 1 Super--c factory, BINP, Sep 2008
Some starting pointsfor discussion
Physics @ Super--c factory
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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
Round table Physics at Super--c factory 3 Super--c factory, BINP, Sep 2008
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
Round table Physics at Super--c factory 4 Super--c factory, BINP, Sep 2008
List of possible topicsPhysics topics -
Round table Physics at Super--c factory 5 Super--c factory, BINP, Sep 2008
List of possible topicsPhysics topics -
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List of possible 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 (, ...)
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List of possible topics
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
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List of possible topics
Round table Physics at Super--c factory 9 Super--c factory, BINP, Sep 2008
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
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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
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~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
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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
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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
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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(
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Backup
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Super-KEKB bckup
KEK roadmapA. Suzuki, KEK Director General, Inaugural meeting of Super Belle
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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;
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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
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Ds leptonic decays bckup
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
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Ds leptonic decays bckup
Ds →l NP
M: NP mass
B.A. Dobrescu, A.S. Kronfeld,, PRL100, 241802 (2008)
type II two Higgs doublets models: destructive interference
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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
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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
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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.
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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