status of lc physics study group in japan (i)
DESCRIPTION
Status of LC physics study group in Japan (I). Nobuchika Okada (KEK). LC Physics Study Meeting March 6 (Sun), 2005. Japanese LC Physics Study Group http://www-jlc.kek.jp/subg/physics/. a mixture of experimentalists and theorists mainly working in Japan. Subgroups - PowerPoint PPT PresentationTRANSCRIPT
Status of LC physics study group in Japan (I)
LC Physics Study Meeting
March 6 (Sun), 2005
Nobuchika Okada (KEK)
Japanese LC Physics Study Group
http://www-jlc.kek.jp/subg/physics/
a mixture of experimentalists and theorists mainly working in Japan.
Subgroups
Higgs, New Physics, Top, Gamma-Gamma (ee–option), Luminosity
Higgs subgroup activities and related works
Higgs physics at LC
Higgs boson EW symmetry breaking
mass generation mechanism
Measurement of Higgs boson mass and self coupling
structure of EW symmetry breaking
New physics if
Priority ⇒ Higgs Physics at TeV LC
1.Higgs self coupling⇒ We started (from 2002)
2.Top Yukawa3.Heavy Higgs, etc.
etc..
etc..
Studies on Higgs self coupling measurement
by Y. Yasui and S. Yamashita
Assumption No bkg effects 100% signal efficiency
by Yasui et.al.
@@LCWS '02 Jeju KoreaLCWS '02 Jeju Korea
LCWS’04 Paris France Quick Simulation (includes bkg.) study!!
dominant for E
CM > 1TeV
Ecm = 1 TeV
main mode W-fusion
Higgs mass = 120 GeV
SM decay Br
ISR/BSR included
Signal & bkg event generator
LCGrace (BASES+SPRING)
Signal MC: X + hh
/SM from 0.0 to 2.0 with 0.2
step
Smearing simulation at parton level
Jet energy resolution ~ 30%/√E (GeV)
(detector R&D target value)
Simulation StudySimulation Study
ννhh quick analyses
only for hh decaying to 4b
Br(hh4b) ~ 47 %
for 120 GeV SM Higgs
Signal characteristics
Large missing energy, missing PtOnly 4 b jetsM1 jj ~ Mh M2 jj ~ Mh
No isolated lepton
Signal and Background processesSignal and Background processes
Signal(for SM)
Main bkg processes 4b + missing
ννbbbb (~ ννZZ, ννZγ*)
ννbbh
(~ ννZh)
By LCGrace
1. Likelihood selection bkg further reduction
2. Separate Zhh & fusion different dependence (positive/negative interferences)
3. Combine with Zhh analyses for s-channel process
4. Check hh invariant mass
5. hhh
measurements
ννhh Analysis Flowννhh Analysis Flow
dep. of cross-section
νeνehh
Zhh
/SM
L = 1 ab-1
ννbbbb
ννbbh =SM
=
Reconstructed ‘Higgs’ mass
ννbbbb
Likelihood
ννbbh
ννhh
=
=SM
coun
ts
L = 1 ab-1
ννhh selection
(~ OPAL Higgs scheme)(~ OPAL Higgs scheme)
Missing mass [GeV]
‘Zhh’
‘fusion’
ννhh channel
coun
ts
Separate Zhh & fusion
(= visible mass)
‘fusion-channel’
hh invariant mass [GeV]co
unts
ννhh
=
=SM
hh invariant mass [GeV]
coun
ts
‘Zhh-channel’
Zhh=SM
=2 SM
HH invariant mass distributionsHH invariant mass distributionsHH invariant mass distributionsHH invariant mass distributions
Mh=120 GeV
Mea
sure
d / S
M
True /SM
95%CL upper bound
95%CL lower bound
67%CL range
Ilumi=1 ab-1
Pol beam= -80%
@1TeV
Mh=120 GeV(SM Higgs Br)
Use only hh4b(Br(hh4b)~47%)
Eff.(4b) 80%
By Yamashita et.al. LCWS 2004
hhh Measurement sensitivityhhh Measurement sensitivity
Precise study Radiative corrections are also important!! Systematic study of the RC for Higgs physics at LC with GRACE
Higgs coupling constants as a probe of new physics
S. Kanemura, S. Kiyoura, Y. Okada, E. Senaha, C.-P.Yuan, PLB558(2003)157.S. Kanemura, Y. Okada, E. Senaha, C.-P. Yuan, PRD70(2004)115002.
Z
h
Z
h
h
h
t
t
Higgs coupling constants as a probe of new physics
Top loop effects (SM)
Z
h
Z
hh
h
Φ
Φ
S. Kanemura, S. Kiyoura, Y. Okada, E. Senaha, C.-P Yuan
Allowed region of the deviation from the SM of the hZZ and hhh coupling
(M = 0 case )
δ= 0 corresponds to the decoupling limit ; sin(β - α) =1
hZZ ⇒ deviation mainly comes from the tree-level mixing effect (radiative correction - 1%)
hhh ⇒ the tree-level mixing effect O(10%) radiative correction O(+100)% due to the non-decoupling loop effect
S. Kanemura, Y.Okada, E. Senaha, C.-P. Yuan
Connection between collider physics and cosmology
Electroweak baryogenesis and quantum corrections to the triple Higgs boson coupling
S. Kanemura, Y. Okada, E. Senaha, PLB606(2005)361.
By the non-decoupling loop effect of extra Higgs bosons, the renormalized hhh coupling (h: SM like Higgs boson) in the 2HDM can differ from the SM prediction by O(100%)
Large deviation in hhh due to the non-decoupling effect corresponds to the successful scenario of electroweak baryogenesis
Baryogenesis : C, CP violation 2HDM Out of equilibrium 1st order PT
Sphaleron condition
Spharelon condition
Cubic term can be sufficiently large due to non-decoupling effect of extra Higgs boson loop
Electroweak Baryogenesis and quantum corrections to the triple Higgs boson couplings
S. Kanemura, Y. Okada, E.Senaha
Search for the lepton flavor violating Yukawa interactionvia the Higgs boson decay
S. Kanemura, K. Matsuda, T. Ota, T. Shindou, E. Takasugi, K. Tsumura, PLB599(2004)83,S. Kanemura, T. Ota, K. Tsumura, work in progress.
Search for LFV via the Higgs decay
S. Kanemura, K. Matsuda, T. Ota,
T. Shindou, E. Takasugi, K. Tsumura
Mh=120GeV, L=1ab^-1
LFV Higgs coupling may be measured at LC
Extension to the general 2HDM S. Kanemura, T. Ota, K. Tsumura
Perturbative unitarityVacuum stability
Constraint on parameters: LEP precision data
Similar to the MSSM, but no SUSY relation among Higgs parameters
For the low tanβ region, no constraint on h →μτ from tau rare decay results
Measurement of h→τμ at LC can give strong constraint on κ32 esp for low tanβ
Possibility of a fixed target experiment at LC
Search for Lepton Flavor Violating Deep Inelastic Scattering Processes
S. Kanemura, Y. Kuno, M. Kuze, T. Ota, PLB607 (2005) 165.
Alternative process for search of the Higgs LFV coupling.
• At future ν factories (μ colliders) , 10^20 muons of energy 50 GeV (100-500GeV) can be available. DIS μ N→ τ X process
• At a LC (Ecm=500GeV L=10^34/cm^2/s)
10^22 of 250GeV electrons available. DIS process e N→ τ X process
μ (e) τ
N
h, H, A
X
A fixed target experiment option of LC
Cross section in SUSY model
CTEQ6L
• Each sub-process e q (μq) →τq is proportional to the down-type
quark masses.
• For the energy > 60 GeV, the total cross section
is enhanced due to the b-quark sub-process
E = 50 GeV 10^(-5)fb 100 GeV 10^(-4)fb
250 GeV 10^(-3)fb
μ (e) τ
N
h, H, A
X
Phenomenology of CP violating Higgs sector in the MSSM
A. Akeroyd, S. Kanemura, Y. Okada, E. Senaha, hep-ph/0409318
A. Akeroyd, S. Kanemura, Y. Okada, E. Senaha
SUSY loop contributions to the W pair production
K. Hagiwara, S. Kanemura, M. Klasen, Y. Umeda, PRD68(2004)1103011.S. Alam, K. Hagiwara, S. Kanemura, Y. Umeda, R. Szalapski, PRD62(2000)095011; NPB541(1999)50.
The one-loop form factors are tested except for
overall renormalization
: Goldstone boson
Gounaris et al
SUSY loop contributions to
• Calculation tested by the – BRS sum rules – Decoupling property
• The typical size of the contributions to M(00)– a few times 0.1 % for sfermion effects – O(1%) for chargino/neutralino effects
• CP phase effect in the chargino/neutralino sector– At most 0.1% in M(0+)
K. Hagiwara, S. Kanemura, Y. Umeda
Sfermion effects
First 2 generation squark effect
Stop-sbottom loop effect
Chargino/neutralino effects
CP phase effect
CP odd form factors F4, F6, F7
New Physics subgroup activities and related works
Collider signal of New Physcs: MSSM, Large extra-dimensions etc.
1) Studies on MSSM
Mass and cross-section measurements of chargino production at LC
by Y. Kato, K. Fujii, T. Kamon, V. Khotilovich, M. M. Nojiri to be published in PLB (hep-ph/0411249)
Chargino pair production process is one of the key
for determination of supersymmetric parameters at LC
If large tan beta
Event:
KK graviton mediated process
Phenomenology of graviton Kaluza-Klein modes
Detection of Extra-dimension @ LC
through KK graviton mediated processes
2) Collider signal of large extra dimensions
Large extra-dimension (ADD) scenario
(Arkani-Hamed-Dimopoulos-Dvali, ’98)
I: total cross section
new physics evidence
II: angular dependence of cross section
effects due to spin 2 particle exchange
Important points:
deviation from the SM collider energy
LC < LHC
precise measurements of angular dependence
LC > LHC
process
KK graviton exchange is dominant
SM background free very interesting
if this cross section is large enough
N. Delerue, K. Fujii & N. Okada
PRD 70, 091701 (2004)
Example:
Comparable to
Characteristic angular dependence of cross section
Reflects spin 2 nature of KK graviton
Invariant mass distributions
Invariant mass distributions
Number of remaining evens per
700 Higgs Pair events @ 1TeV LC
integrated luminosity 500
Essentially No SM backgrounds!
Reconstruction of Angular Distribution (after selection)
integrated luminosity 500
Next example: is now work in progress….
Future plan
• Higgs– SM Higgs/Light Higgs
Study method is already established.
: ~2% accuracy for mh = 120–140 GeV
– Heavy Neutral Higgs in SUSY, 2HDM, etc.
Mass reach is heavier than e+e-
AHee
HA,
eeHA sm 5.0,
eeHA sm 8.0,
pair production
single production
t, b, W, ‥‥
h
γ
γ
subgroup activities and related works
– Heavy Neutral Higgs in SUSY, 2HDM, etc.
(1) Production:
A-H-continuum intreference
Asakawa-Kamoshita-Sugamoto-Watanabe Eur.Phys.J.C14:335(2000)
Large Interference effects !
t
t
t
t- -
A,H
Comparable around the resonance
(2) Phase of γγΦ: magnitude of the vertex ⇔ Γ(φ→γγ) phase of the vertex ⇔ Observables including interference effects They are sensitive to existence of new charged particles.
arg 0
arg 45
b
b
t tm GeV
even
ts /
GeV
for
Lee=
3fb-
1
2RRM
2LLM
*2 RR LLM M *2 RR LLM M
3tan
400
GeVM A
M
σ
σ
σλ
λσ
λ
λ
Asakawa-Hagiwara Eur.Phys.J.C31.351(2003)
bγ
bγ : γγφ vertex
• Large Extra-dimensions
Collaboration is being groped.
• Tools– GRACE/SUSY/1LOOP-CAIN
Automatic calculation up to 1-loop level in SM&MSSM
with REALISTIC photon luminosity simulations
Basically, has been developed.
Other activities Yasui-san’s talk