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Date/Time: 10:30~17:30 JST, April 15th, 2017
Place: Room 425, Building No.3, KEK
Official Language: English
Video Conference ID: 509 (KEK MCU2)
Vidyo connection:
https://vidyoportal.cern.ch/flex.html?roomdirect.html&key=ruNmL42Qu3h6y3CRAdjhwqJMI4
(agenda are developing)
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Summary of The 50th General Meeting of the ILC Physics Subgroup
Feb. 4, 2017 (Sat) at Room 425, Building 3, KEK
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0) Attendants:
Present at KEK:
Y.Sato (Tohoku)
C.Drews (Tohoku)
M.Kurata (Tokyo)
Y.Kato (Tokyo)
K.Hidaka (Tokyo gakugei)
H.Yamashiro (Kyushu)
T.Suehara (Kyushu)
J.Yan (KEK)
Y.Aoki (KEK/Sokendai)
K.Fujii (KEK)
Remote connection:
T.Ozawa (Tohoku)
J.Tian (Tokyo)
0) Opening comments (K.Fujii)
1) Anomalous VVH couplings at the ILC (T.Ogawa)
Status:
Now using new EFT formalism including new terms such as hZA coupling.
1st preliminary results for the new parametrizations.
There seems to be some problem in parameter correlations, etc.
Next Step:
- Write a paper.
- Check the correlation matrix.
- Finalize the analysis.
C: Try using just 250GeV measurements and see what happens for the staging study.
2) Characterizing Light Higgsinos from Natural SUSY at ILC500 (Jacqueline Yan)
Status:
Benchmark points: ILC1, ILC2
mass gap: 15-20GeV, 10GeV, and 4-7GeV for ILC1, ILC2, nGMM1
C1C1: almost Bkg free.
Trying to fix the missing phase space problem with the SM background samples.
ILC2 analyses
H20 -> 0.3% measurements of mN1, mN2, mC1 with 1600fb-1 for each pol.
C1 almost done for muon tag analysis.
Mirrage analysis on going.
H20 -> 1.3% measurements of mN1, mN2 with 1600fb-1 for each pol.
There seems to be a missing phase space problem for some of the SM background
for the muon channel.
ILCSoft version dependence
1-17-08 has a problem with muon ID (peak at around E/P~1)
Started study of overlay effects.
Next Step:
- MarlinReco with 1-17-11.
- Write a paper.
- Investigate the missing phase space problems.
- ILC2 chargino analysis for electron tag channel.
- Study systematic shifts.
- Study the effect of overlay
- Improve low pt tracking with new ILCSoft.
- light higgsino @ Ecm=250GeV
3) Top pair threshold study (K.Ozawa)
Status:
Ecm = 347GeV, mt=174GeV, 100fb-1 for each pol. (+/-80%,-/+30%)
- Use lepton + 4-jet final states
- Investigated jet pairing and found cos(theta_bW) cut is useful.
Momentum peak position
P_peak = 19.9+/-0.24GeV (left) 100fb-1 each
= 19.9+/-0.35GeV (right)
corresponding to delta: Gamma_t = 24 MeV (left)
= 34 MeV (right)
Next Step:
- Systematic shift of P_peak
- Different energy points
- Estimate systematic error.
4) Top EW coupling measurements using di-muon final states at Ecm=500GeV (Y.Sato)
Status:
Trying to optimize event reconstruction
- isolated lepton tagging
- b-jet reconstruction using the thrust axis method
- kinematical reconstruction
Introduction of k_e- and k_e+ to take into account ISR/BS.
-> Case A: no ISR/BS, no gluon emission from t/tbar, overlay
Case B: with all of these effects
-> 10 form factors can be fitted with a % level precision for Case A
Next Step:
- Do the 10 form factor fit for case B
- Visit LAL in March and learn more about MEM.
5) Correlation btw h->gamma gamma and gg in mSUGRA (K.Hidaka)
Setup: Within the experimental constraints including LHC search results (q~, g~, C, N),
MSSM higgs, QFV parameters from B, mh, . . .
-> Full mSUGRA parameter scan Gamma(X) := Gamma(h -> XX) (X=gamma or g) the deviations of Gamma(gamma) and Gamma(g) from SM can be as big as +13% and -18%, respectively, and the two deviations are strongly correlated.
-> DEV(gamma/g) := (G(gamma)/G(g))_SUSY/(G(gamma)/G(g))_SM - 1
+0.15 < DEV(gamma/g) <+0.23 almost independent of A_0, tanb, m_0, m_1/2.
Q: What is the dominant SUSY contributor to the loop?
A: Stop with a typical mass of, say, 2TeV.
C: So 2TeV stop can make 20% deviation.
Q: Do you have results on h -> gamma Z?
A: Not yet.
Q: Is it possible to extract information on stop and chargino?
A: Maybe.
6) Jet Clustering using (REAL) NN (M.Kurata)
Staus:
New method
Minimize L with constraints as in usual parameter fitting
with Langrange multipliers.
-> 2% improvement over Druham.
-> Try REAL NN for 15 (qq)(bb)(bb) events
Next Step:
- Apply REAL NN architecture.
C: What about using OpenCV?
C: What about starting from 20 or so mini-jets?
7) BSM Search Uing Higgs to Invisible Decay (Yu Kato)
He could not attend the meeting but slides are there on the web.
Please take a look.
8) Summary and Discussions (all)
Jackie summarized today’s presentations.
Missing analyses:
2-fermion, single W/Z, multi-gauge boson processes, hadronic recoil, ..
light higgsinos at 250GeV,
tth, exotic higgs decays, light higgs, etc.
systematics concerning luminosity spectrum, etc.
Development of tools.
Jet clustering, b-charge ID