Higgs & Top at LHeC

Monday 22 May 2017, 11:00 → 13:00 Europe/Zurich

CERN

CERN - Tokyo - Liverpool - Johannesburg - Beijing - Hamburg

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exotic Higgs at FCCeh summary:
Uta showed the first results of measuring 10 and 1% branching fractions of a 125 GeV Higgs boson into a pair of light scalars with >5 sigma discovery for 100 and 1000 fb-1, respectively.
Masses of scalars are restricted to twice the mass of bottom quarks and about the 1/2 of the 125 GeV Higgs boson.
The study was done in a safe b-tagging region of eta<2.5 using the same b-tagging performance as planned for FCC-hh, all Delphes parameters were set as in the final card file emailed by Uta a while ago. The delphes card file is now attached to the agenda.

Q:
- Masahiro asked for the cross section errors: this is S+B propagated error of the visible cross section for a BDT cut>0
- Chen asked for the low pT cut : yes, in ep we can measure lower pT jets in contrast to pp, we also expect at most a pile-up of 1 for FCC-eh
- Chen asked for ETmiss cut: ETmiss>20 GeV in the final analysis. Slides are amended and the Etmiss cut is added. Chen suggested testing even higher ETmiss cuts (up to 60 GeV).

Please send Uta ppt files for SM+BSM Higgs to be presented next week in Berlin at the FCC week.

Uta also reported that her BSc student made very good progress in optimising the BDT performance for Hcc at LHeC, and a better optimisation would be perhaps also beneficial for our Higgs to invisible study.

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To inform the group, Orhan has reported the discussion with Olaf 

today from top physics group. They make a second iterations to 

review the FCC-eh top physics studies, it basically includes: charged current 

Wtb anomalous vertex study, Vtb measurement, EDM/MDM studies, 

anomalous top-Higgs coupling studies, and finally top FCNC studies, 

there will be some comparison with the LHeC studies as well.

He also mentioned about preprint version of their 

top FCNC studies, arXiv:1701.06932v1 and arXiv:1705.05419v1.

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11:00 → 11:10 Update on invisible decay study

Speaker: Satoshi Kawaguchi (Tokyo Institute of Technology (JP))

Slides August_28th.pdf

11:10 → 11:20 Hbb coupling measurement

Speaker: Masahiro Tanaka (Tokyo Institute of Technology (JP))

11:20 → 11:30 Liverpool studies for exotic Higgs at FCCeh

I attach the first version of Michael o'Keefe's Master thesis that summarises our main findings (called 'Study of exotics Higgs Decays at FCC-eh')

Speaker: Uta Klein (University of Liverpool (GB))

delphes_card_FCCeh_PK_finalHFL.dat

FCC Slides.pdf

Study of Exotic Higgs Decay at Electron-Hadron Colliders.pdf

11:30 → 11:40 Higgs to charm

Izzy Harris and Uta studied the optimisation of Higgs to charm variables (based on last year MPHYS results obtained with Daniel Hampson) => NEW: 26 variables could be reduced to 14 variables while Hcc coupling error was slightly improved to 3.7% (assuming 2% remaining background)
Izzy's BSc thesis draft is attached. There a few smaller mistakes in, but the BDT optimisation is quite useful.

18.3.19 I also add Daniel Hampson's Master of Physics thesis about the baseline of developing HFL tagging at LHeC (called Thesis.pdf).

Note: Those files are as submitted by the students and no further text iterations were done, so bare with mistakes by the students.

Speaker: Uta Klein (University of Liverpool (GB))

Finding Higgs to charm decays in electron-proton collisions.pdf

Thesis.pdf

11:40 → 11:50 H to phiphi to 4b

Speaker: Mr Chen Zhang (Peking University)

11:50 → 12:00 Higgs couplings at LHeC and FCC-eh

Speaker: Murat Altınlı (Istanbul University)

12:00 → 12:10 Status of RPC SUSY

Speaker: Dr Kechen Wang (DESY / IHEP)

12:10 → 12:20 Status of Wits Studies

Speakers: Mukesh Kumar (University of the Witwatersrand (ZA)), Xifeng Ruan (University of the Witwatersrand (ZA))

12:20 → 12:30 FCNC top-Higgs couplings

Speaker: hao sun (DaLian University of Technology)

12:30 → 12:40 Top-q-gamma FCNC

Speakers: Orhan CAKIR (Ankara University), Prof. Orhan Cakir (Ankara University (TR)), Orhan Cakir (University of Ankara), Orhan Cakir (University of Ankara (TR)), Orhan Cakir (University of Ankara (TR))