Long Fruitful collaboration between DESY and Japanese institutes On High energy physicsDASP at DORIS 1973-Initiated by professor Masatoshi Koshiba since 1973ZEUS at HERA 1992- LHC 2009-Katsuo TokushukuKEK

The ATLAS DetectorDimensions ~25x25x46mWeight7000 ton density 0.31g/cm31/11/2007*

**ATLAS Detector: construction and commissioningLength : ~ 46 m Radius : ~ 12 m Weight : ~ 7000 tons~ 108 electronic channels~ 3000 km of cables Tracking (||

**ATLAS-KEK (active) members K. Tokushuku (Leader, HLT)TGC H. Iwasaki, (M. Ishino left to Kyoto)TGC LVL-1 (+ upgrade) Trigger O. Sasaki + 1 studentSCT (+upgrade)Y. Unno, S. Terada, Y. Ikegami, Y. Takubo (IBL) + 1 student(J. Tojo left to Kyushu)HLT K. Nagano(muon), S. Tsuno(tau)PhysicsS. Tsuno ( Tau )K. Nagano ( W+c , etc.) + 3 studentsJ. Kanzaki (Top) + 1 studentGeneratorsJ. Kanzaki (Madgraph on GPU), S. Odaka (gamma gamma; GRACE)

permanent staff only (+ few students) No post-docs!-> Close collaboration with JP universities

ATLAS only

On going activities on present detector

KEK-ATLAS activities on Muon Trigger and High Level Trigger (HLT) (K.Nagano)ATLAS Trigger System consists of three levels: -- Level-1: Synchronized, hardware-based (custom-made electronics) -- Level-2 and Event Filter (before and after event-building), called Higher Level Trigger (HLT) altogether. Software-based, making use of commodity products e.g. PCs KEK-ATLAS has been working on the muon trigger, in particular HLT muon trigger since year 2006, in the following topics: -- Coordination of ATLAS Muon Trigger Group * K.Nagano: 2010.32012.2 Deputy convener 2012.3 Convener -- ATLAS Muon Trigger Menus * Logic and strategy formulation * Development and maintenance of the logic software -- Level-2 muon-standalone trigger algorithm * Development, commissioning and performance evaluation with the LHC real collision data * Redesigning and upgrading the current software -- Development of the trigger analysis software framework

Some highlights from KEK-ATLAS muon trigger activitiesDevelopment of trigger analysis framework Masters thesis Widely used in Trigger CommunityL2 muon-standalone trigger performance evaluation Masters thesis ATLAS-CONF-2010-095LHCC meeting May/2010 (O. Igonkina)Muon Trigger Menus formulationATLAS Muon Trigger Coordination 2009 runs (900GeV) ATLAS-CONF-2010-013 2010 runs (7 TeV) ATLAS-CONF-2010-095 Trigger paper Eur.Phys.J C72 (2012) 1849 2011 runs (7 TeV) CONF note in preparation Stable, high efficient, and robust (wrt pileup) performance

Physics analyses

Analysis on production of W bosons associated with charm mesonsDirect sensitivity to strange quarks in proton -- Opposite charge between W and c In the current QCD fits for PDFs, strange PDF is only assumed to be 0.31 (in HERA-PDF fits) of d-sea quark PDFs at the evolution starting scale of Q20=1.9 GeV2 (Constraint only from CCFR di-muon data) W+c at LHC expected to give strongest constraint to PDF fits W+D+- -- Cut on decay length etc.Mass(D+- candidates) OS: W+ D-, W- D+ SS: W+ D+, W- D-Join collaboration with Moscow state univ. (L. Gladilin)D-> K modeATLAS only

Standard Model H -> tt search (S. Tsuno) Use double hadronic tau trigger. Nice peak at Z. (well-control of QCD events) Make use of boosted event topology.https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/CONFNOTES/ATLAS-CONF-2012-014/ Introduction of new categories in leplep- and lephad-channel, (4 categories in leplep, 7 in lephad-channel) Inclusion of hadhad-channel (al hadronic).H -> tt -> hadhad (all hadronic) channel :Major update from the previous search :Collinear mass in hadhad-channel

H->tt sensitivitylephad channelhadhad channelThe expected sensitivity is almost comparable between lephad- and hadhad-channels.Combined sensitivity is around 3.0xSMat mH=125 GeV.Combined sensitivity with all channels; leplep, lephad and hadhad.hadhad-channel is comparable withlephad-channel.

Prospect of tau performanceMost of tau-physics analyses are going to use the combined trigger with tau.Offline tau reconstruction will be more and more deeply connected to the tau trigger performance. desired to have a synchronized algorithm between offline and trigger. detailed understandings in term of trigger performance.Plots show the presence of pi0 in the tau decay will prevent the efficient reconstruction at L1 with isolation requirement.3-prong + no pi03-prong + pi0Trigger efficiency measurement will becrucial for combined trigger.L1L1Constant isolationdegraded high pTbut also by presenceof pi0 in tau decay.ATLAS only

Development of the topological triggerOne attempt to improve the trigger acceptance wasto ask the 2-tau + jets or 2-tau with narrower angle.We found they are potentially very useful to tag the Higgs->tautau events while keeping lower rate.Roughly, same acceptance but the rate is reduced down to -50%.Test of di-tau+ jet trigger:Offline selection: two tau pT>20GeV, + jet pT>20GeVTest of di-tau+ jet trigger:Offline selection: two tau pT>20GeV, + Df(t,t) < 3(at EF)If those selection could be done at L1, the physics performance will be much-improved.ATLAS only

Acceptancedi-taudi-tau+jetdi-tau + dfgg-fusion H(120)38.6%28.3%29.7%VBF H(120)47.3%44.6%40.7%

Acceptancedi-taudi-tau+jetdi-tau + dfgg-fusion H(120)41.0%26.2%33.6%VBF H(120)48.5%45.9%45.3%

ATLAS detector upgrade planPhase 1 minor upgrade: An additional pixel layer Replacement of Inner Endcap muon chambersPhase 2: Major upgrade: Complete replacement of the inner trackers (All-silicon tracker)R&D activities in JapanR&D of radiation- tolerant sensorsDevelopment of short strip detector moduleR&D of pixel sensors development of muon and combined triggers. Good collaboration with DESY and Germaninstitutes is essential

Beam testsAt RNCP of Osaka Univ., e.g.392 MeV protons, ~80 HzAt DESY 4 GeV/c electron, ~4 KHzPossible cooperationBeamtests at DESYEUDET telescope modules

Development of Strip SensorsKEKMajor developer of the silicon sensors (strips and pixels)Novel p-type sensors for HL-LHCFocusing barrel sensorsDESYFocusing endcap sensorsPossible cooperationStrip sensors development and evaluationStudy with miniature sensors95 miniature sensors have been at DESYLorentz angle study with BZ3 etc.Irradiations, beamtests, P-type strip sensor 6-in. barrel wafer10 cm x 10 cm barrel sensor

Modules, Macro AssembliesKEK (+Univ. Geneve)High thermal conductivity Cu/Polyimide hybridsCarbon-carbon substrate bridgeMacro assemblyCarbon-carbon cooling platesBus cableSMC (SuperModule Control) hybridPossible cooperationEngineering materials available in JapanSMC hybrid designBus cable development

Macro assembly with ABCN13 chips ABCN25 Doubleside 80 chips module

Universal DAQ moduleSi-TCPTechnology to realize TCP/IP and UDP communication with FPGA.IEEE Trans. Nucl. Sci. Vol. 55, No. 3, 2008Data transfer rate: 100 Mbps (The latest version: 1 Gbps)All the libraries for the communication is prepared in Unix-based OSUser can focus on only development of program in User-FPGASEABAS board4 sub-cards dedicated for each test can be attachedPossible cooperationSEABAS board availabilityApplication for specific DAQ system

Strip sensors beamtest

KEK-ATLAS activities on Muon Trigger Upgrade Feasibility study on Level-1 (L1) Muon trigger upgrade -- Understanding of backgrounds in muon system and origin of L1 muon trigger rates -- Feasibility study to establish new cutsR&D studies for Level-1 Muon trigger by using Monitored Drift Tubes (precision chambers)

Activities on accelerator upgrade

Nb3Al cable produced by NIMS-KEK collaboration.Nb3Al has better performance then Nb3Sn at the high stress condition. (But not it turned out that R&D took longer. -> R&D for HE-LHC) Design work for the separation magnet D2 Toward the LHC upgrade (accelerator R&D)Recently the design group for High-Luminosity LHC is formed.KEK is contributing to the R&D for the two key technologies: High-field magnet for the IP regions, Crab cavity, High-power injectorin close collaboration with CERN and the other labs

Various designs of crab cavity 5 cavities newly installed in CERN PS-B.New metal arroy (FT3L) developed for J-PARC upgrade is used.Toward the LHC upgrade (accelerator R&D)Recently the design group for High-Luminosity LHC is formed.KEK is contributing to the R&D for the two key technologies: High-field magnet for the IP regions, Crab cavity, High-power injectorin close collaboration with CERN and the other labs

SummaryIn the ATLAS collaborations, KEK is responsible for TGC, Endcap LVL1 muon trigger, SCT and HLT.For ATLAS upgrade, KEK is working for LVL1 muon trigger upgrade and tracker upgrade.R&D for the silicon trackers (strips and pixels) are the most important activity in the next several years. In this area, a lot of collaboration between KEK and DESY are possible and plausible.Collaboration on physics analyses can be done at the personal level. Once there is a common interest, it is worth to try to get a fund (JSPS/DAAD JP-DE fund).KEK-CERN collaboration on the LHC accelerator upgrade is in place.