jinr participation, achievements, short- and long-term plans

В.Бедняков, 13 июня 2007, ЛВЭ

JINR participation, achievements,

short- and long-term plans

The ATLAS Physics Program

Diameter 25 mBarrel toroid length 26 mEnd-cap end-wall chamber span 46 mOverall weight 7000 Tons

Bednyakov V.A., HS07


Collisions at the LHC

Slide by T. Virdee


An Aerial View of Point-1

(Across the street from the CERN main entrance)


The Underground Cavern at Pit-1 for the ATLAS Detector


The proposal on the participation of the JINR team in ATLAS was firstly presented in 1995. The PAC recommended this project for approval on 24 November 1995.

Further on status reports on this projects have been regularly (yearly) presented at PAC and JINR Scientific Council meetings.

JINR ATLAS History

In 1995, 6567 kUSD+140 kHours of workshop were requested, including 4069 kUSD from the JINR budget


The ATLAS detector

Over the last decade JINR-ATLAS team was deeply involved in designing, construction, tests and assembly of the major systems of ATLAS:

Inner Detector

Tile Calorimeter

Liquid Argon End Cap Calorimeter

Muon detector

Common Items (Toroid Warm Structure and others)

Participation in the Physics Program was always considered as the most important target. Till 2003 this work has been performed mainly in “background” regime, essentially based on individual efforts, promoted with limited resources case-by-case (as well as for software developments and general computing infrastructure of ATLAS).


15 x 12 x 100 x 6000 = 1.08 108 CHF

ATLAS costs:


JINR Workshops on the ATLAS Physics

Early 2004 the JINR-ATLAS team management decided to establish a regular framework (series of workshops) to promote physics-oriented activities at home, aimed to:

Open the door for new ideas (also attract new collaborators, interested in future physics at LHC);

Monitoring of ongoing activities and select most promising ones to provide the necessary support, in particular for visiting conferences and dedicated ATLAS meetings;

Enrich “home community” by involving physicists from JINR member countries who have less possibilities in computing and networking, to make JINR-ATLAS resources and experience widely available;

Keep people informed about recent software developments and dedicated computing infrastructure at JINR.

Web site: http://www.atlas-jinr.ru/


Main ATLAS Physical topics

Standard Model Physics

Higgs Boson Physics SUSY Physics Exotics Physics Top Quark Physics Heavy Ions PhysicsB Physics


What we are doing

JINR ATLAS Physics team


SANC

Project SANC (Support of Analytical and Numerical Calculations for Experiments at Colliders). http://brg.jinr.ru/

D.Bardin, L.Kalinovskaya, P.Christova, et al (DLNP, JINR), A.Arbuzov, S.Bondarenko (BLTP, JINR).

This very ambitious project starts to produce applications (generators, etc)which allow investigations of prospects for observation of the

physical phenomena at the LHC with ATLAS detector.


SANC


SANC, 2007

В.Бедняков, 13 июня 2007, ЛВЭ 15

Search for Higgs boson with mass 115-160 GeV by means of decay H->Z+gamma and Z->2l within ATLAS software APHENA. (Usubov et al).

Search for Higgs boson (400-1000 GeV) decaying H->ZZ->lljj and being produced via vector boson fusion (Usubov, Kultchitski, et al).

Seach for charged Higgs boson via tau-nu_tau decay (Chelkov, et al.)

Higgs boson(s)

Search for the SM Higgs boson via decay H→4μ.Search for the SM Higgs boson via decay H→4μ.Full ATLAS simulation, etc.

G.Chelkov, I.Boyko, K.Nikolaev, et al

Study of associative production of Higgs boson and top-antitop pair .


JINR

Higgs boson(s)


Higgs boson(s)

Search for the SM Higgs boson via decay H→4μ.Search for the SM Higgs boson via decay H→4μ.Full ATLAS simulation. G.Chelkov, I.Boyko, K.Nikolaev, et al

SIGNAL: At CERN with SANC generator (with 1-loop corrections and quantum effects of final state muon identity, for the 1st time) 30 000 H→ decays were generated for MH=130, 160 GeV/c2. For comparison 10 000 H→ 4 decays were generated with PYTHIA.

BACKGROUND: With PYTHIA (and ACERMC) generators 30 000 background events for pp→ZZ, pp→Zbb, with 4 final state muons were simulated. Single Z boson coincidence events “Z+Z” were also simulated. Almost all background events (1/3 of all data) were simulated at LIT farm in Dubna, where modern (the latest versions) ATLAS software are installed.

Detector simulation and event reconstruction were carried out completely within modern ALTAS software (C++, ATHENA, GEANT-4, AOD, Root). The results were compared with results obtained earlier (with Fortran, ATLSIM, GEANT-3, HBOOK). CERN and Dubna events (signal and background) were developed in the same manner. The CERN and Dubna simulation and analysis gave almost the same results.


130 GeV

160 GeV

Reconstructed events

Higgs boson, H→4μ


Generator SANC predicts higher than PYTHIA number of selected decays H→ (about 10-15%). There are two reasons: a higher selection efficiency and larger predicted width of the decay.

Completed

Higgs boson, H→4μ

The “golden channel” H4leptons is one of the most promissing for the early discovery. For the light Higgs (120-160 GeV) the signal is low (tens events per year), but the selection efficiency is high and the background is almost zero. The full simulation study shows that H4μ alone ensures a ~5σ discovery after one year of nominal luminosity.


Higgs boson(s)

to search for Higgs decay


Higgs boson, H→Zγ, etc

Search for Higgs boson with mass 115-160 GeV by means of decay H->Z+gamma and Z->2l within ATLAS software APHENA. (Usubov et

al). to be completed in 2007


Higgs boson(s)

1) Search for Higgs boson with mass 115-160 GeV/c by means of associative

production of Higgs and Gauge Bosons (pp→W(Z)+H+X) and Higgs decay

into bb-pair (H→2b→2b-jets).

2) Study the ATLAS large-mass Higgs discovery potential by means of

reactions H→2W→2lν, H→2W→lνjj and H→2Z→2lν, H→2Z→lljj.

Proposals rely on the Higgs boson production via the Vector Boson Fusion

mechanism (the two accompanying forward jets allow very good background

reduction) and on the maximal Higgs decay rates into WW- or ZZ-pair at

M=400—1000 GeV.

One needs a Higgs Coherence !


What IS this Higgs Coherence?

Higgs boson main decay channels (in SM and beyond): H HWW* H H4leptons pp ttH+X, Hbb, + Higgs properties (self couplings) …

Our potential important task is to check – How the Higgs boson decaying, for example, into 4 muons “shows” itself in the other allowed decays (into 2 photons, bb-pair, etc)?

One needs this for the cross-check and the SM EWSB: Is this Higgs the same one, or some another one?


Top quark physics

Verification of the top-quark charge (is it +2/3 or -4/3 ?):

ATLAS will be able to verify top quark charge afteranalyzing of data taken 1-2 weeks of LHC operation.

Search for narrow neutral resonance state (like Z‘ boson) decaying into the top-antitop pairs on the basis of ATLAS top WG data challenge (Khramov, Tonojan. Bednyakov, Rusakovich).

Accurate investigation of single top quark production at LHC (in the SANC framework by Bardin et al.)

Study of associative production of Higgs boson and top-antitop pair .


Top quark physics

Verification of the of the top-quark charge (is it +2/3 ?):

ATLAS will be able to verify top quark charge afteranalyzing of data taken 1-2 weeks of LHC operation

The work was presented at ATLAS Top WG Meeting (23 March 2006).

The article was submitted to ATLAS Notes.

Completed

ATLAS-JINR Physics Workshop 14 April 2006 1A. Tonoyan

Top quark charge measurementvia determination of its decay

products charges(Full & Fast Simulation)

V. Bednyakov, E. K hramov, N. Rusakovich, A. Tonoyan(J INR, Dubna, Russia)


Top quark physics

E. Khramov ATLAS-JINR Workshop, 22 Dec 2006 1

Search for resonances at the ATLAS (FullSim)

E. Khramov, V. Bednyakov, N. Rusakovich, A. Tonoyan

tt

5σ discovery level

Completed


Higgs boson, pp→Htt, etc

Early stage

Started search for Higgs boson production together with top-antitop pair pp→Htt (within ATLAS software by Akhmedov, Zorin and Titkova).

Higgs boson mass reconstruction via electron-positron pair within EventView software and Root 5.14 was performed.


Exotics, Spin-2 gravitons (EDs)

The search for and identification of the graviton-like Kaluza-Klein states in the lepton-pair production at LHC via new CENTER-EDGE ASYMMETRYCENTER-EDGE ASYMMETRY

was proposed by A.Pankov (Gomel).

ATLAS-JINR Physics Workshop 14.04.2006 1

Centre-edge asymmetry in the ADD and RS scenarios in lepton pair

production at LHC energies

V.A. Bednyakov, A.A. Pankov, Inna Serenkova, N.A. Rusakovich

LNP, JINR, Dubna

&

Gomel State University

&

ICTP Affiliated Centre at the Technical University of Gomel

PYTHIA+ADDThe A_CE allows isolation of spin-2 graviton contribution -- unique graviton exchange signature.


Exotics, LFV

ATLAS sensitivity is about

10-8 for τ τ μμμ μμμ (better x10 of current

limit) 10-7 for τ τ μγ μγ

Study of rare LFV tau decays in ATLAS: τ τ

μμμμμμ and τ τ μγ μγ

V.Zhuravlov et al

pp W nb19108

pp Z nb3 108

pp BB D

b2.41011

Sources of leptons at LHC 1 year of low luminosity = 10 fb-1

December 22, 2006 JINR ATLAS meeting 1

Proposal f or search ofτ μμμ

@ ATLAS

V.Zhuravlov

NEOVP-ATLAS


Exotics, Monopol

Two-photon production and detection of the monopole-antimonopolemonopole-antimonopole pairs at LHC

Yu. Kurochkin, I.Satsunkevich, D. Shuolkavy, S. Yanush (Minsk),V. Kukhtin, Yu. Kultchitski et al (JINR)

Large ionization, like nucleus with Z=70

pp X M M X

Some remarks about magnetic monopoles at

ATLAS

I.S.Satsunkevich

Дубна, 22.12.2006


g + g → gluino + gluino 1 pb

SIGNATURE:4 b-jets + 4 muons + Et

miss

m0 = 1400 GeVm1/2 = 180 GeVA = 0sign(μ) = +1tanβ = 30

Pythia within ATHENA,

B-vertex taging LARGE!

Almost background-less 150 events/year

Search for gluinos with ATLAS


SUSY, Gluinos

Search for SUSY at ATLAS with leptonsV.Bednyakov, Y.Budagov, A.Gladyshev, D.Kazakov, J.Khubua, E. Khramov


SUSY, Gluinos

m1/2=170 GeV m1/2=180 GeV m1/2=190 GeV

total events 88380 63630 43200

di-lepton 1057 681 529

lepton+jets 17040 12339 8104

Gluinos can be observed and SUSY parameters can be separated

m1/2


SUSY

1. Study (full simulation) of prospects for registration (with ATLAS) the SUSY gluinos (at very specific and very promising EGRET MSSM region) by means of two main gluino decay channels (4b-quarks+4leptons+E_missing and 4b-quarks+2jets+2leptons-E_missing). 2. Search for and investigation of (via fast and full detector simulations) all possible background processes (QCD, qq(gg)->4b+2l+2q, etc) for the above-mentioned SUSY process. Study of influence of relevant miss-tagging of b-jets and muons.

3. Study of prospects of registration of “weak SUSY” processes at the same EGRET MSSM region (complimentary to the above-mentioned gluino production). In these processes one expects, for example, 3leptons+neutrino+E_missing (due to the two lightest neutralinos which escape detection) and one isolated lepton (or jet) accompanied by (very) large missed “transverse” energy (due to W boson decay into neutraino and charghino). Both (gluino and “weak”) investigations are very important for the coherent SUSY search strategy.

(E.Khramov, V.Bednyakov, Yu.Budagov, A.Gladyshev, D.Kazakov, J.Khubua, S.Karpov, I.Titkova + students+ CERN colleagues)


SUSY Exotics

Study of R-hadrons detection possibility with ATLAS

01.09.2007 1

Study of R-hadrons detection possibility at

ATLAS

В. Шмакова

Big mass >100 GeV Big mass >100 GeV R-hadron -- passive gluinoR-hadron -- passive gluino

+ interacting + interacting ππ//ρρ/K/p/n cloud/K/p/n cloudIn a nuclear interaction, they may flip In a nuclear interaction, they may flip charge and baryon number.charge and baryon number.

High transverse momentum for charged hadrons Heavy ionization in the tracking system Missing transverse energy due to large R-hadron mass “Small” E/p distribution Large time-of-flight, measurable with the muon chambers and TileCal

Signatures:

V.Smakova, G.Chelkov, R.Leitner


Heavy Ions

V.Pozdnyakov+Full ATLAS simulation of Z0- in pp-,HIproduction is carried out. Point-like Z0

production isnot influenced by QGP, so the study of jet

quenchingprovided by Z0. One month HI running gives

5000 Z0 in the muon mode. The usage of this mode ishelpful in study of jet quenching.Back-to-back configuration of Z0+jet event is tool for the jet reconstruction.

Jet quenching is one of the probe of the Condensed Nuclear Matter (QG-Plasma)

ffbar*/Z0

Z reconstructionJINR/ ATLAS meet V.Pozdnyakov 22.12.06

and (Z0 +jet) in HI

CONTENT:

• high pT jets• open charm

SUMMARY

• collisions and observables

• (Z0+jet) and an effect of jet quenching

• muon and electron pairs

• jets of interest generator (HIJING)• high pT Z0and jets


Quark-gluon structure functions

The possibilities of measuring at the LHCthe gluon distributions in the proton by means of simultaneous registration of the direct photons (Z-bosons) and jets ("gamma/Z+jet" events)

Investigation (within SANC) of possibility to apply an accurate Drell-Yan calculations for LHC luminosity monitoring and Parton-Distribution-Function measurements.

Development of a new generator for PDFs which obey QCD evolution equations at very low Feynman x and study of their influence on the cross sections of the basic LHC processes (by A.Kotikov, D. and V. Peshekhonov).

PDF monitoring via D- or B-meson yields (Lykasov)?


Standard Model, Drell-Yan

P.Starovoitov et al (Minsk) have considered two-photon mechanism of Drell-Yan lepton pair production in pp-collisions

Two-photon creation of lepton pairs in pp-collisionsN. Shumeiko, A. Soroko, P. Starovoitov

We study another possibility to produce lepton pairs in hadroncollisions, namely, the two-photon exchangeThe two-photon

contribution is not negligible!


Study of Drell-Yan processes in ATLAS

Precision calculations of the Drell-Yan process are carried out (SANC project)

From SM Lagrangian to event distributions

Including EW and QCD NLO corrections

Participating in the international group (Les Houche and TEV4LHC workshops

At the same time, the experimental study of the process is prepared usinig full ATLAS simulation/reconstruction

The results show that already with a decent LHC luminosity the cross-section can be measured with precision about 1% Reconstructed invariant mass

of Z→μμ (1 year of LHC run)


Standard Model, applications


Some short-term plans

Top-quark Physics Can be done rather quickly Important test of SM (charge, mass, etc) Background for SUSY, Exotics, etc Energy calibration via Z,W and top, etc Is the Top “the same” in all ”top” observables?

Heavy Ions Physics QGP jet quenching via Z-jet events, γ-γ physics

Standard Model Physics Parton DF verification in 2-jet events, B-mesons Two-photon Drell-Yan processes Gamma/Z-jet events and Gluon DF W, Z – properties, etc


Higgs Physics H→4μ, H→bb, H→, H→Zγ, All other Higgs decay channels

SUSY Physics How “the first observed” SUSY-particle shows itself in the

other SUSY-channels? (Coherence) SUSY is background for SUSY Stop, Gluinos, Same-sign dileptons Charged Higgs-boson SUSY Dark Matter Search with ATLAS, etc

Exotics Physics SUSY R-hadrons (Travel ATLAS without decays) SUSY long-living Staus, Stops, etc Graviton (Spin=2) via Asymmetry_CE and via resonances Monopoles, etc Rare tau-lepton decays

Some long-term plans


Preparation for the ATLAS data analysis at JINR

Since January 2007 JINR site is successfully integrated in the ATLAS DDM (Distributed Data Management system) Training of use of distributed analysis tools (GANGA) is ongoing. Recent versions of ATLAS software are installed at JINR (11.0.41, 12.0.31, 12.0.6, 12.5.0)

19.04.2007 the Tutorial on ATLAS Grid tools and distributed data analysis took place at JINR – the premier in Russian ATLAS Tier-2!

Russian and JINR physicists participants of ATLAS experiment train and practise with Grid and the GANGA


ConclusionsWe have enough attractive ideas in the ATLAS research program.

Some of above proposals (Higgs, Top) have already passed experimental procedure of simulations, background estimates and reconstructions in the ATLAS. With these tools we are ready to meet the first real data from the LHC.

Have ATLAS software installed at JINR

Have GRID and have participated in the Data Generation

Have clear short- and long-term plans

Have contacts with Russian ATLAS community

Have fruitfully working JINR-ATLAS-Physics Workshops and still invite the other Dubna-LHC groups (CMS, ALICE) to join us. Despite of some differences (detector particularities and software used) we all could get a lot of benefit from mutual discussions.

My urgent goals: My urgent goals: DATA access,DATA access, ATLAS soft at JINR, Early PhysicsATLAS soft at JINR, Early Physics

jinr participation, achievements, short- and long-term plans

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