ECFA Meeting March 9 10, Prague. Alexander Kupčo. Institute of Physics, Center for Particle Physics, Prague

ECFA Meeting March 9, Prague Alexander Kupčo Institute of Physics, Center for Particle Physics, Prague

DIRAC experiment Phase I: Precise measurement of pionium lifetime Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 2

DIRAC experiment Phase I: Precise measurement of pionium lifetime τ 1S = [ 2.91 +0.45 0.38 stat +0.14 0.45 sys] fs Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 3

DIRAC experiment Phase I: Precise measurement of pionium lifetime τ 1S = [ 2.91 +0.45 0.38 stat +0.14 0.45 sys] fs Phase II (in progress): Observation of [π K + ] and [π + K ] atoms and measurement of their lifetimes Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 4

Czech contribution to DIRAC Czech group lead by prof. Čechák (6 physicists + 1 engineer + 1 PhD student + 1 undergrad. student) - Faculty of Nuclear Sciences and Physical Engineering, CTU - Institute of Physics ASCR - Nuclear Physics Institute ASCR Horizontal Hodoscopes for Trigger system Mirrors for Cherenkov detectors Dosimetry measurements of radioactive expositions in the detector Physics: one PhD thesis - study of correlation of particles with small relative velocities Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 5

study of hadron structure and hadron spectroscopy with high intensity muon and hadron beams COMPASS polarized beam (-80%) and target (> 50%) Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 6

COMPASS nucleon spin structure Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 7

Joint Czech Group in COMPASS lead by prof. Finger 18 physicists and engineers, graduate and 8 undergrad. students - Faculty of Mathematics and Physics, Charles University - Faculty of Mechanical Engineering, Czech Technical University - Faculty of Nuclear Sciences and Physical Engineering, CTU - Technical University in Liberec - Institute of Scientific Instruments, ASCR, Brno Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 8

Joint Czech Group in COMPASS Polarized Target - upgrade in 2006 which increased the acceptance RICH detector for particle identification - design of optical imaging system development of multi-channel scintilator detectors for beam monitoring Central data recording - coordinators for muon-beam program Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 9

DØ experiment log(l) 6 4 B s mixing DØ Run II, 1 fb 1 2 90% C.L. (two-sided) 0 14 18 22 26 m s 30 1 [ps ] Amplitude 4 2 data ± 1 σ DØ Run II data ± 1.645 σ (stat.) data ± 1.645 σ (stat. syst.) 0-2 -4 95% CL limit: 14.8ps Expected limit: 14.1ps -1-1 0 5 15 20 25 m s [ps Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 11-1 1 fb -1 ]

DØ experiment - top mass Mass of the Top Quark (*Preliminary) Measurement M top [GeV/c 2 ] CDF-I di-l 167.4 ± 11.4 D -I di-l 168.4 ± 12.8 CDF-II di-l* 164.5 ± 5.5 D -II di-l* 176.6 ± 11.8 CDF-I l+j 176.1 ± 7.3 D -I l+j 180.1 ± 5.3 CDF-II l+j* 173.4 ± 2.8 D -II l+j* 170.6 ± 4.6 CDF-I all-j 186.0 ± 11.5 χ 2 / dof = 8.1 / 8 Tevatron Run-I/II* 172.5 ± 2.3 150 170 190 M top [GeV/c 2 ] Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 12

Single top and Higgs search DØ Run II 0.9 fb -1 Decision trees 4.9 +1.4-1.4 pb Matrix elements 4.6 +1.8-1.5 pb ) - W + Limit / σ(pp WH/ZH/H) BR(H bb/w 2 1 DØ Run II Preliminary 260-950 pb Combination Observed Combination Expected / 14 Analyses 0 1 120 130 140 150 160 170 180 190 200 2 m H (GeV/c ) -1 Bayesian NNs Z. Sullivan PRD 70, 114012 (2004), m t = 175 GeV 5.0 +1.9-1.9-5 0 5 15 σ(pp _ tb+tqb) [pb] first evidence of single top production Higgs is even more challenging Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 13 pb

DØ Collaboration As of today we are: 670 physicists from 91 institutions 50% from non-us institutions (note strong European involvement) 0 post-docs, students 140 graduate Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 14

Czech Group members of the DØ Collaboration since 1997 lead by M. Lokajíček and V. Šimák (6 physicists, 5 graduate student, 4 computer specialists, and 1 technician) As of today we are: 670 physicists from 91 institutions 50% from non-us institutions (note strong European involvement) 0 post-docs, students 140 graduate 8 of us qualified as DØ authors 2 PhD and 1 diploma theses Financed by grants from Ministry of Education and by Center for Particle Physics Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 15

Our contributions in past Run II Upgrade - HV distribution boxes for muon detectors built here in Prague - calibration system for muon trigger (Light Mixing Boxes) - 1 year of silicon detector tests - contribution to the building of Forward Proton Detectors (Roman Pots) Software: code for accessing luminosity information and for normalization of the data Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 16

Computing distributed computing: reconstruction on-site, MC simulation off-site currently, 20 farms provide computing services for DØ DØ computer center in Prague since 1999 (In the beginning, we were using CESNET farms. Currently, we have our own farm built in Institute of Physics) we provide about 5% of total MC production (21M out of 400M events in 2006) which is usually the 4 th to 5 th largest contribution our annual financial contribution to DØ is paid with provided computer services Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 21

Jet energy calibration parton jet particle jet calorimeter jet p CH FH EM hadrons K q g q p Time Motivation: good jet energy calibration is crucial for precision measurements at hadron-hadron colliders where most of the final states involve jets ( E jet ptcl = Ejet det R jet S ) - energy not associated with the hard interaction (U noise, pile-up from previous crossings, additional p p interactions) (R jet ) - calorimeter response to jet (S) - losses due to showering the energy in the calorimeter out or into the jet cone Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 22

JES Group Our responsibilities - offset correction - determination of absolute scale using γ + jet events - closure tests AK is convener of JES group since autumn 2006 Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 23

JES Status DØ preliminary JES based on 0pb 1 sample approved in the end of Feb 2006 first JES version in Run II certified in large enough kinematic 0.14 range ( η < 2.5), 0.12 and reaching uncertainties competitive 0.1 0.08 with Run I Final JES for Run IIa will be based on full Run IIa sample of 1 fb 1 Fractional uncertainty 0.06 0.04 0.02 0 DØ Run II preliminary R cone = 0.7, Total Response Showering Offset 2 η jet = 0.0 uncorr E T,jet (GeV) goal: to improve our understanding of the jet energy calibration and to further reduce the uncertainties Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 24

Physics QCD - high p T jets - multijet final states - diffraction Top physics - top mass in 6-jet channel - t t kinematic properties (p T spectrum) Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 25

High T jet production dy (pb/(gev/c)) T σ/dp 2 d 5 4 3 2 1-1 -2-3 -4 s = 1.96 TeV -1 L ~ 0.8 fb R cone = 0.7 NLO pqcd plus threshold corrections (2-loop) Hadronization corrections applied CTEQ6.1M DØ Run II preliminary µ = µ = p R F T y < 0.4 (x) jet 0.4 < y < 0.8 jet 50 0 200 300 p T (GeV/c) data / theory 2.5 2 1.5 1 0.5 NLO µ R,F = p T CTEQ6.1M R cone = 0.7 Hadronization corrections applied with threshold corrections PDF uncertainty without threshold corrections Data scaled to theory for CTEQ6.1M at p =0 GeV/c at y <0.4 T jet to remove luminosity uncertainty DØ Run II preliminary -1 y < 0.4 L ~ 0.8 fb jet 0 0 0 200 300 400 500 600 700 p (GeV/c) T lumi 8 higher than in RunI reach in p T increased from about 450GeV up to 600GeV good agreement with QCD predictions (no compositeness is seen) systematics (dominated by the JES uncertainty) is smaller than the PDF errors we can learn about gluon structure functions in proton at large x Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 26

Dijet angular decorrelations 1/σ dijet dσ dijet / d φ dijet 5 4 3 2 DØ p T max > 180 GeV ( 8000) 130 < p T max < 180 GeV ( 400) 0 < p T max < 130 GeV ( 20) 75 < p T max < 0 GeV φ dijet 1-1 -2-3 NLO LO NLOJET++ (CTEQ6.1M) µ r = µ f = 0.5 p T max π/2 3π/4 π φ dijet (rad) Phys.Rev.Lett.94:221801,2005 Φ dijet sensitive to the additional radiation in the event first Run II QCD paper first comparison with 2 3 NLO QCD calculation at Tevatron Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 27

Dijet angular decorrelations 1/σ dijet dσ dijet / d φ dijet 5 4 3 2 1-1 -2-3 DØ p T max > 180 GeV ( 8000) 130 < p T max < 180 GeV ( 400) 0 < p T max < 130 GeV ( 20) 75 < p T max < 0 GeV HERWIG 6.505 PYTHIA 6.225 PYTHIA increased ISR (CTEQ6L) π/2 3π/4 π φ dijet (rad) Phys.Rev.Lett.94:221801,2005 data also provide tests of parton shower models in MC event generators CDF Run I tunes of Pythia could not disentangle perturbative effects (represented by parton shower models) from actual non-perturbative contribution from soft underlying event found value of PARP(67)=2.5 used in new Pythia tune (DWT) which is used also at LHC Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 28

Three-jet final states uncorrected dσ / dm3jet [pb/(gev)] 1-1 -2-3 -4-1 L ~ 1.04 fb Jet 8 GeV, P=25960 Jet 25 GeV, P=312 Jet 45 GeV, P=24 Jet 65 GeV, P=5.3 Jet 95 GeV, P=1.3 Jet 125 GeV, P=1 0 200 400 600 800 00 1200 M3jet [GeV] subject of one PhD thesis complete description of three jet final state by measuring all 3-jet observables (M 3jet, jet energy fractions in CMS, angular distributions) tests of 3-jet NLO QCD predictions (NLOJET++) studies of gluon jet properties (3 rd leading jet is mostly a gluon one) improved experimental knowledge about multi-jet final states which are background for various measurements and searches of new physics (top mass, Higgs, ) Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 29

Diffractive physics Diffractive dijets - diffractive dijets more correlated in φ - due to different nature of pomeron induced ISR - thesis finished and will be defended soon Elastic slope dn/dt - dedicated low lumi runs - pots can be moved very close to the beam access to small values of t Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 30

Top mass in 6-jet channel Advantages: statistics, full reconstruction of event (no neutrinos) Disadvantages: no lepton (trigger + significant QCD background), combinatorial ambiguity Run I thesis (m t = 179 14 (stat) 8 (sys) GeV) Run II: vertex b-tagging improved event selection and reduced combinatorial background increased luminosity difficult triggering (kinematic peak of m 3jet near the top mass) Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 31

Top mass in 6-jet channel Advantages: statistics, full reconstruction of event (no neutrinos) Disadvantages: no lepton (trigger + significant QCD background), combinatorial ambiguity increased luminosity difficult triggering (kinematic peak of m 3jet near the top mass) design and effectiveness studies of multi-jet triggers large instantaneous luminosity several p p interactions per bunch X-ing - design of algorithms for jet vertex finding to confirm that all 6-jets are coming from the same p p interaction Top properties - measurement of kinematic properties of t t pairs in l + jets channel Alexander Kupčo, Institute of Physics, Prague ECFA07, Prague page 33