Efficiencies of the BSC Detector at CDF Experiment

Aniel Nieves

Dimitri Tsybychev, Darin Acosta

This Presentation will get into…

• Some insight of what is Particle Physics.

• Proton-antiproton collisions and important concepts related to that subject.

• Simulations of proton-antiproton collisions.

• How we did those simulations.

• Results.

Particle Physics

• Particle physics focus on fundamental particles and their interactions.

• Particle physicists are looking for answers to questions like: Are all the forces a manifestation of a single force? Where does mass come from? or Are there more quarks?

Proton-antiproton Collisions

• We study proton-antiproton (ppbar) interaction with little bias in the type of ppbar interaction.

• The rate is measured. • The rate and the estimated

efficiency are used to calculate the Luminosity (L).

• The Luminosity is used to obtain cross sections of particular processes.

protons antiprotons

p

K

K

K

Cross Section

• Is the effective area a target present to a high energy particle.

• Measured in barns (1barn = 10-24 cm2).

• Useful to compare the probability of a type of interaction to occur against another.

Some Basic Equations

• We measure the rate (R): R = dN / dt = (L )

• L is Instantaneous luminosity:L = N / (t)

• The efficiency is given by: = Ndet / N

• The integrated Luminosity (L) is obtained:

2

1

t

t

// dt det

2

1

NNLt

tL

Fermilab

Beam energy is 1 TeV

The CDF Experiment

BSC

Simulations ppbar Collisions

• Our goal was to estimate the efficiencies.

• To achieve that, we simulate ppbar interactions and the BSC.

• The BSC are scintillators

How we did the simulations

• The simulation is divided in two parts:1st the simulation of the ppbar collision (Pythia and MBR).2nd the simulation of particles interacting with the material of the detector (GEANT).

But to give you an idea…

Particle coming from interaction point and colliding with the detector.

What is coincidence?

A special arrangement of the detectors useful to rule out particles that do not came from IP.

Results

Beam Shower Counters' EfficienciesThe energy of the simulated interaction was 2 TeV. Total cross section for semi-hard interaction for PYTHIA was 74.22mbarn (HC - 39.6 mbarn), for MBR 80.35 mbarn (HC - 40.179 mbarn). Characteristics of run <E1> <E2> <E3> <E4> <E2*2> <E3*3> sigmaPYTHIA (HC+SD+DD) 0.229 ± 0.004 0.340 ± 0.005 0.397 ± 0.005 0.434 ± 0.005 0.158 ± 0.004 0.213 ± 0.004PYTHIA (HC+SD+DD+spr-z) 0.230 ± 0.004 0.342 ± 0.005 0.398 ± 0.005 0.435 ± 0.005 0.162 ± 0.004 0.214 ± 0.004PYTHIA (HC) 0.366 0.535 0.618 0.674 0.282 0.379 ± 0.005PYTHIA (HC+flanges) 0.365 0.532 0.612 0.670 0.279 0.374 ± 0.005PYTHIA (HC+2*flanges) 0.367 0.537 0.619 0.676 0.286 0.382 ± 0.005PYTHIA (HC+flanges+spr-z) 0.367 0.537 0.618 0.674 0.286 0.380 ± 0.005PYTHIA (HC+2*flanges+spr-z) 0.369 0.539 0.619 0.676 0.290 0.383 ± 0.005PYTHIA (HC+ (z_counter + 5cm)) 0.365 0.532 0.616 0.672 0.281 0.374 ± 0.005PYTHIA (HC+spr-z+flanges+var_e) 0.370 0.543 0.625 0.683 0.298 0.394 ± 0.005

MBR (HC) 0.373 0.520 0.589 0.637 0.320 0.399 ± 0.005MBR (SD+HC) 0.303 ± 0.005 0.426 ± 0.005 0.485 ± 0.005 0.527 ± 0.005 0.234 ± 0.004 0.294 ± 0.005MBR (SD) 0.123 ± 0.003 0.187 ± 0.004 0.220 ± 0.004 0.247 ± 0.004 0.008 ± 0.001 0.013 ± 0.003

Final Remarks and Conclusion

• Simulations of ppbar collisions were made to estimate efficiency of detector.

• This is necessary to obtain other physical information.• We obtain results that will be useful for Luminosity

calculations at Fermilab, that can also tell us how frequent can be a certain type of interaction.

• This is not over. There is a lot to do, for example:

The CLC