Large hadrons collider [ATLAS]

[threadmark]

When protons collide in ATLAS, it shows some of the particles in close proximity to the collision with a curved trajectory. The cool thing is, some curve away from the ground. I’m trying to understand what influences this trajectory. If anyone can give me some info to help that would be great.

thanks TM

 

[ZapperZ]

Er.. lead particles at 7 TeV at the LHC? In ATLAS? When did this happen?

Zz.

 

[threadmark]

Hope this helps; it’s tagged with the date and time.

 

[ZapperZ]

Where does it say that these are LEAD particles?

I know of these displays. I can look at it live upstairs at the ATLAS computing center.

Zz.

 

[threadmark]

the image is showing new particles.I really want to understand how the new particles curve like this.

 

[humanino]

If those are data, they must be proton-proton collision, not lead. The trajectories of charged particles curve in a magnetic field. The sign of the curvature depends on the charge. Gravity is irrelevant.

 

[ZapperZ]

Is ATLAS even designed to look at heavy ion collision? I thought that's what ALICE is for?

Zz.

 

[threadmark]

Sorry, protons not lead.

 

[the_house]

Those look like proton-proton events. Heavy ion collisions create many more particles, http://en.wikipedia.org/wiki/File:First_Gold_Beam-Beam_Collision_Events_at_RHIC_at_100_100_GeV_c_per_beam_recorded_by_STAR.jpg" . Of course, that make sense since there haven't been any heavy ion collisions yet at the LHC. I believe there's still hope for Lead-Lead collisions before the end of the year, but there are no plans for the energy to ever be as high as 7 TeV per nucleon pair. I believe the max was originally going to be 5.5 TeV, although I have no idea what the plan is for the first runs.

Is ATLAS even designed to look at heavy ion collision? I thought that's what ALICE is for?

All the major detectors (maybe not LHCb, I'm not sure) will make measurements for Lead-Lead collisions, but you're right that only ALICE was designed for them, and so will make the most useful measurements.

 

[ansgar]

the curving is due to the Lorentz force, charged particles bend when traveling in magnetic field

 

[threadmark]

Positive charged particles in a magnetic field

Is the magnetic field a constant influence to positive charged particles? If so how can this cause be determined if it cannot be eliminated from the collision? Is the collision put under different magnetic strengths to see if the curved orbits are influenced?

tm

 

[Vanadium 50]

The field is constant. The curvature radius is proportional to B/pT.

 

[threadmark]

When the protons collide, what does it create bosons, fermions or a mix?

 

[diggy]

When the protons collide, what does it create bosons, fermions or a mix?

A mix.