Search found 48 matches

by Anitusar
Sat Dec 19, 2009 11:05 am
Forum: Science
Topic: Uncertainty in calculations
Replies: 12
Views: 5200

Re: Uncertainty in calculations

So, you to make sure it is understood correctly. Imprecise measurements of parameters or initial conditions, might lead to imprecision of a prediction. Yes. There is even a uncertainty principle. It says, that you cannot measure two correlated thinks with infinite precision. For example, if you wan...
by Anitusar
Fri Dec 18, 2009 10:47 am
Forum: New Users Start Here
Topic: LHC exhibition in Germany
Replies: 4
Views: 2253

Re: LHC exhibition in Germany

Yes, its based on the exhibition done in Berlin last year. It has been transformed into a mobile one, so that it can been shown around the country. By the way, the Berlin exhibition had about 30.000 visitors :!:
by Anitusar
Fri Dec 18, 2009 10:40 am
Forum: Science
Topic: Uncertainty in calculations
Replies: 12
Views: 5200

Re: Uncertainty in calculations

Which particles do you mean? The protons in the beam are not treated individually. It's also not neccesary. And all reconstructed particles in the experiment are using measurements. You can calculate back wards using the measured paricles to get the particles which decayed (reconstruct their mass an...
by Anitusar
Thu Dec 17, 2009 6:26 pm
Forum: LHCb
Topic: Q&A with a LHCb expert
Replies: 6
Views: 9219

Re: Q&A with a LHCb expert

At what processes do you look? Of course there are lot of things various people look for (even directly for the Higgs). But there are a few major studies: * The Tree-level determination of gamma * Charmless charged two-body B decays * Measurement of mixing-induced CP violation in B_s -> J/psi phi * ...
by Anitusar
Thu Dec 17, 2009 6:25 pm
Forum: LHCb
Topic: Q&A with a LHCb expert
Replies: 6
Views: 9219

Re: Q&A with a LHCb expert

How do you measure it? In an analyse you look at a specific process (see below). Lets take Bs -> J/Psi (mu+ mu-) Phi(K+ K-) as an example (In this decay the final state y and ay are the same, so look at b going into this state and anti-b going into this state). In a first step the event is reconstru...
by Anitusar
Thu Dec 17, 2009 6:24 pm
Forum: LHCb
Topic: Q&A with a LHCb expert
Replies: 6
Views: 9219

Re: Q&A with a LHCb expert

A tiny bit of theory Within the standard model (SM) there is only one place, where you can generate such processes. It is the CKM matrix (Cabibbo, Kobayashi, Maskawa). This matrix describes, how you can change a downtyp quark (d,s,b) into an uptyp quark (u,c,t) via the weak interaction (emitting a W...
by Anitusar
Thu Dec 17, 2009 6:23 pm
Forum: LHCb
Topic: Q&A with a LHCb expert
Replies: 6
Views: 9219

Re: Q&A with a LHCb expert

Motivation It all starts with the biggest asymmetry one can measure: our universe :) . When the universe was cooling down, photons (radiation) started to converted into particle and antiparticle. And particles and antiparticles annihilated into photons. So one would expect some kind of equilibrium b...
by Anitusar
Thu Dec 17, 2009 6:22 pm
Forum: LHCb
Topic: Q&A with a LHCb expert
Replies: 6
Views: 9219

Re: Q&A with a LHCb expert

WOW, I am an expert :D Okay, i tried to summarise the informations. But first i have to say that i am not an expert on the theory or the final results LHCb wants to measure. Nevertheless i picked up some informations from various talks given about these subjects, which i will try to explain in the n...
by Anitusar
Thu Dec 17, 2009 6:08 pm
Forum: LHCb
Topic: Event Display
Replies: 12
Views: 15397

Re: Event Display

As promised in the live chat, i asked for the colour codes. Turns out, not as simple as one would think. So i hope i understood this correctly. The program that produces this Plots is called Panoramix. This package visualises all objects, that can be generated by other LHCb software packages. So wha...
by Anitusar
Mon Dec 14, 2009 2:16 pm
Forum: The Accelerator
Topic: basic accelerator theory from a great discussion in chat
Replies: 7
Views: 10610

Re: basic accelerator theory from a great discussion in chat

So from an engineers POV the LHC is a very complex control loop with lots of non-independent tuning parameters and lots of disturbances. Now I have an idea why there was LHC@Home to simulate the behavior of the beams. I wonder if they have to find new settings after the break, small hysteretic effe...
by Anitusar
Sun Dec 13, 2009 4:44 pm
Forum: The Accelerator
Topic: LHC Theme Song ?
Replies: 13
Views: 6206

Re: LHC Theme Song ?

DCWhitworth wrote: I happen to think it's the best explanation of the LHC I've ever come across. Probably what got me interested in it in the frst place.
Yeah, it is really all one needs to know about the LHC in just under 5min.
by Anitusar
Sun Dec 13, 2009 4:27 pm
Forum: The Accelerator
Topic: LHC Theme Song ?
Replies: 13
Views: 6206

Re: LHC Theme Song ?

Not bad.

Of course, there is always the Large Hadron Rap:

http://www.youtube.com/watch?v=j50ZssEojtM

:D 8-)
by Anitusar
Sat Dec 12, 2009 9:44 pm
Forum: New Users Start Here
Topic: LHC exhibition in Germany
Replies: 4
Views: 2253

LHC exhibition in Germany

If you are in Germany, look out for the exhibition "Die Weltmaschine". It presents spare pieces from the experiments and you can get in direct contact with physisits working at the LHC experiments.

It is currently in Heidelberg until the 20th of December. In January it will be in Frankfurt.
by Anitusar
Sat Dec 12, 2009 9:36 pm
Forum: New Users Start Here
Topic: Hello to all
Replies: 7
Views: 3209

Re: Hello to all

Please somebody explain me: What is a color charge? ;-) It is the charge of the strong force ;) Think of it the same way as about electric charge. The only difference is, that there is not only 2 kinds (+ and -), but three types of charge. As you have to name it someway, someone choose red, green a...
by Anitusar
Sat Dec 12, 2009 6:24 pm
Forum: New Users Start Here
Topic: Hello to all
Replies: 7
Views: 3209

Re: Hello to all

Please somebody explain me: What is a color charge? ;-) It is the charge of the strong force ;) Think of it the same way as about electric charge. The only difference is, that there is not only 2 kinds (+ and -), but three types of charge. As you have to name it someway, someone choose red, green a...