World's largest particle accelerator built by the CERN (European Organization for Nuclear Research) near the Franco-Swiss frontier near Geneva, Switzerland. It is designed to collide beams of protons of up to 7 TeV. It contains the important detectors ALICE, ATLAS, CMS and LHCb.

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Hadron Supercollider - How does smashing protons reveal facts of the inception of our universe?

How does smashing protons at high velocity reveal how our universe was formed? At some point, wouldn't the atoms need to come together in order to form planets etc? I am a curious student- not a ...
7
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2answers
273 views

How detectors in particle colliders can differentiate neutrons from antineutrons?

Their mass is the same. None of them interacts with EM fields. And their decay (around 1000s) is far too slow to see their decay products yet in the detector. How is it then possible to differentiate ...
3
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2answers
49 views

Nuclear fusion using electromagnetic fields

I was just thinking about how deuterium and tritium are charged particles and so I couldn't help but wonder why we don't use the same process used in the LHC(electromagnetic fields to accelerate ...
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2answers
69 views

Where can I find the datasets from LHC?

I know that most of the datasets from ATLAS or other particle physics experiments are terabytes, but I was just curious is there any place where one can find them to download? And one more question, ...
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116 views

LHC data and mathematics of QFT

I'm reading Frederic's Paugam Towards the Mathematics of Quantum Field Theory, an advanced theoretical physics book. I would like to know how I could apply the theories in this book. For example, ...
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2answers
94 views

Can the Large Hadron Collider break the speed of light? [closed]

Can Large Hadron Collider experiments break the speed of light at some point in the future?
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3answers
145 views

What are the main algorithms the LHC particle detectors use to reconstruct decay pathways?

I am just starting to look into how we understand the data from particle collisions. My question is, what are the algorithms or ways that these detectors interpret the data? Are there standard ...
3
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1answer
74 views

Has the possibility of Higgs boson being a composite particle excluded already?

I heard some theory, such as technicolor, predicts the Higgs-like particle discovered at LHC should be a composite particle (correct me if I am wrong). Has this possible been completely excluded ...
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3answers
93 views

Why do physicists use LHC?

My question is why are we colliding particles in LHC to produce new ones? And these particles that they sometimes say live for a fraction of a second, how in space they exists then? In space all ...
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2answers
84 views

For what rare events was the LHC built?

I understand that for low cross-section events a very high luminosity is necessary in order to obtain enough data to produce meaningful statistics. That is why the LHC was built. But which are these ...
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0answers
595 views

Impostor Higgs?

I recently came across this article, published in the respectable European Physical Journal A. (Apparently, there isn't any corresponding arXiv article for this, so I'm sorry if everyone isn't able to ...
3
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1answer
70 views

Why can't we measure branching ratios of the Higgs at LHC?

There are theoretical predictions for SM Higgs decay branching ratios. What about the experimental results on BRs? All that I found was measurements of signal-strengths $\mu = \frac{(\sigma \cdot ...
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1answer
61 views

Different cross section for W and Z boson

At hadron colliders the cross section for W production is about ten times larger than the production cross section for Z bosons (e.g. Figure 2 in this review article). I guess the dominant ...
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1answer
99 views

What would happen if two entangled particles collided?

Does that is even possible? I have almost zero knowledge in quantum physics, it is just a curiosity that popped in my mind.
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0answers
150 views

Baryonic density in collision experiments

Does anyone know any way of estimating the net baryon density in collision experiments, e.g. in LHC, RHIC, or the upcoming ones at GSI-FAIR? I have comes across many hand-waving arguments, sample - ...
2
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1answer
38 views

Easy formula for ultrarelativistic bremsstrahlung?

I am very curious if an easy calculable formula for the bremstrahlung radiation of deeply relativistic, charged particles exists, if they are moving on circular orbit: $P(E,m_0,Q,r)=?$ ...where ...
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2answers
67 views

What were the maximal collision energy of the LHC if it were rewired to $e^{-}-e^{+}$ collisions?

Yes, I know, that it weren't a large hadron collider then. No, I don't think, that the creators of the LHC didn't know what they do. I am just curious. How could it be calculated? A such rewiring ...
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0answers
67 views

Jet rapidity vs. Pseudorapidity

thanks to this post Why is pseudorapidity defined as $-\log \tan \theta/2$ I got a better understanding of what makes (pseudo) rapidity an interesting an often-used concept. Tangentially working ...
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1answer
59 views

Reusing the bremsstrahlung energy in circular accelerators?

I think the Bremsstrahlung happens as a strong radiation emitted by the accelerated particle stream. As in this question is visible, it is the main cause of the energy loss in such big particle ...
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4answers
3k views

Why doesn't the LHC accelerate electrons?

Electrons have a much bigger charge density as the protons (and especially lead nuclei), aren't compound particles as the protons (and especially lead nuclei) are able to get a much bigger energy ...
3
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1answer
75 views

W + jets at NLO

I would like to calculate $pp \rightarrow W (\rightarrow \ell \nu)$ + n-jets (n=2, maybe also 3) at NLO, with some cuts and plot some distributions. I used MadGraph extensively for LO processes and I ...
6
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2answers
189 views

Could a tetraquark $q \bar{q} q \bar{q}$ be colorless?

CERN just posted this article where it informs that it was found an hadron which cannot be classified within the traditional quark model. What other models are there to explain this result? Or is it ...
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0answers
24 views

The Magnetic Field around the Proton Beams in the LHC

How would one most appropriately model the magnetic field around each bunch of protons in the LHC at maximum operating speed? Is the assumption of a wire of the same length of the beams (~30cm) with ...
2
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0answers
150 views

How far could the LHC “fire” a particle

Very simple question, and frankly quite a silly one, but I'm currently writing a lecture for secondary school kids and I'd love to tell them how far the Large Hadron Collider could fire a proton. The ...
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3answers
175 views

Are there any Meson colliders?

There are no stable mesons as far as I know. Are there any meson-colliders analogous to for example proton-proton colliders?
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35 views

References on the LHC experiments

I'm looking for a references / short book which discusses what is going on LHC collider - specific experiments, collision processes, analysis of data, how exactly the facility is operating (not ...
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1answer
136 views

Why 1 Month LHC Magnet Cooling Times

An often quoted figure is that the LHC magnets take a month to completely cool and a month to warm. There is never an explanation as to why that is. I can conjure any number of reasons (slow changes ...
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1answer
145 views

LHC Experiments for finding parallel universes?

I watched this video featuring Michio Kaku explaining parallel universes. In the last two minutes he said that experiments in the LHC could reveal that there might be parallel universes and then he ...
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70 views

How do they draw collision pictures in Atlas?

Is the picture below a simulation? How to they draw these pictures? The picture is from here.
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4answers
322 views

how long do large hadron collider experiments take?

This travel stackexchange answer has kinda got me wondering... how long do experiments involving the large hadron collider usually take? I'd expect you run it for a few seconds and bam - higgs boson ...
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2answers
106 views

Deciding what to collide at particle accelerator

Different particle accelerators use different types of collisions. For instance at the LHC they investigated p Pb collisions while its predecessor (LEP), used to collide electrons with proton and at ...
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29 views

what does “medium-induced gluon radiation” mean

I've often run across phrases such as "medium-induced gluon radiation" from some papers,what is "medium-induced gluon radiation"?
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3answers
539 views

The LHC - Proton Speed Limit [duplicate]

I'm originally from stack overflow, so this is my first foray into this particular community. I've read in numerous places that the Large Hadron Collider is capable of accelerating protons at ...
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0answers
35 views

Why don't photons crash into each other occasionally? Or do they? [duplicate]

At the LHC, researchers smash particles into each other at speeds close to speed of light. Photons, on the other hand, already move at the speed of light. Do they ever smash into each other? Or do ...
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1answer
117 views

Can micro black holes form in the Sun?

Wikipedia writes to say ...
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1answer
318 views

The future of supersymmetry [duplicate]

Considering the fault of any experimental evidence from LHC for supporting the supersymmetry idea until now, can we say that it is dead? Generally the people who are working on this subject say that ...
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2answers
185 views

Achieving almost the speed of light

I am much interested in physics. I have been caught up with one serious question related to speed of light. Hearing about Large Hadron Collider (LHC), it is said that protons in there are accelerated ...
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3answers
96 views

Predicting the mass of the Higgs particle

Physicists in Europe said that only after combining data collected at a laboratory in Switzerland with data collected at a laboratory in the U.S, were they finally able to announce the discovery of a ...
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2answers
265 views

Why is the Higgs boson created so infrequently at the CERN collider?

Although each collision at CERN has the available energy to create a Higgs boson each time, the vast majority of the time it does not create one. I suspect that part of the reason for this is that ...
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3answers
297 views

LHC vacuum tube diameter [closed]

What's the diameter of the tube where the protons fly around? I dont mean the overall diameter (~1-10 m), instead the inner most ultra-high vacuum tube where the protons are. The inner pipe, the ...
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1answer
99 views

how do they rip one single atom from something?

this is simple. what i actually want to ask is, when they do the subatomic particle collision experiments, how do they produce one single subatomic particle, e.g proton, neutron? how do they rip one ...
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4answers
330 views

SUSY and the Large hadron collider

Did the LHC rule out SUSY as a solution to the hierarchy problem ? What's the common belief among theorists regarding the possibility of discovering SUSY in the 2015 run of the LHC ? Did the absence ...
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2answers
153 views

How does the Cern LHC collide particles head on if uncertainty principle limits the precision

I have been wondering why doesn't the uncertainty principle prevent the LHC experiment as if one want to collide two particles together one must accelerate a particle to certain speed and aim it at ...
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0answers
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Can TOTEM's T2 detector measure differential cross sections?

My current research involves making a prediction for data collected by the TOTEM experiment at the LHC. The experiment is primarily designed to measure the total inelastic and elastic scattering cross ...
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5answers
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Is a proton collision (collisions like in the LHC) visible to the human eye?

I was curious if a proton collision is visible to the human eye. (This might sound like a really basic question and forgive me if it is. I am very inexperienced in Physics and just wanted an answer ...
3
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1answer
108 views

What is the $t\bar{t}$ production supposed to bring up

The $t\bar{t}$ production, I've read, that will somehow confirm the QCD and might bring up new physics. Why are we studying $t\bar{t}$ production from $p-p$ collisions at the LHC? What are we trying ...
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0answers
40 views

Limits on stable charged particles

Are there generic model-independent limits on massive stable charged particles (say 10-500GeV)? I mean SU(2)/color singlets with just a hypercharge. For example the LEP search (CERN-EP/99-075) was ...
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2answers
239 views

If you could look at the LHC beam, what would you see?

Kind of a weird question compared to what I normally ask on here, but I've been wondering about this for a while. Does the LHC beam generate any photons within the visible light spectrum? Assuming ...
3
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1answer
106 views

Convolving Parton Distribution Functions

I have the cross-sections as a function of $\sqrt{s}$ for a process with a $u$-quark and $u$-antiquark in the initial state (eg.: $u \bar{u} \to e^- e^+$). I have a standard parton distribution ...
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2answers
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Do the proton PDFs change much with Q?

Specifically, the second moments, do they change much from say 100 to 1000 GeV? Why or why not?