6
votes
3answers
141 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?
0
votes
0answers
27 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 ...
6
votes
2answers
97 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 ...
0
votes
1answer
271 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 ...
0
votes
2answers
160 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 ...
2
votes
2answers
216 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 ...
1
vote
0answers
42 views

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 ...
3
votes
1answer
80 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 ...
1
vote
0answers
33 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 ...
3
votes
1answer
91 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 ...
4
votes
2answers
78 views

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?
1
vote
0answers
88 views

What are the implications if Supersting theory is discredited? [duplicate]

Please forgive my ignorance, I am not a student of physics in any capacity, therefor my understanding of string theory is extremely limited to say the least. Based on the recent lack of evidence in ...
15
votes
7answers
2k views

What would happen if Large Hadron Collider would collide electrons?

After some reading about the Large Hadron Collider and it's very impressive instruments to detect and investigate the collision results, there is a remaining question. What would happen if the ...
11
votes
2answers
167 views

What is the 'bump' near $M_{\mu\mu}\approx 30\text{ GeV}$

In this (attached) Summer 2011 plot from CMS (twiki page), they have a plot of the dimuon invariant mass spectrum across 3 orders of magnitude in energy. There seems to be a 'bump' near ...
4
votes
2answers
254 views

Assuming that extra dimensions will not be visible at LHC, what motivation will still remain to study them?

Many physicists believe that there is little possibility of observing extra dimensions at LHC so that some extra dimension models originally designed to solve hierarchy problem (ADD/Randall-Sundrum) ...
3
votes
1answer
131 views

Will Randall-Sundrum extra dimension scenario become defunct if not supported by LHC?

The Randall-Sundrum extra dimension scenario had been one of the most extensively studied class of theories. This offered a solution to the hierarchy problem. However, if this picture is not supported ...
10
votes
1answer
420 views

What does the latest $B_s^0\rightarrow \mu^+\mu^-$ results mean for SUSY?

A paper from the LHCb collaboration just came out last week, stating basically that the $B_s^0\rightarrow\mu^+\mu^-$ decay matches standard model predictions, and people are already shouting that SUSY ...
3
votes
2answers
429 views

Missing transverse energy, exact definition

This might seem basic, but it is a bit confusing. You hear about missing transverse energy a lot in SUSY searches due to the LSP which cannot be detected. Let's say I have the 4-vector for the LSP. ...
4
votes
6answers
289 views

Why not using cosmic rays to study HEP, since they are way more energetic than LHC?

Cosmic rays energies can exceed $10^{8}$ TeV, way higher than the energy scale achieved in the LHC or that can be achieved in the near future. cannot we just use them to study fundamental ...
1
vote
0answers
358 views

What is the relationship between Luminosity, Intensity, and Flux?

I am always confused by the terminology: In high energy particle scattering, and in particular, in the context of collider physics, what is the relationship between luminosity, intensity and flux? ...
2
votes
1answer
86 views

random triggers

I understand that a small proportion of events at the LHC that would not trigger on any deterministic trigger are saved on what might be called a random trigger, so that, amongst other uses, proposed ...
0
votes
1answer
142 views

From where this number of 14 Tev has arised for proton-proton head on collision in LHC?

I am interested in finding out, why are collisions at 14TeV done in the LHC, instead of some other energy?
2
votes
2answers
195 views

Batting averages of the Large Hadron Collider

As I understand it, the Large Hadron Collider's function is to throw particles into each other while avoiding hitting the nucleus? If quantum mechanics dictate the position of a particle can only ...
4
votes
2answers
544 views

Can black holes be created on a miniature scale?

A black hole is so powerful to suck everything into itself. So is it possible that mini black holes can be created? If not then we could have actively disproved the rumors spread during LHC ...
0
votes
1answer
279 views
4
votes
1answer
663 views
3
votes
1answer
493 views

What are the advantages of the ILC over the LHC?

USA Today has an article on Japan's interest as the site for the $10 billion future International Linear Collider. This accelerator will utilize electron/positron collisions (like CERN's former LEP ...
5
votes
1answer
225 views

Inelastic nucleon-nucleon cross section at LHC energies

I am trying to reproduce the number of participants $N_{part}$ in Pb-Pb Collisions at LHC using a Glauber Monte Carlo simulation, specifically aiming to reproduce the values given in Phys. Rev. Lett. ...
2
votes
2answers
374 views

If LHC is the most powerful microscope in the world, what does it magnify?

Some experts (and non experts) have called LHC the most powerful microscope in the world. I am wondering, what does the LHC magnify? Or is calling it a microscope just wrong and misleading?
7
votes
2answers
596 views

What does the data in various stages of analysis from a particle collision look like?

I've been following the news around the work they are doing at the LHC particle accelerator in CERN. I am wondering what the raw data that is used to visualize the collisions looks like. Maybe someone ...
17
votes
2answers
767 views

Correlation between outstanding hints in experimental particle physics

The 115 GeV ATLAS Higgs with enhanced diphoton decays has gone away but there are several other recent tantalizing hints relevant for particle physics, namely CoGeNT's 7-8 GeV dark matter particle ...
7
votes
2answers
225 views

What are the main differences between $p p$ and $p \bar p$ colliders

I know that it is somehow related to the parton distribution functions, allowing specific reactions with gluons instead of quarks and anti-quarks, but I would really appreciate more detailed answers ! ...
7
votes
1answer
353 views

Decay of SUSY particles

In discussion of LHC searches for SUSY particles, physicists seem to assume they will decay quickly to the lightest SUSY particle which then remains stable (at least within the time it takes to leave ...
8
votes
2answers
783 views

What if LHC finds SUSY?

Here and on many other forums and blogs people ask the question "What if LHC does not find SUSY?". I would like to ask the opposite. What if it finds it? What would the implications be? Is it going to ...
1
vote
1answer
286 views

With estimates of mass constraints on magnetic monopoles, how likely is one to be found by the LHC(MoEDAL)?

Fermilab seems to have ruled out monopoles with mass less than 850 GeV, but I have seen some estimates of the mass thought to be in the order of up to $10^{18}$ GeV, which, of course, would make them ...
4
votes
2answers
377 views

Will negatively charged strangelets be produced by the LHC?

Witten (and earlier, Bodner) hypothesized that strange matter (up, down, strange quarks) should be more stable than "regular" nuclear matter(The strange matter hypothesis). That is that the typical ...
9
votes
2answers
682 views

ATLAS and CMS calorimeters

I was reading this interesting recent review on arxiv about particle identification: Particle Identification In figure 2, there is an interesting comparison between the CMS and ATLAS calorimeter ...
10
votes
7answers
1k views

What would happen if you put your hand in front of the 7 TeV beam at LHC?

Some speculation here: http://www.youtube.com/watch?v=_NMqPT6oKJ8 Is there a possibility it would pass 'undetected' through your hand, or is it certain death? Can you conclude it to be vital, or ...
3
votes
1answer
263 views

What is jet quenching and how far can the hydrodynamic analogy go?

I recently heard about jet quenching concerning data taken by the experiments at the LHC. Apparently it is related to the existence to the quark-gluon plasma. As far as I understood this ...
4
votes
1answer
783 views

Advantages of high-energy heavy-ion collisions over proton-proton collisions?

Some high-energy experiments (RHIC, LHC) use ion-ion collisions instead of proton-proton collisions. Although the total center-of-mass energy is indeed higher than p-p collisions, it might happen that ...
2
votes
3answers
487 views

What does it mean a temperature of billions of degrees?

I read a few days ago that in the LHC temperatures of billions of degrees were achieved. I'm curious to know what does it really mean such a temperature? The concept of temperature is easy to grasp ...