Skip to main content

Questions tagged [large-hadron-collider]

World's largest particle accelerator built by the CERN (European Organization for Nuclear Research) on the Franco-Swiss border near Geneva, Switzerland. It is designed to collide beams of protons with a centre of mass energy of up to 14 TeV. It contains the large detectors ALICE, ATLAS, CMS and LHCb.

Filter by
Sorted by
Tagged with
0 votes
0 answers
30 views

QCD parton shower hard scale

Currently I'm studying parton showers from QCD and I'm having trouble with understanding how the hard scale $Q$ is related to the virtuality and energy of the parent parton. The Sudakov factor $\Delta(...
Jesse's user avatar
  • 291
0 votes
0 answers
35 views

Difference between jets and inclusive hadron production

I know both jets and inclusive hadron production are measured in high energy collisions. Is the difference just the way you measure it, or are there differences in the process behind them? If you ...
rafa's user avatar
  • 13
0 votes
0 answers
63 views

Are there any recorded time-of-flight (ToF) measurement data for the $H\to\gamma\gamma$ collision products at the LHC Atlas detector?

Especially, I am interested in the time-of-flight (ToF) measured recorded values of the two $\gamma$-photons (diphotons) during $H \to\gamma\gamma$ Higgs boson detection events at the LHC Atlas ...
Markoul11's user avatar
  • 4,170
0 votes
0 answers
20 views

What information we can obtain from total transverse energy and transverse momentum plots on particle physics

I am working on particle physics simulations and making some plots for which the purpose are not yet clear to me, as I am a novice in this field of study. To make my doubts clear, let's consider an ...
dumb physicist's user avatar
1 vote
1 answer
92 views

Simultaneous operations of LHC and LIGO

I once asked a question regarding atomic clocks near particle accelerators. Where the high-energy of the accelerators would be considered a source of stress energy. I was made to understand that the ...
Precious Adegbite's user avatar
5 votes
2 answers
191 views

Why using sigmas instead of p-values in particle physics?

Motivated by this question in Statistics community: Why do physicists use sigma while biologists use p values/posterior probabilities?. After discussion it essentially reduces to: why assuming normal ...
Roger V.'s user avatar
  • 60k
2 votes
1 answer
62 views

How do you calculate the centrifugal force generated by the bunches of protons inside the LHC?

I've determined that, during operation, the LHC accelerates 2808 bunches of protons with roughly 120 billion protons per bunch up to 99.9999991% the speed of light. I'd like to calculate how much ...
phil1008's user avatar
  • 271
2 votes
3 answers
276 views

Experimental status/test possibilities for baryon number conservation in LHC?

Violation of baryon number is hypothesized e.g. for baryogenesis (more matter than antimatter from Big Bang) or Hawking radiation (baryons -> black hole -> massless radiation) - quite extreme ...
Jarek Duda's user avatar
2 votes
1 answer
62 views

Why LHCb detector is one-sided?

In LHCb, how do all the produced particles go in one direction i.e. in the forward direction? Is the proton beam at rest coming from the opposite direction?
Souvik Maity's user avatar
0 votes
2 answers
112 views

Detection of the Higgs-Boson Graph Interpretation

I am reading up on the detection of the Higgs-Boson at the LHC and more specifically at CMS. I found the following graphic: I understand that the peaks correspond to the mass of the Higgs-Boson but I ...
Tuhande's user avatar
  • 11
3 votes
1 answer
409 views

Is the collision in LHC quantum mechanically so we cannot predict the trajectory?

I'm puzzled as always. In the LHC 2 streams of particles are accelerated in opposite direction and allowed to smash against each other in a controlled accident, then is it classical or quantum ...
user6760's user avatar
  • 13k
1 vote
2 answers
205 views

How to obtain the center of mass energy needed to form a black hole in a particle accelerator?

Once, Hawking has brushed aside the worries about LHC forming black holes massive enough to actually cause damage. I want to know which estimate he has used. After all, it is not possible to asign a ...
Confuse-ray30's user avatar
1 vote
0 answers
23 views

Synchronous phase value for CERN LHC [closed]

How to find out that the value of the synchronous phase for CERN LHC in the case where beams undergo collision, and the RF cavities provide only longitudinal focusing with no net acceleration.
Harryddd09w's user avatar
0 votes
0 answers
95 views

How much time passes relative to the protons inside the LHC?

The time depends on the speed of movement. Protons in the LHC move at near-light speed. Therefore, they perceive a different time than the scientist who is observing them. My question is how much time ...
nilecrocodile's user avatar
0 votes
1 answer
80 views

What advantages might the Circular Electron-Positron Collider have over the Compact Linear Collider?

Despite Chen-Ning Yang's objections, the Circular Electron Positron Collider (CEPC) project is progressing. The CEPC research team officially released its Technical Design Report (TDR) for the ...
Bababeluma's user avatar
3 votes
2 answers
86 views

What does it mean to probe a certain energy scale?

For example, what does it mean that the LHC probe the electroweak scale, $M_{EW} \sim 10^3 GeV$? Also why is this energy called the electroweak scale?
TaeNyFan's user avatar
  • 4,235
4 votes
1 answer
104 views

Does CERN produce more matter than antimatter?

CERN's LHC has seen matter-antimatter asymmetry, such as CP symmetry breaking and $B_s^0$ meson decay. The universe produced about 1 part per billion excess of baryons over anti-baryons. My ...
Kevin Kostlan's user avatar
0 votes
0 answers
20 views

Derivation of hypercharge neglecting squared amplitude for WZ helicities in paper

I am trying to get from equations (20) and (21) in this paper to equations (13) in this one. I will start with my attempt at deriving this for the LL case. (With $F$ from equation (4), $g_2-g_1$ from (...
J.N.'s user avatar
  • 111
1 vote
1 answer
60 views

Can not follow derivation of $WZ(0, 0)$ amplitude in paper

i am re-reading this paper and trying to follow the derivation of equation (21) from equation (15). Maybe someone can tell me where i am going wrong. So the original equation 15 is: $$M(0,0) = F\frac{\...
J.N.'s user avatar
  • 111
1 vote
1 answer
47 views

Is impact parameter a initial condition for collision in colliders?

In colliders what is the initial condition for 2 electrons collision (Møller scattering). I know that the momentum is one the initial condition but what about impact parameter? For example if we have ...
amilton moreira's user avatar
0 votes
0 answers
29 views

Good resource to learn more about background reduction CERN data analysis

So I am working on a project which involves data analysis of LHCb data and I have to plot invariant mass histograms. Where can I learn more about background reduction in my analysis. I have to use ...
1 vote
0 answers
33 views

The difference between High energy SUSY and low energy SUSY

In the literature and comments, I have met two pieces of jargon: Low energy SUSY, High energy SUSY I'm confused about the technical and well-defined conceptual differences between the two type of ...
Bastam Tajik's user avatar
  • 1,212
0 votes
0 answers
74 views

Project for Elementary Particle Physics Course

Good day! Are there any publicly available dataset in the field of particle physics that can be treated as time series? I am hoping to use methods in white noise analysis to somehow determine ...
Newbie's user avatar
  • 3
2 votes
0 answers
54 views

Could the LHC create a strangelet by creating another multi-strange particle that then interacts with a nucleus?

I became interested in the discussions about potential catastrophic risk from colliders and I have some questions about it. I am particularly interested in the strange matter scenario, and there is ...
Alex319's user avatar
  • 209
1 vote
0 answers
20 views

LHC observables that gives you the number of Jet Constituents

What is the name of a observable in LHC that will somehow count the number of constituents of a jet. Say the number of neutral or charged constituents of a jet.
King Meruem's user avatar
0 votes
1 answer
21 views

Why were multiple layers of absorbers and scintillators used in the CMS HCAL?

Why were multiple layers of absorbers and scintillators used in the CMS HCAL? Couldn't they have used just one absorber and one scintillator layer? Why was the choice made to have multiple layers?
secondquark's user avatar
0 votes
0 answers
81 views

Axial Vector and Vector Coupling Constants for General Quarks

I am studying particle physics and a bit confused about something. The expression for the interaction vertex where a $Z$ boson couples to a pair of fermions is $i \frac{g}{cos \theta_w} \gamma_{\mu} (...
Tom's user avatar
  • 1,410
0 votes
1 answer
97 views

Why aren't the Standard Model predictions of $R(D)$ and $R(D^\ast)$ equal to 1?

The observables $R_K$ and $R_{K^\ast}$ are defined as $$R_{K,K^*}(q_a^2, q_b^2) = \frac{\int_{q_a^2}^{q_b^2} \frac{d \Gamma (B^{(+,0)} \rightarrow K^{(+, \ast 0)} \mu^+ \mu^- )}{dq^2} dq^2}{\int_{q_a^...
jmaguire's user avatar
  • 313
-5 votes
1 answer
121 views

Can a massless virtual graviton decay into a Higgs Boson and two γ-photons in the LHC at CERN? [closed]

Τheoretically, is it possible? G--> H--> γγ And if not, why?
Markoul11's user avatar
  • 4,170
0 votes
1 answer
200 views

What is vetoing in the context of experimental particle physics?

I saw in this paper by the CMS Collaboration that two of the selection requirements defining the signal regions are the requirements on $b$ jet veto and $\tau_h$ veto. What is, in this context, a veto ...
jmaguire's user avatar
  • 313
1 vote
1 answer
83 views

What is the difference between 7TeV and 13.6 TeV ? Why don't we just dump the low energy data and use the one with highest energy?

I saw some results from particle physics that combines 7 TeV and 13.6 TeV results but they are different. Why they are different? Why do we combine them? If we need them why did LHC stopped taking ...
newkidintown's user avatar
2 votes
1 answer
40 views

What are Semi-Visible Jets?

I'm working on a project that aims to discriminate semi-visible jets (SVJs) in a QCD background, through learning from simulated data in the context of the LHC. I know that these are related to hidden ...
Luca Anzalone's user avatar
2 votes
0 answers
70 views

Why are there no antimatter-antimatter collisions in CERN?

The labs at CERN create anti-Protons, and have collided them with Protons. Anti-Hydrogen is used to study matter-antimatter asymmetry. Were there any attempts to collide anti-Protons with anti-Protons?...
Rd Basha's user avatar
  • 2,141
1 vote
3 answers
49 views

Meson-Meson Scattering Data

Recently, I have been interested in the scattering amplitudes of mesons in the high-energy fixed-angle regime. I have come across a simple result, due to Brodsky et al., that predicts the scaling of ...
clavecin847's user avatar
0 votes
0 answers
66 views

Why on the ATLAS Higgs discovery paper there are uncertanties on the expected cross section upper limits but not on the observed upper limits?

I was reading the ATLAS paper on the Higgs discovery and a question came to my mind. In the plot I attached, there are uncertainty bands on the background only hypothesis upper limits, and not on the ...
Matthew D.'s user avatar
-1 votes
2 answers
116 views

Why can't we slap a proton for instead of using particle accelerators?

Very stupid question, but since the mass of a hand is very large compared to a proton, one should be able using a solid slap to accelerate a proton to ultra-relativistic speeds. If I consider a ...
krabby patty's user avatar
3 votes
1 answer
245 views

How do particle accelerators like the LHC bend beams of particles?

I know they use dipole magnets to curve the beams, and quadrupoles to focus them, but how do they know how powerful the magnets need to be so they bend the beams sufficiently but not too much so that ...
crvcio's user avatar
  • 165
2 votes
0 answers
47 views

Elementary particle detection post-collision

How do you detect elementary particles? What do you aim your detector at? What's a detector physically? How do you know that a particle "happened", if (I assume) you can't see it? Is the ...
grzesiubdg's user avatar
-2 votes
3 answers
222 views

Typically energy of black hole compared to a planet or star of the same mass

Is the typical energy of a black hole much lower than the typical energy of a same-mass planet or star? I guess the answer is yes, energy of black hole is much lower. Otherwise, physicists would ...
Bohan Xu's user avatar
  • 708
1 vote
0 answers
14 views

are there any equation which tell us the energies of for example a neutron emitted during photodisintegration from the energy of radiation subjected [closed]

So my question is that if we have a pile of Be9 which can decay upon being subject to radiation with energies of 13 Mev. So that 13 Mev represents the binding energy of the Nucleas of Beryllium 9? and ...
Moiz khokhar's user avatar
0 votes
0 answers
35 views

If a beam of particles travelling at high speeds/ has high energy and decay is induced in the beam will the particles produced also be high energy

If we have a high energy beam of for example Beryllium 9 (this element emits neutrons when subject to high intensity radiation) and we hit it with high energy gamma radiation will the neutrons emitted ...
Moiz khokhar's user avatar
0 votes
0 answers
82 views

Filtering combinatorial background in $B_0$ -> $\mu^+ \mu^- K^{*0}$ decay

We are looking to isolate a signal representing this decay from all possible background candidates produced in a pp collision in the LHCb. We have already dealt with all the peaking backgrounds (J/Psi ...
NX37B's user avatar
  • 239
2 votes
2 answers
202 views

Have the $W_0$, $W_1$, $W_2$ and $B$ bosons of Electroweak fame ever been discovered experimentally?

I have read that the LHC, and perhaps other collides, have reached so-called electroweak energies, where the two forces are unified.... So how much energy, exactly, is needed to produce fields/...
Kurt Hikes's user avatar
  • 4,509
3 votes
1 answer
277 views

What does an LHC Beam Dump sound like?

What does an LHC Beam Dump sound like? Is it under a vacuum so that it doesn't make a sound, or does it go boom? Surely the heat generated instantly would make some kind of noise. This article https://...
Lone Coder's user avatar
0 votes
0 answers
65 views

What is the angle between two $b$-quarks when a Higgs boson decays to a $b$-quark pair, in the rest frame of Higgs boson?

I am generating events of $ep -> Xjv$, ($j$ is a jet, and $v$ shows a neutrino) where $X$ particle decays to a $b$-quark pair. I am going to calculate the angle between two b-quarks in the rest ...
Reza's user avatar
  • 1
0 votes
1 answer
59 views

Why didn't the particle-antiparticle pairs collided at the LEP and Tevatron just instantly annihilate into pure energy? (presumably gamma rays?)

I wonder if the fact that protons and antiprotons are roiling seas of non-valence quarks and such with very brief lifetimes means that when they collided at Fermilab they were not perfectly identical (...
Kurt Hikes's user avatar
  • 4,509
-2 votes
1 answer
107 views

The elusive graviton particle. Why does Hadron colider fail to find this elusive particle. It does exist but i think method for finding it is wrong [closed]

Why does Hadron colider fail to find this elusive particle. It does exist but i think method for finding it is floored.i think that trying to find it by collision is a floored method. My theory is ...
Malko's user avatar
  • 1
0 votes
1 answer
100 views

Why does Pseudorapidity distribution have two peaks?

I found plots(fig2) that state that it is the sum of two gaussian distributions, but I am not able to understand its physical significance. Any help would be appreciated.[PS Why does rapidity not have ...
hawexrutile's user avatar
1 vote
1 answer
91 views

On slip factor and phase transitions in particle accelerators

In a uniform magnetic field $B$, a particle with mass $m$, charge $q$ and initial velocity $v$, undergoes a centripetal force (Lorentz force) which makes it travel on a circular orbit, with angular ...
ric.san's user avatar
  • 1,644
1 vote
1 answer
684 views

Why does the LHC use lead ions?

The obvious answer is more energy per collision. This is discussed on p21 in this brochure of FAQs: CERN-Brochure-2017-002-Eng, which I found linked in this old question: Why not build a particle ...
mmesser314's user avatar

1
2 3 4 5
9