for questions about design, process, data, or analysis of experiments and observations.

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4
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2answers
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What do “local” and “global” mean when talking about standard deviations in experimental particle physics?

I found the following sentence: The excess is most compatible with a SM Higgs hypothesis in the vicinity of 124 GeV and below, but the statistical significance (2.6σ local and 1.9σ global after ...
1
vote
1answer
219 views

Light vs neutrino speed comparison in a real tunnel

Given current accuracy of the techniques, is it possible to identify a real, existing tunnel (stright I think) to make the direct comparison of the speed of light and of neutrinos? The hypotetical ...
6
votes
2answers
181 views

How should one combine the uncertainties from the ATLAS and CMS measurements?

First off, a naive theorist question - How are measurements divided between the different detectors at the LHC? I would imagine that for a short run time, say, the CMS detector is active and all the ...
5
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1answer
1k views

What's the Standard Model width of a 125 GeV Higgs?

There's a fairly broad mass spread in the new results out of Atlas and CMS. I'm curious how this fits with the expected SM width.
2
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0answers
356 views

Levitation rotation speed involving laser acceleration, pyrolytic graphite and a vacuum

The experment would involve a small NIB magnet levitating between or on the diamagnetic material pyrolytic graphite, unlike other forms of levitation this doesn't require power to run such as ...
4
votes
2answers
6k views

Testing the temperature of an open flame

How, and what device do you need, to obtain the exact temperature of an open flame? For the purpose of this question, you wanted to maintain 375 degrees. You can control the flame, but have no idea ...
8
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2answers
751 views

Quantum Computing, Qubit Creation/Entanglement

I am currently a high school student researching quantum computing. I was referred to this site by Google and a friend. Currently I am researching the qubit part of quantum computing. My question is ...
5
votes
1answer
387 views

What is the smallest distance between a decaying vertex and an interaction point a detector can measure?

A short lived particle is created at the interaction point and then decaying a distance $d$ away, in some detector. My question is what is the smallest distance $d$ that can be measured ...
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0answers
181 views

What are the most seminal Soviet papers in experimental physics? [closed]

Soviet physicists have made well-known contributions to many areas of theoretical physics, but I've heard much less about their experimental work. What are the most seminal experimental papers that ...
1
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1answer
172 views

Spin Echo Experiment [closed]

I'm doing an spin echo experiment for different dilutions of Glycerol as an undergraduate physics lab experiment. At the end of my experiment I will need to extend it and do some initiatives! I have a ...
3
votes
1answer
2k views

Escape velocity of a rocket standing on Ganymede (Moon of Jupiter)

I want to calculate the escape velocity of a rocket, standing on the surface of Ganymede (moon of Jupiter) and trying to leave Ganymede. My thinking was, the kinetic energy $E_{\text{KIN}}$ must be ...
0
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1answer
658 views

Where to find experimental/theoretical value of (charge) radius of particles?

Where to find experimental/theoretical value of (charge) radius of particles like proton, neutron, $\pi^+$, etc.?
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0answers
85 views

How to set the electric potential on a certain boundary to a certain value experimentally?

In electrostatic boundary value problems, usually the potential is set to some function or a constant on a certain boundary. It is never taught or told in textbooks how such assignment might be ...
3
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5answers
2k views

About the Ether Theory acceptance

Why was the Ether Theory refused by Modern Physics? If you please explain me, I just wanted to understand it more.
1
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1answer
247 views

Depalma Free Energy fields

Few years ago I read some papers about Free Energy, written by Bruce de Palma, a physicist who is said to be the inventor of the N-Machine, which is an device that works with free energy latent in the ...
7
votes
2answers
400 views

How do the LASERs in LIGO realize that space has expanded as a gravitational wave passes by?

I read an article on LIGO, and I heard it mentioned that it is a nontrivial argument to say that the effect can be measured by interferometry. What happens to space as the wave passes? Does the light ...
4
votes
1answer
377 views

Photoelectric effect: Experimental Physics

Suppose you are doing an experiment to determine the work function of a metal.  You get $KE_1$, $\nu_1$ and $KE_2$, $\nu_2$.   We know that $KE = h\nu - W$ but when you solve the simultaneous ...
28
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2answers
352 views

experimental bounds on spacetime torsion

Did Gravity Probe B provide any bounds on Einstein-Cartan torsion? is a non-zero torsion value at odds with the results regarding frame-dragging and geodetic effects?
5
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6answers
6k views

How to guess the correct fitting function to some data?

Imagine we are plotting some date points $\left(x_i,f(x_i)\right)$ that we obtained experimentally, and that we want to know what $f(x)$ is. The way to do this is to use some software and try to fit ...
9
votes
3answers
3k views

Why do neutrino oscillations imply nonzero neutrino masses?

Neutrinos can pass from one family to another (that is, change in flavor) in a process known as neutrino oscillation. The oscillation between the different families occurs randomly, and the likelihood ...
5
votes
1answer
1k views

What's jet multiplicity?

That's a basic thing, but, surprisingly, it is very difficult to find concise explanation of: What is the definition of jet multiplicity? Why is it interesting?
3
votes
2answers
319 views

What is the highest accuracy of measuring time differences achievable today?

I was wondering if it would be possible to shorten the distance between detectors when measuring the speed of neutrinos to, say, 7m rather than the current ~700km? In this way the distance traveled ...
11
votes
5answers
12k views

How do you determine power flow direction in a transmission line?

Below is a picture of a typical transmission line(about 200 kV). Is there a simple physics experiment which can be performed safely near the line, to determine the power flow direction. Or in other ...
10
votes
3answers
428 views

Reproducing the OPERA result

Are there any other facilities that would be capable of independantly verifying the opera result? In other words, a completely different source/detector for $\nu_{\mu}$ beams? Alternatively, there ...
0
votes
1answer
103 views

OPERA. Dates of figure 10

What are the real dates that are represented in the figure 10, page 17, in the OpERA paper Imo the X axis labels are inconclusive, or absent. (in the investigation of a crime it is relevant ...
13
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1answer
406 views

How are neutrino beams emitted at CERN?

As far I know they come from accelerator collisions, but I have read confusing things like magnetically focused. How could neutrinos be guided magnetically if they aren't affected by the ...
10
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2answers
146 views

ATLAS Higgs Interpretation

I came across this abstract, and I am curious as to what the ATLAS Team has actually discovered: Abstract Motivated by the result of the Higgs boson candidates at LEP with a mass of about ...
1
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0answers
66 views

What is the variable plotted on the y-axis on these Higgs exclusion graphs? [duplicate]

Possible Duplicate: Particle physics plots I have seen graphs like this in lots of talks by phenomenologists talking about the Higgs search (see for example FIG 3 in this paper or this blog ...
12
votes
1answer
273 views

Cleaning Already Mounted Microspheres on an AFM

I am running an experiment that uses a microsphere (Diameter ~ 50um) mounted onto the end of an AFM cantilever. I run several experiments in a row, but somewhere during a sequence, the microsphere ...
7
votes
4answers
813 views

Experimental evidence for parallel universes/multiverses

My idea of physics is that it is a collection of mathematical laws relating observables. And that one can perform alot of mathematical derivations on these laws to produce new laws between ...
12
votes
2answers
421 views

Is there a way to directly observe the spin texture of the surface states of topological insulators?

Is there a way to directly, here I means in real space, observe the interaction of the surface states of 3D topological insulators with defects (dopings and adatoms)? How to observe the spin texture ...
1
vote
1answer
801 views

Estimation of accuracy of measurements?

When stating an estimation of the accuracy of my measurements (of electric current, in this case) would I state that it is equal to the residual error, or the limit of reading? (in this case, ±0.2 or ...
10
votes
1answer
655 views

What makes us think we can actually detect gravitational waves?

This refers to the discussion about gravitational waves for the YouTube video LIGO Gravitational Wave Observatory. I have two questions: When the gravitational wave passes through the space where ...
17
votes
5answers
19k views

How was Avogadro's number first determined?

I read on Wikipedia how the numerical value of Avogadro's number can be found by doing an experiment, provided you have the numerical value of Faraday's constant; but it seems to me that Faraday's ...
2
votes
2answers
526 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
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3answers
3k views

Left and Right-handed fermions

Is there a simple intuitive way to understand the difference between left-handed and right-handed fermions (electrons say)? How to experimentally distinguish between them?
11
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4answers
533 views

How do we know that the nucleus isn't a quark-gluon plasma?

The standard picture of the nucleus of atom is that is several distinct nucleons, which themselves are composed of quarks. However, it seems to me like a much simpler picture is that the nucleus is ...
7
votes
1answer
792 views

What does “tagging” mean in experimental high energy physics?

Could someone explain in details the meaning of the terminology "tagging" in experimental high energy physics and how is it used in the analysis?
10
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2answers
1k views

How are Monte Carlo simulations used in experimental high energy physics?

How are Monte Carlo simulations used in experimental high energy physics? Particularly in studying detectors limitations (efficiencies?) and data analysis. I will appreciate giving a simple example ...
3
votes
1answer
769 views

Fitting to a high density scatter plot

I am trying to do a crude particle identification, using a Bethe Bloch tenchnique. Here is a plot I made from the data that I have From what I've read, the standard method to identify charged ...
5
votes
2answers
503 views

How are the HEP experiments' invariant mass plots generated?

I am experimenting and playing around with some data, and I'm having trouble seeing how to generate invariant mass plots. The data I have has a bunch of events, and variables such as ...
6
votes
1answer
854 views

How to prepare a desired quantum state?

Given a quantum state function, we can Fourier expand it in terms of stationary states of the Hamiltonian. So if we want to build that same quantum state approximately all we need to do is to ...
2
votes
1answer
148 views

Measuring concentration

I am trying to measure the concentration of a Volatile Organic Compound (VOC) inside a liquid using Gas Chromatography (GC). The liquid contains particles that cannot be sent to a GC, so I am using ...
5
votes
2answers
1k views

What is meant by “combinatorial background” in experimental high energy physics

My guess is that they find a certain tracks coming from a certain source by "combintaorially" selecting all track pairs and finding their invariant mass. If this is true, of which I am not sure, how ...
6
votes
1answer
185 views

Recent news about Tokamak

I first heard about the Tokamak in highschool 10 years ago and was wondering how far the technology has come since then. Can it sustain a reaction for more than a few seconds? Are these devices ...
4
votes
2answers
1k views

How Can We Measure The Mass Of Particle?

As we know, the mass of well known particles are below. $m_{n}\approx0.0000000000000000000000000016749286[kg]$ $m_{p}\approx0.0000000000000000000000000016726231[kg]$ ...
13
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1answer
1k views

How to determine the mass of a quark?

As far as I know quarks are never found in isolation, so how can we determine their rest mass?
3
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1answer
286 views

Coincidence detectors in Bell tests: How close is close enough?

When is a coincidence a coincidence? We know that to identify entangled photons, the electronics is set to look for simultaneous clicks at opposite detectors. The size of the window is to some degree ...
3
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0answers
26 views

Review of Gas Chromatographs?

Could anyone suggest a recent review article or book on gas chromatography instrumentation? My interest is in the devices themselves, rather than using them for a particular application. This ...
8
votes
2answers
256 views

How to predict how much data to collect

The same question on CrossValidated Apologies if I'm being a bit vague in what follows, I've been asked to keep certain aspects of the experiment confidential for the time being. An analogous ...