for questions about design, process, data, or analysis of experiments and observations.
10
votes
2answers
261 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 ...
4
votes
2answers
256 views
Basic question on experimental plots
On the following Higgs $\rightarrow$ Tau Tau plot, since we are plotting the ratio of $\frac{\sigma}{\sigma_{SM}}$ on the y axis, shouldn't the expected for this be 1? i.e., shouldn't the expected 68% ...
-1
votes
2answers
120 views
Bolometer calibration - voltage and intensity
I am interested in possible hazards due to high intensy infrared light sources. Therefore I want to use the "PASCO TD-8553 radiation sensor" (website) to measure the intensity of the radiation of an ...
4
votes
1answer
131 views
On the Aharonov-Bohm effect, and the reality of the classical fields
As far as I can check, the Aharonov-Bohm effect is not -- contrary to what is claimed in the historical paper -- a demonstration that the vector potential $A$ has an intrinsic existence in quantum ...
2
votes
1answer
47 views
Is this the correct way to I combine multiple interdependant pressure readings?
I want to measure the density in different layers of a suspension. To do this I want to place pressure sensors at different heights. Let's assume that the sensors are not by orders of magnitude more ...
2
votes
1answer
118 views
Good algorithm for in-experiment 1-D optimization?
I'm running an experiment -- for the question, it doesn't matter which one, but I'm measuring an optical intensity $I$ as a function of two parameters: reflection angle $\theta$ and wavelength ...
2
votes
1answer
123 views
Consistently oscillating micron sized particles in a liquid
I have an idea that would involve the measurement of an oscillating substance whilst the substance is immersed in a liquid. However, the method that I would use to measure the frequency of these ...
0
votes
1answer
36 views
Why pulse waves results in wave packets?
I was doing experiments of measuring sonic velocity and I generate pulse waves from sensor 1, but when they are received by sensor 2, I saw wave packets on the oscilloscope, can you explain why?
I was ...
26
votes
0answers
505 views
What is the upper-limit on intrinsic heating due to dark matter?
Cold dark matter is thought to fill our galactic neighborhood with a density $\rho$ of about 0.3 GeV/cm${}^3$ and with a velocity $v$ of roughly 200 to 300 km/s. (The velocity dispersion is much ...
8
votes
0answers
80 views
+250
Best current bounds on nonconservation of momentum?
It's not straightforward to test conservation of momentum experimentally, and many experiments that seem like tests really aren't. For example, in a Newtonian system of identical particles that ...
6
votes
0answers
85 views
Status of experimental searches for tachyons?
Now that the dust has settled on the 2011 superluminal neutrino debacle at OPERA, I'm interested in understanding the current status of experimental searches for neutrinos. Although the OPERA claim ...
6
votes
0answers
197 views
Predicting the ratio of translational diffusion coefficients for a sphere and a sheet
Imagine that I have a spherical particle of molecular weight $M$, volume $V$, and some experimentally observed center-of-mobility translational diffusion coefficient $D_{sphere}$ in water. I take ...
5
votes
0answers
169 views
Quasi 1D insulators with strong spin-orbital interaction
We know that the spin-1 chain realizes the Haldane phase which is an example of
symmetry protected topological (SPT) phases (ie short-range entangled phases with symmetry). The Haldane phase is ...
4
votes
0answers
74 views
Mechanical Equivalent of Heat
Recently I have been looking up James Joule's experiment regarding the mechanical equivalent of heat. After viewing some drawings of the apparatus, I assumed that the lines holding the weights would ...
4
votes
0answers
67 views
Design of experiments to determine proportionality
A common result of theoretical analysis in physics is some sort of relation derived from physical parameters and typically expressed in the form of a non-dimensional parameter. These scale relations ...
4
votes
0answers
150 views
Parity and Helicity of the Higgs Boson
I have been studying how the spin and parity of the new boson discovered at the LHC will be studied and have run into some confusion. The Standard Model Higgs is expected to be a scalar (i.e. have ...
4
votes
0answers
38 views
Experimental tests of Cluster Decmposition
How tight are experimental and astrophysical tests on whether Cluster Decomposition is satisfied at various space-like separations?
Is there a review paper or a standard reference on the question?
I ...
4
votes
0answers
103 views
Is there precision experimental evidence for Furry's theorem — that only even degree VEVs are non-zero?
Is there precision experimental evidence for or contradicting Furry's theorem -- that only even degree VEVs are non-zero, specifically for the EM field?
3
votes
0answers
49 views
List of cross sections?
Sometimes I need to look up a certain cross section, say the inclusive Z production cross section at $\sqrt{s}$ = 7 TeV. Is there a place where 'all the' cross sections are tabulated ...
3
votes
0answers
70 views
What is the importance of the Higgs-strahlung process in the Higgs search?
I would particularly like to know why this process is considered the main search mode for Tevatron but useless for search at LHC.
3
votes
0answers
38 views
What is meant by the quantum integrity in a superconducting loop
I encountered this in the context of using squid microscopy to test for d-wave pairing in an iron arsenide superconductor where the goal of the experiment was to detect half integer flux quantum ...
3
votes
0answers
90 views
Why is a washing machine unable to spin-dry a duvet?
Background story: I put my duvet (synthetic filling) into a washing machine, and the machine was unable to spin-dry it. My mom told me: "It's because it is full of air".
I was not satisfied with the ...
3
votes
0answers
23 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 ...
2
votes
0answers
18 views
Concerning Scattering Intensity and Particle Concentration
I am trying to determine what governs my sensor output. I have an optical sensor that emits infrared radiation on a sample volume and gives me a voltage output from the scattering of (1 to 10 micron) ...
2
votes
0answers
46 views
Robot controling pouring process from a bottle
I need to solve a problem within mechanic of fluids for a part of my thesis. Robot will pick up a bottle of beer, cola, julebrus or any other kind of beverage. And then it has to bring it to the glass ...
2
votes
0answers
79 views
Question on “new CNGS/OPERA measurement of neutrino velocity” (hep-ex/1212.1276)
A "new measurement of the limit on muon neutrino velocity with respect to the speed of light " by the OPERA neutrino experiment in collaboration with CERN has become public recently, as preprint ...
2
votes
0answers
135 views
How do I do error calculus right using gnuplot as an example?
Given is a set of measurements with their respective errors for example an energy spectrum. In gnuplot one is to fit a function $ f(x;\{p_i\})$ depending on a variable $x$ and on fit parameters $p_i$. ...
2
votes
0answers
58 views
Remaining Potential Experimental Particle Physics Discoveries at the TeV Scale?
With the discovery of the Higgs Boson, some have been calling it the end of experimental particle physics for our generation, due to the fact that all of the particles predicted by the standard model ...
2
votes
0answers
58 views
How can one activate the decay of the quark b with PYTHIA event generator?
This is my problem and I hope finding a solution.
_In the simplest alternative, MSTJ(22) = 2, the comparison is based on the average lifetime, or rather (c*tau "time life") , measured in mm. Thus ...
2
votes
0answers
193 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 ...
1
vote
0answers
22 views
Easy to do experiments that clearly show outstanding properties of graphene
By chance we received for free some monolayer graphene sheets (20 cm x 20 cm) and mixed coper-graphene wires at our University. I would like to prepare some very easy to do experiments for the ...
1
vote
0answers
77 views
Easy question about magnetism?
I have to build a simple electric motor by attaching a magnet to a battery, extending the terminals of the battery (with stiff wires so they could act as supports), and placing a coil of wire on top ...
1
vote
0answers
38 views
Truck driven from a small motor that can carry a heavy load, yet can travel fast.
I am building a truck from trash as materials. I have one small motor and a a few small gears, but no other engineered materials are allowed. The truck must carry a load for a distance of 3m. The ...
1
vote
0answers
33 views
Improvements on a makeshift dessicator
I am a first year undergrad working in a lab, and I have these Plexiglass containers that I tried to convert to dessicators, since the commercial bell jars are really expensive. I used these weather ...
1
vote
0answers
30 views
What is the status of the Gennes - Alexander theory of Superconducting Micronetworks?
I have started reading the book Connectivity and Superconductivity which gives an introduction to the ideas of de Gennes-Alexander theory. My question is: how is this theory regarded experimentally? ...
1
vote
0answers
93 views
How do I calculate the Radiation length of a Molecule
I want to calculate the Radiation length in a Molecule with the Formula given on wikipedia. How do I calculate Z and A for a molecule to put it into the Formula?
1
vote
0answers
53 views
What is the standard way to find averages of measurement values that contain statistic and systematic uncertainties?
How to find the average value of several measurement results if we know their statistical and systematics uncertainties?
There might be that there is no such thing as best way to do it, but it would ...
1
vote
0answers
88 views
Is there analysis library for stress-strain data?
I have three column data that has time-displacement-force from 1D tensile/compression test. Now I would like to get the standard mechanical properties of the material, like Young modulus, yield ...
1
vote
0answers
99 views
What narrow-linewidth laser system runs at 2100nm with 1W of power?
For an experiment at our university we need a laser that runs at about 2.1 μm (about 20nm higher or lower would be fine too.
We have found a multitude of lasers that achieve this (typically Thulium- ...
1
vote
0answers
74 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 ...
0
votes
0answers
13 views
Potential E alternation
Considering a permanent magnet moving in a trajectory perpendicular to a straight wire of a given lenght, in a way that the magnet expose always the north face towards the wire, no matter the ...
0
votes
0answers
15 views
How wide is a pre- and post-selected light beam?
To pre-select the beam, we will require that it pass through two holes A and B.
This will allow us to select both a diameter and a divergence angle.
To post-select the beam, we will require that it ...
0
votes
0answers
55 views
Experimental realization of Quantum Teleportation of Spin, not polarization, not ions or atoms
I've looked everywhere in databases my school provides, to google searches, to the questions asked in physics forums, and here. As I understand, the original QT (quantum teleportation) protocol ...
0
votes
0answers
48 views
Numerical value of surface dipole moment/charge of a solid
Due to the open boundary, electric potential near the surface are distorted and hence there exist finite dipole moment/charge distribution. (I think it is a few angstrom thick)
Can I calculate the ...
0
votes
0answers
48 views
What sort of thin film experiments can be done in zero gravity and in the presence of cosmic radiation?
I recently found out about sending stuff into space and using the unique zero gravity and cosmic radiation riddled environment to investigate stuff like crystal growth. Since thin film science is a ...
