Hi, I'm working on LLP exclusion plots on my current paper. I need to add a discussion regarding the most sensitive ATLAS/CMS searches why they come out on top when constraining LLPs. These "searches" are usually the ones that CheckMATE outputs in its result file e.g. "atlas_conf_2020_048" or "atlas_conf_2019_040". Do u know any relevant paper that I can consult about them? I just need to know why they are stronger in constraining LLPs than the other searches. I also wouldn't mind any paper that can be relevant in comparing the different signal regions that constrains LLPs e.g. "EM12" or "MB-SSd-2-4000-28".

I have known for a while that a 2-spinnor can be visualized like a vector moving through a Möbius strip, the first trip around leaves the vector inverted and the second trip leaves it how it was at first

But recently I learned that there is a whole branch of Math called "Ribbon Theory" which is like the digievolution of Knot Theory

In Ribbon Theory we don't have just a path, we also have a normal vector which describes a surface along this path. In this formalism the Möbius strip can be seen as a kind of ribbon, but there are many other kinds of ribbons with different loops and normal vectors

This made me wonder if we can use Ribbon Theory to describe other properties in Particle Physics, like chirality, isospin, maybe even color charge

Can this be done? Has this been done?

The only equation that I have is L=1/2vt were L is the length v is the velocity and t is the time given by 1/Hz will this work or not?

HI-

So on the subject of particle entanglement/spooky action at a distance, could anyone explain how these particles are experimented on? For example, how are they first located, then how are they separated, and how are they measured? And does anyone know what they are? I realize larger things like humans, rocks, etc are made of particles, but what are these particle gleaned from? Also, how does this activity or phenomenon relate to all the world made of particles? Sorry if these are disjunct or dumb questions.

I was recently watching Dark series and i came across 'GOD PARTICLE" or also called as Higgs Boson and i did some research. As i was learning about it i came across higgs boson and its importance but couldn't find the exact reason why atoms would be unstable without the higgs field and also is it possible to split a higgs boson and could it be weaponised?

they would just be a +2 helium atom, so theoretically it could for molecules

I am first year graduate student in particle phenomenology and I am interested in dark matter pheno.

I am trying to decide on topic of my research and I don't want it to be a dying research area (such as susy ).

I want to know how much active is dark sector and axions ?

I was wondering if it’s possible to “excite” an isotope’s nucleus into a metastable state using gamma. For example, turning Tc-99 into Tc-99m using a beam of 0.140MeV photons.

I'm doing a high school project for which I'm training a Neural Network to classify signal and background events with this dataset: https://www.kaggle.com/datasets/janus137/supersymmetry-dataset/data and the output I receive is a number between 0 and 1 where 0 means the classifier is certain it's background and 1 means the classifier is certain it is signal. My question is that after training and testing it, say I use it to predict 10,000 events that are background and signal, how do I get the significance level? I get that this is not some actual discovery but feel like it would be good for the project but I can't figure out how this works. I get the idea of hypothesis testing, nuisance variables and was understanding likelihood ratio until I read that you can never know the prior distributions so can't really calculate likelihood ratio. I know that this paper (https://arxiv.org/pdf/1402.4735) was able to do it but doesn't really explain how. And as a follow up-question, how do you decide the proportion of background-to-signal events to be used in your "discovery", isn't that influencing the significance level? This paper uses 100 signal with 1000 +- 50 background but doesn't really explain how they got that.

We all know that charge is a linear combination of weak hypercharge and weak isospin. Namely:

Q = I+Y/2

We also know that charge is measured in coulombs, and this made me wonder: what are the units of weak hypercharge and weak isospin?

Usually if you have two units like meters and kilograms you can't add them up and get a third unit, but in this case you seemingly can...

Mathematically the solution would be that in the formula for charge there are constants multiplying each term, canceling out the units of isospin and hypercharge to leave just coulombs. But for some reason I can't quite explain this doesn't sound right in terms of Physics

This left me thinking about units and how we measure them, and I realized that we never actually measure coulombs nor kilograms nor anything, all we can measure is just meters and seconds, distance and time. From there we deduce forces and energy, and from there we deduce everything else

Quantities like mass and charge are just our way of thinking "this is the source of a force", but we can't actually detect them directly, we don't even detect their forces, we just detect how the forces affect the movement of other things

Even our measurement of time relies in our assumption that some things move at a constant rate. Maybe distance is the only thing we can actually measure

Taking this back to hypercharge and isospin, at high temperatures they probably can affect the movement of particles in different ways, meaning they would need different units, but at our temperature range they work together to affect the movement of particles in a single way, and thus we can only give them a single unit

I'm posting this here as a sanity check. Please do let me know if any of this makes sense

For example, lets say we have an electron positron annihilation scenario. What will be the density matrix of the electron and the positron? What will be the density matrix of the photons?

Hey, I’m planing on building a 2.3mev betatron. I pretty sure most of you know that Michio Kaku did something similar when he was in high school. Well, I’m in high school and I don’t really have anything better to do. I have a university professor at UofT helping me with the math and theory. I’ll keep you guys updated on my progress.

I know they are named after the respective Greek letters, but how do they correspond them with letters in the first place?

So I'm watching a series on the big bang on Prime Video, and the professor spoke about the epoch of quarks in the fractions of a second after bb. During that epoch the quarks combined to form the protons and neutrons making up almost all matter today.

Being that a proton has 2 up quarks and 1 down quark, and a neutron has 1 up quark and 2 down quarks, how is it that there are not any unpaired quarks wandering the universe today that couldn't find partners to form hadrons? Do unpaired quarks suffer from some sort of decay if they are 'orphaned' for a certain period of time?

Total layman here. Is their evidence of anything after the collapse of the wave function that isn't deterministic?

Wrong sub? Shoot me a quick reply.

I have a PhD in physics; I studied theoretical AMO/quantum information. I'm starting a new role soon where I will be working at the intersection of quantum information and high-energy physics (think quantum simulators for HEP/QFT applications). There are some good white papers and review articles from both HEP and QIS communities on these crossovers which I am currently working my way through. These will position me well in the short term, but for long-term success, I can tell I'll need to improve my foundational understanding on the HEP/QFT side so I don't have to treat that half of problems as a black box. I've had some coursework, but graduate school classes were a while ago and this subfield was never my main focus.

I'm looking for advice for recommended books, lecture notes, etc for self-study in this space, both in physics (field theory, phenomenology, HEP experiment...) and mathematics. I was hoping people might have some suggestions specific to my needs and prior experience -- I need something more technical than you would give a layperson, but I'm less focused on details of calculations and more interested in hitting key concepts.

Hi guys, I have a question about particle colliders.

I understand that they use electromagnetism (I get that it's more complicated) to accellerate particles to high speeds and collide them, but how do you "get" a subatomic particle, and how do you put it into a collider? Just something I've never understood.

I've tried searching for the answer but I can only find results about how particle colliders work themselves, without the process of getting the particles.

Thanks in advance!

The Thomas Jefferson National Accelerator Facility in Newport News, VA is having its biennial open house tomorrow Saturday June 8 from 9am-3pm, admission and parking is free. Learn about superconducting materials, supercomputers, particle accelerators, particle detectors, nuclear physics research and much more. See our web page for more information.

Hi folks. I have 0 formal education in physics but with a strong interest and the incredible resources on the internet and some well written books, I have managed to acquire a small bit of knowledge. My question concerns thermal radiation and bremsstahung radiation. Please correct any errors in my understanding. To The best of my knowledge, bremsstahung radiation is the electromagnetic energy that is emitted when a charged particle give up kinetic energy. Thermal energy is kinetic energy at the molecular level and thermal radiation occurs when the molecular kinetic energy is given up as electromagnetic energy. My question is: is there a relationship between bremsstahung radiation and black body or thermal radiation? Any thoughts are much appreciated.

Hello, I would like to know if anyone is familiar with corsika 7 o 8 and to know if you could please explain to me how you created an animation of an EAS, either resulting in a GIF or a video, I saw that it could be used using them such as map3plot or coast but I can't find a specific manual for that or any paper that explains it in detail. Or if you have any other suggestions on how to do it, I would appreciate it.

^(As a note, in Corsika 8 I have an error that I don't know how to solve when running the ctest, an error appears in point 6, I suppose it is due to fluka.)

I asked a question earlier, and I don’t think I properly asked it, thank you if you answered my last post.

Protons isolated have no elemental properties, but when clumped together they take the shape of a unique character. Why would 8 protons make oxygen? In another universe could 8 protons be gold?

If you have a video game that would create universes, what game settings could you tweak to where the recipe for copper is 31 protons.

What game settings could you change for material to look the same, but swap properties? So for example, tin and copper everything is the same except tin is more conductive in your new universe?

As I understand it, finding the Higgs boson was really important because it proved that the Higgs field (and therefore, the Higgs mechanism) is real. But is it possible that the Higgs field might exist, but for whatever reason not be able to form real particles? Is it possible that only virtual particles are possible in a field?

Basically what information sets the laws of physical properties based on a clumping of protons. Thanks I’m going crazy.

Tell me anything wrong with it or if I'm missing any crucial information (thanks)

I recently watched a video by "float head physics" explaining how photons can push charges by the oscillation of electric field and the magnetic field, which made me question how does this interaction cause the attractive force of opposite charges? From what i understand virtual photons are exchanged between charged particles and the force the virtual photons can produce increases inversely to distance (due to energy-time uncertainty principle), but if a photon can only push, then how does it cause the attractive force? Can photons pull? Does the pulling force also increases inversely to distance?

I was just wondering if there is a way to make an accelerator because the cyclotron that I made with aluminum didn’t work as I didn’t have enough voltage, is there a way to make a low voltage accelerator, although this completely is the opposite of reality?

So me and my friend both want to pursue physics, specifically nuclear or particle. The problem is I’ve been searching all over and I don’t even understand what job positions are available, what would I even do with a degree in particle/nuclear physics, and where would I find these jobs.

I am super young and have started getting into this field of particle physics...

Just so that I know that I properly understand:

Graviton – AntiGraviton

• Obliterate each other
• Supposedly “antimatter” is “less than” “matter” 
  • Gravitons remaining are the matter that creates gravity today
• Gravitons are essentially needed to exist because gravity is one of our four fundamental forces that make us up (strong nuclear, weak nuclear, electromagnetic, and gravity)
  • So if all other forces have these particles (such as W and Z Bosons, etc.), gravity must have something (correlating to photons in the electromagnetic field)
• It may be hard to understand gravitons as it is the weakest of the four fundamental forces
• Is there concrete evidence of its existence?
• I don’t fully understand particle accelerators, I may be stupid (probably, just spilling my thoughts), if we make a vertical particle accelerators would it be possible to use the nature of gravity in order to discover more concrete evidence of gravitons? Excuse me on this point, I may be slow…
• Is there evidence that gravitons don’t fully exist?

I am young and new so please excuse any of my irrational comments... I am well open to learning and to understand my curiosity.