Why has anyone not tried to give elementary particles a finite shape. Currently things like quantum gravity yield to infinity because the elementary particles are dimensionless and as radius tends to 0, things go infinite.

So, my simple question is, why not give the particles a shape with finite dimensions?

Getting ready for Beam on Target and intentional neutron production.
https://ess.eu/article/2026/07/07/ess-completes-beam-dump-2-advancing-toward-first-neutrons

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Hi everyone, I just had a great conversation with Cambridge particle physicist and author Harry Cliff about some of the biggest unanswered questions in fundamental physics. We discuss the remarkable success of the Standard Model, the mysteries it still leaves unexplained, and why physicists believe there may be new physics waiting to be discovered.

Harry explains what the Large Hadron Collider has and hasn't revealed about the universe, why finding evidence of physics beyond the Standard Model has proven so difficult, and how small anomalies can sometimes point the way to major scientific breakthroughs.

We also talk about the future of particle physics, the proposed successor to the LHC, the power of international scientific collaboration, and how science manages to uncover reliable truths about the universe.

Harry Cliff is a particle physicist at the University of Cambridge working on the LHCb experiment at CERN's Large Hadron Collider. He is also the author of "How to Make an Apple Pie from Scratch" and "Space Oddities".

If you're interested in these subjects, you can check out this conversation: https://www.youtube.com/watch?v=IsMnWZdMH3s&t=2469s

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Hi! I and my friend once discussed about problems with environmet needed for accelerator. We got some things we couldn't find definite answers about. For example hypothetically if we could would it be good idea to put particle accelerator or storage ring in space? Assuming it would be shielded from radiation sufficiently wouldn't it make much easier to keep vacuum? and in one game (I know, it's not great source) there was character convincing to built huge accelerator around sun or Earth. I read somewhere that the bigger accelerator the better my friend also said that, but what would that do? If yuo can can yuo put me some links to good answers?

I'll be doing undergrad soon. I'm interested in particle physics. I was wondering what exactly it is that experimental particle physicists do, and the difference between what an experimental particle physicist does, and what a theoretical particle physicist does. Also, is it possible to shift to particle physics if you major in engineering?

I have been rereading Anathem by Neil Stephenson, and part of the plot involves aliens coming to a world from other cosmoses that have slightly different physical constants than the one the story is set

This got me thinking about how long that situation would be viable before matter loss became a big problem, which sent me down another mental rabbit hole. (I think of stupid stuff while mowing the lawn).

Eventually I came to this thought experiment. Say I was in a universe with no other matter, just pure void. My body would of course quickly die and float in nothingness. But how long would that body exist? I would be emitting blackbody photons, but what about particle decay itself? Would the particles composing my body eventually decay over time into nothing but fermions, neutrinos and photons?

Maybe I should just go back to bed and have a few cups of coffee in a few hours. Thanks everyone, have a good weekend.

Hey, Im kinda new to this field and subreddit, so please dont shame me if its a dumb question.

Ive been wondering why the PDG booklet doesnt list the intrinsic parities of the Higgs boson as well as the charged leptons. For all other particles (except obviously W and Z where it wouldnt make sense) it does list P. It seems that wikipedia, while listing a positive parity for the Higgs, also doesnt list parities for the charged leptons. I wonder if this is something fundamental or an experimental subtlety. In my lecture, the parity of quarks and leptons was introduced as positive and there was no further elaboration on this detail.

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I have limited my PLB to the statement of the finding

https://www.sciencedirect.com/science/article/pii/S0370269326003631

but obviusly the question is if there is some model that simultaneusly offers the direct formula for charged leptos and the inverse one for down type quarks. The motivation of the search was to produce a architecture where two sets of mesons obey these formulae. Seiberg duality?

I honestly have no business posting here. But I thought I’d post a recent project I built. I’m using a PBW34 photodiode to try and detect muons. Once I obtain the data, I’m analysing and classifying all the events to try and maybe highlight a muon amongst the EMI noise.

It took a while to get it all working after the “weekend project” phase. But I’m happy with the data I’m now collecting.

In sections discussing spontaneous symmetry breaking, textbooks usually cover some lagrangian with Z2 or some rotational symmetry, then show that the ground state of the field also ends up changing upon application of the symmetry. I think I get the basic concept but it’s not clear why exactly it’s something we care about.

I have two questions about this: 1: it’s not clicking for me why exactly we care about this. I’ve seen the idea applied to goldstones theorem which is cool, but it’s still not obvious why so much emphasis is placed on spontaneous symmetry breaking, and not just something like a “special Lagrangian where goldstones theorem can be invoked”. It’s not clear to me what the significance of such a system is.

2: does spontaneous symmetry breaking only arise from Lagrangians that contain fields with nonzero VEV?

Been in the making for over a year. Highly detailed. Works best on desktop. Just curious if I'm missing anything so I'd love to hear your thoughts.

https://physics-simulator-delta.vercel.app/

I am currently applying for masters programmes, considering phd right after. Based on my understanding of the field, most work done for say ATLAS or LHCb is mostly just data analysis in different channels or similar. Is this too simplistic of a view on the field? Its kinda the impression i got based on my undergrad projects and reading through the latest papers on collider experiments.

Mostly asking because my applications currently sound so data and ml focused where the only physics connection I have is that data is directly relevant to the field.

A lot of PhD programmes i am seeing are essentially precision measurements and similar work. Which is actually what i am interested in, but i feel like I may be lacking some context of the field.

I'm trying to understand this paper by A. J. Millis (can't link to scihub because I'm on university's wifi and we live in a dystopia)

What has me utterly perplexed is something he says at the start of section 2: "One may question the validity of integrating out the low energy excitations..."

You're damned sure I question it. This seems like the exact opposite of what renormalization is supposed to be. You are zooming in, not out, right? I've been trying to see if there's a way in which keeping high energy excitations could result in a divergent correlation length, but I can't. The uncertainty principle guarantees: high energy -> high momentum -> small space. I lack the ability to conceive of a way this wouldn't be true

Now, Millis says: "Chill out babe, if we get analytic results, how bad can this be?" and like... I guess?

Does that mean that the correlation length converges to a finite value? Because when I look at the formulas he gives for the correlation length for different systems, like equations 3.9, 3.11, 4.5... They don't seem to diverge when T=0... Then again, he uses this variable r which is defined at 3.3b and I can't say if that diverges or not

But even if the correlation length diverged... how is that possible when we only have high energy excitations?!?!?!?!?!

Thanks for at least reading this

as the title says, i'm looking for some books more on the historical side of particle physics and the formation of the standard model. i've been looking for some online, but goodreads didn't offer many recommendations :( i feel like i did not get enough education on the background of all the theories i learned during my bachelors and masters, so it would be fun to learn a bit more :)

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I'll write this so the link to the code is visible, it's here:

https://github.com/MasterOgon/Newtonian-Superfluid-Simulation