Now with MAX IV and ESS in the area as well, what does the particle physics community think about Lund University?

I'm finishing my bachelors next year and thinking about Lund's particle physics master. Thanks.

Anybody know where I can find this?

and/or does someone know of the breit-wigner single resonance formula with h-bar instead of \sigma?

I was just going to start learning Particle Physics from David Tong's papers (University of Cambridge). I already know the base of modern physics (starting from Bohr's Model, Photo electric effect up until nuclear physics) should I know something else before starting? Any suggestions are appreciated. Thanks.

I'm in a group with 4 people and we decided to make a particle accelerator for a research paper that is a pass or fail. This research paper decides whether we pass high school or not, so it's extremely important we can do our project We've built a homemade linear particle accelerator that shoots helium at 2000 eV, but we can go higher. The setup consists of a rough vacuum pump and diffusion pump, an electron gun and a phosphor screen at the end of the accelerator. The method of acceleration is through radio frequency acceleration in drift tubes. Lastly, there are two deflecting plates before the phosphor screen which slightly change the trajectory of the particle before hitting the phosphor screen.

We can measure the energy of the beam and pressure. Is there any research question that we can use that doesn't end with binary results?

Is there a meaningful difference in how we consider the location of nuclei vs electrons? My layman’s understanding is that electron cloud model describes the location of electrons as a cloud of possible locations with the nucleus at its center. Less mass + higher velocity = really hard to observe so maybe the nucleus is just significantly more concrete in its position?

Is the nucleus more locked in place because of mass or does it have its own kind of cloud of possible location when we try to observe it?

What kind of incorrect assumptions might I be making?

Hello everyone Is any body here in CERN or went to CERN before? I would like to ask some questions please Thanks in advance Actually, I'am going to CERN in two months from now So, I would like to get feedback from the people who went there ! How much did you benefited from your visit and if you can mention some of the points that really benefited you ? Tell me everything, you see there in CERN I would like to ask about accomodation, the best place to stay at, best restaurants, prices for accomodation and food, what else can you visit in Geneva?

In the ckm mechanism, the angles are generally described as arg(- something) , while in the actual diagram the the sides are opposite (no - value).

Take beta for example, it is written as arg(-Vcd Vcb(star)/(Vtd Vtb(star)). But it's different in the triangle diagram!

Is it possible to do away with the sign and invert the thing ofcourse?

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Hi all. I've just finished watching Richard Feynman's New Zealand lectures on QED. The lecture was in the late 70s, and I'm wondering if we've learned any more since then about how Bosons 'travel'? (In that the percentage of photons that reflect of, say, a glass surface is dependent on the thickness of the glass, raising the question of how does the photon know whether to reflect or not), or are we no closer to figuring out what is going on at that level? I've only studied physics to high school standards, but do have a surface level 'knowledge' of particle physics (unfortunately my maths really lets me down).

As the title suggests, I want to know which is better career wise if I want to work in experimental particle physics ( Data analysis). Also do all US universities require GRE physics?

Hello I’m an incoming freshman at Purdue university for First Year engineering. I’ve always been interested in aerodynamics, propulsion, and particle physics. If I were to major in MechEng can I still do a PhD in physics straight away? Or should I look into transferring to better colleges? I heard Purdue is not worth for physics (should’ve committed to UIUC smh)

Hello, I am a physics student at a University in India and I am about to complete my Bachelor's in May. I guess it maybe too late now to apply for any internship or summer school that may start in June or July but I would still like to know if there are any institutes abroad that accept international students and preferably provide some stipped and/or accomodation. Thank you in advance!

If you have a pair of entangled photons and one hits an atom is absorbed and a new photon is emitted, is the entanglement broken? (Or are more particles/atoms now entangled?)

It could be positrons with the nucleus having a negative charge. How do the particle physicists explain it?

I am learning about Feynman diagrams. Is it correct that this diagram describes the "collision" aka repulsion of two electrons? And is this the collision that fx prevents my hans from going through a wall?

Hey guys!

Now I'm recreating this topic after taking the time to study more

Context: I am an Aerospace Engineering student and I am in my first year of graduation. I attended Technical College of Telecommunications in Brazil in high school. And last week my professor of fluid mechanics and wave physics called me for a crazy idea that the University raised some money for: He wants to make a linear particle accelerator.

The question: What is the best project to flow? We want something that can provide many experiences, something usable that isn't just used for one or two purposes

I'm thinking about an ion accelerator

Other questions: what is the difference between proton accelerators and ion accelerators? Because to me this is literally the same thing

Sorry for a some bad chose of words, I am new in English and especially on Redid

Hello! I am a academic of Aerospace Engineering and i am working in find a new project to my university. Can someone help me? I want build a Linear Particle Accelerator to us and I don't no any project. I want accelerate neutrons.

Sorry for my English, it is my first time write a something

Edit: I created a new topic for this

How come kaons are detected as their mass eigenstates (Ks and Kl) as opposed to their flavour eigenstates (K0 and K0bar). But for B mesons, we detect them as their flavour eigenstates (Bd and Bd(bar) ) and not their mass eigenstates (Bh and Bl)?

Can someone explain the difference in these two 'mixing' ?

Thanks!

Anyone know how the current job market looks? Or have tips on getting a resume on someone's desk? I'm ABD on a HEP PhD with CMS and looking for a job. Got unexpectedly laid off in January from a ML Engineer position and the job search has been extremely slow.

Why can't BSM particles enter at tree level and why can they only exist in loops? Afterall, whether the W boson(say) enters at tree level decay or in loops, it is an off-shell W boson regardless!

For example Tree level : B --> J/psi Ks (Off shell W boson, two weak vertices ) Loop level: B --> Ks Ks (Gluconic penguin decay with an off-shell W boson, two weak vertices+ two strong vertices) ?

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I have heard that if an electron collides with another atom in an accelerator, the electron jumps to another excitement level but soon it falls back and emits a photon. Please correct me if I'm wrong. I was just wondering, how do we know which excitement level did it hop on? I don't know much about it and I'm sorry if it's a stupid question for you.

Thanks in advance

I want to know if there is a formula for calculating the angle of deviation or deflection a charged particle experiences while exiting a magnetic field

Basically the question. I want to understand how exactly the GIM mechanism suppress FCNC at tree level but allows at loop level. I understand the Z to ffbar thing, were ∆S = 1 cancels out. But I am still a bit confused on this as why FCNC this happen?

Thank you!

And/or how can I get them?

In the book "The historical development of Quantum Theory", volume 3, chapter 5, page 202 of my edition, there's a quote from Bohr I really want to understand

For context, the idea of spin had been published just a few weeks ago by Samuel and George, Bohr read it but he was unconvinced, then he found Einstein at a party and they talked about it. Then as Bohr wrote in a letter to Ralph Kronig:

"...Einstein asked the very first moment I saw him what I believed about the spinning electron. Upon my question about the cause of the necessary mutual coupling between the spin axis and the orbital motion, he explained that this coupling was an immediate consequence of the theory of relativity. This remark acted as a complete relivation [sic, revelation] to me, and I have never since faltered in my conviction that we at last were at the end of our sorrows"

Bohr to Kronig, 26 March 1926

Here's the thing, I know that if you take Schrödinger's Equation, you apply relativity to it and then you "take the square root" you get Dirac equation and then you get spin for free. I've done that derivation many times, i saw it in class, I understand that part

The problem is that back then they didn't have Dirac's equation, they didn't even have Schrödinger's, so how did Einstein see this? What reasoning led him to conclude this? I am so supremely confused

Also, I'm not entirely sure what Bohr means by "mutual coupling between the spin axis and the orbital motion". Is he talking about about the relationship between the quantum numbers for the energy level and the angular momentum? Is he talking about the fact that each combination of angular momentum and energy level has to be unique, in other words, is he talking about the exclusion principle?

This conversation was important because Einstein convinced Bohr to take the idea of spin seriously, Bohr convinced Heisenberg, and Heisenberg convinced Pauli, who then finally found his famous matrices, so this conversation is like the first domino in the chain and that's why I want to understand it