Particle physics Definition and 537 Threads

Hello! Is there any rule to do sums and products like the one in the attached picture (Lie.png) without going through all the math theory behind? I understand the first (product) and last (sum) terms, but I am not sure I understand how you go from one to another. Thank you!

We know that pions can be produced through decaying of kaons via weak interaction, but we also know in the acclerator the pions can be produced in pair via strong interaction. So my question is pions are produced via both strong and weak interactions?

Hi, I'm looking at the unitarity constraints for the Two-Higgs Doublet Model and I'm trying to follow what they do in the attached article, which can also be found here: https://arxiv.org/pdf/hep-ph/0312374v1.pdf. However I do not know how to get the scattering matrices in eq. (7). They say...

Homework Statement I have the decay K+ → μ+ + νμ Calculate: 1. Momentum of μ+ 2. Total energy of νμ 3. Mass of K+ 4. Speed of μ+ 5. Speed of νμ Homework Equations The only thing we get are the kinetic energy of μ+ so Kμ+ = 152.53 MeV and the mass of mμ+ = 105.658 MeV/c2 The Attempt at a...

Homework Statement Working through problems in Mahan's 'Many Particle Physics' book, and at the end of the 1st chapter there's a question where we're asked to consider a fermion system with three energy states with eigenvalues E1, E2, E3, and matrix elements M12, M23, M13 which connect them and...

According to observations and known models mass is equal to the amount of atoms in a given space, and gravity is proportional to the amount of mass in a given space (ie. Sun > Earth > Moon) If those observations are undeniable then my question remains: is gravity directly related to groupings of...

Consider the case in which an incoming particle collides with stationary target particle producing new particles through the interaction. For example, $$e^{-}+e^{+}\rightarrow X+\bar{X}$$ My question is, why in general do the particles produced in such an interaction propagate outwards are...

Hi guys! I'm doing a research about teaching elementary particles in the middle school, something that isn't the reality in my country. Despite of the research in Physics Teaching be a lot advanced, the proposals made by them are not applied in the practice of the teachers. I want to propose...

Homework Statement Consider the Klein-Gordon equation ##(\partial_\mu \partial^{\mu}+m^2)\varphi(x)=0##. Using Noether's theorem, find a continuity equation of the form ##\partial_\mu j^{\mu}=0##. Homework Equations ##(\partial_\mu \partial^{\mu}+m^2)\varphi(x)=0## The Attempt at a Solution...

I'm in a deep discussion with a friend. He says that the Standard Model of particle physics is actually known by Standard Model of cosmology and that both are the same and that the SM of particle physics is in the Minkousky geometry... I disagree about this, I do think that the SM of particle...

I suppose that my questions are pretty basic, but I've been trying to find out the answers and not succeeded. 1.- Do cosmologists really think that the vacuum state suddenly changed in the early Universe? If so, would it be like a phase transition? If so, first or second orther? 2.- Does the...

Hello! I am sorry that this questions is not actually directly related to physics, but, can anyone recommend me a good book about abstract algebra (basically lie algebra, representation theory etc.) used in physics? I have tried for a long time to find something online but I haven't find a...

mfb submitted a new PF Insights post LHC Part 4: Searching for New Particles and Decays Continue reading the Original PF Insights Post.

Hi, I'm recently reading some text on particle physics and there is a section on symmetries and group theory. It gave the definition of SU2 as the group of unitary 2*2 matrices and that SU3 is the group of unitary 3*3 matrices. However, it kind of confuses me when it mentioned representations...

Is there a peer reviewed paper that proposes a way to connect the relativity of time dilation, length contraction and the relative effects of gravitation per acceleration with respect to mass with the standard model of particle physics? An established theory which also takes into account both...

I'm looking for help in understanding the meaning, nature and/or concept of singularity as such applies to the mechanics of a black hole ...

Good Evening Everyone, A group of friends and I were having a mini-contest, to see who could theoretically make anti-matter using the most simplistic design in terms of cost and general complexity. The obvious choice for us was the Positron, due to low energy requirements on all fronts. One of...

Homework Statement In electromagnetic interactions, the force carrier is the photon, and it interacts with anything which has electric charge. Electric charge can be represented by the integers on a single number line and photons themselves carry no electric charge. (a) In the case of the...

Hello I encountered a problem in which it is specify that there are 2 time-ordered diagram for the s-channel for a certain process a+b->c+d. I understand that there is the one that can be associated with annihilation, but what would be a second one? Thank you!

Well, I'm planning to learn from this book when i finish Shankar's Principles of Quantum Mechanics, if it fulfills the requiriments in this part, but from where i can learn the Special Relativity necessary to tackle this book?

Hi guys. This is my first post here. Here it goes. I'm attending an introductory course on particle physics. By now, I'm supposed to know how to find out if a given reaction, say νμ+p→μ++n (for example) is possible or not. Unfortunately, the rules by which a reaction must abide are still foggy...

Hey! I am a year 11 student from Australia and I am wanting to take course(s) in particle physics at university/college after high school. I am just wondering where I can do this as I haven't found many universities (In Victoria) that offer this. If anyone has experience from overseas I would...

I want to start studying particle physics on my own and wanted to know what the prerequisite are? I'm in my second year of college and have finished Calc. 3 and Physics with calc. 3. I'd also be interested in textbook recommendations.

Hello all, I'm just doing some practice for an upcoming exam and came upon this question in my notes: One experimental way to generate very high energy photons is to ”collide” a laser beam against an electron beam, the photons that recoil in the direction parallel to the electron beam will have...

Hi; I've been doing some research for my master's on gauge theory in the language of fiber bundles, and something occurred to me. Both GR and the Standard Model (SM) can be described in terms of connections (potentials) and curvatures (field strengths), but there's this generalization of GR...

Hello all. This is my first thread. I am 23y/o male. After my high school I wanted to go for physics but due to family pressure I went for marine engineering but bailed out after two years as I find it boring and unappealing. After that I tried two and half year for a government job but lost...

Homework Statement I am trying to calculate the ratio of the density of states factor, ##\rho(p)##, for the two decays: $$\pi^+\rightarrow e^++\nu_e~~$$ and $$\pi^+\rightarrow \mu^++\nu_{\mu}~~$$ Homework Equations ##\rho(p)~dp=\frac{V}{(2\pi\hbar)^3}p^2~dp~d\Omega## Which is the number...

Homework Statement See the PDF. I would like some pointers as to what would be most relevant to talk about Homework Equations Amplitude, cross sections and decay rates. The Attempt at a Solution 1) Particle classification: From the Eightfold way to the quark model[/B] Particles are...

Let's start with a vacuum, I will write |0000...> as |0>. $$ \psi^+ (x) |0\rangle = \sum_k e^{-ikx} a^+ (k) |0\rangle $$ Qns: What happens if you superpose/add up state vectors corresponding to a particle of momentum k and you add up with coefficient e-ikx? $$ \sum_k e^{-ikx} a^+ (k) |0\rangle...

Homework Statement For the reaction below draw three Feynman diagrams, one that proceeds through exchange of a gluon, one through a photon and one exchanging a weak W-Boson. ##\pi^0+\pi^0\rightarrow \pi^++\pi^-## Which diagram provides the dominant contribution for this reaction? Explain how...

Homework Statement Calculate the wavelength of an electron which has 5eV of energy.Homework Equations de Broglie's equation: lambda=h/p , kinetic energy equation: K=0.5mv^2 The Attempt at a Solution My attempt: I figured out that using de Broglie's wavelength equation was necessary for this...

Hello all, This is most likely a question for those who have experience/knowledge of theoretical/mathematical physics at the graduate level and can provide recommendations following my criteria. Here is some background about me: I am a senior majoring in math and physics at a small...

Are there any particles known in the Physics world with an either positive or negative charge that can be viewed by the human eye under LED light illumination and have an attraction/repulsion to magnetism?

I am a 49 years old electrical engineer who lectures Optical Communications at the University of Seville. I learned QED because I wanted to understand the ground principles of my area of expertise. I was amazed and thrilled by the beauty of QFT, so I decided to keep on studying. Fearly recently...

1.- Electroweak interaction broke its symmetry about 1ps after the Big Bang and two different types of interactions appeared: weak interactions and electrodynamics. 2.- The LHC at Geneva is routinely conducting experiments above the energy threshold of electroweak unification. Could these...

Among the following programs, which are the best for theoretical particle physics? Stony Brook, Penn State, Iowa State, Urbana Champaign, Arizona, Arizona State, Georgia Tech, Florida, Tennesse KnoxVille Are there some other programs of lower ranking in the league tables, but has a strong high...

I'm halfway through my junior year and I'm hoping to do Quantum Optics or Particle Physics in graduate school (I'm doing the recommended courses for both since I'm still undecided). Besides the math required from the physics major (ie. Calculus, linear algebra, ODEs, PDEs, complex analysis)...

Hello, So before I start, I realize that this question has been asked in the past, but all of the threads were over several years old so I'm not sure if the information is still current. I've been thinking about this decision for a while: I'm currently in my second year at a respected...

Homework Statement Estimate the magnetic field required to maintain protons at 7TeV in the LHC at CERN. The LHC has a circumference of 27 km. State any assumptions or approximations you make. Homework Equations lorentz force, assuming magnetic field is always perpendicular to the direction of...

Homework Statement I'm trying to confirm the speed of an antimuon in the \pi^+ \rightarrow \mu^+ \nu_{\mu} decay through the laws of conservation but it doesn't add up. Homework Equations [/B] 1.Energy-momentum relation: E^2 = (pc)^2 + (mc^2)^2 2. Rest masses: m_{\pi} = 139.6 \...

In Mark Thomson's Modern Particle Physics, Problem 6.7, I am wondering how we obtain: 2(ms, 0, 0, 0) and -2(ms, 0, 0, 0) for the RL and LR helicities (likewise for the muon) in the electron currents using helicity combinations. My solutions for the other helicities (RR, LL) work out, but I am...

So my university offers two programs focused on particle physics. One is simply masters in nuclear/particle physics, the other is masters in mathematical modelling with focus on particle physics. I want to go into mathematical modelling and I'm choosing what I will focus on. I'm not really...

Hi everyone! I'm a newbie in this forum. And I need your help for making the right career path for my future. I've been graduated from Physics three months ago and I took some exams (like TOEFL and GRE) for applying master's degrees programs in Turkey. I'm from Kosovo and Kosovo is a developing...

Homework Statement Three point charges are located on the positive x-axis of a coordinate system. Charge q1 = 2.0 nC is 2.0 cm from the origin, charge q2 = -3.5 nC is 4.0 cm from the origin and charge q3 = 5.0 nC located at the origin. What is the net force ((a)magnitude and (b) direction) on...

Okay so i have a question for you guys if I have a positron striking an electron at rest to create 2 pions( + and -) and I want to calculate the minimum kinnetic energy that the electrons can possesses to create these pions... then the created pions will be at rest correct? so this gives me two...

Does anyone know of any schools that offer degrees specifically in particle physics?

I am looking for a short pedagogical introduction to Young-tableaux and weight diagrams and the relationship between them, which contains many detailled and worked out examples of how these methods are applied in physics, such as in the context of the standard model and beyond for example. I am...

The decay \rho^0 \rightarrow \pi^- \pi^+ occurs with a probability of 100\%, whereas the decay \rho^0 \rightarrow \pi^0 \pi^0 does not occur in nature, due to isosphin conservation. I don't understand this. Looking at the Isospin and its third component ¦I,I_3\rangle we have in the first...

I've been checking a university's descriptions of its research groups and their interests, where I encountered the phrase "Topological effects in Particle Physics" which had no explanation. I searched in the internet, but I couldn't find anything. Could anyone explain about such effects and...

Hi guys, I don't know if there's any similar thread (I didn't find any, but in case I missed it); if so please suggest them to me. It's time to apply to college again. I personally think particle physics (experimental) would be my top choice (I understand that only phd has the specialized...