Questions tagged [protons]

A proton is a positively charged particle which is generally considered to be a composite particle comprising of three quarks interacting through the strong force (e.g. in the standard model.)

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Is an alpha particle four nucleons or dodecaquark?

In a $\alpha$ particle, do the 4 nucleons stay distinct in any meaningful manner, or is it more accurately considered to be a hadron composed of 12 valence quarks that are not subdivided into nucleons?...
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Are protons and neutrons 2 dimensional given that they consist of 3 quarks?

Assuming the following: Neutrons and protons are made of 3 quarks (of different types). All quarks are point particles Then a neutron or proton cannot be 3 dimensional because three points cannot ...
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What is the maximum speed Hadrons can move? [closed]

How fast can protons and neutrons move. Also, how fast can the quarks they are made of move?
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What's the difference between these two 'process'?

In my text book it talks about about protons colliding: to demonstrate the idea of pair production and quark confinement. In both scenarios two protons collide (the energies of each are not stated ...
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What's the maximum magnetic field a electron can generate?, What the max for a proton? [closed]

I actually have multiple questions, What's the maximum magnetic field an electron can generate?, What the max for a proton? Is there a limit to how powerful a magnetic field you can generate with a ...
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1answer
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How does electrostatic attraction work?

We're doing electrostatics in my physics class and have just finished discussing the fact that like charges repel one another, whereas unlike charges attract. I have a vague notion that a charge is ...
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Why are protons heavier than electrons?

Our teacher told us that protons are nearly 1800 times heavier than electrons. Is there any known reason as to why this is so? Or is this just an empirical value, one we do not know the reason to?
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Cold neutron radiative capture by proton

What is the mechanism of cold neutron radiative capture by proton? I have seen some experimental papers on studies of parity violation via this reaction, but I haven't seen a fundamental description ...
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Confusion in proton decay

I read that a proton cannot decay because it is the least massive baryon. However, in positron emission, the proton converts to a neutron a releases a positron. Is that considered a proton decay?
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Question about Woods-Saxon density distribution [closed]

So the Wood-Saxon density distribution for protons in a nucleus is given as follows: $$\rho_p(r) = \frac{\rho_{p0}}{1+e^{[(r-R_0)/a]}}$$ Here $r$ is the distance to the centre of the nucleus, and $a$ ...
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Why could the Yukawa potential explain how protons can be bound in the nucleus?

The Yukawa Lagrangian $$\mathcal{L}=-\dfrac{1}{4}F_{\mu\nu}F^{\mu\nu}+\dfrac{1}{2}m^2A_\mu A^\mu-A_\mu J^\mu$$ can be used to derive the equations of motion $$\Box A_\mu=J_\mu-m^2A_\mu$$ for the ...
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Compton-like scattering for protons

Why don't we usually calculate scattering cross sections for Compton scattering of photons (gamma rays) off protons? After all both electrons and protons are fermions. Hence shouldn't the amplitude be ...
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Is the Charge on proton is $3.2\times10^{-19}$ greater than that of charge on electron?

As the charge on electron is $$e^-=-1.6\times10^{-19}C$$ and charge on proton is $$p^+=+1.6\times10^{-19}C$$ Does this mean that the charge on electron is $3.2\times10^{-19}C$ less than that of ...
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When does a proton break?

I have read that most proton-proton collision are elastic, and that rarely a proton is smashed, and that happens only at large angles: can you expand on this situation? What does a large angle mean? ...
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What makes the number of neutrons the number of proton similar?

In basic chemistry, we are taught that an atom has roughly the same number of neutrons and number of protons, this doesn't seems to hold for larger atoms, but it is always roughly proportional (i.e. ...
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Is there a term for electron capture outside the nucleus?

My textbook says that electron capture is when an electron is 'captured' by a proton in the nucleus which causes them to turn into a neutron and an electron neutrino. The name kind of suggests it only ...
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Is quark and gluon orbital angular momentum predicted to have the rest of the proton's spin?

The Phys.org news item How did the proton get its spin? outlines various experiments that probe proton structure and are sensitive to spin, and the current news is that CEBAF's major energy upgrade ...
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Why don't we have proton/neutron microscopes?

According to wave-particle duality it should be possible for protons/neutrons to have wavelengths shorter than those of electrons having similar velocity. So why don't we use proton/neutron ...
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Position of protons and neutrons in a nucleus

According to the Wikipedia article on atomic nucleus, captioned on an impression of helium atom, it states that This depiction shows the particles as separate, whereas in an actual helium atom, the ...
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Why do we see positive charges move if protons do not move in a solid conductor?

I know the fact that protons don't have the mobile ability like electrons to move freely because they are bounded to the nuclei due to the $VW$ forces apparent in the object but I've read that there ...
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Can mass number of nucleus be equal to it's atomic number? [closed]

The mass number of a nucleus is always less than its atomic number always more than its atomic number equal to its atomic number sometimes more than and sometimes equal to its atomic ...
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1answer
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What happens when 1000's of protons falls on us? [closed]

When electrons flow through us we get an electric shock. What would happen when protons flow through us?
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What is the temperature of a single proton? [duplicate]

As it is said in general classical statistical mechanics, that temperature is nothing but just an integrating factor and T($E_{avg}$). And as proton is not a fundamental particle rather have inner ...
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Accelerated charges

I was reading about the cyclotron and how it acelerates charges. I just had this really dumb question. What would happen if I'm in the path of the accelerated charge? Say a proton accelerated to very ...
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1answer
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Can an electric circuit board have more electrons than protons?

Current flows from $+$ to $-$ but electrons go the opposite direction. When I connect the GND of a positive charged electric circuit board to earth, then the board accepts electrons from the earth ...
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4answers
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Do physicists use particle “energy” to refer to kinetic energy?

In 1963, this paper was written about the effects of radiation on solar panels. The paper states that: When electrons at energies greater than 145 KeV and protons at energies greater than 98eV ...
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1answer
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Magnetic moments of nucleons

I was comparing my notes of the nuclear physics class (undergraduate level) on magnetic moments of nucleons with the Krane's explanation. In my notes I wrote that there are two types of magnetic ...
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Proton spin/flavor wavefunction

I am currently working through Griffiths' Introductory to Elementary Particle Physics and I'm a little confused about a particle's spin/flavor wavefunctions. As a specific example, I've attached ...
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How does the semi-empirical mass formula prove or detract from the existence of the “valley of stability”?

I came across this passage in my lecture notes. The semi-empirical mass formula (SEMF) is a better estimator of atomic mass than the standard mass formula, which neglects spatial arrangement of ...
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1answer
553 views

Does an antiproton have a proton number of 1 or -1

I have a disagreement with someone; they have written this equation: $$ \,^{0}_{0}\gamma\to\,^1_1p+\,^1_1\bar p $$ I disagree, and say that the anti-proton should have a proton number of -1, not 1. ...
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1answer
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Radiation issues dealing with the formation of Hydrogen from an isolated proton and electron

Please excuse me if this question has been asked and/or even partially answered here before... (I did search about, and did not see it specifically asked) In particular, and being purposefully '...
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1answer
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Sum of nucleus less than sum of neutrons & protons? [duplicate]

The mass of a nucleus is less than the sum total of the individual masses of the protons and neutrons which form it. How this is possible?
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2answers
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Nuclear forces so strong that they can attract other atoms too?

this pic is from the book the theory of everything by Stephen Hawking: My question is that whether the nuclear forces inside the atom are so strong that they can attract other atoms (para 1, line -4&...
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What if I shot protons and electrons at a neutron star

Could I create a massive element simply by putting protons into a neutron star? And then forcing electrons to orbit it?
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Why is proton so dense?

A question in Serway's book asked the density of proton and to compare it to osmium's density. I found 2.88*10^16 kg/m^3. Isn't it so much dense ? I mean, 10^16. What is the reason behind it's density'...
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1answer
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Basic electric field - extremely granular question

In an effort to understand a basic electric field at its most granular (as per scientific community collective understanding in 2016) I thought I'd finally ask a question that's been on my mind for ...
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1answer
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Towards a matrix element definition of PDF

In Schwartz's book, 'Quantum Field Theory and the Standard Model' P.$696$, he starts to derive an expression for a parton distribution function in terms of matrix elements evaluated on the lightcone. ...
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5answers
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On the relationship between mass-energy and electric field energy

Note: I acknowledge that this thought experiment is rather crude due to it's lack of quantum mechanical emphasis however I am really looking for a more principled explanation if possible. All I ...
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Where is the mass of a proton coming from? From empty space or gluonfields?

Protons are made quarks and bosons. I think most physicists would agree that the mass of a proton is not coming from the quarks itself. About 90% is coming from something else, but what is that. I ...
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1answer
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Way to express charge

i would like to ask a question regarding electric charge. I see that charge has 3 units Elementary charge Coulomb Esu For example A proton has a charge of $+1e$ or of $+1.602 * 10^{-19}$ Coulombs.. ...
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2answers
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How protons come near to during the formation of a nucleus?

It is known that protons are held together inside the nucleus by nuclear forces which are short range forces. Now my question is how are the protons brought together when they are far apart despite ...
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1answer
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If we are able to contain the energy released by the center of atom or manipulate the amount of electron neutron and proton it contain,what'll happen? [closed]

I mean, if we could actually manipulate the amount of electron proton and neutron an atom contains and can actually contain all the energy released by it, are we going to be able to shape shift? So, ...
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1answer
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What happens to the electron if the nuclues instantaneously disappears? [closed]

Imagine a hydrogen atom alone within an empty universe. Now imagine that the proton that the electron in the our hypothetical atom is bound to instantaneously disappears. From a quantum perspective, ...
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Theoretically, could there be different types of protons and electrons?

Me and my friend were arguing. I think there could theoretically be different types of protons, but he says not. He says that if you have a different type of proton, it isn't a proton, it's something ...
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1answer
338 views

Missing energy in proton decay

According to wikipedia: some grand unification theories, such as the Georgi–Glashow model, require it. According to such theories, the proton has a half-life of about 1031 to 1036 years and decays ...
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2answers
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Are there ever electrons in the outcome of proton-proton collisions?

I have explored a google-search for days but I could not find a list of stantard outcomes of p-p collisions: they just say there are tens up to hundreds particles. Can you say (or give a link) what ...
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1answer
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Are the electrons and protons electric potential in bonded state are the same as if they are free particles?

During the approach of an electron and a proton into a hydrogen atom, are their electric fields unchanged? Or do they cancel each over out (more or less, only a weak electric dipole alive).
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1answer
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Why must nuclei contain both protons and neutrons? [duplicate]

In most atomic nuclei there are both protons and neutrons. Having a poor understanding of the strong interaction, it puzzles me why a nucleus must consist of both. Namely, why can there not be ...
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1answer
326 views

How are the spins of three quarks in a nucleon aligned?

A proton is composed of uud. Are the two up quarks paired up to cancel each other's spin or are one up quark and one down quark paired up? I know the three quarks may only carry a small proportion of ...
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1answer
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What is the significance of the proton and neutron being approximately the same mass?

The mass of a proton is $1.673 \times 10^{-27}$ kg and the mass of a neutron is $1.675\times10^{-27}$ kg. (Approximate.) Would anything be different if they had different masses? Is there a "reason" ...

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