Proton Definition and 845 Threads

  1. reemie

    How to calculate the mass of a hydrogen atom

    The answer according to my booklet is 1.6734×10-24 (g), but I don't understand how we got this answer. proton: 1.6725×10-24 neutron: 1.6748×10-24 electron: 0.0009×10-24 To get the mass, I added protons with neutrons, but I got 3.3473×10-24. What am I doing wrong?
  2. A

    Large nuclei to proton ratios reduce repulsion in a nucleus

    Hi, I am new here. I am just reading over my notes for stable and unstable nuclei and I came across this sentence: 'Large nuclei require a higher neutron proton ratio as this adds more nuclear attraction without adding repulsion'. I was wondering why the large ratio would reduce repulsion? Thank...
  3. C

    The Mystery of Proton Decay: Unveiling the Role of the Higgs Field

    What is so special about the Higgs field that causes protons to decay?
  4. B

    Proton-proton I chain and mass defect reactants and products

    Hello there, I'm starting S382 astrophysics with the OU. The course book says "The proton-proton chain converts four hydrogen nuclei (protons) into a ^4_2He nucleus, two positrons that quickly collide with electrons and are annihilated, and two neutrinos. Hence, branch I of the p-p chain may be...
  5. K

    Proton Proton Annihilation: The Energy Behind Fusion

    How much force (<10kN) is needed to compress two protons into each other? When it happens, when they are annihilated, the energy of the released gamma rays E=Mp *c^2 ? or some are carried away by short-lived byproducts? Regards Karoly
  6. J

    Proton Plasma Wakefield Accelerators

    Why do all wakefield accelerators seem to use either electrons or positrons? Is there any reason you would have difficulty creating a laser driven proton plasma wakefield accelerator? (that is, in comparison to an electron accelerator) Thanks.
  7. Devin

    What is the frequency of proton oscillation?

    How do protons oscillate? Do they move back and forth with a constant velocity, or sort of like a mass on a spring? If so, what is the frequency of oscillation? Thanks
  8. Anchovy

    Calculating proton decay lifetime correctly?

    I'm trying to calculate the SU(5) model's prediction for the lower limit of a proton decay lifetime, for the channel p \rightarrow \pi^{0} e^{+}. I'm following this paper: arXiv:hep-ph/0504276v1 It contains the following equation: As far as I can tell this actually contains a prediction...
  9. Anchovy

    Confused by these proton decay diagrams

    I have some confusion over some diagrams involved in proton decays in SU(5). I've seen a few like this that look weird to me. Here is one I found where the colored Higgs triplet does the job: Straight away I don't know what to make of this because I've only ever seen diagrams where fermions are...
  10. Anchovy

    Proton decay lifetime prediction SU(5)?

    I'm trying to understand how the SU(5) prediction for the proton decay lifetime of \tau_{p} \sim10^{31} yr has been arrived at. I keep seeing it stated that \tau_{p} \sim \frac{4\pi}{g_{5}^{2}} \frac{M_{X}^{4}}{M_{p}^{5}} where g_{5} is the SU(5) coupling and M_{X,p} are the X boson and proton...
  11. E

    Proton Velocity After Atom Release: An Overview

    Is there a standard velocity for a proton when and if it is released from an atom?
  12. J

    How are the quarks in a proton or neutron held together?

    I've been trying to find a source for this somewhere, but I always end up with different sources explaining what holds protons and neutrons together in the nucleus of an atom. I know that the gluons hold them together, but I'm not sure exactly how they do this, and what type of transfers occur...
  13. Buzz Bloom

    What is the correct solar neutrino reaction equation and how was it discovered?

    Hi mfb: The following messages were in the now closed thread "Neutrinos-Antineutrinos in the universe". Bill_K said (msg #2): Most of the neutrinos we detect are solar neutrinos coming from p + P → d + e+ + ν. I said (msg #5): Is the "P" here a typo where "p" was intended? If not, what does...
  14. J

    Why are fundamental particles round?

    why is each fundamental particle round
  15. J

    Are There More Than 3 Quarks in a Proton? The Truth Revealed by Scientists

    I read some time ago there are many more as 3 quarks in proton but lot of publications mention only 3 quarks! Where is the truth?
  16. S

    Magnitude of electric force on a proton

    Homework Statement Two protons are 2.5fm apart. What is the magnitude of the electric force on one proton due to the other proton? Homework Equations Fe = K|q1||q2| / r2 The Attempt at a Solution Fe = (9 x 109)x(1.6 x 10-19)2 / (2.5 x 10-15)2 Fe = 37 N I got the answer but I don't...
  17. Anchovy

    Prerequisites for learning MSSM --> proton decay prediction?

    Hi all, I'm attempting to write something on proton decay (specifically in the p \rightarrow K^{+} \nu channel) and need to understand some theory that predicts it. I'm under the impression that the MSSM is the most straightforward theory. However, I look through introductory texts/documents...
  18. blue_leaf77

    Distinguish between positron and proton

    Probably a basic question in this field but I haven't been able to find the answer upon internet search. Suppose I send a beam consisting of protons and positrons with a given momentum into a cloud chamber, how can then I tell them apart? My own rough guess: Suppose the two particles undergo...
  19. Stephanus

    Can Protons and Electrons Combine to Form Neutrons in Stars?

    This the answer that I have from Chalnoth in my other thread about nuclear fusion inside the sun (or star in main sequence). And after iron burning in the core of massive star, the star explodes and leaves a neutron star (or a black hole) behind. Is producing neutron in P+P reaction chains and...
  20. edguy99

    Insights How to Stop an Electron from Falling into a Proton - Comments

    edguy99 submitted a new PF Insights post https://www.physicsforums.com/insights/quantum-animations-stop-electron-falling-proton/ https://www.physicsforums.com/insights/wp-content/uploads/2015/05/quantumanimations-80x80.png...
  21. D

    Equation used to find kinetic energy of proton

    I am having trouble deciding when to use which equation. If you're given the wavelength of a proton, let's say 100 fm, and have to find the kinetic energy of it, how would you do this? Here are my ideas: Idea 1: Use lambda = h/p, where p = sqrt(2Em). Idea 2: Use E=(pc)^2+(mc^2)^2 =...
  22. J

    Electrostatic Force Between Proton and Neutron?

    After calculating the force upon an electron and a force upon a proton in the atom of hydrogen, my result was a force of ≈8.2x10-8 Newtons acting upon the electron and proton each. If found this by using the formula Fe = (ke q1q2)/r2 Taking this number, I then applied it in the formula F = ma...
  23. T

    Why electron doesn't fall on proton, quantum explanation

    According to Feynman's lecture in physics an electron doesn't fall on the proton because of the uncertainty principle. Now, if electron falls on the proton, it's position and momentum can be known so it leaves some place for it to move. But uncertainty principle is applicable for all particles...
  24. Stephanus

    Can Protons and Electrons Combine to Form Neutrons?

    Dear PF Forum, I have a question to ask. Supernovae produce neutron star (or Black Hole). This is what I summarize from wikipedia. 1. Is P + e = N? Is it that simple? Judging by its mass, altough slightly off. 2. Is Up Quark + e = Down Quark? Thanks for any answer
  25. Matt atkinson

    Maximum Positron Energy in Proton Fusion and Beta + Decay

    Homework Statement Consider; p+p \rightarrow d + e^+ + \nu_e Assume the binding energy of deuteron is 2.2MeV, calculate the maximum energy that the positron can have. Homework Equations m_p=938.28MeV/c^2 m_n=939.566MeV/c^2 m_d=1875.6MeV/c^2 The Attempt at a Solution Assuming the neutrino was...
  26. SU403RUNFAST

    Does the annihilation of a proton always result in gamma radiation emission?

    When a proton is annhilated, is there gamma radiation emitted?
  27. binbagsss

    Gauss's law, nucleus, potential proton due to other protons

    I'm a little out of touch with this stuff , but I'm really not getting it.. So my book is considering: in a nucleus of ##z## protons, consider one proton in spherical charge distribution to other protons. So ## \rho = (z-1)e/(4/3) \pi R^{3}##, where ##R## is the radius of the nucleus, is the...
  28. binbagsss

    Why do proton and neutron form isospin doublet? I3 or I?

    As far as I understand, ##I_{3}##, the component of isospin in a certain direction is additive, but ##I## is to be treated as a vector sum, is this correct? So, ##I_{3}=1/2## for ##u## quark, ##I_{3}=-1/2 ## for ##d## quark. Adding ##I_{3}## then for a proton we find ##I_{3}=1/2## and for a...
  29. V

    Proton movement in an electric field

    A proton initially moves left to right along the x-axis at a speed of 2 x 10^3 m/s. It moves into an electric field, which points in the negative x direction, and travels a distance of 0.15m before coming to rest. What acceleration magnitude does the proton experience? equations E = kq/r^2...
  30. akashpandey

    Effect of proton spin & nuclear interaction on binding energy

    I just want to know what is the effect of proton spin & coloumbs repulsive force & nuclear interaction on binding energy. Please explain with derivation.
  31. C

    Proton Collision Feynman Diagram

    Supposed to represent a relativistic proton colliding with a stationary proton, leading to changes in the momentum of both and the production of a neutral pion. The pion then decays into two photons. No clue if this is right. I've never drawn anything much more complicated than...
  32. C

    Wavefunction normalisation for proton beam

    Homework Statement Calculate the normalization parameter A in the wavefunction ## \varPsi(x,t) = A e^{i(k\chi - \omega t)} ## for a beam of free protons traveling in the +x direction with kinetic energy 5 keV and a density of ##7.5 * 10^9 ## particles per meter beam length. Homework...
  33. C

    Charge radius of a proton as a function of its mass

    Hello ! I would like to know if the following relation, which numerically holds true according to the data available on wikipedia, can be analytically deduced from the current standard physics and model of a proton: R = 4 x L x ( M / m ) =4 x 1.61619997e−35 x 2.1765113e−8 / 1.67262177774e−27 =...
  34. L

    Particle Interactions, proton + antiproton

    Quite a simple query really, The question wants me to draw a Feynman diagram for a number of particle interactions, some are not possible, some are. This interaction: proton + antiproton ----> 3 gamma This would require each quark (uud) to annihilate with its anti matter counter part. This...
  35. M

    Fuel Cells; PEMFC; Cause of Proton Movement

    Lately I've started learning about fuel cells, particularly proton exchange membrane fuel cells (PEMFC), and a fairly basic question that has been bugging me is: Since the cathode is positive, it is clear why the electrons flow through the load and to the cathode, but why do the...
  36. W

    Tangential acceleration of a proton in an increasing B

    1. Consider free protons following a circular path in a uniform magnetic field with a radius of 1meter . At t=0 , the magnitude of the uniform magnetic field begins to increase at 0.001Tesla/second . Enter the tangential acceleration of the protons in meters/second2 : positive if they speed...
  37. squelch

    Lorentz momentum: A proton of mass m is accelerated up

    Homework Statement A proton of mass "m" is accelerated up to a kinetic energy "K" and then collides with a stationary proton at rest. All that is left after the collision is a new particle of mass "M". (a) Write out the momentum and energy equations for the collision. (b) What is the maximum...
  38. C

    Orthohydrogen to Parahydrogen: What particle?

    What subatomic particle is emitted when a diatomic Hydrogen molecule transitions from Orthohydrogen to Parahydrogen? e.g. during cooling And why can you cool a sample of Hydrogen to assure that all H2 molecules are para-, but you cannot heat to have any more than 3:1 ortho-:para- ?
  39. grandpa2390

    Proton Rest Mass: Is c^2 a Variable or a Unit?

    When we say 938 MeV/c^2, is the speed of light already factored in? because I have read in some places where if you multiply this by c^2 you get the energy, and that is 938 MeV rather than 938* (2.998e8)^2 so when considering the rest mass of the proton, is the c^2 a variable, or a unit?
  40. K

    Difference between charge of electron and proton?

    Hey guys, I understand it would be logical for electron and proton to have the same charge but with opposite signs... Why then is there a smalll difference between their charges? Thank you
  41. DiracPool

    Proton creation and annihilation

    1. Can a proton be created in a particle accelerator that doesn't use protons? For instance, an "electron-positron" collider? I understand baryon number needs to be conserved, so this would necessitate the accompanying creation of an anti-proton, but I'm wondering if these colliders have...
  42. Q

    Inside protons: origin of the sea quarks

    I have seen in many places, for example here, the statement that the proton consists of valence quarks and sea quarks. I am somewhat confused as to where this picture comes from. The sea quarks are virtual quark-antiquark pairs. I have encountered virtual particles only in the context of...
  43. kingsmaug

    1-D elastic collision between proton and nucleus

    Homework Statement A proton of mass m is moving with initial speed v0 directly toward the center of a nucleus of mass 31m, which is initially at rest. Because both carry positive electrical charge, they repel each other. Find the speed v' of the nucleus for the following conditions: a) the...
  44. M

    Measurement techniques for high temp. proton conductors

    Hi, my ph.d. thesis is related to high temperature proton conductors. So, I would like to ask about proton conductivity measurement techniques. I know one, electrochemical impedance spectroscopy (EIS). Who knows more? Another question is about EIS measurements. Why conductivity measurements are...
  45. B

    Proton through a Particle Accelerator

    This is 2 questions in 1 go. So my first question is how much does a Proton weigh? My second question is, what is the mass of the Proton in a particle accelerator going nearly the speed of light. I know that as you speed something up its mass increases. Also could you show me how you came to...
  46. Davephaelon

    DeBroglie wavelength of Proton in H atom

    How would one calculate the de Broglie wavelength of the proton in the hydrogen atom as the electron and proton pirouette around their common center of mass, for the lowest orbital? I believe the center-of-mass of the system would actually be inside the proton due to the great differential in...
  47. R

    NMR: Why do "identical" protons not experience splitting?

    Hey, I've been trying to figure out why a protons in identical environments will not undergo spin-spin splitting with one another. From what I understand splitting of a signal for a proton is due to the nucleus of another nearby either opposing the external magnetic field or acting in the same...
  48. waver.

    Ratio between electron to proton

    Homework Statement A 10 gram silver sphere is charged until it acquired a charge of -1.2 coulomb. Find ratio of number of electron to number of proton in spere. Given that silver atomic weight and atomic number 107.87 and 47 Homework EquationsThe Attempt at a Solution first i calculated extra...
  49. S

    Rotation period of electron orbiting a proton

    Homework Statement An electron is rotating around a proton (at rest) in a perfect circular orbit. If the radius of the orbit is r=10^-10 m, how long is the rotation period [hint: the radial acceleration is entirely due to the electric force] k=9*10^9 q=1.6*10^-19 Homework Equations 1...
  50. S

    Calculating the Mass of a High-Speed Moving Proton Experimentally

    how is a mass of a proton moving at a high speed calculated experimentally?
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