Beta Definition and 403 Threads

Beta (UK: , US: ; uppercase Β, lowercase β, or cursive ϐ; Ancient Greek: βῆτα, romanized: bē̂ta or Greek: βήτα, romanized: víta) is the second letter of the Greek alphabet. In the system of Greek numerals it has a value of 2. In Ancient Greek, beta represented the voiced bilabial plosive /b/. In Modern Greek, it represents the voiced labiodental fricative /v/ (while /b/ in foreign words is instead commonly transcribed as μπ). Letters that arose from beta include the Roman letter ⟨B⟩ and the Cyrillic letters ⟨Б⟩ and ⟨В⟩.

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  1. Andy Resnick

    How is overall charge neutrality conserved in beta decay?

    This is probably a dumb question, but a student asked me and I can't figure out the answer: When a nucleus decays via beta decay, for example (in poorly formatted text): 55 Cs → 56 Ba + e− + ν How is overall charge neutrality conserved? Clearly, the reaction appears to conserve...
  2. O

    What nuclei are stable against beta decay?

    I know odd-odd nuclei are generally unstable against beta decay as the pairing term in the semi-empirical mass formula is less than zero, and I know even-even nuclei are generally stable, but I don't get the rules you apply for even-odd or odd-even nuclei. Do you have to work out the binding...
  3. J

    What Is the Decay Process for Be7 to Li7?

    Homework Statement Sorry charge conservation is not really part of the problem. Question I'm stuck on is: What is the process of decay for Be7 to Li7Homework Equations Qb+=[M(Be)-M(Li)-2Me]c2 Qb-=[M(Be)-M(Li)]c2 Qe=[M(Be)-M(li)]c2-Bn The Attempt at a Solution I know that t is not beta minus...
  4. B

    Beta Emission and Atom Deflection

    I'm dealing with this problem for an MCAT review: Following beta-emission by a neutral atom at rest, the respective linear momentums of the beta(-) particle and the resulting atom are shown below. (see attachment for message) It wasn't too difficult to see that an extra force is in play, and...
  5. S

    Beta or Alpha emitter nuclear fuel cycle?

    Do exist some proposed nuclear fuel cycle in which uranium or thorium whoud be first converted in some beta or alpha emitting isotope and after energy whould be harnessed with direct energy conversion methods?Possibly, it could reduce size of power plant and make steam turbine unnecessary.
  6. U

    Feynmann diagram for beta decay, direction of arrows confusion

    For beta minus decay, I know the reaction is given by neutron -> proton+electron+anti(electron)neutrino. This is an image of the Feynman diagram for the reaction: http://tmp.kiwix.org:4201/I/280px_Beta_Negative_Decay_svg.png I get that the neutron changes to a proton releasing a w-...
  7. sophiecentaur

    Is Beta+ Decay of a Proton Just a Fictional Event?

    The A level book that AS students have for the AQA course has a Feynman diagram of a proton decaying into a neutron - via a W boson, producing a beta+ and a neutrino. afaiaa, protons have a lifetime of 1033 years, so this doesn't seem a likely event. Is this just a 'fictional' event, put in the...
  8. G

    Protection from both beta particles & Gamma rays?

    What would be the best protection from these two at the same time? Lead alone or a mixture of something like lead and Plexiglas?
  9. S

    Beta Decay Charge Conservation

    Hey so, I was just wondering: If Carbon-14 (6 protons, 8 neutrons) decays into an electron, a neutrino, and Nitrogen 14 (7 protons, 7 neutrons) How is charge conserved? I get that nucleons are conserved, but if nitrogen-14 is neutral, then it has 7 protons and 7 electrons, versus Carbon...
  10. J

    Beta decay Charge conservation

    In beta decat the u quark fromthe proton and the d quark from the neutron interact to produce a electron and it's neutrino. I'm wondering about the charge conservation of this process because a neutron has zero charge and a proton has charge of 1. How do we end up with a electron charge of -1 at...
  11. I

    Comparing Beta: Baseball vs Balloon on a Slinky

    Homework Statement Does a baseball on a slinky have a smaller Beta, or balloon on a slinky? Explain. Homework Equations Beta = b/sqrt(mk) b: damping coefficient m: mass k: spring constant The Attempt at a Solution I see that the spring constant k is the same for either...
  12. A

    What is B (beta) for transistor?

    Homework Statement On one of the homework problems on NPN type transistor, I am asked to find Beta. What does Beta mean? Is it amplification? Is there equation for it? Homework Equations I'm looking for an equation The Attempt at a Solution
  13. P

    Curvature radius of alpha and beta particles

    Homework Statement An alpha particle and beta particle, each with kinetic energy 35keV , are sent through a 1.1T magnetic field. The particles move perpendicular to the field. Homework Equations no idea. The Attempt at a Solution theres nothing on curvature radius in my...
  14. P

    Alpha, beta particle radius of curviture

    Homework Statement see attachment Homework Equations r=RoA1/3 Ro=1.2*10-15 The Attempt at a Solution 35 kiloelectron volts = 5.60761762 × 10-15 joules I could calculate the velocity if I knew mass but that wouldn't help with the radius? I think that I need to find A from the...
  15. K

    What Causes Alpha, Beta, and Gamma Rays?

    What CAUSES alpha, beta and gamma rays?
  16. H

    Beta decay and Heisenberg principle

    Homework Statement One could imagine that beta decay was due to a electron initially inside the nucleus and than leaving it. Proof by using Heisenberg uncertainty principle that this is not possible. There is a hint which says you can use energy spectra and values for the energy of beta...
  17. M

    Can the Beta Function be Solved? A Demonstration of the Beta Function Problem

    Beta Function Demonstration Problem. I pushed the "Enter" key by accident and the topics name got ruined. Good Day to everyone, I have this problem, (In the context of the Gamma and Beta functions) I have to demonstrate that: Homework Statement Demonstrate that...
  18. C

    Beta Negative Decay: Is Mass Defect Calculated Correctly?

    During beta negative decay, in an unstable isotope, a neutron is converted into a proton, electron, and antineutrino. The electron and antineutrino are ejected from the atom and the proton remains in the nucleus to become the new daughter element. For a beta negative decay reaction for some...
  19. M

    Solving Limits Problem with Beta Function

    Homework Statement \int_1^{\infty}\frac{dx}{x^2(x-1)^{1/2}} Homework Equations \int_0^1t^{x-1}(1-t)^{y-1}\,dt \int_0^\infty\dfrac{t^{x-1}}{(1+t)^{x+y}}\,dt, The Attempt at a Solution Hi all, I have another beta function problem. This time I'm unsure how to deal with the limits, as the...
  20. M

    Solving the Beta Function Problem: Integrating (2-x)/(2+x)^(1/2) from -2 to 2

    Homework Statement \int_{-2}^{2}\left(\frac{2-x}{2+x}\right)^{1/2}\hspace{1mm}dx Homework Equations B(p,q) = \int_0^{\infty}\frac{y^{p-1}}{(1+y)^{p+q}}\hspace{1mm}dy The Attempt at a Solution I am completely stuck on this one, just a total mental block. The answer in the book...
  21. S

    Coulomb correction for beta decay spectrum

    Hello I am re-reading some of my old textbooks and have come across a simplified (non-relativistic) term used to correct the beta decay spectrum for the coulomb effect of the nucleus on the ejected beta particle. The expression is; F(Z,E) = (2*Pi*n) / (1 - exp(-2*Pi*n)) where n =...
  22. M

    Beta -decay converting u to MeV

    hi i'm new so i hope i am writing this in the correct part of the forums this is the question i have been given: --- What is the energy Q released when ^{131}_{\ 53}{\rm I}decays and ^{131}_{\ 54}{\rm Xe} is formed? The atomic mass of ^{131}_{\ 53}{\rm I} is 130.906118 \rm u and the...
  23. S

    Influencing Beta Decay: Electron & Neutrino Density Effects

    Because electrons are known to be participants in the beta-decay reaction, electron density has been shown to influence the rate of beta decay: http://prl.aps.org/abstract/PRL/v98/i25/e252501 http://www.phys.ncku.edu.tw/mirrors/physicsfaq/ParticleAndNuclear/decay_rates.html...
  24. Q

    Nuclear Beta Decay (Parity, deta[L])

    I do not get the concepts of the parity change and how do I find the deta (l) for beta decay. Please Help! Classify the following decays according to their degree of forbiddenness, all ground states decays. 89Sr (5/2+) -> 89Y (1/2-) 26Al (5+) -> 26Mg (2+) 97Zr (1/2+) -> 97Nb (1/2-)...
  25. M

    Creating a Quadratic Equation with Inverted Roots

    Homework Statement The quadratic equation x^2 + kx + 2k = 0 where k is a non-zero constant, has roots \alpha and \beta. Find a quadratic equation with roots \frac{\alpha}{\beta} and \frac{\beta}{\alpha}. {one is meant to be inverted - the code isn't working properly :( } Homework...
  26. Dadface

    Inverse Beta Decay: Can Free Protons Change to Neutrons?

    With this mechanism a nuclear proton can capture an inner orbit electron and change to a neutron with the emisssion of a neutrino.Can this mechanism also operate with free protons if ,say, bombarded by free electrons?I have tried researching this but have found no reference other than a Wiki...
  27. I

    Speed and Momentum of a Beta Particle

    Homework Statement A 14C nucleus, initially at rest, emits a beta particle. The beta particle is an electron with 127 keV of kinetic energy. A) What is the speed of the beta particle? B) What is the momentum of the beta particle? C) What is the momentum of the nucleus after it emits...
  28. L

    Calculating Q for {}^{12}_{7}N Beta+ Decay

    Homework Statement {}^{12}_{7}N undergoes \beta^{+} decay. i. Write the corresponding equation. ii. Calculate the decay energy, Q. Homework Equations M\left({}^{12}N\right)=12.018613u m_{e}=0.511\frac{MeV}{c^{2}} The Attempt at a Solution i. For the equation...
  29. E

    Inverse Beta Decay: Why is it Forbidden for a Free Proton?

    Homework Statement Why is the inverse Beta decay forbidden for a free proton? Homework Equations p -> n + e(+)(positron) + v (neutrino) The Attempt at a Solution Is it because, the change in the Q value must be the same for each decay?
  30. M

    Beta functions and the energy-momentum tensor

    Hi all, In Polchinski's string theory text he asserts (volume 1, section 3.4) that the trace of the energy-momentum tensor of a classically scale -invariant theory becomes proportional in the quantum theory to the beta function of the coupling, as a general point of QFT. This makes a kind of...
  31. R

    Problem with WinRAR 3.71 Beta 1

    Whenever I try to compress files & make an Archive of them using WinRar , I am presented with 6 Compression method choices - Store , Fastest , Fast , Normal , Good & Best . Regardless of whichever Option I choose , the file or collection of files is only compressed to 98 or 99% of the original...
  32. J

    Back scattering of beta perticles by foil experiment

    Beta particles are fast moving electrons emitted by the nuclei of certain atoms. When beta particles enter a material they may be deflected, and after penetrating a short distance into the material, may be moving in any direction. Some of these particles may have their motion reversed by their...
  33. S

    Beta function in Euclidean and Minkowskian QFT

    Hi! I have a question regarding the renormalization group Beta function, i.e., \beta = \mu \frac{dg_R}{d \mu} where g_R is the renormalized coupling constant and \mu the renormalization scale. My question in a nutshell: are the Beta functions calculated for QFT and, respectively...
  34. N

    Beta Function in String Theory

    I've heard that that origin of String Theory was in Gabriele Veneziano's analysis of the Euler beta function in relation to the strong force. I was wondering if anyone could refer me to a paper or derivation describing how this function ended up describing particles as strings.
  35. J

    Quick question about positive beta decay and mass defect?

    Hi, I was wondering about something in my notes that I don't quite understand. In positive beta decay in nuclear physics, we have a proton becoming a neutron and kicking out a positron and an electron neutrino (which is assumed massless here). In the expression for the energy released, Q =...
  36. R

    Beta Decay Experiment: Investigating Maximum Energy

    this isn't actually a homework question I am just interested in doing it for an experiment I am running. basically I am using different aluminium plates inbetween a GM counter and 204 Tl beta source. I've already ran the experiment and have a number of readings, I've plotted them...
  37. K

    Why Does Alpha & Beta Particle Emission Occur in Radioactive Nuclei?

    Do we know why radioactive nuclei only decay through emission of alpha and beta particles? There is spontaneous fission in some cases, of course, but what I mean to ask is, why should just a proton or just a neutron or a particle X with 2 protons and 3 neutrons, or whatever else not be emitted...
  38. N

    Alpha, Beta, Gamma , neutron ray, which one is harmful?

    Homework Statement If you were given 4 cookies, each emitter different ray 1)Alpha, 2)Beta,3) Gamma , 4)neutron You have to make decision of the following: a)eat one of the cookies b)dispose one of the cookies at storage facility called WHIP c)put one of the cookies in your pocket...
  39. C

    Understanding Neutron Beta Decay: The Role of W Boson and Energies Involved

    Most accepted theories make sense, but the energies involved in the beta decay of a neutron into a proton confuses me. How can a down quark change into an up quark by emiting an electron and an anti electron neutrino via a w boson, the figures don't add up! Using the figures of mass it goes...
  40. B

    Why is the equation for beta decay written as e- = 0 and what does it mean?

    I was reading a text, describing the following disintegration: ^{234}_{90}Th\xrightarrow{}~^{0}_{-1}e+~^{234}_{91}Pa However, I prefer to understand it as, ^{234}_{90}Th\xrightarrow{}~e^{-}+~^{234}_{91}Pa Of course, the above two equations are missing out the antineutrino. Could someone...
  41. B

    Beta Decay of 32 Phosphorus - Is It Positively Charged?

    Hi all, when an atom goes through a beta decay, say 32 phosphorus. The final state is then 16 protons, 16 neutrons, and 15 electrons. This seems to be an ion of sulfur. My question is, does the atom remain in a positively charged state? or does it ionize it suuroundings and captures an...
  42. M

    Radiation Emission Spectrums for Alpha, Beta, and Gamma

    Homework Statement I'm taking a nuclear physics seminar, and I'm wondering what causes the differences in the energy spectra between alpha, beta, and gamma emissions. Specifically, why is dispersion for energy values in alpha radiation so different from that of beta? I'm also looking for a...
  43. U

    Alpha & Beta Glucose: How to Differentiate

    Hi all, I find difficulties in recognizing between alpha and beta Glucose. Can anybody explain briefly how can I differentiate between them ?
  44. V

    Beta Particles vs. Electrons: Comparing Properties

    what is the difference between a beta particle and an electron in terms of its behaviour and physical properties like mass etc..?
  45. T

    Calculating energy released from beta decay

    I have been learning particle physics lately but it's been mostly from a theoretical perspective and not a mathematical one so I have yet to come across any such math but my curiosity is peaked. From what I understand it, this is the process: n \rightarrow p + W^{-} Followed by...
  46. S

    Beta decay fundamental question

    Can someone please clarify beta decay for me. As I understand it, in B- decay, a neutron turns into a proton, electron, and anti-neutrino, then the electron and anti-neutrino are ejected. But from this example, it looks like there are two additional electrons as a result of decay. 19/8 O ->...
  47. J

    Electromagnetic field, finding beta.

    Hi, I am not sure whether this falls into a math category or here, I hope you can help me. I came across a problem in a book [bare with me, please] (Fundamentals of engineering electromagnetics by Cheng) and asked my electromagnetics profesor, but his response did not help me into getting to the...
  48. A

    Beta Decay: Experimental Demonstration & Critique

    Hello everyone, Newbie here. I am student/enthusiast of science but tend to stay away from physics. This excerpt is written by creationist John Woodmorappe concerning accelerated nuclear decay done in the lab, and I was wondering if there was anyone here would like to critique it. I'm not...
  49. O

    Neutrino energy from beta+ decay

    I'm trying to understand the energy spectrum of neutrinos ejected from the sun. Any suggestions on a book that covers this aspect of beta+ decay? I'm just not sure how to treat the kinematics of a fusion reaction or decay- only collisions. Thanks.
  50. R

    Beta Function for QED: 20/9 or 8/3?

    The beta function for QED is given by: \beta=\frac{e^3}{16 \pi^2}*\frac{4}{3}*(Q_i)^2 where (Q_i)^2 represents the sum of the squares of the charges of all Dirac fields. For one generation, for the charge squared you have (2/3)^2 for the up quark, (-1/3)^2 for the down quark, but this is all...
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