Neutrino Definition and 379 Threads

  1. 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.
  2. nicksauce

    Detect the cosmic neutrino background

    I'm wondering if it will ever be possible to detect the cosmic neutrino background. I don't know all that much about neutrino detection, so I'd really like to hear some thoughts / speculations.
  3. O

    What Property Influences a Neutrino's CC Interaction Outcome?

    I'm a new grad student preparing to do some work on Daya Bay, and I'm basically taking in all the information on neutrinos that I can right now. It's pretty interesting stuff, but I was wondering if anyone has any thoughts on the following: Assuming I correctly understand that neutrino flavor...
  4. daisey

    What is the energy dependence of photon cross sections at high energies?

    Hello All, I have read that because the Neutrino has so little mass, and because it is not affected by the Electromagnetic Force that it can travel through light years of solid lead. The photon is also mass-less, I believe. Why can it not do the same as neutrinos? I understand the photon...
  5. M

    Pion decay in electron and neutrino

    Hi, I have a question about this decay: \pi^- \rightarrow e^- \overline{\nu_e} there is a factor: 1 - \frac{v_e}{c} what are these values, v_e,c, and why this quantity is equal to: \frac{m^2_e}{m^2_\pi + m^2_e}? Thank you Ciccio
  6. W

    How do solar neutrinos interact with nuclei to create radioactive elements?

    I was reading about the South Dakota Homestake Solar Neutrino detector and I have a question? What I am getting from reading about it is that, they detect solar neutrinos by looking for a neutrinos interaction with a (Cl) nucleus to make a radioactive (Ar) Nucleus. (Ar) is one atomic...
  7. J

    Harnessing Neutrinos for Energy: Possibilities and Limitations

    I have a question is it possible to make an engine that is powered by neutrinos? i read that neutrinos can change nuclei and that they can become protons so can that in any way be used to create a nuclear fusion reaction which in turn would power the device?? thank you guys for your help...
  8. A

    Was Pauli Aware of Angular Momentum Violation in Beta Decay?

    A historical question: The neutrino was proposed by Pauli in 1930/31 to solve the crisis caused by the continuous energy distribution of the beta rays (electrons). The neutron was not discovered until 1932. Was Pauli aware, or did he even suspect, at the time of his proposal, the violation of...
  9. D

    Neutrino Oscillation <-> Neutrino Mass

    Wikipedia says that the phenomenon of Neutrino Oscillation implies that the neutrino has a non-zero mass (http://en.wikipedia.org/wiki/Neutrino_oscillation" ). Why is that? Why is it that Neutrino Oscillation can only exist, if neutrinos do have mass?
  10. S

    Do Neutrinos Violate Energy Conservation During Oscillation?

    I have many doubts about neutrinos..can someone explain me? 1. All neutrinos and anti neutrinos have different masses..and if the neutrinos oscillate, how the difference in mass is justified? is there any violation of energy conservation? 2. If neutrinos which are leptons oscillate, then...
  11. U

    Understanding Neutrino Oscillation: Explaining Flavor & Mass States

    I don't really understand why neutrino oscillation occurs so I looked it up on wikipedia: http://en.wikipedia.org/wiki/Neutrino_oscillation I went to the "Theory, graphically" section and it gives quite a good explanation. However, there are a few details I don't get. It says: "This...
  12. R

    CNB (Cosmic Neutrino Background)

    From a thread on “void theory vs. acceleration” (link in quote below); Rather than hijack the other thread for more detail on a side topic, I’ve opened this new thread. I’m interested in how science hopes to use “Neutrino observatories”. I’ve not seen much on the hopeful physics of making...
  13. D

    Neutrino Oscillation Survival Probability

    Homework Statement I'm lost at how to derive the probability of a neutrino species surviving an oscillation. After performing calculations, I can't seem to get it into the nice tidy form 1-\sin^{2}2\theta\sin^{2}\left(\frac{\Delta m^{2}t}{4p}\right) Homework Equations Whatev...
  14. J

    Neutrino Flux: Sun vs Reactors

    Regardless of the measured flux, is the expected neutrino flux from the sun greater or less than the expected flux from nuclear reactors? I don't know if I'm using the word flux correctly. I mean number of neutrinos per square meter per second on the surface of the earth.
  15. Ed Aboud

    Difference between a neutrino and an antineutrino

    Hi all. What is the difference between a neutrino and an antineutrino if they both have no charge and aren't made up of quarks? Thanks.
  16. Y

    Why is the Majorana mass of a neutrino so big compared to the

    [Moderator's note: Quoted-printable stuff NOT corrected. Sometimes I correct small errors, but a) there are several here and b) it is not obvious what the meaning should be. Please submit only 100% 7-bit ASCII plain-text posts. Even if YOU can read something fancier, many readers can't...
  17. V

    Calculating the Neutrino Spectrum for Cr Decay to V

    One more question (I'm wary I'm totally spamming the forum!).. its in reference to the decay of Cr to V, see attached files. The decay is clearly beta plus decay. p->n+positron+antineutrino The question asks to determine the neutrino spectrum. Now the energy of the neutrino is simply...
  18. W

    How Does the Sudbury Neutrino Observatory Confirm Neutrino Interactions?

    I've been reading about this very fascinating experiments there and one thing I can't figure out--either from their literature or that from other places--is how they can be sure that the reactions producing the Cherenkov light are caused by *neutrinos*. That is, how do we know that it's...
  19. humanino

    What are the implications of neutrino mass on the universe?

    Hi everyone, I have always been very worried about the possible consequences of neutrino masses. I just came accros a paper which I thought I would share with you. First, the reference : Neutrino mass and mixing implied by underground deficit of low energy muon-neutrino events John G...
  20. S

    Can neutrino detectors measure energy?

    Do the neutrino detectors measure only the number of events but not the energy of the detected neutrino?
  21. I

    Can a neutral pion decay to a neutrino and an anti-neutrino?

    Is it allowed? such as a electron neutrino and an electron anti-neutrino. And why? Now, I am confused... Thanks.
  22. OmCheeto

    The internet, Physics Forums, and Dr. Neutrino

    How many people remember the days of the birth of the www? I cut my teeth on Dr. Neutrino back in '96. It's only been 12 years, but seems like a lifetime.
  23. K

    How Can Neutrino Spin Be Measured Beyond Decay Processes?

    If a neutrino is unaffected by EM and strong forces, and only interacts weakly, how is it possible to measure its spin? I don't mean measurement in a practical sense, as in looking at pion decay.. but how it could be measured in principle. I guess what I mean is are there any physical phenomena...
  24. U

    Is Lepton Number Conserved in Electron and Muon Neutrino Mixing?

    Homework Statement In some theory the electron neutrinos and the muon neutrinos mix like this: \mathcal{L}_{m} &= -\frac{1}{2}m\left(\overline{ \nu^{C}_{\mu\text{R}} }\nu_{\text{eL}} + \overline{ \nu^{C}_{\text{eR}} }\nu_{\mu\text{L}}\right) + \text{h.c.} Show that there exists a...
  25. S

    How Does the Existence of Sterile Neutrinos Impact Big Bang Nucleosynthesis?

    Because of the existence of sterile neutrino, how and why it gives effect on the big bang nucleosynthesis more than active-active neutrino oscillation. Its a question on behalf of my friend. thanks for any help
  26. B

    Stargazing Neutrino Telescopes may have nothing to see

    With physicists building big neutrino detectors like IceCube and Anteras astrophysicists where hoping for a completely new way of seeing the universe. However the first results for neutrino astronomy coming the old Super Kamiokande labs, and from around 1500 neutrino in the TeV range, the've...
  27. Y

    Questions About Neutrino Oscillations - Answered by Sam

    I have a few questions about Neutrino Oscillations... Firstly, why are they called oscillations? Is it because they can go back and forth to different flavours/masses? Next, if, for example, a tau neutrino is produced in the sun, will it oscillate to the other flavours on its way to earth...
  28. T

    Solving the Solar Neutrino Problem

    In the solar neutrino experiments, there were deficits in the observed solar neutrino flux when compared with the theoretical values. If i just focus on the Cl-37 and Ga-71 reactions to detect solar neutrinos, there is a question confuses me a lot. That is, from the result of experiment...
  29. T

    Neutrino Oscillations: Massiveness & Non-Oscillation of Electrons, Muons & Taus

    Why do only neutrino oscillates (showing massiveness of neutrino)? Why don't electron, muon and tau oscillates?
  30. S

    What role does the neutrino play?

    What exactly are neutrinos doing(their purpose)?
  31. M

    Does 1a supernova release the same amount of neutrino as type2 supernova?

    Does 1a type supernova release the same amount of neutrino as 2 type supernova?
  32. T

    Measuring Neutrino Mass from a Supernova

    I tried and I got a ridiculous large number for the neutrino mass. I basically used E=\gamma m c and then, for 10 MeV neutrinos, time taken is t + 10 seconds to reach Earth, for 50 MeV neutrinos, time taken is t seconds. Speed = \frac{100 000}{(t+10)} for 10 MeV and Speed = \frac{100 000}{t}...
  33. E

    Recoil energy from neutrino question

    Hi guys, I've been struggling with this problem for a while now and can't seem to get anywhere with it. Roughly speaking: We are given that an Ar37 atom decays through electron K capture into a Cl37 atom and a neutrino, plus a gamma ray of wavelength 4.2 Angstroms. The binding energy of...
  34. K

    Atmospheric Neutrino: Pion Decay to Muon & Muon Neutrino

    Why does pions(coming through atmosphere) decays into a muon and a muon neutrino, not directly into electron and lelectron neutrino?I know it's because splin angular momentum conservation...but I need to be more clear about it.
  35. S

    Can Dark Matter Be Explained by a New Nonrelativistic Fermion?

    The mass of sun is determined by measuring the distance of a planet from the sun,the speed of that planet around the sun ,and then using Newtons law of gravity.In the same fashion one can determine the distribution of mass in a galaxy by observing the position adn motion of the stars in that...
  36. B

    So does the Higg field give the neutrino mass, and can neutrino velocity change?

    so does the Higg field give the neutrino mass, and can neutrino velocity change? how close to c is neutrino velocity?
  37. A

    The difference of neutrino and anti-neutrino? If Majorana

    People say that if neutrinos are Majorana particles, they are "identical to their anti particle". But anti neutrinos are obviously different from neutrinos. They produce anti-leptons rather than leptons in the scattering process. So the only difference I can image is the helicity, however that...
  38. marcus

    New Connes: Gravity and the standard model with neutrino mixing

    I put a notice of this earlier today in the QG links thread https://www.physicsforums.com/showpost.php?p=1134904&postcount=529 https://www.physicsforums.com/showthread.php?p=1134904#post1134904 This thread is in case anyone wishes to discuss the paper: http://arxiv.org/abs/hep-th/0610241...
  39. M

    What Is the Solar Neutrino Problem?

    hello everyone, what is the solar neutrino problem ?
  40. Orion1

    What are the Origins and Characteristics of Cosmic Neutrinos?

    Cosmic Neutrino Background... What was the temperature and age of the Universe, when it became 'transparent' to cosmic neutrinos? From what type of nuclear reaction did cosmic neutrinos originate? What is the peak temperature of cosmic neutrinos? [/Color]
  41. J

    Neutrino as alternative to Higgs boson

    The Higgs boson was proposed to provide a mechanism for mass and is posited, as a field, to extend throughout the Universe. But this was before we started thinking the neutrino, which is also (almost) omnipresent, must have a mass. Could the neutrino substitute for the Higgs in this role?
  42. Loren Booda

    Relative peculiar velocity of MBR vs that of neutrino background

    To what degree is the microwave background radiation isotropic to its precursor, neutrino production?
  43. F

    How Is the Lower Bound of Neutrino Mass Calculated?

    I was wondering if anyone could help clarify this problem I am having. Upon reading a section in a paper, I am a bit stuck as to how this value of the lower bound of the neutrino mass is reached here. I have highlighted the relevant part in the snapshot...
  44. F

    Unraveling the Mystery of Neutrino Oscillations: What is the Coherence Length?

    I was wondering if anybody would be able to explain to me what this means? I can't seem to find out!
  45. C

    CMB vs Neutrino BG: Why Does Neutrino Transparency Occur First?

    Hey, Was reading how the CMB is ~2.75 Kelvin, while the Neutrino BG is ~2 Kelvin. Clearly this means that neutrino transparency occurred before photon transparency did in the early evolution of the universe. My question is why? Does is have anything to do with neutron-to-proton decay...
  46. marcus

    Does Sundance preon kit match Kovtun-Zee composite neutrino?

    new paper by Kovtun and Zee http://arxiv.org/abs/hep-ph/0604169 idea of composite neutrino earlier we discussed Sundance Bilson-Thompson topological preon model incorporated into quantum gravity by Lee Smolin and described in the online Lecture Series Introduction to Quantum Gravity, Lecture...
  47. M

    Neutrino Oscillation: Learn About the Experiment

    cann anyone tell me about tghe neutrino oscillation experimtent
  48. M

    Raw data for neutrino oscillations

    I'm looking to analyse data in favour of neutrino oscillations for my masters project. I know John Bahcall has some on his website, but this is for solar neutrino oscillations and takes account of the MSW effect. Does anyone know where any raw data for atmospheric neutrino oscillations (i.e...
  49. P

    Solve Neutrino Oscillations Homework: Eigenspinors & Particle Masses

    I have to make a homework problem about neutrino oscillations, but I already don't know how to answer the first question. Let \Psi_i, i = 1,2 be two spinor fields, with field equation \gamma^{\mu}\partial_{\mu}\Psi_i = - \sum_{j=1}^2 M_{ij} \Psi_j where M_{ij} is a hermitian matrix. Suppose...
  50. E

    Neutrino detection by inverse beta decay

    Hi, I have the following question: Neutrinos can be detected by an inverse beta-decay. The probability for an interaction of a neutrino and a proton is 10^(-43). How large should be a detector filled with water in order to let interact one of 1 million neutrinos with a proton? What would be...
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