Read about neutrino | 42 Discussions | Page 1

  1. nomadreid

    I Probability of neutrino switching: more massive, more probable?

    In Scientific American, July 2020, the article "The Darkest Particle" by Louis and Van de Water, page 46, discussing the hypothetical sterile neutrino, there is the sentence: "Because sterile neutrinos are likely to be more massive than the regular flavors, however, particles could make the...
  2. Helena Wells

    A Neutrino decay before electroweak breaking

    Most scientists believe neutrinos don't get their mass from the Higgs field due to their tiny mass compared to the next lightest particle(electron).During the electroweak epoch the rest particles were massless but neutrinos shouldn't be. The neutrinos would then decay to the other massless ( i...
  3. Arman777

    A N-body simulation with varying neutrino mass

    I am trying to find a picture of the N-body simulations that shows the LSS. Particularly I am looking for different neutrino masses without the CDM. For instance pictures likes this But with more varying/different neutrino masses. I am looking for articles
  4. Coltrane8

    I Neutrino Helicity and Spin Uncertainty

    In the context of non relativistic quantum mechanics, or better, if I consider the neutrino's mass to be zero, the phrase seems to me puzzling. What I know is that if I know the direction of motion, I know the spin projection onto that direction, say ##\hat{z}##-direction. But to not violate...
  5. A

    Neutrinos and their detection

    Assuming that this sphere has a radius of 50kpc, I've converted to m (1.543e21) and plugged into the area equation for a total area of 2.992e43 m^2. From here I've talked myself into circles, and I honestly don't know where to go next. Any help or guidance would be greatly appreciated!
  6. Michael Price

    A Measurements and electroweak gauge invariance/transformations

    Most gauge transformations in the standard model are easy to see are measurement invariant. Coordinate transformations, SU(3) quark colours, U(1) phase rotations for charged particles all result in no measurable changes. But how does this work for SU(2) rotations in electroweak theory, where...
  7. lLehner95

    Longitudinal distribution for a neutrino beam

    In the center of mass frame of reference i found that ##p^{*}=\frac{[(M^{2}-m_{\nu}^{2}-m_{K}^{2})^{2}-4m_{\nu}^{2}m_{K}^{2})]^{1/2}}{2M}##. I don't know how to find the momentum distribution ##p_{L}(\theta)## considering that i have 2 different mesons with a specific number ratio...
  8. M

    Calculate the energy release of an atom

    First of, I have no idea what I'm supposed to do with the neutrinos and the photons. Can somebody explain how to handle these? The rest of what I tried is quite straight forward $$\begin{align*}\Delta E &= 4M_p - M_{He} - 2 M_e + E_{\text{Neutrino and Photons}}\\&= 4M_p - (2[M_p+M_n]-E_B) - 2...
  9. S

    Admissions PhD in Particle Physics: Oxford or Imperial?

    Hi all, I recently got accepted to do a PhD into High Energy Physics groups at Oxford, Imperial, UCL, Cambridge and Manchester. My main interest is neutrino physics, which all of these places are offering. However, I am struggling to pick between Oxford and Imperial. I have met and discussed...
  10. T

    Fraction of solar neutrinos arriving at the Earth

    Homework Statement Consider solar neutrinos of energy 1 MeV (EDIT: 10 MeV not 1 MeV) which are formed at the center of the sun in the ##\nu_2## eigenstate. What fraction of it do you expect to arrive at earth as ##\nu_\mu## and what fraction as ##\nu_\tau##? Assume that it evolves adiabaticaly...
  11. S

    I Do black holes accumulate neutrinos?

    Do black holes accumulate neutrinos ? Do the neutrinos that fall in, decay in some way , maybe interact with the condensed matter, or just stay "parked" in perpetual loops ?
  12. Zypheros_Knight

    B E- p+ collision product energies

    Greetings! This is probably the most simplest of questions but I wanted to ask that which particle carries most of the energy of an electron-proton collision (as in p + e− → n + νe), the neutron or the neutrino? What happens if we use a higher energy proton or electron? For example we use...
  13. ohwilleke

    I What false hints of new physics were most notable?

    Sometimes experimental or observational evidence from credible physicists points to new physics and then turns out to be wrong due to statistical flukes, experimental error or a theoretical analysis mistake. What cases of this happening do you find most notable, what showed that the hints were...
  14. ohwilleke

    I B, L and Majorana Neutrinos

    Background The Standard Model conserves baryon number, which is equal to (quarks divided by three) minus (anti-quarks divided by three) and lepton number, which is equal to leptons minus antileptons, separately, except in sphaleron processes which conserve B-L, but not B or L separately. There...
  15. C

    B Is neutrino spin-parity 1/2+ or 1/2-?

    Wikipedia only tells neutrino spin 1/2, but no tell parity sign: positive or negative?
  16. J

    A Is it possible that a particle is much heavier through a loop correction

    Let's assume, we have standard model singlet particle s that mixes after electroweak symmetry breaking with an exotic, vectorlike neutral lepton N The relevant part of the Lagrangian reads $$ L \supset h^c s N + h s N^c + M N N^c, $$ where h is the standard model higgs and M is a superheavy...
  17. A

    I Neutrino Oscillation

    If we have a beta decay where a solar neutrino is produced: a proton converts into a neutron ,emitting a W. the W decays into an anti electron and a neutrino. So in the end of the chain we have a neutrino that will travel through space and oscillate. Neutrino Oscillation happens because of...
  18. C

    A Do "thermal neutrinos" exist

    Would neutrinos emitted in the distant and early universe be slowed enough to become thermal neutrinos? Could these be detected?
  19. edguy99

    I Does the Chirality match the helicity?

    In trying to understand the Neutrino where it has mass and its chirality is the same as its helicity, I have always had trouble visualizing a particle. I recently ran into this particle. I believe the "the chirality is the same as helicity" as in one direction it would feed things through the...
  20. L

    What is the kinetic energy of a proton when neutron decays?

    Homework Statement What is the kinetic energy given to the proton in the decay of a neutron when: a) The electron has negligibly small kinetic energy b) The neutrino has negligibly small kinetic energy Homework Equations Q = (mn - mp - me - mv ) c2 = .782MeV Where T is kinetic energy, and...
  21. R

    Pi meson decay (relativistic momentum)

    Homework Statement A charged π meson (rest mass = 273me) decays into a neutrino (zero rest mass) and a μ meson (rest mass = 207me). Find the kinetic energies of the neutrino and the mu meson. Homework Equations E = moγc2 K = mo(γ-1)c2 v = pc2/E p = moγv The Attempt at a Solution In the rest...
  22. 1

    I I don't understand this Feynman Diagram

    Question: Draw the lowest-order Feynman diagrams for the e+e- --> W+W-process The answer gives three diagrams. I understand the first two, but the third makes no sense to me. Here it is: So this is a t-channel Feynman diagram. As far as I can tell regarding how these types of Feynman...
  23. Daaavde

    A Flavour neutrino masses

    Hello everyone! I've a question regarding the neutrino masses. When neutrinos interact they must do so in a specific flavour (e.g. e, μ,τ) and if we go to find out what their flavour is at the interaction we get a specific answer. However, it is not clear to me what we would find out if we...
  24. O

    Schools University of Hawaii physics PhD-neutrino physics?

    Was wondering if anyone could give me some stats about the University of Hawaii. I'm tentatively looking at them for particle astrophysics or neutrino physics. Anyone know what the acceptance rate is/how hard it is to get in? Any reviews of the school? Should ranking concern me? They seem to do...
  25. B

    Particle Prerequisites for Giunti and Kim's Neutrino Physics

    Hi, I'm a physics 2nd yr undergraduate and know some quantum physics, but I haven't been formally introduced to particle physics or QFT yet. What all do I need to learn before I start reading Giunti and Kim's Fundamentals of Neutrino Physics and Astrophysics? And which books should I refer for...
  26. F

    I How can photons interact if they travel at the speed of ligh

    I was listening to a podcast about the solar neutrino problem, and they discussed how we have deduced that neutrinos are not massless due to the fact that they interact with other particles (even if this interaction occurs rarely). I paraphrase: "a particle traveling at the speed of light is...
  27. M

    A What was the explanation of OPERA superluminal neutrinos?

    When I first heard about the OPERA apparent superluminal results on the measurement of neutrinos speed, I tried to locate an explanation using all the possible relativistic effects. All were too small to account for a difference of 18 meters of virtual distance among photons and neutrinos. Then...
  28. Garlic

    Neutrino flavor conservation

    Hello everyone, Are neutrino flavors conserved in interactions other than neutral particle oscillations?
  29. C

    How Neutrinos Prevent Cavities

    They make fluorine, according to a large new study. Link: ScienceNOW
  30. aztronut

    Neutrino Anti-Particle and Flavor Mass Hierarchy

    "Other experiments to test whether the neutrino is, weirdly, its own antiparticle may be feasible only if the hierarchy is inverted." Why?