Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

B CPT asymmetry question, in regards to recent experiment@CERN

  1. Dec 13, 2017 #1
    Hi, I'm a high-school student, so it would be nice if someone could answer this question without a huge amount of terminology. I heard that recently at CERN at the BASE experiment, the magnetic moment of an antiproton (to nine places is the exact same as the magnetic moment of a proton..) I was wondering if there are any hypotheses on why this is; do antiparticles and particles behave differently at all? Are there any theories as to why there is baryonic asymmetry? And I have endeavored to consult more recently published sources (have been fruitless), apart from a few contemporary articles here and there. In one of the articles, I’m slightly confused with “All of our observations find a complete symmetry between matter and antimatter, which is why the universe should not actually exist,” says Christian Smorra, a physicist at CERN’s Baryon–Antibaryon Symmetry Experiment (BASE) Does CPT asymmetry really have this implication to the formation of our universe? I'm slightly confused with the entire concept of Baryonic Asymmetry and the scientific implications this has. Thanks so much!
     
  2. jcsd
  3. Dec 13, 2017 #2

    Orodruin

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member
    2017 Award

    Yes, they do behave differently, but there needs to be certain symmetries for the theory to be internally consistent. One such symmetry is CPT, which is changing the charges of all particles, makes a spatial reflection, and reverses the direction of time. This symmetry requires that the proton and anti-proton have the same magnetic moment.

    Yes, there are several. However, the symmetries that you need to break in order to generate a baryon asymmetry is not CPT, but C and CP.

    This is not a proper reference as it does not give the actual reference. Note that forum rules require you to provide the actual reference. If you do not we have no way of checking the actual statements and cannot judge what it is actually saying. Misunderstandings can arise from several sources, from the reference being bad to your interpretation of it being bad. We also cannot solve your problems by guessing what the reference states. Therefore, please provide the actual references instead of saying "I read somewhere that ..."
     
  4. Dec 13, 2017 #3
  5. Dec 13, 2017 #4

    Orodruin

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member
    2017 Award

    Taken at face value, the statement is wrong. What the magnetic moment tests is CPT symmetry. What is necessary to create a matter-antimatter asymmetry (among other things) is breaking of C and CP violation. There is known CP violation in the quark sector through the phase in the CKM matrix. However, this is not large enough to explain the baryon asymmetry. The original article also clearly states that what they are testing is related to CPT.
     
  6. Dec 13, 2017 #5

    mfb

    User Avatar
    2017 Award

    Staff: Mentor

    As simplified description: Finding an unexpected new source of CP violation would mean we habe to adjust or extend our formulas - that would be great. Finding CPT violation (what BASE is looking for) would mean the way we write down formulas itself needs to be changed - that would be amazing.
     
  7. Dec 13, 2017 #6
    Thanks again for your answer! So, just to clarify, baryonic asymmetry would require asymmetry in C and CP? The CERN test was the magnetic moment, and is only a test for CPT symmetry. So the only thing they have confirmed is that there is no asymmetry in CPT? Please tell me if I have made any misunderstandings.
    Have there been any tests for C and CP violations yet? Thanks!
     
  8. Dec 13, 2017 #7

    Orodruin

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member
    2017 Award

    As I said, we have already discovered those, but not at the level that would explain the baryon asymmetry.
     
  9. Dec 13, 2017 #8

    mfb

    User Avatar
    2017 Award

    Staff: Mentor

    At least not one larger than the uncertainties of the measurement.

    C violation is very large in the weak interaction, but P violation is very large ("maximal") as well, if you combine them you get CP where all violations seen so far are very small.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: CPT asymmetry question, in regards to recent experiment@CERN
  1. Proton beam questions (Replies: 1)

  2. CERN quark experiments (Replies: 6)

  3. CERN SPS, some questions (Replies: 10)

  4. Question about CERN (Replies: 19)

Loading...