Why is there any matter in the universe at all? New study sheds light

Discussion in 'Astronomy, Exobiology, & Cosmology' started by paddoboy, Feb 28, 2020.

  1. paddoboy Valued Senior Member

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    https://phys.org/news/2020-02-universe.html

    Why is there any matter in the universe at all?
    New study sheds light:

    Scientists at the University of Sussex have measured a property of the neutron—a fundamental particle in the universe—more precisely than ever before. Their research is part of an investigation into why there is matter left over in the universe, that is, why all the antimatter created in the Big Bang didn't just cancel out the matter.

    The team—which included the Science and Technology Facilities Council's (STFC) Rutherford Appleton Laboratory in the UK, the Paul Scherrer Institute (PSI) in Switzerland, and a number of other institutions—was looking into whether or not the neutron acts like an "electric compass." Neutrons are believed to be slightly asymmetrical in shape, being slightly positive at one end and slightly negative at the other—a bit like the electrical equivalent of a bar magnet. This is the so-called "electric dipole moment" (EDM), and is what the team was looking for.

    more at link....

    the paper:
    https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.124.081803


    Measurement of the Permanent Electric Dipole Moment of the Neutron:

    ABSTRACT:
    We present the result of an experiment to measure the electric dipole moment (EDM) of the neutron at the Paul Scherrer Institute using Ramsey’s method of separated oscillating magnetic fields with ultracold neutrons. Our measurement stands in the long history of EDM experiments probing physics violating time-reversal invariance. The salient features of this experiment were the use of a 199Hg comagnetometer and an array of optically pumped cesium vapor magnetometers to cancel and correct for magnetic-field changes. The statistical analysis was performed on blinded datasets by two separate groups, while the estimation of systematic effects profited from an unprecedented knowledge of the magnetic field. The measured value of the neutron EDM is dn=(0.0±1.1stat±0.2sys)×10−26e.cm.

     
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  3. mathman Valued Senior Member

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  5. James R Just this guy, you know? Staff Member

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    From the above, it looks like the electric dipole moment of the neutron that they measured is zero (within experimental error).

    How does this result shed light on why there is matter in the universe?
     
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  7. Derek.H. Registered Member

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    Interesting , doesn't this suggest to you some type of motion-asymmetry , in the context of the beginning energy-injection which engendered the creation of the early GUT-matter ?
     
  8. exchemist Valued Senior Member

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    What "beginning energy injection" would this be? Injection from where to where, and by what?
     
  9. DaveC426913 Valued Senior Member

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    Paragraphs 5 and 6 seem to suggest newer tests found otherwise.
     
  10. exchemist Valued Senior Member

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    Oh? Which article (there are several links in this thread)? I had read it the same as James, viz. a null result, to a better precision than previous measurements.
     
  11. DaveC426913 Valued Senior Member

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    OK, I guess I misinterpreted what they are saying.
     
  12. paddoboy Valued Senior Member

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    Perhaps.....https://physics.aps.org/articles/v13/25
    "Researchers believe that a more complete theory is likely to involve breaking of the standard model’s so-called CP (charge-parity) symmetry of the strong force, which binds quarks into baryons (such as neutrons and protons). If such a symmetry violation did indeed occur in the early Universe during the formation of baryons, it would explain why there are many more baryons than antibaryons.



    CP violation is predicted to create an asymmetric distribution of quarks inside the neutron, which would result in a nonzero EDM. So a neutron EDM would be a kind of fossil remnant of the symmetry breaking that occurred in the early Universe. And the size of the EDM, if it exists, might offer clues to when the event happened.



    Attempts to measure the neutron EDM have been made since the 1950s [1]. More recently, researchers have also looked for the EDM of the electron [2] and of the nuclei of mercury atoms [3]. An attempt to detect a neutron EDM in 2006 [4] by an international team using the neutron source at the Laue-Langevin Institute (ILL) in France found no sign of it within the experimental uncertainty (an improved data analysis was published in 2015 [5]). A new effort led by Philipp Schmidt-Wellenburg of the Paul Scherrer Institute (PSI) in Switzerland and Guillaume Pignol of the Laboratory of Subatomic Physics and Cosmology (LPSC) in France has now searched with more sensitivity than any previous experiment".
    extract:
    "At this stage, the tighter constraint on the neutron EDM doesn’t rule out any candidate theories, says Schmidt-Wellenburg. But he adds that the result, taken together with those for other particles such as the electron, suggests that strong CP violation may have occurred earlier than the separation of the electromagnetic force from the weak nuclear force in the early Universe"
     
  13. Derek.H. Registered Member

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    Ahh , a quantum-man I see ! I personally find universe’s exploding up out of quantum fluctuations , just a tad hard to believe . My instincts tend to say "matter/energy cannot be created or destroyed" , so serendipitous creation of universes does not sit well with me . Having said that , I admit to having limited insight into exactly what space/matter/universal.genesis/and the multiverse are . I learned long ago (from Dustin Hoffman) , to say "I don't know" !
    So...your answer lies above .
    D.H.
     
  14. DaveC426913 Valued Senior Member

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    That is an emergent property of our universe - the one that got created by the Big Bang.
    There's no reason to assume there was such a property before our universe's properties were set.


    (And what do you mean your "instincts"? Those are usually based on past experiences. How many other 'Beginning of All Creation's have you observed?

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    I've never observed an elephant up close unless it was dead. My instincts should tell me that live elephants are implausible.

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    )
     
    Last edited: Apr 3, 2020 at 12:21 AM
  15. Derek.H. Registered Member

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    But...we're those properties set during the creation , or were they inherent in this universe before it "banged/ expanded.?" . It is possible that space itself was created first , and then continued energy-introduction caused the "pot to boil over" and GUT-matter to be created . This process may not have been instantaneous either , complicating our picture of the "Big-Bang" even further .
    D.H.
     
  16. exchemist Valued Senior Member

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    I do not know what you mean by a "quantum man", nor how you deduce I must be one from my question, which you have not answered.

    Can you answer it? What do you mean by "beginning energy injection"? Injection from what into what?
     
  17. Derek.H. Registered Member

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    I deduced that you followed the recent trend of believing that the Universe burst forth from a single , random quantum-fluctuation in a proto-universe .
    Personally , I think that multi-universal physics applied great energy to create the field-matrix of space , and continued to apply energy even when space was "full" . This caused the "pot" to "boil-over" , thus creating the "energy-explosion" we call "The Big-Bang" .
    *As an aside ; Lorentz effects dictate that the more dense things are , the slower time passes in them . This means that in the beginning Universe , time crawled. Thus , a steady and powerful injection of energy then , would appear to be a past explosion, to us now.
    **Capiche ?
    D.H.
     
  18. exchemist Valued Senior Member

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    Non capiche. What does it mean to say that "multi-universal physics" "applied" energy? Applied it to what? And physics is a discipline of study, not a physical entity.

    Bear in mind also that energy is not stuff: you cannot have a jug of energy. Energy is a property of a physical system of some kind.

    So, all in all, this doesn't seem to make a great deal of sense.
     
    Last edited: Apr 3, 2020 at 6:40 PM

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