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Is this possibly the answer to the post Big Bang matter, anti matter imbalance?


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Posted (edited)

https://phys.org/news/2021-06-subatomic-particle-antiparticle.html

Subatomic particle seen changing to antiparticle and back:

Physicists have proved that a subatomic particle can switch into its antiparticle alter-ego and back again, in a new discovery revealed today.

 

The extraordinarily precise measurement was made by UK researchers using the Large Hadron Collider beauty (LHCb) experiment at CERN.

It has provided the first evidence that charm mesons can change into their antiparticle and back again.

Mixing phenomenon

For more than 10 years, scientists have known that charm mesons, subatomic particles that contain a quark and an antiquark, can travel as a mixture of their particle and antiparticle states.

It is a phenomenon called mixing.

However, this new result shows for the first time that they can oscillate between the two states.

more at link.............

extract:

"Using data collected during the second run of the Large Hadron Collider (LHC), researchers from the University of Oxford measured a difference in mass between the two particles.

There was a difference of 0.00000000000000000000000000000000000001 grams—or in scientific notation 1×10-38g.

A measurement of this precision and certainty is only possible when the phenomenon is observed many times."

the paper:

https://arxiv.org/pdf/2106.03744.pdf

Observation of the mass difference between neutral charm-meson eigenstates:

LHCb collaboration†

Abstract:

A measurement of mixing and CP violation in neutral charm mesons is performed using data reconstructed in proton–proton collisions collected by the LHCb experiment from 2016 to 2018, corresponding to an integrated luminosity of 5.4 fb−1 . A total of 30.6 million D0 → K0 S π +π − decays are analyzed using a method optimized for the measurement of the mass difference between neutral charm-meson eigenstates. Allowing for CP violation in mixing and in the interference between mixing and decay, the mass and decay-width differences are measured to be xCP = [3.97 ± 0.46 (stat) ± 0.29 (syst)] × 10−3 and yCP = [4.59 ± 1.20 (stat) ± 0.85 (syst)] × 10−3 , respectively. The CP-violating parameters are measured as ∆x = [−0.27 ± 0.18 (stat) ± 0.01 (syst)] × 10−3 and ∆y = [0.20 ± 0.36 (stat) ± 0.13 (syst)] × 10−3 . This is the first observation of a nonzero mass difference in the D0 meson system, with a significance exceeding seven standard deviations. The data are consistent with CP symmetry, and improve existing constraints on the associated parameters.

Edited by beecee
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To the titular question: probably not. 

These are mesons and the issue you raise is about baryons. If the paper doesn’t mention the baryon asymmetry, you shouldn’t assume that this is relevant to that problem.

From an older Sean Carroll blog post about a different meson CP violation:

The logic seems to be something like this:

1. CP violation has something to do with baryogenesis.

2. This experiment has something to do with CP violation.

3. Therefore, this experiment has something to do with baryogenesis.

I’ll leave it to the trained philosophers in the audience to find the logical flaw in that argument. Try substituting “George Washington” and “cherry trees” for “CP violation” and “baryogenesis.”

The point is that the conclusion doesn’t hold — not everything about CP violation is necessarily related to baryogenesis.

 

https://www.preposterousuniverse.com/blog/2010/06/04/marketing-cp-violation/

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54 minutes ago, swansont said:

To the titular question: probably not. 

These are mesons and the issue you raise is about baryons. If the paper doesn’t mention the baryon asymmetry, you shouldn’t assume that this is relevant to that problem.

Point taken.

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