LHCb experiment finds another case of CP violation in nature

The LHCb experiment at the Large Hadron Collider is dedicated mainly to the study of mesons [objects made from a quark of one type, an anti-quark of another type, plus many other particles] that contain bottom quarks (hence the `b’ in the name).  But it also can be used to study many other things, including mesons containing charm quarks.

By examining large numbers of mesons that contain a charm quark and an up anti-quark (or a charm anti-quark and an up quark) and studying carefully how they decay, the LHCb experimenters have discovered a new example of violations of the transformations known as CP (C: exchange of particle with anti-particle; P: reflection of the world in a mirror), of the sort that have been previously seen in mesons containing strange quarks and mesons containing bottom quarks.  Here’s the press release.

Congratulations to LHCb!  This important addition to our basic knowledge is consistent with expectations; CP violation of roughly this size is predicted by the formulas that make up the Standard Model of Particle Physics.  However, our predictions are very rough in this context; it is sometimes difficult to make accurate calculations when the strong nuclear force, which holds mesons (as well as protons and neutrons) together, is involved.  So this is a real coup for LHCb, but not a game-changer for particle physics.  Perhaps, sometime in the future, theorists will learn how to make predictions as precise as LHCb’s measurement!

15 responses to “LHCb experiment finds another case of CP violation in nature

  1. Thanks for this piece Matt. I went back in my mind to the 1950s & thought that TD Lee had won the Nobel for CP violation. That was not the case! He proved that that elementary particles were either right handed or left handed. &, as usual, women experimentalists were overlooked, as was Madame Wu, who proved Lee & Yang’s hypothesis. Moving on – The LHCb experiment really deserved your Congratulations!

    • That Chien-Shiung Wu did not receive the Nobel Prize for her discovery of the 100% parity violation in the weak nuclear force is one of the many unconscionable things that have happened to first-rate women scientists. (Also, is it not odd that she was often referred to as Madame Wu and not as Professor Wu, despite being a full professor at Columbia. I have never heard a male professor of physics referred to as Mister or Monsieur.)

      • Curious George

        Sorry, Mr. Strassler, I just could not resist. The urge to be the first one was too strong 🙂

  2. Torbjörn Larsson

    Thanks for the heads up, nice to see activity there (and here, of course).

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  4. Thanks, Professor
    for educating Common folks like me.
    bob-2

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  7. David Schwartz

    Always love your blog. My dad was a particle physicist – co-discovered of the muon neutrino – so I follow these things sort of closely. It’s a good result for the Standard Model, which continues to be supported by experimental evidence. See also the recent results from BELLE re: R(D) and R(D*)which also are consistent with SM predictions. I recently published a bio of Enrico Fermi -“The Last Man Who Knew Everything” (Basic Books 2017) and I always wonder what Fermi would make of all this. I think he’d be quite pleased with these incredibly precise experimental results.   All the best David Schwartz   David Schwartz160 W 71st St Apt 12HNew York, NY 10023

    From: Of Particular Significance To: dschwa8059@yahoo.com Sent: Thursday, March 21, 2019 7:53 AM Subject: [New post] LHCb experiment finds another case of CP violation in nature #yiv5816395607 a:hover {color:red;}#yiv5816395607 a {text-decoration:none;color:#0088cc;}#yiv5816395607 a.yiv5816395607primaryactionlink:link, #yiv5816395607 a.yiv5816395607primaryactionlink:visited {background-color:#2585B2;color:#fff;}#yiv5816395607 a.yiv5816395607primaryactionlink:hover, #yiv5816395607 a.yiv5816395607primaryactionlink:active {background-color:#11729E !important;color:#fff !important;}#yiv5816395607 WordPress.com | Matt Strassler posted: “The LHCb experiment at the Large Hadron Collider is dedicated mainly to the study of mesons [objects made from a quark of one type, an anti-quark of another type, plus many other particles] that contain bottom quarks (hence the `b’ in the name).  But it a” | |

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  9. Momentum is a particle only at Equivalence principle as p^2 (ball on the spring), violates relativity and Lorentz invariance – unlike QCD flavour parity is like “Penrose stairs”, so violate parity – p^2 = c^2. ?
    If we have knowledge of the statistical distribution of 𝒴i in an hypothetical multiverse where the laws of physics follow our fundamental theory, we can ask how typical are the Yukawa couplings that we observe.

    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4538584/

    • Each spin of a singularity (thezeros and ones) at the speed of light is equivalent of the ultimate micro unit of time. This absolute unit of time measurement doesn’t change at all and therefore using it will not lead to time dilation. Time dilation is like changing the length of a given distance due to using the same number of meters (color) and yards (flavour).

      According to a thought experiments, the change in local ST curvatures are due to the gravitational Field space particle (FSP) having lower radii than those associated with Vacuum space particle (VSP). This drop (Fluorescence? – gravitational field energy is always negative) in the local SP radii lead to increase in their spinning angular momentum in line with the law Sam= c/(2π r). They assume vector orientations toward the centre of the mass (recoil? – gravitational acceleration is a vector field), hence the formation of the gravitational flux lines. In Doppler effect, the speed of light does not change, only the wavelength. Spinors (vector Stress-energy-tensor) nearer to the centre of the mass would have shorter radii. Photons which accelerate to the central of a large mass would experience blue shift.

      • Red shift, Blue shift at constant ‘c’.

        • In order to obtain a reliable signature for the presence of DM particles in the galactic halo, it is necessary to follow a suitable model independent approach. In particular, the only DM model independent signature presently feasible is the so-called DM annual modulation signature. For completeness, we also mention a different approach described in the following for the direct detection of DM candidates inducing just nuclear recoils; it is based on the study of the correlation of the nuclear recoil direction with the Earth velocity.

          • Penrose stairs: Time dilation at eventhorizon is infinity.
            The connection (penrose stairs) between color (yard) and flavour (meter) at HighEnergy with same number was not completly Spontaneous Symmetry Broken – due to blue shift, unlike the red shift (past).