Sunday, July 16, 2017

A New Particle Discovered at CERN

About a week ago, an experiment at CERN announced the discovery of a new particle, the Ξcc++ (pronounced Ksigh-see-see-plus-plus). Many people who have read about this discovery have asked me about its significance and if I was involved. So, this post will deviate from the usual discussion of the relationship between Christianity and science and focus on the discovery of the Ξcc++ with a few additional observations in my conclusion.

A little background information is needed to understand this discovery. Since the 1960's particle physicists have developed a model that describes the fundamental particles and forces in the universe, called the Standard Model of Particles and Fields. With the discovery of the Higgs boson in 2012, this model has been completely verified experimentally. There are two classes of fundamental particles that make up matter, quarks and leptons with six known types of quarks (given the names up, down, charm, strange, top, and bottom), and six known types of leptons (electron, electron neutrino, muon, muon neutrino, tau, and tau neutrino). The six different types of quarks are often referred to as the "flavor" of the quark. Quarks are always bound together in particles called hadrons so quarks are never found as individual particles by themselves in nature. Three quarks bound together is called a baryon, and a quark bound with an anti-quark is called a meson. A proton is a baryon made of two up quarks and a down quark and a neutron is a baryon made of two down quarks and an up quark (in the simplest model). So most of everything we know of in nature, everything made of atoms, is ultimately made of up and down quarks and electrons.

However, any combination of three quarks bound together, or a quark and an anti-quark bound together, could in theory, exist (except the top quark can't be bound because it decays too rapidly). In the 1960's particle physicists were discovering dozens of new particles that were like the proton and neutron but heavier, as well as many particles like the pi meson but heavier. At first this "zoo" of particles seemed overwhelming and no one knew what to make of this vast proliferation of particles. Eventually, Murray Gell-Mann and George Zweig independently proposed that this zoo of particles could be easily explained if each particle was actually composed of some combination of three more fundamental particles, which eventually became known as the up quark, the down quark, and the strange quark. At that time only three types of quarks were needed to explain all the known particles, although we now know that six flavors of quarks exist. If you had only the three flavors of quarks and put them together in different combinations, you would get the zoo of known particles discovered in the 1960's. Using u for up, d for down, and s for strange, we could have baryons like uuu, ddd, uds, uus, dds, etc. and using ubar to mean the u antiquark, and so forth, mesons could exist like u-ubar, u-dbar, u-sbar, d-ubar, d-sbar, and so forth.

Most particles made of quarks decay rather quickly, in less than about 10-10 seconds, eventually decaying through different processes to stable protons, neutrons, electrons and neutrinos. For instance, the baryon called a lambda (Λ0) made of an up quark, a down quark and a strange quark, will often decay to a proton and a pi meson with the pi meson further decaying.

The up and the down quarks are the lightest quarks, with the strange quark being slightly heavier, the charm being heavier still, the bottom being quite heavy, and the top being the heaviest known fundamental particle. Although we know of every type of hadron that could exist in nature, not all have been seen. In general, if a hadron is composed of heavier quarks it is harder to make in our colliders and, thus, harder to discover in our detectors. So, for instance, up until last week the existence of a baryon made up of an up quark and two charm quarks was expected but not yet unambiguously discovered. The Ξcc++ is that particle. So this is not an unexpected, unknown, or startling discovery, but a newly observed particle, nonetheless.

Like all particles that are composed of at least one heavy quark, the Ξcc++ only exists for a fraction of a second and then decays to other particles we call "daughters." Certain patterns of these daughter particles give unambiguous signatures that indicate they could only come from another "parent" particle, in this case the  Ξcc++. Thus, the Ξcc++ was discovered by one of the four major experiments on the Large Hadron Collider (LHC) at CERN called LHCb, whose primary purpose is to study the b-quark and its immediate decays. Studying the b-quark exclusively has the potential of helping us understand some mysteries of the universe such as why matter dominates over anti-matter in our universe. Since I am a member of the ATLAS collaboration, and not the LHCb collaboration, I had nothing to do with this discovery.

However, the discovery of the Ξcc++ has presented somewhat of a new problem because in 2002 another experiment called SELEX thought they saw evidence (3 standard deviations above background) for the Ξcc++ though not technically a discovery (5 standard deviations above background). However the measured mass of the SELEX particle is not really compatible with the measured mass of the LHCb particle, though both experiments claim they are the same particle. This discrepancy is likely to get sorted out as LHCb gets more data and makes more measurements including the expected future observation of the Ξcc+ particle, composed of a down quark and two charm quarks.

I would guess that most readers of this blog are not looking simply for the latest news and explanations about particle physics since that information can be found elsewhere. So you may want to know if I, as a particle physicist, have any insight into the nature of God or spiritual topics based on the discovery of the  Ξcc++. The short answer is, "not particularly." Because this discovery was expected and is well within the known physics of the Standard Model, it is not revolutionary. But this discovery and much of what I observe in nature does cause me to reflect on something Albert Einstein once said, "The most incomprehensible thing about the universe is that it is comprehensible." Like Einstein, I find it remarkable that the universe is comprehensible and appears ordered and designed. Why would a universe spawned accidentally without a creator or designer have coherence, order, and regularity? Shouldn't a randomly produced universe exhibit random laws, irregularity, and arbitrariness? Our universe shows such cohesiveness and precision. We can predict that nature should have a baryon consisting of three particular quarks and be confident that such an object exists simply based on the patterns and laws already discovered. In any other arena we would be confident that this order, design, precision, consistency, innovation, and predictability are sure signs of an intelligent designer and builder behind it all. I think the same can be inferred about this universe from all that we discover in science.





Top image is supplied by Daniel Dominguez and CERN and depicts the three quarks inside the Xi_cc_++
Bottom image is of the LHCb detector and taken from the magazine Fermilab Today.

14 comments:

  1. Yes, our universe is ordered and very well MAY have been designed to be that way by an unknown Designer. The question is, if this Designer exists, who is he (she/they/it)?

    Could such a complicated universe be the design of a god who stated in Genesis that a "firmament" (dome) hangs over the earth? I don't think so.

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    1. Gary, I don't know where you are getting your understanding of Hebrew from, but the Hebrew word sometimes translated "firmament" doesn't have as its primary meaning that of a dome. My Hebrew dictionary defines it as "vault of heaven, firmament, sky; pavement, floor." Many translations translate the word as "atmosphere" since this is the best Hebrew word to describe the atmosphere. As I have written in my blog, ancient Hebrew has only about 3000 words, so many words have multiple meanings and the context tells the meaning. Gary, the more you comment, the more it becomes clear that for just about any subject, you will choose one and only one perspective that supports your biased view and ignore all of the other possibilities even when they are much more probable. Your bias and assumptions seem to overshadow your ability to see these subjects with any degree of open-mindedness or objectivity.

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    2. Your interpretation of the Hebrew word translated in the King James and other English Bibles as "firmament" is a minority position. Once again, you find yourself opposing the majority of scholars, Mike.

      From Theopedia:

      The view of the expanse as a literal firmament was shared by "virtually everyone else up to the time of the Renaissance!" Of the Jews and early Christians Seely writes,

      "Jews speculated as to what material the firmament was made of: clay or copper or iron (3 Apoc. Bar. 3.7). They differentiated between the firmament and the empty space or air between it and the earth (Gen. Rab. 4.3.a; 2 Apoc. Bar. 21.4). They tried to figure out how thick it was by employing biblical interpretation (Gen. Rab. 4.5.2). Most tellingly they even tried to calculate scientifically the thickness of the firmament (Pesab. 49a). "Christians speculated as to whether it was made of earth, air, fire, or water (the basic elements of Greek science). Origen called the firmament "without doubt firm and solid" (First Homily on Genesis, FC 71). Ambrose, commenting on Gen 1:6, said, 'the specific solidity of this exterior firmament is meant' (Hexameron, FC 42.60). Augustine said the word firmament was used 'to indicate not that it is motionless but that it is solid and that it constitutes an impassable boundary between the waters above and the waters below' (The Literal Meaning of Genesis, ACW 41.1.61)."^[4]^

      Gary: The article goes on to discuss that this was the concept of ALL ancient cultures, with the possible exception of the Chinese. All ancient peoples, including the Hebrews, believed that the sky had a ceiling, a FIRMament, a solid overturned "bowl", Mike. Not a space. It was solid. I know that is distressing for you, but that is what the evidence strongly indicates.

      I suggest that you are latching onto the minority position, once again, because you so desperately want the evidence to fit with your primarily faith-based, preconceived, world view.

      That is not good scientific practice.

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    3. I simply quoted the definitions from a reliable Hebrew dictionary in which "dome" is not used even though you said it was a dome.

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    4. ...and the appropriate definitions included "sky" but not "dome". Hmm.

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    5. From Theopedia:

      "Raqiya is a Hebrew word that has been translated as "firmament" (KJV, ASV), "expanse" (NIV, ESV, NASB), "dome" (NRSV), and "vault" (TNIV, NJB)."

      Check out the NRSV, Mike.

      The fact that some English translators have translated this Hebrew word as "expanse", which you are calling "sky", is irrelevant. The question is: which definition of this word did the ancient Hebrews (and early Christians) understand the word to mean? And the evidence, which I cited above, is that both Jews and early Christians understood this word to mean the concept of a overturned bowl...which is another way of saying a dome.

      Evidence shows that the Hebrew concept of the universe came from surrounding cultures in the Levant. Did you know that there are actually THREE Creation stories in the Old Testament? The Jewish website/newspaper had a very interesting article on this subject. I will give the link below.

      Mike: The simple truth is that the reason that the Hebrew Bible uses a term that incorrectly indicates that there is an upside-down bowl above the earth is because these ancient peoples were scientifically ignorant. Face the facts, my friend.

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  2. Source for above excerpt:

    https://www.theopedia.com/raqiya

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  3. Haaretz article on the THREE creation stories in the Bible:

    http://www.haaretz.com/jewish/features/.premium-1.678408

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  4. Mike,

    Have you heard of the group called "Biologos"? They are a group of Christian scientists essentially attempting to do the same thing as you: Reconcile Christian teaching with Science. However, you seem to have a more conservative view (dare I say it...fundamentalist) than these Christians, who to me, talk like moderate Christians.

    The Christian scientists agree with me that the Hebrew word which the KJV translates as "firmament" is most definitely solid. It is NOT an expanse, or a description of the sky or atmosphere. So how do the harmonize an obviously incorrect description of the universe as found in Genesis with modern science with has proven beyond any doubt that no solid structure hangs above the earth?

    Answer: They deny that the literal interpretation of the text was the true INTENT of God, when he was speaking in that passage. God was simply speaking in terms that Bronze Age or Iron Age people could understand. God, of course, KNEW that the earth did not have a solid firmament (upside down bowl) hanging above it, but he chose not to give a scientifically accurate description of the atmosphere above the earth...because ancient peoples would not have understood this.

    Hmm. That brings up a point: Why didn't God simply tell us about gravity, atmospherics, proper agriculture techniques, disease prevention, etc., when he was writing his Holy Word to mankind. Why give us silly, unscientific descriptions of the universe and leave us to flounder about in the darkness of ignorance, only to discover the majority of scientific truths during or after the Age of Enlightenment??

    Here is an excerpt from these "moderate" Christian scientists on the Firmament:

    "Arguing for a non-solid raqia in Genesis is extremely problematic, for two reasons. First, the biblical and extrabiblical data indicate that raqia means a solid structure of some sort. The second problem is a much larger theological issue, but is actually more foundational. Regardless of what one thinks of the raqia, why would anyone assume that the ancient cosmology in Genesis could be expected to be in harmony with modern science in the first place?

    This second issue creates a conflict where they need not be one. The raqia “debate” is not the result of new evidence that has come to light. Our understanding of ancient perceptions of the cosmos has not been overturned by more information. The debate exists because of the assumption made by some Christians that the ancient biblical description of the world must be compatible on a scientific level with what we know today.

    Genesis and modern science are neither enemies nor friends, but two different ways of describing the world according to the means available to the people living at these different times. To insist that the description of the sky in Genesis 1 must conform to contemporary scientific [evidence] is a big theological problem. It is important to remember that God always speaks in ways that people can actually understand. In the ancient world, people held certain views about the world around them. Those views are also reflected in Genesis. If we keep this in mind, much of the conflict can subside."

    Or there is a more simple solution, my dear moderate Christians: Recognize that PEOPLE wrote the Bible, not an omniscient deity, and the people who wrote the Bible were scientifically ignorant. The reason the authors of the Bible wrote about a "firmament" is because that is what ALL ancient peoples believed from their natural observations of the sky. This interpretation made sense, just as it makes sense to think that the earth is flat...(unless you live on the coast and pay attention to what happens to ships on the horizon).

    Bottom line: Yahweh is the invention of ancient, scientifically ignorant people trying to make sense of their scary, dangerous world. Let's admire the beauty and entertainment of these ancient tales and stop trying to turn them into...MESSAGES FROM A GOD WHO LIVES IN OUTER SPACE.

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  5. Link to article and quote from Biologos:

    http://biologos.org/blogs/archive/the-firmament-of-genesis-1-is-solid-but-that’s-not-the-point

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    1. I do know biologs well and agree with some of their positions and disagree with others. Of course looking through the internet for articles that agree with your preconceived positions is easy to do. I can do the same to show that the firmament is not a solid disk and so I guess that proves I'm right. For instance, see http://apologeticspress.org/apcontent.aspx?category=11&article=194

      Suppose for this discussion we could show that the writer of Genesis did mean a solid disk. That would still not be a problem since the sky does look like a solid disk from our point of view. Clearly you don't understand how language is used if you are nitpicking at something like this. I'm a little shocked. I guess then that you and I in the 21st century are ignorant people because we say the sun rises and sets. I guess if Yahweh were to call it a "sunset" we would know he is simply the invention of an ignorant ancient culture since the sun doesn't really set but the earth rotates.. Please Gary, don't just write comments to be argumentative. Using language in a point-of-view sense is common and accepted and doesn't denote anything about the science behind it.

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  6. And that is the great conundrum for Christians: Although there may be good evidence for a Creator (or Creators), the evidence strongly points to the fact that the Judeo-Christian god is the invention of ancient, scientifically-ignorant people.

    Yahweh does not exist.

    And if Yahweh does not exist, Jesus was mistaken. And if Jesus was mistaken about the existence of Yahweh, Jesus was not God, because Jesus claimed that he and Yahweh were one and the same.

    Skeptics do not need to prove all the claims of Christianity false, they only need to prove ONE claim false and the entire belief system collapses. The false biblical claim of the existence of a firmament proves Christianity false.

    Yes, scientists have discovered a new particle at CERN. Let us marvel at the evidence for this amazing new discovery! Let us ponder the origin of the universe! But let's not insult the beauty and complexity of the universe by asserting that a being who could not pass an 8th grade science quiz is it's Creator.

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  7. Dr. Strauss, this is Neal Stetson, Autumn Thigpen's sig other you had lunch with. I have been keeping up with most of your posts and find them absolutely fascinating. I always have more questions but I'm not on the same level as a lot of the people I read the comments of below your posts and do not have a firm grasp of much of the content having never taken a formal physics class. A lot of my questions have to do with the physics of the posts so I do not want to waste your time with them as I could easily just google them. I am happy to say I have a 3.9 GPA and will have finished taking all the prerequisites to take physics when I get to OU and will do what I need to so I can take it with you if possible. Autumn and I have also been listening to The Case for Christ on audiobook. We both enjoy it a lot. It has not made a believer out of me yet but we just started. And it is helping Autumn a lot I think. Anyway, I do feel like I can comment on this post because this is something I think about all the time. It is not just that this universe has obviously been designed in a way that can be quantified and measured and observed that is the most interesting to me...its that a species of life on a planet in a galaxy was able to evolve enough to understand it. Thats not coincidence. As with humans ability to predict gravitational waves and then build a machine that would detect them within years of them being detected from two black holes colliding 1.4 billion light years away...its just too much to apply randomness to the whole thing. Does that mean we're special or unique? Not in my opinion. I do not think we can know we if we are or aren't so I do not see the point in believing one way or the other. What it does mean is that the universe is meant to be observed and we have the capability. It's ridiculous to try to explain this as chance. Thank you for taking the time to write this blog. And I look forward to taking your class at OU!!

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    1. It is amazing that we can comprehend the universe to some degree. I'm always amazed by that as someone who studies the universe every day in my job.

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