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Quigg, Chris

Publications and source records attributed to Quigg, Chris.

52 records · Page 3
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Stable Tetraquarks

For very heavy quarks, relations derived from heavy-quark symmetry imply novel narrow doubly heavy tetraquark states containing two heavy quarks and two light antiquarks. We predict that double-beauty states will be stable against strong decays, whereas the double-charm states and mixed beauty+charm states will dissociate into pairs of heavy-light mesons. Observing a new double-beauty state through its weak decays would establish the existence of tetraquarks and illuminate the role of heavy color-antitriplet diquarks as hadron constituents.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2018

Stable, Doubly Heavy Tetraquark Mesons [Slides]

Heavy-quark symmetry implies stable heavy tetraquark mesons $Q_{i}Q_{j}\overline{q}_{k}\overline{q}_{l}$. in the limit of very heavy quarks Q, novel narrow double heavy tetraquark state (DHTQ) must exist. HQS relates DHTQ mass to masses of a doubly heavy baryon, heavy-light baron, and heavy-light meson. The lightest double-beauty states composed of $bb\overline{ud}$, $bb\overline{us}$, and $bb\overline{ds}$ will likely be stable against strong decays. Heavier $bb\overline{q}_{k}\overline{q}_{l}$ states, $cc\overline{q}_{k}\overline{q}_{l}$ states, and mixed $bc{q}_{k}\overline{q}_{l}$ states, will likely dissociate into pairs of heavy-light mesons. Some might be seen as "double-flavor" resonances near threshold. Observing a weakly decaying double-beauty state would establish the existence of tetraquarks and illuminate the role of heavy color-$\overline{3}$ diquarks as hadron constituents.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2018

I Would Like to Know... [Slides]

Problems of High-Energy Physics (NAL Design Report, January 1968) We would like to have answers to many questions. Among them are the following: Which, if any, of the particles that have so far been discovered, is, in fact, elementary, and is there any validity in the concept of “elementary” particles? What new particles can be made at energies that have not yet been reached? Is there some set of building blocks that is still more fundamental than the neutron and the proton? Is there a law that correctly predicts the existence and nature of all the particles, and if so, what is that law? Will the characteristics of some of the very short-lived particles appear to be different when they are produced at such higher velocities that they no longer spend their entire lives within the strong influence of the particle from which they are produced? Do new symmetries appear or old ones disappear for high momentum-transfer events? What is the connection, if any, of electromagnetism and strong interactions? Do the laws of electromagnetic radiation, which are now known to hold over an enormous range of lengths and frequencies, continue to hold in the wavelength domain characteristic of the subnuclear particles? What is the connection between the weak interaction that is associated with the massless neutrino and the strong one that acts between neutron and proton? Is there some new particle underlying the action of the “weak” forces, just as, in the case of the nuclear force, there are mesons, and, in the case of the electromagnetic force, there are photons? If there is not, why not? In more technical terms: Is local field theory valid? A failure in locality may imply a failure in our concept of space. What are the fields relevant to a correct local field theory? What are the form factors of the particles? What exactly is the explanation of the electromagnetic mass difference? Do “weak” interactions become strong at sufficiently small distances? Is the Pomeranchuk theorem true? Do the total cross sections become constant at high energy? Will new symmetries appear, or old ones disappear, at higher energy?

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Physics Beyond Colliders Annual Workshop [Slides]

Fermilab Theoretical Physics Seminar, December 12, 2017, reporting on the CERN Physics Beyond Colliders Annual Workshop, 21–22 November 2017. Study Group mandated by CERN Management to prepare the next European HEP strategy update (2019-20). Explore the opportunities offered by the CERN accelerator complex and infrastructure to get new insights into some of today’s outstanding questions in particle physics through projects complementary to high-energy colliders and other initiatives in the world. The focus is on fundamental physics questions that are similar in spirit to those addressed by high-energy colliders, but that may require different types of experiments.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Heavy-Quark Symmetry Implies Stable Heavy Tetraquark Mesons Q i Q j q ¯ k q ¯ l

For very heavy quarks Q, relations derived from heavy-quark symmetry predict the existence of novel narrow doubly heavy tetraquark states of the form Q i Q j ¯q k ¯q l (subscripts label flavors), where q designates a light quark. By evaluating finite-mass corrections, we predict that double-beauty states composed of bb¯u¯d, bb¯u¯s, and bb¯d¯s will be stable against strong decays, whereas the double-charm states cc¯q k ¯q l , mixed beauty+charm states bc¯q k ¯q l , and heavier bb¯qk¯ql states will dissociate into pairs of heavy-light mesons. Furthermore, observation of a new double-beauty state through its weak decays would establish the existence of tetraquarks and illuminate the role of heavy color-antitriplet diquarks as hadron constituents.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Stable, Doubly Heavy Tetraquark Mesons [Slides]

Heavy-quark symmetry implies stable heavy tetraquark mesons $Q_iQ_j \overline{q}_k\overline{q}_l$ In the limit of very heavy quarks Q, novel narrow doubly heavy tetraquark states must exist. The lightest double-beauty states composed of $bb\overline{u}\overline{d}$, $bb\overline{u}\overline{s}$, and $bb\overline{d}\overline{s}$ will be stable against strong decays. Heavier $bb\overline{q}_k \bar{q}_l$ states, double-charm states $cc\overline{q}_k \overline{q}_l$ , mixed $bc\overline{q}_k\overline{q}_l$ states, will dissociate into pairs of heavy-light mesons. Observing a weakly decaying double-beauty state would establish the existence of tetraquarks and illuminate the role of heavy color-antitriplet diquarks as hadron constituents.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2015

Electroweak Symmetry Breaking in Historical Perspective

The discovery of the Higgs boson is a major milestone in our progress toward understanding the natural world. A particular aim of my review is to show how diverse ideas came together in the conception of electroweak symmetry breaking that led up to the discovery. Furthermore, I survey what we know now that we did not know before, what properties of the Higgs boson remain to be established, and what new questions we may now hope to address.

1-TeV scale↗
DOE OSTI2015

Particle Physics after the Higgs-Boson Discovery: Opportunities for the Large Hadron Collider

The first run of the Large Hadron Collider at CERN brought the discovery of the Higgs boson, an apparently elementary scalar particle with a mass of 125 GeV, the avatar of the mechanism that hides the electroweak symmetry. Then, a new round of experimentation is beginning, with the energy of the proton–proton colliding beams raised to 6.5 TeV per beam, from 4 TeV at the end of the first run. I summarize what we have learned about the Higgs boson, and calls attention to some issues that will be among our central concerns in the near future.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2014

CERN - Six Decades of Science, Innovation, Cooperation, and Inspiration

The European Laboratory for Particle Physics, which straddles the Swiss-French border northwest of Geneva, celebrates its sixtieth birthday in 2014 CERN is the preeminent particle-physics institution in the world, currently emphasizing the study of collisions of protons and heavy nuclei at very high energies and the exploration of physics on the electroweak scale (energies where electromagnetism and the weak nuclear force merge). With brilliant accomplishments in research, innovation, and education, and a sustained history of cooperation among people from different countries and cultures, CERN ranks as one of the signal achievements of the postwar European Project. For physicists the world over, the laboratory is a source of pride and inspiration.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2013

Beyond Confinement

A digest of my closing remarks at ConfX.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗