Professor Andrew Puckett’s research group is currently leading, as part of a collaboration of approximately 100 scientists from approximately 30 US and international institutions, the installation in Jefferson Lab’s Experimental Hall A of the first of a series of planned experiments known as the Super BigBite Spectrometer (SBS) Program, with beam to Hall A tentatively […]
It seems that the muon, a heavier partner of the electron, may be breaking what have been understood as the laws of physics. The findings announced on April 7th were met with excitement and speculation at what this might mean. UConn physics researchers Professor Thomas Blum and Assistant Professor Luchang Jin helped pioneer the theoretical physics behind the findings.
Mark Rayner/CERN The Fermilab E989 experiment announced the first new result on the muon’s anomalous magnetic moment in almost 20 years. The new measurement, combined with Brookhaven’s E821, has increased the discrepancy with the Standard Model value to 4.2 standard deviations. UConn Professors Tom Blum and Luchang Jin explain the theory calculations in a feature […]
Kyungseon Joo, a professor of physics, has been named Chair of the CLAS Collaboration, one of the largest international collaborations in nuclear physics. CLAS involves 50 institutions from 9 countries and has about 250 collaborators. The collaboration recently completed the upgrade of the CEBAF Large Acceptance Spectrometer (CLAS12) for operation at 11 GeV beam energy […]
Assistant Professor of Physics Luchang Jin has been chosen to receive a prestigious Early Career Award from the US Department of Energy’s Office of High Energy Physics (HEP) for 2020. The amount of the award is $750,000 to be used over five years. The DOE Early Career Award is extremely competitive: this year only 16 scientists in […]
Professors Tom Blum and Luchang Jin, along with colleagues at BNL and Columbia, Nagoya, and Regensburg universities have completed a first-ever calculation of the hadronic light-by-light scattering contribution to the muon’s anomalous magnetic moment with all errors controlled. The work is published in Physical Review Letters as an Editor’s Suggestion and also appeared in […]
Could traveling into the past be part of our future? Quite possibly, says Ron Mallett, a UConn emeritus professor of physics who has studied the concept of time travel for decades. Earlier this month, he spoke with NBC Connecticut reporter Kevin Nathan about his life and work as a theoretical physicist, and discussed how time […]
The Daily Campus published an article highlighting the research of Prof. Thomas Blum about Quantum Chromodynamics, a theory which describes the interactions between elementary particles. The development of this theory could help further understanding of the Standard Model of particle physics. The Standard Model is what physicists use to describe the fundamental building blocks of […]
May 27-June 5 UConn Physics Department hosted an international summer school Strong interactions beyond simple factorization: collectivity at high energy from initial to final state. The school was supported by an NSF grant to Prof. Kovner and was devoted to modern approaches to the physics of high energy hadronic and heavy ion collisions.
Dynamic Quantum Matter, Entangled orders and Quantum Criticality Workshop, June 18- June 19, 2018, sponsored by UConn, NSF, Nordita, Villum Center for Dirac Materials, Institute for Materials Science. The conference focused on entangled and non-equilibrium orders in quantum materials.
Prof Alan Wuosmaa has been awarded a grant for 3 years for Studies of exotic nuclei with transfer reactions. For the information about Prof. Wuosmaa research visit his home page.
Professor Tom Blum has been selected a “Fermilab Distinguished Scholar”. Fermilab Distinguished Scholars are rotating multi-year appointments for U.S. theorists in either the Fermilab Theoretical Physics Department or the Theoretical Astrophysics Group. The Fermilab Distinguished Scholars program aims to: Strengthen connections between the Fermilab Theoretical Physics and Astrophysics groups and the wider U.S. particle-theory community. […]
Muon g-2 Theory Initiative Hadronic Light-by-Light working group workshop
Workshop participants will discuss recent progress and plans to determine the hadronic light-by-light scattering contribution to the muon anomalous magnetic moment, which is expected to contribute the largest uncertainty in the Standard Model prediction. The goal of the workshop is to estimate current and expected systematic errors from lattice QCD, dispersive methods, and models and create a plan to address them in time for new experiments at Fermilab and J-PARC.
In May, 2017 UConn alumnus Alex Barnes was awarded a postdoctoral fellowship in Nuclear Physics at Carnegie Mellon University, working in the group of Prof. Curtis Meyer. Alex begins this appointment immediately after completing his PhD at the University of Connecticut in April 2017, under the guidance of Prof. Richard Jones. In his new position, […]
The U.S. Centers for Disease Control lists radon as a primary cause of lung cancer, second only to smoking. The Environmental Protection Agency estimates that 20,000 deaths each year from lung cancer in the U.S. are the result of exposure to radon in the living environment. It is believed that as many as 1 in […]
Scientists have been rigorously commissioning the experimental equipment to prepare for a new era of nuclear physics experiments. This equipment is at the newly upgraded Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab in Newport News, Virginia. These activities have already led to the first scientific result. This research demonstrates the feasibility of detecting a potential new kind of particles known collectively as exotic hadrons. The existence and spectrum of these new particles hold important clues to unlocking the mystery of “quark confinement” — why no quark has ever been found alone.
As a theoretical physicist studying the fundamental elements of matter, UConn graduate student Daniel Hoying creates calculations so large and complex they require supercomputers to perform them. So Hoying is obviously excited that he will soon have regular access to one of the world’s most powerful supercomputers at the U.S. Department of Energy’s Brookhaven National […]
Instead of directly searching for new particles as the LHC experiments are doing in Geneva, the muon g-2 experiment at Fermilab measures a well-known physical property of the muon to ever greater precision, looking for deviations from the value it should have based on the Standard Model of particle physics, assuming that no new forces […]
Researchers working with the Continuous Electron Beam Accelerator Facility (CEBAF) at the U.S. Department of Energy’s Jefferson National Accelerator Facility (J-Lab) have published their first scientific results since the accelerator energy was increased from six billion electron volts (GeV) to 12 GeV. The upgrade was commissioned to enable the next generation of physics experiments that will allow scientists to see smaller bits of matter than have ever been seen before. The first publication from the upgraded CEBAF was published by the GlueX collaboration in the April issue of Physical Review C.
We discuss the anharmonic oscillator in quantum mechanics using exact WKB methods in a ‘t Hooft-like double scaling limit where classical behavior is expected to dominate. We compute the tunneling action in this double scaling limit, and compare it to the transition amplitude from the vacuum to a highly excited state. Our results, exact in the semiclassical limit, show that the two expressions coincide, apart from an irreducible and surprising instanton contribution. The semiclassical limit of the anharmonic oscillator betrays its quantum origin as a rule showing that the quantum theory is intrinsically gapped from classical behavior. Besides an example of a resurgent connection between perturbative and nonperturbative physics, this may provide a way to study transition amplitudes from tunnelling actions, and vice versa.
Dr. Fatma Aslan, Jefferson National Laboratory and UConn
Hadron structure-oriented approach to TMD phenomenology
We present a first practical implementation of a recently proposed hadron structure oriented (HSO) approach to TMD phenomenology applied to Drell-Yan like processes. We compare and contrast general features of our methodology with other common practices and emphasize the improvements derived from our approach that we view as essential for applications where extracting details of nonperturbative transverse hadron structure is a major goal. These include the HSO’s preservation of a basic TMD parton-model-like framework even while accounting for full TMD factorization and evolution, explicit preservation of the integral relationship between TMD and collinear PDFs, and the ability to meaningfully compare different theoretical models of nonperturbative TMD parton distributions.
Fully Consistent NLO Calculation of Forward Single-Inclusive Hadron Production in Proton-Nucleus Collisions
We study the single-inclusive particle production from proton-nucleus collisions in the dilute-dense framework of the color glass condensate (CGC) at next-to-leading order (NLO) accuracy. In this regime, the cross section factorizes into hard impact factors and dipole-target scattering amplitude describing the eikonal interaction of the partons in the target color field. For the first time, we combine the NLO impact factors with the dipole amplitude evolved consistently using the NLO Balitsky-Kovchegov (BK) equation with the initial conditions fitted to HERA structure function data.
The resulting neutral pion cross section with all parton channels included are qualitatively consistent with the recent LHCb measurement. In particular, the NLO evolution coupled to the leading order impact factor is shown to produce a large Cronin peak that is not visible in the data, demonstrating the importance of consistently including NLO corrections to all the ingredients. Furthermore, the transverse momentum spectrum is found to be sensitive to the resummation scheme and the running coupling prescription in the BK evolution. This demonstrates how additional constraints for the initial condition of the BK evolution can be obtained from global analyses including both the HERA and LHC data. In light of the upcoming upgrades to the LHC, the dependence of our results on rapidity will also be discussed.
Scattering amplitudes are the arena where quantum field theory meets particle experiments, for example at the Large Hadron Collider where the copious scattering of quarks and gluons in quantum chromodynamics (QCD) produces Higgs bosons and many backgrounds to searches for new physics. Particle scattering in QCD and other gauge theories is far simpler than standard perturbative approaches would suggest. Modern approaches based on unitarity and bootstrapping dramatically simplify many computations previously done with Feynman diagrams. Even so, the final results are often highly intricate, multivariate mathematical functions, which are difficult to describe, let alone compute. In many cases, the functions have a “genetic code” underlying them, called the symbol, which reveals much of their structure. The symbol is a linear combination of words, sequences of letters analogous to sequences of DNA base pairs. Understanding the alphabet, and then reading the code, exposes the physics and mathematics underlying the scattering process, including new symmetries. For example, the two scattering amplitudes that are known to the highest orders in perturbation theory (8 loops) are related to each other by a mysterious antipodal duality, which involves reading the code backwards as well as forwards. A third scattering amplitude, which contains both of these as limits, has an antipodal self-duality which “explains” the other duality. However, we still don’t know `who ordered’ antipodal (self-)duality, or what it really means.
Daniel Norman, Department of Physics, University of Connecticut
The Complex Analytic Properties of Bandwidth Limited Signals and their Application to Conformal Cosmology and Signal Processing
Conformal gravity is an alternative theory of gravity derived from the conformally invariant Weyl squared action as opposed to the standard Einstein-Hilbert action. The general equations of conformal gravity were applied to the cosmological scale to create a theory of Conformal Cosmology where the geometry of space-time is described by first order fluctuations on a conformal-to-flat background of constant negative curvature. The differential equations of this cosmological model have solutions in terms of Legendre functions with complex degree and order. In order to calculate the multipole expansion of Cosmic Background Radiation (CMB) anisotropy within this model, it is necessary to integrate the Legendre function solutions with respect to their complex degree. An analytic method for solving this integration problem was developed which makes use of the fact that the Legendre functions are Bandwidth Limit Signals (BLS’s) which are functions with a finite domain in frequency space. A general analysis of the properties of BLS’s in the complex plane was done which has yielded new theorems and expansion formulas applicable to all BLS’s as well as to other related families of complex functions. These results have both specific applications to Conformal Cosmology as well as broader applications to the field of signal processing. The methods of complex integration developed in this work, initially for the purpose of computing the CMB anisotropy in Conformal Cosmology, have been used to provide a novel solution to the infamous Borweinn integral as well as a novel proof of the Nyquist-Shannon sampling theorem.