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Nuclear and Particle Physics Colloquia

Mondays ~ Refreshments 3:30pm Talk: 4:00pm ~ Kolker Room, 26-414

 

Committee:
William Detmold, Chair ~ Mike Williams ~ Lindley Winslow

 

Colloquia Archives

 

Sebtember 12, 2016

hosted by: Bolek Wyslouch

Grodzins Prizewinner

Dennis Perepelitsa, University of Colorado, Boulder

Novel probes of the proton wavefunction through collisions with nuclei

Abstract:

Ultrarelativistic proton– and deuteron–nucleus collisions at RHIC and the LHC have traditionally been motivated as a way to understand how the longitudinal momentum structure of partons in nucleons is modified in the nuclear environment. When compared to proton–proton collision data, measurements of hard-scattered jet production in these systems have demonstrated that these nuclear modifications are mild at large-Q2. On the other hand, jet production rates have been found to correlate with global properties of the collision in an unexpected way.

By analyzing the jet-kinematics- and collision-energy-dependence of simultanous measurements at RHIC and the LHC, the data indicate that particle production downstream of the nucleus decreases systematically with increasing Bjorken-x in the proton or deuteron. This has been quantitatively interpreted as evidence that proton configurations with large Bjorken-x ≥ 0.1 have a compact transverse spatial extent relative to the average configuration. In this picture, the nucleus acts as a large-area target which can be used to measure, through the suppression of soft particle production, the shrinking of the traversing proton's size.

In this Colloquium, I will discuss how collisions with nuclei have provided unexpected insight into the correlations between the longitudinal momentum and transverse spatial configurations in the proton wavefunction, drawing a connection between heavy ion and hadron structure physics.

 

time:    4:00 p.m.
place:   Kolker Room (26-414)

(refreshments at 3:30 p.m.)



September 19, 2016

hosted by: Jesse Thaler

Tulika Bose, Boston University

Recent results from exotic searches at the CMS experiment

Abstract: The LHC re-started last year at an unprecedented center of mass energy of 13 TeV and the CMS experiment has already successfully collected more than ~30 fb^-1 data this year. In this talk, I will review recent searches for exotic physics with special focus on final state topologies with heavy standard model particles. This includes searches for diboson resonances, vector-like quarks and resonances with top quarks among others.

 

time:    4:00 p.m.
place:   Kolker Room (26-414)

(refreshments at 3:30 p.m.



September 26, 2016

hosted by:  Jesse Thaler


Kev Abazajian, UC Irvine

The Saga of Sterile Neutrino Dark Matter

Abstract: Sterile neutrinos as dark matter has been of interest for over twenty-three years. It ranges from "cold" to "warm" dark matter in its effects on structure formation. I will discuss increased accuracy in calculations of its production in the early universe through structure formation in the local universe today, as well as recent candidate detections of an X-ray line that could be produced via its decay.

 

time:    4:00 p.m.
place:   Kolker Room (26-414)

(refreshments at 3:30 p.m.)



October 3, 2016

hosted by: Lindley Winslow


Yannis Semertzidis, CAPP/IBS and KAIST, South Korea

The axion dark matter search at CAPP: a comprehensive approach

Abstract: Axions are the result of a dynamic field, similar to Higgs field, a result of the so-called Strong CP-problem solution.  The Strong CP-problem, i.e., why the electric dipole moment (EDM) of the neutron (and proton) has not been observed so far even though the theory of QCD predicts values by about ten order of magnitude larger than current experimental limits.  Axions as dark matter can be thought of as an oscillatory field interacting extremely weakly with normal matter.  The oscillation frequency is unknown, it can be anywhere between f = 200MHz to 200GHz and it’s expected to be a very narrow line, with df/f=10^-6.  A strong magnetic field can be used to convert part of that field into a very weak electric field oscillating at the same frequency and phase as the axion field.  In the coming years we plan to develop our experimental sensitivity to either observe or refute the axions as a viable dark matter candidate in a wide axion mass range.  That approach includes the development of ultra strong magnets, high quality resonators in the presence of strong B-fields, new resonator geometries, low noise cryo-amplifiers and new techniques of detecting axions.

 

Another related subject, through the strong CP-problem, is the search for the EDM of the proton, improving the present sensitivity on hadronic EDMs by more than three orders of magnitude to better than 10^{-29} e-cm.  Usually the study of EDM involves the application of strong electric fields and originally neutral systems were thought to be easier to work with.  Recently it became clear that charged particles in all-electric storage rings can be used for sensitive EDM searches by using techniques similar to the muon g-2 experiment.  The high sensitivity study of the proton EDM is possible due to the high intensity polarized proton beams readily available today, making possible to reach beyond 103 TeV in New Physics scale.

time:    4:00 p.m.
place:   Kolker Room (26-414)

(refreshments at 3:30 p.m.)



October 10, 2016



COLUMBUS DAY HOLIDAY

NO TALK



OCTOBER 17, 2016

hosted by: Mike Williams

Tomas Skwarnicki, Syracuse

Tetra- and Penta-quark Results from LHCb

Abstract: The last decade has seen upheaval in exotic hadron spectroscopy related to the observations of tetraquark, and more recently pentaquark, candidates with heavy quark pairs inside. Thanks to its unique capabilities, the LHCb experiment has left a strong mark on this topic. I will discuss the most important LHCb results related to this subject and I will put them in a context of the status of the field.

time:    4:00 p.m.
place:   Kolker Room (26-414)

(refreshments at 3:30 p.m.)



October 24, 2016

hosted by: Janet Conrad

Michelle Dolinski, Drexel University

Studying neutrino physics with liquid xenon

With the discovery of neutrino oscillations and neutrino mass, the field of experimental neutrino physics has exploded in recent years. It is an experimentally open question whether or not neutrinos have distinct antiparticles, and the answer is directly related to the origin of neutrino mass. The observation of neutrinoless double beta decay, a non-Standard Model version of a rare nuclear process, would prove that neutrinos are their own antiparticles. I will report on the status and recent results of the EXO-200 experiment, a liquid xenon time projection chamber that uses 100 kg of enriched xenon to search for neutrinoless double beta decay of Xe-136. I will also discuss research toward nEXO, a planned next generation neutrinoless double beta decay experiment, and efforts to understand the microscopic physics of liquid xenon detectors.

time:    4:00 p.m.
place:   Kolker Room (26-414)

(refreshments at 3:30 p.m.)

 



October 31, 2016

hosted by: Lindley Winslow


Minerba Betancourt, FNAL

Latest Results from MINERvA

Abstract: MINERvA is a neutrino scattering experiment to make precision measurements of cross sections and investigate nuclear effects. A precise understanding of neutrino interactions is crucial for the neutrino oscillation program. Several cross sections will be presented, including quasi-elastic, pion production, kaon production as well as direct comparisons of the same process on different nuclei.

time:    4:00 p.m.
place:   Kolker Room (26-414)

(refreshments at 3:30 p.m.)



November 7, 2016

hosted by: Jesse Thaler



Yonit Hochberg, Cornell University

New Directions in Light Dark Matter Detection

Abstract: The exploration of dark matter beyond the WIMP is of vital importance towards resolving the identity of dark matter. One promising possibility is light dark matter, which has gained much traction in recent years. In this context, I will present two new proposals for direct detection of light dark matter. The first utilizes superconducting targets which are sensitive to milli-eV energy deposits from dark matter-electron interactions. Such devices could detect dark matter as light as the warm dark matter limit of a keV with moderate size exposure. In the second, two-dimensional targets such as graphene are proposed as the first directional detectors of
sub-GeV dark matter--a proposal which can be implemented by the PTOLEMY experiment. Considering dark matter scattering and absorption
processes, I will demonstrate the potential of the light dark matter direct detection program in upcoming years.

time:    4:00 p.m.
place:   Kolker Room (26-414)

(refreshments at 3:30 p.m.)



November 14, 2016

hosted by: Jesse Thaler



Kyle Cranmer, NYU

Physics-aware Data Science: A convergence of ideas from machine learning and particle physics

Abstract: Recent advances in "deep learning" and the buzz around "data science" have rekindled the love-hate relationship physicists have with machine learning techniques. However, long standing open problems still need to be addressed. How do we inject our physics knowledge into these algorithms? How do we incorporate systematic uncertainties? How do we expand the scope of applications from signal vs. background classification to the other data-intensive challenges that particle physics faces. I will discuss a recent convergence of ideas that begin to address these questions and give a glimpse into a new class of machine learning techniques imbued with physics knowledge.

time:    4:00 p.m.
place:   Kolker Room (26-414)

(refreshments at 3:30 p.m.)



November 21, 2016

hosted by: Will Detmold


Ira Rothstein, CMU

High Accuracy Analytic Predictions for Gravitational Radiation Signals Utilizing Techniques from QCD

Abstract: Given the recent discovery of gravitational waves there is a pressing need for high accuracy templates in order to, not only extract precise values of black hole masses and spins, but also to learn about the equation of state of neutron stars. While late stages of the inspiral necessitates numerical simulations, the early stages can be calculated analytically in an expansion in the relative velocity (the Post-Newtonian approximation). This situation is reminiscent of quarkonia as both General Relativity and QCD have non-linearities controlled by the relative velocity of the bound state constituents. In this talk I will discuss how state of the art predictions have been generated using NRGR (Non-Relativistic General Relativity) which draws on ideas from NRQCD. I will also show how modern scattering amplitude techniques can be used to derive higher order Post-Newtonian potentials, which via the double copy relation, generates solutions to Einsteins equations directly from QCD. Finally I will discuss how the remarkable claim that black holes have vanishing tidal Love numbers implies, from the field theory point of view, that black holes are finely tuned objects. Remarkably, this claim can be tested in gravitational wave experiments.

time:    4:00 p.m.
place:   Kolker Room (26-414)

(refreshments at 3:30 p.m.)

 



November 28, 2016

hosted by:Mike Williams

Christine Aidala, University of Michigan

Spin-Momentum Correlations, Aharonov-Bohm, and Color Entanglement in Quantum Chromodynamics

Abstract: After the development of QCD in the last quarter of the 20th century, we are now in the early years of an exciting new era in which much more quantitative QCD calculations can be tested against increasingly sophisticated experimental measurements.  Advances include a greater focus on the dynamics of quarks and gluons within bound states and in the process of bound-state formation.  Over the last decade and a half, studies initially focused on spin-momentum correlations in the proton have brought to the fore several deep, fundamental issues within QCD.  We are now exploring the physical consequences of gauge invariance in QCD as a quantum field theory, analogous to the Aharonov-Bohm effects familiar to many from QED but predicted for any gauge-invariant quantum field theory.  Given the unique non-Abelian nature of the QCD gauge group, these quantum mechanical phase effects lead to an exciting novel prediction of entanglement of quarks and gluons across QCD bound states.  Recent results from the PHENIX experiment at the Relativistic Heavy Ion Collider will be highlighted.

time:    4:00 p.m.
place:   Kolker Room (26-414)

(refreshments at 3:30 p.m.)



December 5, 2016

hosted by: Jesse Thaler

Frank Petriello, Northwestern Univeristy/ANL

New tools for precision calculations in perturbative quantum field theory

Abstract: With the advent of Run II of the LHC, high energy physics is exploring a new frontier in physics at the smallest scales and searching for ever-more subtle deviations from the Standard Model. Future collider experiments promise to provide further insight into the structure of fundamental particles. Associated with the great experimental progress have been matching theoretical advances allowing us to predict precisely the predictions of the Standard Model in order to definitively search for its possible breakdown. Much of this theoretical progress would have been unthinkable several years ago, and arose from an influx of new ideas from many different areas: the introduction of new mathematical concepts into physics, an improved understanding of effective field theory, and powerful new computational algorithms. In this talk we review recent progress in precision calculations for the LHC, focusing on the enabling power of these new ideas. New phenomenological results to which they have led are also discussed.

 

time:    4:00 p.m.
place:   Kolker Room (26-414)

(refreshments at 3:30 p.m.)



December 14, 2016

hosted by: William Detmold



Yen-Jie Lee, MIT

TBA

Abstract: TBA

 

time:    4:00 p.m.
place:   Kolker Room (26-414)

(refreshments at 3:30 p.m.)