hosted by: Daniel Harlow
IN-PERSON
Pouya Asadi, MIT
Darkness Beyond Unitarity
Abstract:
While it is of paramount importance to make sure there are no stones left unturned in the search for dark matter, it is of equal importance to map out all possible dynamics in the dark sector. Aside from its (obvious) theoretical significance, this can guide us toward new search strategies or new parts of the parameter space that were thought to be irrelevant before. In this talk, I discuss some interesting dynamics within a confining dark sector with only heavy quarks and show that hitherto unexplored dynamics during its confinement phase transition can dramatically move the lamppost under which we should be looking for such sectors. I will also reiterate the effect of entropy dump in the early universe on the dark matter abundance in the context of one such model. Both these effects can open up parameter space above the often-quoted unitarity bound on the dark matter mass. This expansion of viable parameter space calls for furthering the scope of many dark matter searches.
time: 4:00 p.m.
place: Kolker Room (26-414)
hosted by: Or Hen
IN-PERSON
Sylvester Gates, Brown University
Adinkras, Adynkras, Permutahedra, Polytopes and SUSY
Abstract:
The emergence of the "Eightfold Way," introduced by Gell-Mann and Yuval Ne'eman, in the early sixties revolutionized high energy particle physics. Moreover, it played a critical role in pointing toward the Standard Model...the most successful and stringently tested paradigm in all of science. This talk reports on current efforts to uncover a new "Eightfold Way" for the concept of fundamental Supersymmetry.
time: 4:00 p.m.
place: Kolker Room (26-414)
hosted by: Philip Harris
IN-PERSON
Kevin Pedro, FINAL
Is the Dark Force Strong? New Directions for LHC Dark Matter Searches
Abstract:
The nature of dark matter remains one of the outstanding questions in particle physics. To date, collider searches have produced no evidence of an excess of events with large missing transverse momentum, which would be an indicator of the simplest models of weakly interacting massive particles. Instead, we pursue a new strategy based on models of composite dark matter, specifically "dark hadrons" that arise from a dark sector with a new strong force called "dark QCD". These models are motivated by both theoretical and experimental considerations. We present the latest results from Run 2 CMS searches for the novel phenomenological signatures of dark QCD, including semi-visible jets and emerging jets. The prospects for the future and evolution of the dark QCD program will also be discussed.
time: 4:00 p.m.
place: Kolker Room (26-414)
hosted by: Aram Harrow
VIRTUAL
Matthew Hastings, Microsoft
The Power of Adiabatic Quantum Computation With No Sign Problem
Abstract:
Hamiltonians with "no sign problem" are very important because they can often be efficiently studied on classical computers using algorithms such as path integral Monte Carlo. This leads to the question: how computationally difficult are these Hamiltonians? Can we always efficiently simulate them? One obstacle to simulating them can occur due to glassy physics, and problems with equilibration are well-known. However, I'll discuss other topological obstructions that can make them difficult to simulate even in the case that we consider adiabatic evolution of these Hamiltonians. To be precise and formal, I'll show that this problem is hard "relative to an oracle" which I will explain. This is based on [2005.03791] The Power of Adiabatic Quantum Computation with No Sign Problem (arxiv.org), and [2011.09495] (Sub)Exponential advantage of adiabatic quantum computation with no sign problem (arxiv.org) is a follow-up by Gilyen and Vazirani tightening the result and simplifying the construction.
hosted by: Or Hen
IN-PERSON
Sherry Yennello, Texas A&M
Nuclear Science Serving Society: Advances in 211At production at Texas A&M University
Abstract:
Alpha emitting radionuclides with medically relevant half-lives are interesting for treatment of tumors and other diseases because they deposit large amounts of energy close to the location of the radioisotope. Researchers at the Cyclotron Institute at Texas A&M University are developing a program to produce 211At, an alpha emitter with a 7.2 h half-life. The properties of 211At make it a great candidate for targeted alpha therapy for cancer due to its short half-life and decay mechanism. Astatine-211 has now been produced multiple times and novel chemistry has been developed for the separation of the At from the Bi target. Innovations to improve the safety and reliability of this process have been enacted.
time: 4:00 p.m.
place: Kolker Room (26-414)
hosted by: Boleslaw Wyslouch
IN-PERSON
Zeynep Demiragli, BU
A shot in the dark
Abstract:
The experiments at the Large Hadron Collider (LHC) at CERN are at the energy frontier of particle physics, searching for answers to fundamental questions of nature. In particular, dark matter presents strong evidence for physics beyond the standard model. However, there is no experimental evidence of its non-gravitational interaction with standard model particles. If dark matter has non-gravitational interactions with the standard model particles, we could be producing the dark matter particles in the proton-proton collisions at the LHC. While the dark matter particles would not produce an observable signal in the detector, they may recoil with large transverse momentum against visible particles resulting in an overall transverse momentum imbalance in the collision event. In this talk, I will review the searches for dark matter particles in these missing momentum final states in association with jets at the Compact Muon Solenoid (CMS) experiment.
time: 4:00 p.m.
place: Kolker Room (26-414)
hosted by: Boleslaw Wyslouch
IN-PERSON
Christophe Royon, KU
Measuring intact protons at the LHC: From the odderon discovery to the search for axion-like particles
Abstract:
In the first part of the talk, we will describe the odderon discovery by the TOTEM and D0 experiments. The analysis compares the p pbar elastic cross section as measured by the D0 Collaboration at a center-of-mass energy of 1.96 TeV to that in pp collisions as measured by the TOTEM Collaboration at 2.76, 7, 8, and 13 TeV. The two data sets disagree at the 3.4 sigma level and thus provide evidence for the t-channel exchange of a colorless, C-odd gluonic compound, also known as the odderon. We combine these results with a TOTEM analysis of the same C-odd exchange based on the total cross section and the ratio of the real to imaginary parts of the forward elastic strong interaction scattering amplitude in pp scattering, leading to a combined significance larger than 5 sigma.
In a second part of the talk, we will describe the perspective on the search for quartic anomalous couplings and axion-like particles using tagged protons in the final state, leading to sensitivities to beyond standard model physics that improve by 2 to 3 orders of magnitude on the coupling. We will finish by describing briefly the ultra fast silicon detectors for timing measurements as well as for medical and cosmic ray applications.
time: 4:00 p.m.
place: Kolker Room (26-414)
hosted by: Or Hen
IN-PERSON
Chen-Yu Liu, Indiana University
Fundamental Neutron Physics: Probing TeV Physics with neV Neutrons
Abstract:
Ultra Cold Neutrons (UCN) are free neutrons with kinetic energies up to several hundred nano-eV. Storage of UCN allows for the long observation times needed for precision measurement of many neutron observables. High-precision measurements, confronted with theoretical predictions, probe high-energy physics through loop effects. To illustrate the power of precision measurements in the fundamental neutron physics program, I will discuss two recent measurements: the lifetime and the electric dipole moment of the neutron.
The UCNtau experiment recently reported the most precise measurement of the neutron lifetime, 877.75 +/- 0.28 (stat) +0.22/-0.16 (sys) s [PRL 127, 162501 (2021)]. This result, together with improved measurements of the axial coupling constant, will provide a determination of the CKM matrix element Vud, independent of nuclear decays, and address the recent tension in the CKM unitarity test. The search for the CP-violating electric dipole moment (EDM) of the neutron has reached, with the latest result from PSI, a sensitivity of (0.0±1.1(stat)±0.2(sys))×10−26 e-cm [Phys. Rev. Lett. 124, 081803 (2020)]. In many scenarios, successful baryogenesis leads to strict lower bounds on the neutron and electron EDMs, only a factor of 2–3 below the current experimental limits. The new generation of nEDM searches will be sufficiently sensitive to provide a conclusive test of the origin of matter in the minimal supersymmetric model. In the US, two efforts are underway: the nEDM@LANL plans to reach 3e-27 e-cm with the upgraded UCN source, and the nEDM@SNS aims for 5e-28 e-cm using an innovative superfluid helium technique. I will discuss the designs and report on the status of these experiments.
time: 4:00 p.m.
place: Kolker Room (26-414)
hosted by: Daniel Harlow
IN-PERSON
JiJi Fan, Brown University
Kaleidoscope of axion models and probes
Abstract:
Axions, periodic pseudo-scalars, enjoy a wide range of phenomenological applications, from solving the strong CP problem to providing DM and inflaton candidates. Justifiably, they have been the subject of prolonged theoretical interest, which has intensified over the past few years. In this talk, I will discuss several small but fun developments in axion models and probes, including: a recently identified source of axion potential, new axion cosmological models, and novel astrophysical probes. A
time: 4:00 p.m.
place: Kolker Room (26-414)
hosted by: Philip Harris
VIRTUAL
Sarah Malik, UCL
Pushing the precision frontier of LHC physics with the measurement of the Z invisible width at CMS
Abstract:
The Large Hadron Collider (LHC), was built in the tunnel originally excavated for LEP, the highest energy electron-positron collider ever built. LEP was a precision machine and one of it's greatest legacies is the unprecedented accuracy with which it constrained the properties of the Z boson. One of the highlights is the measurement of the Z boson decaying to invisible particles, which was used to deduce that there are 3 species of light neutrinos that couple to the Z. These measurements have remained unsurpassed for two decades.
LEP gave way to the construction of the LHC and the first phase of the LHC led to the triumphant discovery of the Higgs boson in 2011. The LHC has now accumulated a very large dataset and is entering a precision era of physics, with the ability to test the Standard Model at a new energy regime and in a different environment. In this talk, I will present a measurement of the Z invisible width at the CMS experiment, the first of its kind at a hadron collider. The measurement uses the experimental signature of a hadronic jet and missing transverse momentum and exploits the relationship between the decay to neutrinos and to charged leptons to extract a value for the Z invisible width.
time: 4:00 p.m.
hosted by: Daniel Harlow
IN-PERSON
Ibrahima Bah, Johns Hopkins University
Topological solitons in gravity
Abstract:
In this colloquium I will discuss aspects of microscopic degrees of freedom of gravity as motivated by string theory. Although these are expected to be generically quantum mechanical, our goal is to understand a class of such states that are coherent enough to admit classical descriptions in Einstein gravity. The construction of such states corresponds to adding interesting topological structures in spacetime with the help of compact extra dimensions. The constructions manifestly behave like ultra compact objects, dubbed topological stars, which can also model black hole microstates. I will discuss why it is interesting to understand such objects in a new age of gravitational waves astrophysics.
time: 4:00 p.m.
place: Kolker Room (26-414)
hosted by: Janet Conrad
IN-PERSON
Georgia Karagiorgi, Columbia University
TBA
Abstract:
TBA
time: 4:00 p.m.
place: Kolker Room (26-414)
