Hadron Ion Tea (HIT) Seminar
[formerly Heavy Ion Tea Seminar]
Nuclear Science Division
Lawrence Berkeley National Laboratory
Tuesday, 2021.11.30, 3:30 PM, Virtual Zoom HIT
Prof. Stan Brodsky (Stanford/SLAC)
I will also review recent developments in intrinsic heavy quark phenomena, including predictions for intrinsic charm-anticharm asymmetry in the nucleon.
Nov. 30, 2021 - Stan Brodsky (SLAC)
Dec. 1, 2021 - Jean-François Paquet (Joint NT and HIT seminar at 1:00 pm)
Dec. 7, 2021 - Dien Nguyen (JLab/MIT)
Dec. 14, 2021 - Yu Zhang (CCNU)
Jan. 18, 2022 - Tanja Horn (JLab)
Jan. 25, 2022 - Rene Belleweid (U.Houston)
Tuesday, 2021.11.23, 2:30 PM, Virtual Zoom HIT
Please note special time, one hour earlier than usual!
Dr. Feng Yuan (Berkeley Lab Senior Scientist)
Near Threshold Heavy Quarkonium Photoproduction
There has been a claim in the literature that the near threshold photo-production of heavy quarkonium can measure the gravitational form factors and hence to directly measure the proton mass distribution. In this talk, we will present our recent analysis based on perturbative QCD calculations for this process at large momentum transfer. We take into account the contributions from the leading three-quark Fock states of the nucleon. The dominant contribution comes from the three-quark Fock state with one unit quark orbital angular momentum (OAM) whereas that from zero quark OAM is suppressed at the threshold. From our analysis, we also show that there is no direct connection between the near threshold heavy quarkonium photoproduction and the gluonic gravitational form factors of the nucleon. Based on the comparison between our result and recent GlueX data of J/\psi photoproduction, we make predictions for \psi' and \Upsilon (1S,2S) states which can be tested in future experiments.
Tuesday, 2021.11.16, 11:00 AM, Virtual Zoom HIT - Note special time for this seminar!
Prof. Elena Santopinto (INFN Genoa,Italy)
Quarks that combine in much more complex ways than scientists expected can have repercussions in many fields, not only in particle physics. The recent observation by LHCb of a meson made of four charm quarks (T_cccc) and of new strange hidden charm tetraquark and pentaquark states has consecrated the subject of exotics as a hot topic. New experiments at LHC and Belle plan to shed light on this unexpected behavior and try to understand the strong force at long distances.
In this talk, some of the main experimental findings and theoretical predictions given before the experimental discoveries, regarding fully charm tetraquarks and pentaquarks, will be presented and discussed. Finally, the Electron Ion Collider (EIC) has the potential to produce such states in photoproduction reactions, which would confirm the observations in previous experiments and provide complementary insight into their composition.
Tuesday, 2021.11.02, 3:30 PM, Virtual Zoom HIT
Dr. Xin Dong (LBNL)
Tuesday, 2021.10.26, 3:30 PM, Virtual Zoom HIT
Prof. Simonetta Liuti (University of Virginia)
Gearing up for the EIC era: precision computations in the CGC
Tuesday, 2021.09.28, 3:30 PM, Virtual Zoom HIT
Dr. Saehanseul Oh (LBNL)
Wednesday, 2021.09.15, 1:00 PM, Virtual Zoom HIT
Joint Nuclear Theory and HIT seminar (note special day and time)
Dr. Liliana Apolinario (LIP/Lisbon)
Tues. 2021.06.22, 3:30 PM, Virtual Zoom HIT
Dr. James Brandenburg (Stony Brook Univ.)
Tues. 2021.05.18, 01:30 PM, Virtual Zoom HIT
Prof. Vincenzo Greco (Catania University, INFN-LNS)
Joint Nuclear Science and Physics Division Seminar on muon g-2
We are having a special seminar followed by a panel discussion on the recent g-2 result for the muon, with an emphasis on the theoretical prediction for this quantity.
10:30am : Welcome
10:35am: Laurent Lellouch
11:10am: Martin Hoferichter
11:40am: Panel discussion + audience question/answer
Panelists: Gilberto Colangelo (chair), Aida El-Khadra, Christoph Lehner, Bill Marciano and Thomas Teubner
Tues. 2021.03.23, 3:30 PM, Virtual Zoom HIT
Dr. Kei Nagai (LANL)
The phenomenon of anomaly plays an important role in quantum field theory. In QCD how axial anomaly manifests itself in the two-point correlation functions of iso-triplet scalar and pseudo-scalar mesons affects the nature of chiral phase transition. In this talk I first review current studies of the fate of UA (1) anomaly in the finite temperature lattice QCD, and then propose novel relations between the quark mass derivatives of Dirac eigenvalue spectrum and correlation functions among eigenvalues in order to study the microscopic origin of the axial anomaly. We finally show our results in the chiral and continuum limit in (2+1)-flavor lattice QCD at 1.6Tc. Our results suggest that the axial anomaly is driven by the weakly interacting (quasi-)instanton gas motived eigenvalue spectrum above 1.6Tc and the chiral phase transition is of 2nd order and belongs to 3-d O(4) universality class (talk is based on https://arxiv.org/abs/2010.14836).
Tues. 2021.01.26, 1:30 PM, Virtual Zoom HIT
What can we learn from heavy neutron stars?
The observation of gravitational waves from a blackhole-mystery object binary opens the possibility for heavy neutron stars of 2.5 solar masses (potentially seen in GW190814). If this mystery object is a neutron star of 2.5 solar masses, it poses direct challenges to models of the equation of state. Interestingly, introducing non-trivial structure in the speed of sound sourced by changes in the degrees of freedom (possibly quarks) of ultra-dense matter can resolve this conflict, which may have large ramifications in nuclear and astrophysics. However, for a clear smoking gun signature of the mystery object being a neutron star, one requires a measurement of the tidal deformability that is non-zero. Because the predicted values are very small, a tenfold increase in sensitivity may be needed to test this possibility with gravitational waves, which is feasible with third generation detectors. Finally, I will comment on opportunities in heavy-ion collisions that exist for further constraining the equation of state relevant to neutron stars.