LGRT 419B

The gamma-boson exchange diagram plays an important role in a number of different areas of nuclear and particle physics. Two-photon exchange in elastic lepton-nucleon scattering is believed to become large at high momentum transfers to explain a large discrepancy in the proton elastic form factor determination. The gamma-Z box diagram is a significant contribution to the asymmetry in parity-violating electron scattering. Finally, the gamma-W diagram enters into beta-decays which are used to constrain fundamental elements of the Standard Model.

The purpose of the workshop is to bring together both theorists and experimentalists in these different areas to improve our understanding of this important process. An important focus will be on the interplay between the gamma-boson exchange contributions to different electroweak observables and the opportunities to exploit measurements to calibrate theoretical predictions. We hope to develop a roadmap for theory and experiment through a set of informal talks and discussions.

Co-organizers

Jan Bernauer, Massachusetts Institute of Technology

Doug Hasell, Massachusetts Institute of Technology

Michael Kohl, Hampton U & Jefferson Lab

Richard Milner, Massachusetts Institute of Technology

Michael Ramsey-Musolf, UMass Amherst

## Schedule

9:00am |

9:15am |

10:00am |

10:45am |

11:15am |

12:00pm |

12:30pm |

2:00pm |
Overview of two-photon and two-boson exchange
Peter Blunden University of Manitoba electroweakbox_blunden.pdf |

2:30pm |
Two-Photon Theory: Inelastic Effects and Partonic Approach
Andrei Afanasev George Washington University afanasev_ewbox17.pdf |

3:00pm |
Two-Photon Exchange Calculations Versus Data
Oleksandr Tomalak Mainz University tomalak_talk_amherst.pdf |

3:30pm |

4:00pm |

5:00pm |

6:30pm |

9:00am |
The Current Evaluation of V_{ud} and the Role Played by Radiative Corrections
John Hardy Texas A&M University hardy_amherst_talk.pdf |

9:45am |
Parity-Violating and Parity-Conserving Asymmetries in ep and eN Scattering in the Qweak Experiment
Wouter Deconinck William and Mary wdeconinck_electroweak_box_qweak.pdf |

10:30am |

11:00am |
Dispersion Corrections to Hadronic Weak Charges
Misha Gorshteyn Mainz University gorshteyn_ew_boxes_sep29-2017.pdf |

11:30am |
Dispersive Approach to the Gamma-W Box Diagram in Beta Decay
Chien Yeah Seng Shanghai Jiao Tong University gamma_w.pdf |

12:00pm |

12:30pm |

2:00pm |

2:30pm |
Searching for Tensor Currents by Detection of Cyclotron Radiation
Alejandro Garcia University of Washington tensor-via-cres.pdf |

3:00pm |
Measurements of Beta Energy Spectra in Gamow-Teller Decays
Oscar Naviliat Cuncic Michigan State University naviliat-gtdecays.pdf |

3:30pm |

4:00pm |

5:00pm |

6:30pm |

9:00am |

9:30am |
Baryon Chiral Perturbation Theory for the Two-boson Exchange Graph
Vadim Lensky Mainz University lensky_ew_box.pdf |

10:00am |
RC's to ep scattering and the Weak mixing angle
Kyle Shiells University of Manitoba kshiells_sin2w_talk2017finalpdf.pdf |

10:15am |
Using the Qweak Apparatus to Probe the Gamma Z Box
Jim Dowd Jefferson Lab/ William and Mary jdowd_electroweak_box_talk_2017_v2.pdf |

10:30am |

11:00am |

11:30am |

12:00pm |
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