Page History

...

Heavy photons have become a hot topic because they may be intimately linked to hidden sector light dark matter, an interesting alternative to the SUSY wimps which no one is finding. If the Dark Matter is lighter than about 1 GeV, there is a strong case that a new force, like the hidden photon, must mediate dark matter decays and interactions. Our primary effort at SLAC is the Heavy Photon Search experiment (HPS). During 2011 and 2012, we built, installed, commissioned, and ran the HPS Test Run Experiment at JLab. The experiment used LHC style readout of silicon microstrip detectors for tracking and vertex reconstruction of e+e- pairs and a PbWO₄ crystal calorimeter to deal with the extremely high trigger rates expected. The run successfully demonstrated that backgrounds are manageable and that the apparatus works as designed. Following the run and the submission of a new proposalFollowing a successful test run, DOE approved and funded the Heavy Photon Search Experiment. The full experiment , using the same technologies as the test run, has now been was installed and commissioned at JLAB early in 2015, and took its first data during the Spring of 2015. More has taken data in two Engineering Runs, one in 2015 and the second in 2016, which demonstrated its physics readiness and led to full JLAB approval. The bulk of our running is scheduled for 2016 and beyond2018-2020.

HPS offers many opportunities for rotation students to begin work in a number of areas. We are just are  analyzing our first data from the 2015 and 2016 runs, so bump hunt and vertex search analyses are being developed and refined. In addition to searching for heavy photons, we've recently expanded our menu to search for Strongly Interacting Massive Particles (SIMPs) that decay via a heavy photon. As we prepare the data for these analyses, we are putting the finishing touches on calibrations, alignment, and improvements to improved tracking algorithms are needed and physics analyses need to be developed. We will be running the experiment in 2016 and beyond, so HPS data acquisition and operations need to be mastered. In addition, we have begun considering upgrades to the experiment and new experiments aimed at finding hidden sector particles. . To prepare for major data taking runs in 2018 and beyond, we are training a new crew to operate the silicon vertex tracker (SVT), the SVT DAQ, and the HPS beamline. We are also building new silicon modules to upgrade the performance of the SVT. This project will offer new students hardware, commissioning, and data taking experience.   HPS is a very small experiment by modern standards, but exploits cutting edge detection and readout technologies to address a very fascinating piece of physics. It provides a perfect opportunity broad education for a thesis studentstudents, offering including all aspects of experimental work, from design to hardware implementation to data analysis. Rotation Projects are available for Summer 2017 and the 20162017-2017 2018 academic year, outlined below. 

Our SLAC The HPS group is also helping to initiate a new experiment, the Light Dark Matter Experiment (LDMX), which would run in 2020 at SLAC. LDMX is a search for invisible decays of a heavy photon, complementary to the direct decays sought in HPS. LDMX will be sensitive to thermally produced light dark matter. A hidden sector is expected to have both force particles, like the heavy photon, and matter particles, like the light Dark Matter. Accelerator experiments like HPS and LDMX may be the key to finding the first evidence of hidden sectors in nature.

involved in the APEX experiment at JLAB, which has already completed a test run in 2010 and published results of its initial search, excluding a new region of heavy photon parameter space. The experiment makes use of two existing spectrometers in Jlab's experimental Hall A. The experiment hopes to take more data during the 2015-2016 JLab cycle and we hope to contribute. John Jaros.

An introduction to HPS for Physics 290 is given here: Physics290 10.14.2015Physics 290 11.07.2016.pptx

Possible Projects

...

for 2017-

...

2018