Jefferson Lab Weekly Briefs November 15, 2017


Hall D
The first of four DIRC modules has been transported from the SLAC National Accelerator Laboratory to Jefferson Lab’s Hall D. The DIRC (Detector of Internally Reflected Cherenkov light) was used in the BaBar experiment and provided pion to kaon separation up to momenta of about 4 GeV/c. A part of the BaBar DIRC will be recycled for particle identification in the GlueX experiment.  One DIRC module contains 12, five-meter-long fused silica bars manufactured to high precision. The transportation of these very delicate modules is a challenging task. One has to minimize the shocks and temperature variations, flush the detector volume with pure nitrogen and monitor the readings of accelerometers and other sensors. The preparations and the execution were led by the Indiana University, assisted by MIT, the Catholic University of America and Jefferson Lab.

Jefferson Lab Published Journal Articles, Nov. 5-11

  • P. Degtiarenko. "Precision analysis of the photomultiplier response to ultra low signals." Nucl. Instrum. Meth. A 872, 1 (2017).
  • A. J. R. Puckett et al. "Polarization transfer observables in elastic electron-proton scattering at Q2 = 2.5, 5.2, 6.8, and 8.5 GeV2." Phys. Rev. C 96, 055203 (2017).
  • Kostas Orginos et al., "Lattice QCD exploration of parton pseudo-distribution functions." Phys. Rev. D 96, 094503 (2017).
  • Maksim Ulybyshev et al., "Collective charge excitations and the metal-insulator transition in the square lattice Hubbard-Coulomb model." Phys. Rev. B 96, 205115 (2017)
Remember to submit your papers for approval to the Jefferson Lab Publications database.

Archives Photo of the Week
This week's photo shows the results poster of the First Annual CEBAF Run-A-Round, which took place May 2, 1986. You might be surprised to find familiar names and faces 31 years later!

Center for Theoretical and Computational Physics

Quark pseudo-distributions (pseudo-PDFs) are a recently introduced concept that generalizes the usual parton distributions (PDFs) for situations where the separation between the quarks is not on the light cone. The short-distance behavior of the pseudo-PDFs from the gluonic corrections has just been worked out at the one-loop order. These results will be used in future extractions of the PDFs from lattice calculations.

Jefferson Lab Calendar of Events

Nov. 23-24: Thanksgiving holiday, Jefferson Lab closed
Dec. 9: JAG Children's Holiday Party
Dec. 25-Jan. 1: Holiday Shutdown, Jefferson Lab closed
Jan. 19: Mobile Mammography Unit On-site
Jan. 22-23: Hall C Collaboration Meeting
Jan. 24-25: Hall A Collaboration Meeting

Environment, Safety, Health and Quality

Sleepiness vs. Fatigue
The American College of Occupational and Environmental Medicine defines occupational fatigue as the body’s response to lengthy physical or mental hard work. Factors that cause occupational fatigue include long work hours, heavy workload, lack of sleep, environmental factors, or a medical conditions. While sleepiness is relieved by normal-quality sleep, fatigue is not. People who feel fatigued may take a nap, but symptoms will re-present upon waking.

According to University Health News, medical researchers do not completely understand what specific factors cause fatigue. The five common causes that are agreed upon include the following.
  • Stress: Fatigue is a common consequence of excessive or prolonged stress factors.
  • Poor nutrition/digestion: Food allergies, blood sugar dysregulation, and excessive permeability in the lining of the intestines can all cause fatigue.
  • Hormone imbalances: Low or imbalanced levels of common hormones such as thyroid, testosterone, estrogen, and progesterone.
  • Anxiety and depression: Mood disorders such as depression and anxiety are strongly associated with fatigue and daytime sleepiness.  Depression-related fatigue is often associated with impaired concentration, irritability, and reduced productivity.
  • Sedentary lifestyle and deconditioning: Not getting enough exercise or physical activity causes deconditioning of the body’s musculoskeletal and cardiovascular systems and depresses mood, all of which lead to fatigue.
Why does this matter?  Effects of fatigue include slower reaction time, indifference to errors, and decreased cognitive ability. Studies have focused on fatigue effects on shift workers, health care workers and drivers, but it can occur during any shift, in all industries, and during any activity.

Computing and Networking Infrastructure

Jefferson Lab Site Wireless Changes Take Effect Thursday
On Thursday, Nov.16, the certificate used for wireless authentication will change. Some devices may require that you accept the new certificate. It will be named "” This affects both the jlab and eduroam wireless networks. As a note, the eduroam network is now preferred and has the same features at jlab in addition to working at many other labs and educational institutions. Remember when configuring eduroam to use your email address as the username. If you have questions or concerns about this change, contact the IT Division Helpdesk at or x7155.

IT Division Maintenance Period Planned for Tuesday, Nov. 21
The IT Division is planning a maintenance period for 5-7 p.m. on Tuesday, Nov. 21. During this time, the CNI maintained Core CUE Apps, such as Adobe Reader and Mozilla Firefox, will be updated to the latest versions. In addition, the division will release Windows and Linux patches to all CUE-managed servers and desktops. Central services may be briefly unavailable overnight while the servers on which they run are rebooted to finalize patch installation. In order to finalize patch installations, plan on rebooting your CUE-managed Windows or Linux desktop no later that Wednesday, Nov. 22. If you have any questions or concerns about this maintenance period, contact the IT Division Helpdesk at or x7155.


Two Scientists Affiliated with Jefferson Lab Named APS Fellows
Fulvia Pilat and Kawtar Hafidi have been named fellows of the American Physical Society. The honor is bestowed by members of APS on their peers for exceptional contributions to their fields. Read more about Pilat here. Read more about Hafidi here.

Join the Jefferson Lab Activities Group
The Jefferson Lab Activities Group (JAG) is seeking a few good people who are eager to bring great ideas and energy to the committee. Individuals should be outgoing, enthusiastic, energetic, available to attend planning meetings, and actively participate in planning and preparing for JAG events. For more information, see the full memo.

Jefferson Lab 2018 Holiday Calendar Is Now Available
The official holiday calendar for the next calendar year has been posted on the Human Resources website. You can access the calendar here.

Quark Cafe Plans Thanksgiving Warm-up Buffet for Thursday, Nov. 16
Quark Cafe staff will host a Thanksgiving Warm-up Buffet 11:30 a.m. - 1:30 p.m. on Thursday, Nov. 16. The menu will include herb-roasted turkey, maple-glazed ham, candied yams, green bean casserole, mashed potatoes and gravy, collard greens, sweet potatoes, stuffing and fresh-baked rolls. The price for one self-serve buffet plate will be $12.99. For additional details, see the full memo.

Pre-Order Your Thanksgiving Pie through Nov. 16
The Quark Cafe staff is taking Thanksgiving pie orders through 2 p.m. on Thursday, Nov. 16. Selections that may be purchased to take home for the holiday include pumpkin, apple, pecan, buttermilk, and Kentucky Derby pies. See the full memo for order information.

JAG Hosts Food Drive Through Nov. 17
The Jefferson Lab Activities Group has positioned food drive collection boxes for nonperishable food items for the 21st Annual Mayflower Marathon Food Drive. All donations will be collected around 3 p.m. on Friday, Nov. 17, and delivered to the Peninsula Food Bank. Boxes are located in the CEBAF Center lobby, Support Service Center lobby (Bldg. 28), the TED 2nd floor lobby (Bldg. 55), and the ESH&Q Building entrance (Bldg. 52). For more information, see the full memo.

SOTR Training Offered Nov. 29
A Jefferson Lab training session for any new Subcontracting Officer Technical Representatives (GEN020) or anyone who wants a refresher class will take place Wednesday, Nov. 29, 8 a.m.-12:30 p.m. in room 53 of the Support Service Center, Bldg. 28. Registration for this class is required. See the full memo for details.
JLab Weekly Briefs is an ongoing publication providing information on the status of safety, accelerator operations, experiments, reviews, upcoming activities and special events. Deadline for submission is every Tuesday by 10 a.m. Submit new items to: the Communications Office or contact Kandice Carter at x7263.