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In this issue:
Physicists Discover New Particle: The Bottom-Most "Bottomonium"
Erik Jongewaard Made Head of Klystron/Microwave Department
Elizabeth Mullen, 2008 Katherine Pope Fellow

SLAC Today

Thursday - July 10, 2008

BaBar Collaborators Chris West, Peter Kim, Silke Nelson, Veronique Ziegler and Philippe Grenier.

Physicists Discover New Particle:
The Bottom-Most "Bottomonium"

Thirty years ago, particle physics delighted in discovering the "bottomonium" family—the set of particles that contain both a bottom quark and an anti-bottom quark but are bound together with different energies. Ever since, researchers have sought to ascertain the lowest energy state of these tiny yet important particles. Now, for the first time, collaborators on the BaBar experiment at the U.S. Department of Energy's (DOE) Stanford Linear Accelerator Center (SLAC) have detected and measured the lowest energy particle of the bottomonium family, called the ηb (pronounced eta-sub-b).

"Faced with the end of its run, the BaBar collaboration decided to focus its remaining time on investigating some of the states of bottomonium," said Associate Director of the DOE Office of Science for High Energy Physics Dennis Kovar. "This exciting result achieves one of the principal aims of this final data collection run."

SLAC Director Persis Drell added: "This is a tremendous achievement for both the PEP-II accelerator and the BaBar collaboration. Congratulations to everyone involved."  Read more...

Erik Jongewaard Made Head of Klystron/Microwave Department

Erik Jongewaard, with the symbolic "baton"—really a klystron tuning tool—that Chris Pearson passed to him at last month's Klystron Department meeting.

Congratulations to Erik Jongewaard, the new Acting Head of SLAC's Klystron/Microwave Department. Late last month, Associate Laboratory Director for the Engineering and Technical Support Directorate Lowell Klaisner announced Jongewaard's appointment at a department meeting. Jongewaard previously served as the program manager for the L-band sheet beam klystron.

"Erik has made major contributions to the success of the PEP-II program and lead the design of L-Band tubes for accelerator research," said Klaisner. "He is now playing a key role in building a solid future for the Klystron Department, which is recognized around the world as a unique facility for the design and fabrication of high-power klystrons."

As the new Klystron/Microwave Department Head, Jongewaard is now working on a five-year plan charting future department activities in support of many SLAC programs. The Department is heavily involved in maintaining linac radio frequency (RF) systems in support of Linac Coherent Light Source (LCLS), as well as various R & D activities such as RF source development and high gradient breakdown research. He takes over from Chris Pearson, who will retire later this year to work on his ranch along Highway 84.

"Chris has left big shoes to fill," Jongewaard said. "He's been my supervisor since I came to SLAC 15 years ago, and I've learned a lot from him. He will be greatly missed, and I look forward to running the department as well as he has."

Elizabeth Mullin, 2008 Katherine Pope Fellow

This year’s Katherine Pope fellow is Elizabeth Mullin, a physics student and rising junior at U.C. Riverside. She’s working with Owen Long to analyze data from the BaBar detector’s recordings of electron-positron collisions, looking for “rare and forbidden decays” of D-mesons, a class of intermediate-mass subatomic particles receptive to the strong interaction.

“When I first got here, it was kind of overwhelming,” said Mullin, adding that she did not know what to expect. However, her past few weeks, spent preparing computer programs to tackle the meat of her analysis, appeared to bode well; “Just being here, a big big place with a whole lot of physics people—it’s really really cool.”

Why particle physics? Mullin’s response is simple: “It’s fascinating.” Intrigued by the standard model’s weaknesses and its gamut of theoretical extensions—such as string theory, super-symmetry and other dimensions—Mullin gravitated towards the field after reading books on the subject. However, the seeds for this foray were planted even earlier: growing up as a child, Mullin recalled hearing her father, himself a former physics student, talk about physics and “complain about quantum mechanics.” Familiar with concepts such as tunneling by the time she started her undergraduate coursework, Mullin attributes her decision to pursue physics over engineering to her father’s influence. “I knew about quarks before I knew about atoms,” she said.


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