dimensions volume 04 of particle physics symmetryA joint Fermilab/SLAC publication issue 01 jan/feb 07 On the Cover Babar the elephant made its debut in a 1931 children’s book by Jean de Brunhoff. BaBar the particle detector has been collecting data at Stanford Linear Accelerator Center since 1999, studying the tell-tale signs of the quantum world. One type of rare quan- tum process that the BaBar collabor- ation is studying is called the “penguin.” Photos: Reidar Hahn, Fermilab symmetryA joint Fermilab/SLAC publication volume 04 | issue 01 | jan/feb 07 2 Editorial: 8 BaBar’s Window on 30 Deconstruction: Budget Progress the Weak Force CMS Assembly The proposed US budget has prom- The BaBar B-factory experiment at Moving and assembling a particle ising developments for the particle Stanford Linear Accelerator Center detector underground is a delicate physics community but physicists looks to double its data in a mere operation, especially when the detec- need to do what they can to support two years as it hunts for hints of tor weighs more than 12,000 tons. their interests. spectacular new physics and guide future experiments. 32 Essay: 3 Commentary: Reality—Better than Fiction Prioritizing US Particle Physics 14 Evolution of a Collider A literature student, excited by physics A roadmap produced by the US parti- As physicists and engineers devise but turned off by how it was taught, cle physics community sets a direc- ways to make the International took to inventing her own theories of tion for how the research community Linear Collider perform better at a the universe. Then a university course can answer its most pressing scien- lower cost, the design evolves, showed her that reality is more inter- tific questions in particle physics over sometimes with tweaks, but other esting than anything she could invent. the next five years. times with major reconfigurations. ibc Logbook: 4 Signal to Background 20 And They Lived in Physics Single Top Production Delicate detector surgery; walking in Bliss Forever After… In 1985, physicists were wondering the dark; dark matter song; flying When physicists marry physicists, the whether particle colliders could dis- across Antarctica to catch particles; beginning may be a “big bang,” but cover new, heavier generations of big bang re-enactment; letters. issues of life, love, and family gravitate quarks. Twenty years later, the calcu- toward the universal. lation applies to the production of single top quarks at the Tevatron. 28 Day in the Life: Stanford Guest House bc Explain it in 60 Seconds: Guest houses are common among Simulations particle physics labs. But in many Simulations are used in physics to ways, the Stanford Guest House, sit- explore many “What if?” scenarios. In uated on the grounds of Stanford particle physics, they are used for Linear Accelerator Center, is different. application from designing new types of accelerators and detectors to evaluating the final analysis of data. Office of Science U.S. Department of Energy from the editor Budget progress The Fiscal Year 2008 budget request has just been released by the President of the United States. At the roughest cut of the figures, the FY08 high- energy physics program within the Department of Energy gets a 12% increase over the enacted FY06 budget level. (Comparisons with FY07 are not meaningful as Congress had not yet passed a budget at the time we went to print.) The FY08 increase takes the place of a similar request in FY07. Given that there had not been much budgetary growth for particle physics in recent years, any increase is welcome at this time, and these requests are a positive sign. Not all members of the particle physics community will see the FY08 budget request as good news since money would be shifted from one research program to another and some research efforts would see delays. This process is a stark reminder for all scientists about how money is allocated and who decides how money is spent in the United States: the people, through their elected representatives. Photo: Fred Ullrich, Fermilab Photo: Fred Scientists are beholden to the people who provide their funding. That’s how it should be. As a result, scientists’ proposals will only be enacted if they are consistent with a government’s priorities. The particle physics community has conducted a few prioritization analyses of their own, including the P5 report mentioned in Abe Seiden’s commentary (page 3). Those analyses are meant to provide advice and guidance, and the FY08 request reflects some of the priorities established by the particle physics community. In particular, R&D for the International Linear Collider would receive $60 million. With this item being one of the highest established priorities in particle physics, the strategic work by the community begins to pay off. In the reality of the current US budget climate, there are further steps the physics community should take. It should continue to present its achievements, prove that it is using its funds wisely, and ask to launch new research initiatives when the budgetary circumstances are right. Pushing too hard too soon will only attract a “No” for an answer, the last thing research-driven physicists would like to hear. Right now, the priority for physicists is to do what they can to ensure the US Congress passes a bud- get that satisfies their needs. David Harris, Editor-in-chief Symmetry Editor-in-Chief Publishers Print Design and Production PO Box 500 David Harris Neil Calder, SLAC Sandbox Studio MS 206 650 926 8580 Judy Jackson, FNAL Chicago, Illinois Batavia Illinois 60510 USA Executive Editor Contributing Editors Art Director Mike Perricone Roberta Antolini, LNGS Michael Branigan 630 840 3351 telephone Peter Barratt, PPARC 630 840 8780 fax Managing Editor Stefano Bianco, LNF Designers www.symmetrymagazine.org Kurt Riesselmann Reid Edwards, LBNL Aaron Grant Anilou Price [email protected] Catherine Foster, ANL Staff Writers Tara Kennedy Elizabeth Clements James Gillies, CERN (c) 2006 symmetry All rights Silvia Giromini, LNF reserved Brad Plummer Web Design and Production Heather Rock Woods Jacky Hutchinson, RAL Xeno Media symmetry (ISSN 1931-8367) Siri Steiner Youhei Morita, KEK Hinsdale, Illinois is published 10 times per year Kelen Tuttle Marcello Pavan, TRIUMF by Fermi National Accelerator Mona Rowe, BNL Web Architect Laboratory and Stanford Interns Perrine Royole-Degieux, IN2P3 Kevin Munday 07 symmetry | volume 04 issue 01 jan/feb Linear Accelerator Center, Rachel Courtland Yuri Ryabov, IHEP Protvino D.A. Venton Yves Sacquin, CEA-Saclay Web Design funded by the US Department Karen Acklin of Energy Office of Science. Jennifer Yauck Boris Starchenko, JINR Maury Tigner, LEPP Alex Tarasiewicz Jacques Visser, NIKHEF Web Programmer Linda Ware, JLab Mike Acklin Ute Wilhelmsen, DESY Tongzhou Xu, IHEP Beijing Photographic Services Fermilab Visual Media symmetry Services 2 commentary: abe seiden A program to understand dark matter, com- The plementary to work in astrophysics, seeks to Particle study its particle nature directly in the laboratory. However, dark energy can only be studied (at Physics our present level of understanding) through astro- Roadmap nomical observations; therefore, projects typically involve interagency collaborations with the astron- In October 2006, the omy programs at NSF or NASA. Particle Physics For major construction and R&D over the rest Project Prioritization of this decade, P5 set these three priorities: Panel (P5) provided a new roadmap for a broad research at the energy frontier, including the full and very exciting science agenda in particle LHC program and R&D for the ILC; a near-term physics research. The roadmap’s destinations program in dark matter and dark energy, as Photo: Monica Lee are among the most intriguing questions in sci- well as measurement of the small neutrino-mixing ence: the origins of mass and the search for the angle; and construction of the NOνA neutrino- Higgs boson; extra dimensions; dark matter oscillation experiment, along with related modest and dark energy; unification of the known forces Fermilab accelerator complex improvements. and possible new forces; the three families of The dark matter and dark energy program matter, from the massive top quark to the near- includes the 25 kg Cryogenic Dark Matter massless neutrino; and CP violation, the key Search (CDMS), the Dark Energy Survey (DES), to the imbalance between matter and antimatter and finalizing a cost and schedule plan for two in the universe. dark energy projects: The Large Synoptic Survey The P5 plan recommends construction and Telescope, in collaboration with the NSF; and R&D toward major projects for the next five SNAP, one of three options for a dark energy years, within an international context, and within space mission. DOE should work with NASA budget guidance from the US Department of to determine the best space mission. Energy (DOE) and the National Science Neutrino efforts include the Daya Bay (China) Foundation (NSF). There are recommended reactor neutrino experiment, along with R&D for review dates for projects anticipated to be ready a Deep Underground Science and Engineering for construction early in the next decade. Along Lab (DUSEL), R&D for a large dark matter with ongoing projects, and projects with con- detector, and a neutrinoless double-beta decay struction nearing completion, these recommen- experiment to be located at DUSEL. dations form the new roadmap. P5 advocated a review toward the end of this P5 is a subpanel of the High Energy Physics decade for a number of projects, many of which Advisory Panel, chartered jointly by DOE and could start construction soon thereafter. ILC pro- NSF. HEPAP endorsed the P5 plan in October gress will be reviewed, including a possible US 2006. The P5 panel received important input bid to host the ILC. The LHC upgrade construc- from specialized assessment panels in individual tion is required to raise LHC luminosity tenfold.