QED is not endangered by the proton's size

Pohl et al. have reported a very precise measurement of the Lamb-shift in muonic hydrogen (Pohl et al., 2010) [1], from which they infer the radius characterizing the proton's charge distribution. The result is 5 standard deviations away from the one of the CODATA compilation of physical constants. This has been interpreted (Pohl et al., 2010) [1] as possibly requiring a 4.9 standard-deviation modification of the Rydberg constant, to a new value that would be precise to 3.3 parts in 10¹³, as well as putative evidence for physics beyond the standard model (Flowers, 2010) [2]. I demonstrate that these options are unsubstantiated.     

In Appreciation

Leslie Foldy’s diminutive stature and modest demeanor gave little clue to the powerful intellect responsible for several significant advances in theoretical physics.Two were particularly important. His 1945 theory of the multiple scattering of waves laid out the fundamentals that most modern theories have followed (and sometimes rediscovered), while his work with Siegfried Wouthuysen on the nonrelativistic limit of the Dirac equation opened the way to a wealth of valuable insights. In this article we recall some of the milestones along Foldy’s path through a life in physics. Some of the anecdotes we report here were related to one of the authors (PLT) just before an event in 2000 celebrating Foldy’s 80th birthday, while others were told to us over the course of the nearly forty years during which we were colleagues. Still others were uncovered during the course of WJF’s research for his book, Physics at a Research University: Case Western Reserve 1830–1990 (Cleveland: Case Western Reserve University, 2006). Other details were provided by Foldy’s widow, Roma. Philip L. Taylor is the Perkins Professor of Physics and Professor of Macromolecular Science and Engineering at Case Western Reserve University. William J. Fickinger is Professor Emeritus of Physics at Case Western Reserve University.     

Generalized Shuffles Related to Nijenhuis and TD-Algebras

Shuffle type products are well known in mathematics and physics. They are intimately related to Loday's dendriform algebras and were extensively used to give explicit constructions of free Rota–Baxter algebras. In the literature there exist at least two other Rota–Baxter type algebras, namely, the Nijenhuis algebra and the so-called TD-algebra. The explicit construction of the free unital commutative Nijenhuis algebra uses a modified quasi-shuffle product, called the right-shift shuffle. We show that another modification of the quasi-shuffle, the so-called left-shift shuffle, can be used to give an explicit construction of the free unital commutative TD-algebra. We explore some basic properties of TD-operators. Our construction is related to Loday's unital commutative tridendriform algebra, including the involutive case. The concept of Rota–Baxter, Nijenhuis and TD-bialgebras is introduced at the end, and we show that any commutative bialgebra provides such objects.     

First observation of electronic structure of the even parity boron acceptor states in diamond

We use electronic Raman scattering for studying the band structure of the ns$\mathrm{n}s$ boron acceptor states in diamond. For the first time, the spin–orbit splitting of these acceptor states and the 1s→ns$1s\to \mathrm{n}s$ Lyman series of transitions are observed. The spin–orbit splitting linearly increases with n number. Lyman series exhibit fine structure consisting of four bands each. The energy spacing between series is equal to ∼13 meV$\sim 13\text{meV}$. Evolution of Raman spectra of the boron-doped diamond with increasing boron concentration is shown. Mott transition is revealed in Raman spectrum. Correct values of Luttinger parameters for diamond are specified.     

Lyman transitions of high rovibrationally excited H2, HD and D2 molecules

Energies and probabilities of Lyman transitions of high rovibrationally excited H₂, HD and D₂ molecules have been measured and compared with calculations. The experimental results are obtained from laser-induced fluorescence spectra that have been recorded in the spectral range from 60 500 to 83 500 cm⁻¹, covering 2/3 of the hydrogen Lyman band system. The necessary vacuum-UV radiation is produced by stimulated anti-Stokes Raman scattering, providing a widely tunable radiation source with narrow spectral bandwidth to resolve single Lyman transitions. The highest internal energies of detected hydrogen isotopologues are close to the dissociation limit. This extends the available data base of Lyman transitions from and to higher rotational states (J > 10) of HD and D₂.     

Upgrading the RIKEN-RAL Muon Facility

We report a major upgrading work currently underway at the RIKEN-RAL Muon Facility. A slow muon beam line has been constructed at Port 3 experimental area in order to generate a low-energy, low-emittance positive muon beam, which will open many new possibilities for use of the muon beam. Meanwhile, a new experimental port is under construction to accommodate new experimental programs such as measurement of muonic X-rays from ions implanted to deuterium layer. This revised version was published online in August 2006 with corrections to the Cover Date.     

日-地系拉格朗日L1点太阳观测器热设计

对将运行于日-地L1点的太阳观测器进行了热设计,重点论述了日-地L1点的轨道外热流计算和Lyman α日冕仪（LACI）反射镜M2光阱、Lyman α日冕成像仪（LADI）滤光片组件、CCD组件、电箱、观测器主体等部分的热设计方案。通过在探测器对日面设置集热板,将观测器的主动加热功耗降低了73％;选用预埋热管的设计方案解决了对日定向观测导致的框架温差问题。仿真分析结果表明,在对日高温工作、对日低温工作、低温存储、轨道转移等4个极端工况下,观测器各组件温度均满足指标要求。该热设计方案以较低的加热功耗,解决了太阳观测器在轨工作阶段的散热、轨道转移阶段的保温等问题,满足CCD焦面工作温度＜-50℃的要求。     

Properties and Phenomena: Basic Plasma Physics and Fusion Research in Postwar America

I review the changing conceptions of basic physics that the U.S. plasma-physics community put forward in postwar America. I give special attention to the tense relationship between fusion research and the more general study of plasmas in astrophysics, space science, and industry.Although fusion research often led to results that were regarded as basic plasma physics, its dominating influence tended to weaken other plasma work, as becomes evident when I compare the public statements and professional fortunes of plasma scientists during the 1960s, when fusion research experienced a downturn, with those of the 1970s, when fusion research flourished. I also show that the plasmaphysics community’s conceptions of basic physics were not highly regarded or easily understood by science administrators and the general physics community. To make this point, I contrast two general ideas of basic physics: the Big Questions conception and the Properties and Phenomena conception. Gary J.Weisel; Gary J.Weisel is Associate Professor of Physics at Penn State Altoona in Altoona, Pennsylvania. His historical research focuses on the development of subdisciplines in twentieth-century physics. He also carries out research in nuclear physics and materials science.