The Gribov horizon and the one-loop color-Coulomb potential

We recalculate the color-Coulomb potential to one-loop order, under the assumption that the effect of the Gribov horizon is to make i) the transverse gluon propagator less singular; and ii) the color-Coulomb potential more singular, than their perturbative behavior in the low-momentum limit. As a first guess, the effect of the Gribov horizon is mimicked by introducing a transverse momentum-dependent gluon mass term, leading to a propagator of the Gribov form, with the prescription that the mass parameter should be adjusted to the unique value where the infrared behavior of the Coulomb potential is enhanced. We find that this procedure leads to a Coulomb potential rising asymptotically as a linear term modified by a logarithm.Comment: 15 pages, 2 figure

Measurement crosstalk between two phase qubits coupled by a coplanar waveguide

We analyze the measurement crosstalk between two flux-biased phase qubits coupled by a resonant coplanar waveguide cavity. After the first qubit is measured, the superconducting phase can undergo damped oscillations resulting in an a.c. voltage that produces a frequency chirped noise signal whose frequency crosses that of the cavity. We show experimentally that the coplanar waveguide cavity acts as a bandpass filter that can significantly reduce the crosstalk signal seen by the second qubit when its frequency is far from the cavity's resonant frequency. We present a simple classical description of the qubit behavior that agrees well with the experimental data. These results suggest that measurement crosstalk between superconducting phase qubits can be reduced by use of linear or possibly nonlinear resonant cavities as coupling elements.Comment: 4 pages, 3 figure

Investigating the canon in A-Level music: Musical Prescription in A-Level Music Syllabuses (for first examination in 2018)

The canon forming the backbone of most conceptions of Western music has been a feature of musical culture for decades, exerting an influence upon musical study in educational settings. In English school contexts, the once perceived superiority of classical music in educational terms has been substantially revised and reconsidered, opening up school curricula to other musical traditions and styles on an increasingly equal basis. However, reforms to GCSE and A-levels (examinations taken aged 16 and 18 respectively) which have taken place from 2010 onwards have refocused attention on canonic knowledge rather than skills-based learning. In musical terms, this has reinforced the value of ‘prescribed works’ in A-level music specifications. Thus far, little attention has been paid to the extent to which a kind of scholastic canon is maintained in the Western European Art Music section of the listening and appraising units in current A-level music specifications. Though directed in part by guidance from Ofqual (Office of Qualifications and Examinations Regulation, the regulatory body for qualifications in England), there is evidence of a broader cultural trend at work. The present article seeks to compare the historical evidence presented in Robert Legg’s 2012 article with current A-level specifications. Such a comparison establishes points of change and similarity in the canon of composers selected for close study in current A-levels, raising questions about the purpose and function of such qualifications

Teacher perceptions of A-level music: tension, dilemmas, and decline

A-level music, a qualification taken most often in English and Welsh school contexts around the age of 18, has been a long standing feature of the musical training of many musicians. Historically bound up with Western European Art Music, the qualification has somewhat broadened its horizons in recent times, though with mixed success in opening up new ways of thinking about music. Recent research has highlighted the seemingly precarious nature of A-level music in many English schools (Bath, Daubney, Mackrill, & Spruce, 2020). The reasons for this picture of decline are highly complex and difficult to disentangle, and are part of a much broader diminishing of creative subjects in the school curriculum. Decreasing number of A-level music entries run somewhat counter to popular policy discourse which celebrates flagship announcements of £79 million given to Music Education Hubs (in 2019-2020) each year, and 2018 survey results that reported more than 700,000 children learning to play a musical instrument each year through music hub provision. However, behind these headlines, although there are many children having the opportunity to learn a musical instrument, few continue through to A-level and beyond. Despite its declining numbers, A-level music is recognised as a valuable qualification amongst music teachers, offering something distinct from graded music examinations and other Level 3 musical qualifications. This article presents the results of a recent nationwide survey of A-level music teachers to offer an insight into teacher perceptions of current A-level music specifications, the extent to which it prepares students for entry into higher musical education, and its appropriateness for aspiring young musicians

Sounding Jacqueline du Pré through ballet: classical music and The Cellist (2020)

Few cellists of the twentieth century were as recognisable as Jacqueline du Pré. Her dazzling and distinctive talent, said to have enraptured audiences the world over, was overcome by a tragic diagnosis of MS. This sense of tragedy was all the more heightened by Du Pré’s famed physicality on the stage, leading critics to describe her playing as a physical (and even sexual) experience. Her status as a musical celebrity, further intensified as she became one half of a classical music power couple, has led to numerous dramatic retellings and reimaginings of her biography, played out in film and TV, and now on stage. The most recent example of this fascination with Du Pré is the ballet The Cellist, Cathy Marston’s new work for the Royal Ballet, premiered in February 2020 at the Royal Opera House (London) to much critical acclaim. Its score, composed by Philip Feeney, features a cello soloist and interweaves extended extracts from repertoire that became so associated with Du Pré alongside newly composed musical materials. Along with the characters of Barenboim, Du Pré, and her family, her 1673 Stradivarius cello is given a starring role in the form of Marcelino Sambé, a new take that makes this a distinctive contribution to media representations of Du Pré. This article examines the interactions across this complex web of musical representations of musical personae by analysing depictions of acts of musical performance and the representation of a performer-instrument relationship in The Cellist. Ultimately, it considers the ways the disciplinary partnership of music and dance combine to establish new layers of interpretive meaning and to represent classical music. Key words: ballet music; classical music; cello; Jacqueline du Pré