Light Hadron Spectroscopy: Theory and Experiment

Rapporteur talk at the Lepton-Photon Conference, Rome, July 2001: reviewing the evidence and strategies for understanding scalar mesons, glueballs and hybrids, the gluonic Pomeron and the interplay of heavy flavours and light hadron dynamics. Dedicated to the memory of Nathan Isgur, long-time collaborator and friend, whose original ideas in hadron spectroscopy formed the basis for much of the talk.Comment: to be published in "Lepton Photon 2001 Conference Proceedings" (World Scientific Publishing), 19 pages with 6 figure

The First Direct Distance and Luminosity Determination for a Self-Luminous Giant Exoplanet: The Trigonometric Parallax to 2MASS1207334-393254Ab

We present the first trigonometric parallax and distance for a young planetary mass object. A likely TW Hya cluster member, 2MASSW J1207334-393254Ab (hereafter 2M1207Ab) is an M8 brown dwarf with a mid to late L type planetary mass companion. Recent observations of spectral variability have uncovered clear signs of disk accretion and outflow, constraining the age of the system to <10 Myr. Because of its late spectral type and the clearly youthful nature of the system, 2M1207b is very likely a planetary mass object. We have measured the first accurate distance and luminosity for a self-luminous planetary mass object. Our parallax measurements are accurate to <2 mas (1sigma) for 2M1207Ab. With 11 total epochs of data taken from January 2006 through April 2 007 (475 images for 2M1207Ab), we determine a distance of 58.8+-7.0 pc (17.0{+2.3}{-1.8} mas, 1.28sigma) to 2M1207Ab and a calculated luminosity of 0.68-2.2x10^-5 Lsun for 2M1207b. Hence 2M1207Ab is a clear member of the TW Hya cluster in terms of its distance, proper motions, and youthful nature. However, as previously noted by Mohanty and co-workers, 2M1207b's luminosity appears low compared to its temperature according to evolutionary models.Comment: 12 pages, 3 figures, accepted to ApJ Letter

A detector for continuous measurement of ultra-cold atoms in real time

We present the first detector capable of recording high-bandwidth real time atom number density measurements of a Bose Einstein condensate. Based on a two-color Mach-Zehnder interferometer, our detector has a response time that is six orders of magnitude faster than current detectors based on CCD cameras while still operating at the shot-noise limit. With this minimally destructive system it may be possible to implement feedback to stabilize a Bose-Einstein condensate or an atom laser.Comment: 3 pages, 3 figures, submitted to optics letter

Quantum-field dynamics of expanding and contracting Bose-Einstein condensates

We analyze the dynamics of quantum statistics in a harmonically trapped Bose-Einstein condensate, whose two-body interaction strength is controlled via a Feshbach resonance. From an initially non-interacting coherent state, the quantum field undergoes Kerr squeezing, which can be qualitatively described with a single mode model. To render the effect experimentally accessible, we propose a homodyne scheme, based on two hyperfine components, which converts the quadrature squeezing into number squeezing. The scheme is numerically demonstrated using a two-component Hartree-Fock-Bogoliubov formalism.Comment: 9 pages, 4 figure

Novel Details of Calsequestrin Gel Conformation in Situ

Calsequestrin (CASQ) is the major component of the sarcoplasmic reticulum (SR) lumen in skeletal and cardiac muscles. This calcium-binding protein localizes to the junctional SR (jSR) cisternae, where it is responsible for the storage of large amounts of Ca2+, whereas it is usually absent, at least in its polymerized form, in the free SR. The retention of CASQ inside the jSR is due partly to its association with other jSR proteins, such as junctin and triadin, and partly to its ability to polymerize, in a high Ca2+ environment, into an intricate gel that holds the protein in place. In this work, we shed some light on the still poorly described in situ structure of polymerized CASQ using detailed EM images from thin sections, with and without tilting, and from deep-etched rotary-shadowed replicas. The latter directly illustrate the fundamental network nature of polymerized CASQ, revealing repeated nodal points connecting short segments of the linear polymer. © 2013 by The American Society for Biochemistry and Molecular Biology, Inc. Published in the U.S.A

Legal needs of adults with life-limiting illness: what are they and how are they managed? A qualitative multi-agency stakeholder exercise

Objective: Little is known about legal needs in the context of life-limiting illness, particularly the need for advice concerning legal arrangements, rights and entitlements. This UK-based multiagency stakeholder engagement exercise scoped legal needs associated with life-limiting illness and identified support structures, gaps and opportunities for practice improvement. / Method and analysis: Snowball sampling generated a stakeholder group from a wide range of regional and national organisations involved in care of people with life-limiting illness, spanning health, social care, legal support, advice, charities, prison services as well as patient and carer representatives. A coproduced survey of three open questions generated qualitative data, interpreted by thematic analysis. Results Stakeholders reported a broad spectrum of problems and needs raising legal issues, with no consistency of definition. A classification is proposed, identifying matters concerning rights and entitlements of patients/carers in day-to-day life and decisions around care, both immediate and in the future, as well as professional responsibilities in delivering personalised care. The support structures identified were predominantly online literature, although there was some availability of remote and face-to-face services. Limited awareness of the issues, variable service configuration, fragmentation of care and inequitable access were identified as barriers to support. Stakeholders recognised the need for education and closer multiagency working. / Conclusions: ‘Legal needs’ incorporate wide-ranging issues, but there is inconsistency in perceptions among stakeholders. Practice is variable, risking unmet need. Opportunities for improvement include more formal integration of social welfare legal services in the health context, generating clearer pathways for assessment and management

Classical noise and flux: the limits of multi-state atom lasers

By direct comparison between experiment and theory, we show how the classical noise on a multi-state atom laser beam increases with increasing flux. The trade off between classical noise and flux is an important consideration in precision interferometric measurement. We use periodic 10 microsecond radio-frequency pulses to couple atoms out of an F=2 87Rb Bose-Einstein condensate. The resulting atom laser beam has suprising structure which is explained using three dimensional simulations of the five state Gross-Pitaevskii equations.Comment: 4 pages, 3 figure

Pulsed pumping of a Bose-Einstein condensate

In this work, we examine a system for coherent transfer of atoms into a Bose-Einstein condensate. We utilize two spatially separate Bose-Einstein condensates in different hyperfine ground states held in the same dc magnetic trap. By means of a pulsed transfer of atoms, we are able to show a clear resonance in the timing of the transfer, both in temperature and number, from which we draw conclusions about the underlying physical process. The results are discussed in the context of the recently demonstrated pumped atom laser.Comment: 5 pages, 5 figures, published in Physical Review

The \rho\rho interaction in the hidden gauge formalism and the f_0(1370) and f_2(1270) resonances

We have studied the interaction of vectors mesons within the hidden gauge formalism and applied it to the particular case of the $\rho \rho$ interaction. We find a strong attraction in the isospin, spin channels I,S=0,0 and 0,2, which is enough to bind the $\rho \rho$ system. We also find that the attraction in the I,S=0,2 channel is much stronger than in the 0,0 case. The states develop a width when the $\rho$ mass distribution is considered, and particularly when the $\pi \pi$ decay channel is turned on. Using a regularization scheme with cut offs of natural size, we obtain results in fair agreement with the mass and the width of the $f_0(1370)$ and $f_2(1270)$ meson states, providing a natural explanation of why the tensor state is more bound than the scalar and offering a new picture for these states, which would be dynamically generated from the $\rho \rho$ interaction or, in simpler words, $\rho \rho$ molecular states.Comment: Version accepted for publicatio