Charged Particle Multiplicities in Ultra-relativistic Au+Au and Cu+Cu Collisions

The PHOBOS collaboration has carried out a systematic study of charged particle multiplicities in Cu+Cu and Au+Au collisions at the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory. A unique feature of the PHOBOS detector is its ability to measure charged particles over a very wide angular range from 0.5 to 179.5 deg. corresponding to |eta|<5.4. The general features of the charged particle multiplicity distributions as a function of pseudo-rapidity, collision energy and centrality, as well as system size, are discussed.Comment: Proceedings of "Lake Louise Winter Institute 2006", Lake Louise, Alberta, Canada, February 17-23, 2006, World Scientific 5 pages, 3 figure

BaBar B Decay Results

Data from the first run of the BaBar detector at the PEP II accelerator are presented. Measurements of many rare B decay modes are now possible using the large data sets currently being collected by BaBar. An overview of analysis techniques and results on data collected in 2000 are described.Comment: 16 pages, 35 figures. Submission to Lepton-Photon 2001 Rome conference proceeding

Uniform semiclassical expansions for the direct part of Franck-Condon transitions

Semiclassical expansions for traces involving Greens functions have two contributions, one from the periodic or recurrent orbits of the classical system and one from the phase space volume, i.e. the paths of infinitesimal length. Quantitative calculations require the control of both terms. Here, we discuss the contribution from paths of zero length with an emphasis on the application to Franck-Condon transitions. The expansion in the energy representation is asymptotic and a critical parameter is identified. In the time domain, a series expansion of the logarithm of the propagator gives very good results. The expansions are illustrated for transitions onto a linear potential and onto a harmonic oscillator.Comment: 11 pages, Revtex, 7 figures, Encapsulated Postscript, submitted to Phys. Rev.

Inclusive Charmed-Baryon Decays and Lifetimes

We have quantitatively reanalyzed the inclusive charmed-baryon decays. New ingredients are the Voloshin preasymptotic effects in semileptonic decays and the Cabibbo-subleading contributions to both semileptonic and nonleptonic decays. It has been found that the Cabbibo-subleading Voloshin contribution essentially improves the theoretical semileptonic branching ratio of $\Lambda_c^{+}$, in agreement with experiment. The semileptonic branching ratios for $\Xi_c^{+}$ and $\Omega_c^{0}$ are found to be large, i.e., of the order of 20%. The lifetimes hierarchy is in a good qualitative and even quantitative agreement with experiment except for the $\Xi_c^{+}$ lifetime, which is somewhat smaller than the experimental value. Future measurements, especially measurements of the semileptonic branching ratios for $\Omega_c^{0}$, $\Xi_c^{+}$ and $\Xi_c^{0}$ should be decisive for the check of this approach.Comment: 13 pages, Latex, 3 figures included, shortened version, to appear in Z.Phys.

Patients’ attitudes and beliefs to presbyopia and its correction

Objective Presbyopia is the gradual inability to focus near objects with age. This study explores patients’ attitudes and beliefs towards presbyopia including preferred modes of near refractive correction. Methods In the United Kingdom, twenty-four volunteers completed an online questionnaire and attended a structured, recorded focus group. Participants’ age ranged between 36 and 48 years, representing a pre-presbyopic and a presbyopic population. Attitudes and beliefs about presbyopia, its significance, and opinions about current refractive correction including multifocal contact lenses were transcribed and coded using content analysis for overarching themes and patterns. Results Six participants (25%) were already wearing a near visual correction while 18 (75%) were not. Five key primary themes with clear inter-participant similarities were identified as ‘age-related’ (75%), ‘acceptance’ (50%), clear lack of ‘familiarity with the word presbyopia’ (65%), a mixed/ reluctant attitude ‘towards (multifocal) contact lenses’ (62.5%), and ‘comfort and convenience’ of a presbyopic correction (79%) whereby cost is of less importance. Conclusion The need for a reading correction was perceived as a sign of age. Spectacles were the most preferred mode of near vision correction, while comfort and convenience were seen as more important than cost. Patient education about presbyopia is lacking. Multifocal contact lenses are not necessarily the preferred visual correction even if the patient already wears contact lenses for distance

Parallel hybrid textures of lepton mass matrices

We analyse the parallel hybrid texture structures in the charged lepton and the neutrino sector. These parallel hybrid texture structures have physical implications as they cannot be obtained from arbitrary lepton mass matrices through weak basis transformations. The total sixty parallel hybrid texture structures can be grouped into twelve classes, and all the hybrid textures in the same class have identical physical implications. We examine all the twelve classes under the assumption of non-factorizable phases in the neutrino mass matrix. Five out of the total twelve classes are found to be phenomenologically disallowed. We study the phenomenological implications of the allowed classes for 1-3 mixing angle, Majorana and Dirac-type $CP$ violating phases. Interesting constraints on effective Majorana mass are obtained for all the allowed classes.Comment: Physical Review D (To appear