Dilepton asymmetries at BB factories in search of ΔB=−ΔQ\Delta B =- \Delta Q transitions

In order to detect the possible presence of $\Delta B = - \Delta Q$ amplitudes in neutral $B$ meson decays, we consider the measurement of decay time asymmetries involving like-sign dilepton events at the $B$ factories.Comment: 5 pages, latex, no fig

String-like behaviour of 4d SU(3) Yang-Mills flux tubes

We present here results on the fine structure of the static q\bar q potential in d=4 SU(3) Yang-Mills theory. The potential is obtained from Polyakov loop correlators having separations between 0.3 and 1.2 fermi. Measurements were carried out on lattices of spatial extents of about 4 and 5.4 fermi. The temporal extent was 5.4 fermi in both cases. The results are analyzed in terms of the force between a q\bar q pair as well as in terms of a scaled second derivative of the potential. The data is accurate enough to distinguish between different effective string models and it seems to favour the expression for ground state energy of a Nambu-Goto string.Comment: 9 pages in LaTeX with 2 figures and 2 tables in JHEP style. Replaced to match with shortened published versio

A Simple Model for Pulse Profiles from Precessing Pulsars, with Special Application to Relativistic Binary PSR B1913+16

We study the observable pulse profiles that can be generated from precessing pulsars. A novel coordinate system is defined to aid visualization of the observing geometry. Using this system we explore the different families of profiles that can be generated by simple, circularly symmetric beam shapes. An attempt is then made to fit our model to the observations of relativistic binary PSR B1913+16. It is found that while qualitatively similar pulse profiles can be produced, this minimal model is insufficient for an accurate match to the observational data. Consequently, we confirm that the emission beam of PSR B1913+16 must deviate from circular symmetry, as first reported by Weisberg and Taylor. However, the approximate fits obtained suggest that it may be sufficient to consider only minimal deviations from a circular beam in order to explain the data. We also comment on the applicability of our analysis technique to other precessing pulsars, both binary and isolated.Comment: 35 pages and 8 figures. Published versio

Prevalence of HIV Infection among Trauma Patients Admitted to\ud Bugando Medical Centre, Mwanza, Tanzania and its\ud Influence on Outcome

HIV infection, a major health problem worldwide, has been reported to be prevalent in trauma patients, thus presents an occupational hazard to health care workers who care for these patients. The purpose of this study was to establish the prevalence of HIV among trauma patients in our setting and to compare the outcome of these patients who are HIV positive with those who are HIV negative. This was a descriptive cross sectional study involving trauma patients aged 11 years and above, admitted to the surgical wards of Bugando Medical Centre in Mwanza, Tanzania over a six-month period from October 2008 to March 2009. All eligible patients were consecutively enrolled in the study. Data were collected using a pre-tested, coded questionnaire and analyzed using SPSS computer software. A total of 250 trauma patients were recruited and studied. The mean age of the study population was 36.37±15.35. Males accounted for the majority (N=202; 80.8%) of the study population. The prevalence of HIV among trauma patients was 11.6%. Among the HIV positive patients, 26 (89.7%) were males and majority aged 31-40 years. Seventy two percent of HIV positive patients had CD4+ count of ≥ 200 cells/μl. Overall length of hospital stays (LOS) ranged from 1 - 90 days with mean of 19.11 ± 15.84 days. Using multivariate logistic regression, injury severity score (ISS) (P=0.0026), revised trauma scores (RTS) (P= 0.002,), HIV seropositivity (P= 0.0012) and CD4+ count (P= 0.001) were significantly found to be associated with increased LOS. Mortality rate was 10.8% and was significantly associated with; the body region injured (P < 0.05), ISS (P = 0.026), RTS (P = 0.001), PTS (P= 0.01), HIV positivity (P= 0.0001) and CD4+ count (P= 0.035). HIV is prevalent among trauma patients in our setting. A substantial risk of exposure to HIV exists in health workers who care for these patients. Thus, all trauma health care workers in this region need to practice universal barrier precautions in order to reduce the risk of exposure to HIV infection. HIV positive patients with CD4+ count ≥200cells/μl have similar prognosis as HIV negative patients and therefore should be treated the same way

The confining string beyond the free-string approximation in the gauge dual of percolation

We simulate five different systems belonging to the universality class of the gauge dual of three-dimensional random percolation to study the underlying effective string theory at finite temperature. All the data for the finite temperature string tension, when expressed by means of adimensional variables, are nicely described by a unique scaling function. We calculate the first few terms of the string tension up to order $T^6$ and compare to different theoretical predictions. We obtain unambiguous evidence that the coefficients of $T^2$ and $T^4$ terms coincide with those of the Nambu-Goto string, as expected, while the $T^6$ term strongly differs and is characteristic of the universality class of this specific gauge theory.Comment: 13 pages, 3 figure

Testing the ΔS=ΔQ\Delta S=\Delta Q Rule with Exclusive Semi-Leptonic Kaon Decays

We consider the possibility of violations of the selection rule $\Delta S=\Delta Q$ at an appreciable level in {\it exclusive} semi-leptonic decays of Kaons. At $\Phi$-Factories, intense Kaon beams will be available and will probe among others, the semi-leptonic decays $K_{l4}$ and $K_{l3\gamma}$ in addition to $K_{l3}$ and could provide novel testing grounds for the $\Delta S=\Delta Q$ rule. In particular, the branching ratio of $K_{l3\gamma}$ is non-negligible and could be used to probe new phenomena associated with the violation of this selection rule. Furthermore, we modify certain di-lepton event rate ratios and asymmetries and time asymmetries that have been constructed by Dass and Sarma for di-lepton events from Beon decays to test the $\Delta B=\Delta Q$ at the $\Upsilon (4S)$, to the Kaon system at the $\phi(1020)$. We find that the large width of the $K_S$ relative to that of $K_L$ plays an important role in enhancing some of the time asymmetries.Comment: 10 pages, Plain Latex, To be run twice

Effects of Possible ΔB=−ΔQ\Delta B =- \Delta Q Transitions in Neutral BB Meson Decays}

We explore the possibility that the existing data on like-sign dileptons at the $\Upsilon (4S)$ resonance consist of events arising from $B_{d}^0 -\bar B_{d}^0$ mixing and also from $\Delta B = - \Delta Q$ transitions. The consequences of these nonstandard transitions for certain time-asymmetries which are likely to be measured at the $B$ factories are studied.Comment: {\LARGE \bf 10 pages, no figures, process using latex, TIFR/TH/93-5