Nonfactorization in Hadronic Two-body Cabibbo-favored decays of D^0 and D^+

With the inclusion of nonfactorized amplitudes in a scheme with $N_c=3$, we have studied Cabibbo-favored decays of $D^0$ and $D^+$ into two-body hadronic states involving two isospins in the final state. We have shown that it is possible to understand the measured branching ratios and determined the sizes and signs of nonfactorized amplitudes required.Comment: 15 pages, Late

Large Direct CP Violation in B^0 -> pi^+ pi^- and an Enhanced Branching Ratio for B^0 -> pi^0 pi^0

Recent measurements of B^0 -> pi pi decays reveal two features that are in conflict with conventional calculations: the channel B^0 (Bbar^0) -> pi^+ pi^- shows a large direct CP-violating asymmetry, and the channel B^0 (B^0) -> pi^0 pi^0 has an unexpectedly high branching ratio. We show that both features can be understood in terms of strong-interaction mixing of pi pi and D Dbar channels in the isospin-zero state, an effect that is important because of the large experimentally observed ratio Gamma(B^0 / Bbar^0 -> D^+ D^-) / Gamma (B^0 / Bbar^0 -> pi^+ pi^-) approx. 50. Our dynamical model correlates the branching ratios and the CP-violating parameters C and S, for the decays B^0 (Bbar^0) -> pi^+ pi^-, B^0 (Bbar^0) -> pi^0 pi^0, B^0 (Bbar^0) -> D^+ D^- and B^0 (Bbar^0) -> D^0 Dbar^0.Comment: 10 pages, 2 figures, 1 table; v2: Misprint corrected in Eq. (12), second line: -a_m replaced by +a_m. To appear in Phys. Lett.

Inelastic Final-State Interactions and Two-body Hadronic B decays into Single-Isospin channels

The role of inelastic final-state interactions in CP asymmetries and branching ratios is investigated in certain chosen single isospin two-body hadronic B decays. Treating final-state interactions through Pomeron and Regge exchanges, we demonstrate that inelastic final state interactions could lead to sizeable effects on the CP asymmetry.Comment: 23 pages, Latex, 1 eps-figur

Bolometric technique for high-resolution broadband microwave spectroscopy of ultra-low-loss samples

A novel low temperature bolometric method has been devised and implemented for high-precision measurements of the microwave surface resistance of small single-crystal platelet samples having very low absorption, as a continuous function of frequency. The key to the success of this non-resonant method is the in-situ use of a normal metal reference sample that calibrates the absolute rf field strength. The sample temperature can be controlled independently of the 1.2 K liquid helium bath, allowing for measurements of the temperature evolution of the absorption. However, the instrument's sensitivity decreases at higher temperatures, placing a limit on the useful temperature range. Using this method, the minimum detectable power at 1.3 K is 1.5 pW, corresponding to a surface resistance sensitivity of $\approx$1 $\mu\Omega$ for a typical 1 mm$\times$1 mm platelet sample.Comment: 13 pages, 12 figures, submitted to Review of Scientific Instrument

Atomic and Nuclear Effects in the Slow-Neutron Total Cross Section of Terbium

The total cross section of terbium has been measured for neutron energies En from 0.003 to 1.78 eV. For neutron energies above the Be cutoff a new method employing two crystal monochromators in series was used. For En ≲ 0.005 eV a single-crystal monochromator in conjunction with a Be filter was employed. Using earlier measurements of the radiative-capture cross section, the experimental results have been analyzed to include the contributions due to paramagnetic scattering, coherent scattering, and phonon effects. The analysis shows that the experiment and the calculations are consistent everywhere except 0.015 ≲ En ≲ 0.10 eV. In this energy range inelastic coherent scattering is not accurately accounted for with the use of Placzek\u27s incoherent approximations. In addition crystalline-field effects give rise to further complications. The comparison between the experiment and the calculations for 0.015 ≲ En ≲ 0.10 eV suggests that studies of coherent inelastic scattering and crystalline-field effects in terbium metal are needed. The experimental results for En ≳ 0.12 eV yield the potential scattering cross section as 7.5 ± 0.5 b. This corresponds to a spin-independent nuclear radius of 7.73 ± 0.27 fm and to a radius parameter of 1.43 ± 0.05 fm. The results suggest that the incoherent scattering cross section, if present, is very small (≲ 1.0 b)

Nonet Symmetry and Two-Body Decays of Charmed Mesons

The decay of charmed mesons into pseudoscalar (P) and vector (V) mesons is studied in the context of nonet symmetry. We have found that it is badly broken in the PP channels and in the P sector of the PV channels as expected from the non-ideal mixing of the \eta and the \eta'. In the VV channels, it is also found that nonet symmetry does not describe the data well. We have found that this discrepancy cannot be attributed entirely to SU(3) breaking at the usual level of 20--30%. At least one, or both, of nonet and SU(3) symmetry must be very badly broken. The possibility of resolving the problem in the future is also discussed.Comment: 9 pages, UTAPHY-HEP-

Resonant Two-body D Decays

The contribution of a $K^*(1430)$ $0^+$ resonance to $D^0\to K^-\pi^+$ is calculated by applying the soft pion theorem to $D^+ \to K^* \pi^+$, and is found to be about 30% of the measured amplitude and to be larger than the $\Delta I=3/2$ component of this amplitude. We estimate a 70% contribution to the total amplitude from a higher $K^*(1950)$ resonance. This implies large deviations from factorization in D decay amplitudes, a lifetime difference between D^0 and D^+, and an enhancement of $D^0-\bar D^0$ mixing due to SU(3) breaking.Comment: To be published in Physical Review Letters, some corrections, references update

Electro-Grid Security System Automation

Providing Security is primary concern in a living area. Electro-grid Security System Automation is an idea about providing security to the electric grid system. When the transmission line is affected immediately the flow of current will be terminated by the security module in an automated way.The process consists of an alert module along with the power cut module. The security system will check the flow of current for every interval of time as well as in abnormal situations. If any natural calamities affect the transmission line, the responsible person gets the alert and the flow of current termination occurs instantly

Effect of Low Dose Dexmedetomidine or Clonidine on the characteristics of Bupivacaine Spinal Block

INTRODUCTION: Transurethral Resection Of Prostate (TURP) is the surgical procedure done for benign prostatic hypertrophy. The standard anaesthetic technique for TURP is subarachnoid block1. Lignocaine and Bupivacaine are the local anaesthetic drugs used to achieve the subarachnoid block. Adjuvants are a different pharmacological class of drugs, which are used to enhance and prolong analgesia, to lower the dose requirements and to reduce the dose dependent side effects. Many drugs have been tried as spinal adjuvants. They are Opioids, Sodium bicarbonate, Ketamine, Neostigmine, Midazolam, Clonidine and the latest inclusion is Dexmedetomidine. Initially opioids have been the standard choice as spinal adjuvant. But since there were many side effects and complications like early and late depression of ventilation, pruritus, nausea, vomiting, urinary retention, central nervous system excitation, delayed gastric emptying and ocular dysfunction, there is an active search for an alternative ideal adjuvant which is devoid of these side effects and complications. Preservative free Dexmedetomidine when administered into subarachnoid space produce analgesia. Activation of post synaptic alpha 2 receptors in the substantia gelatinosa of the spinal cord is the presumed mechanism by which it produces analgesia. Dexmedetomidine at appropriate doses when used as an adjuvant with Bupivacaine in subarachnoid block seems to prolong the duration of surgical anaesthesia and postoperative analgesia. The side effects like dry mouth, hypotension, bradycardia, are not usual in this dose. The added advantages are sedation and prevent shivering. Both Clonidine and Dexmedetomidine belong to the same group, α2 agonists. They cause sedation and analgesia, in that Dexmedetomidine produces more analgesia and sedation because of its high selectivity to α2A receptor compared to Clonidine. This study has been taken to compare Dexmedetomidine as well as Clonidine as spinal adjuvants with Bupivacaine. AIM OF THE STUDY: The aim of this study is to compare the onset and duration of sensory and motor block, hemodynamic changes and level of sedation following intrathecal Bupivacaine supplemented with either Dexmedetomidine or Clonidine. MATERIALS AND METHODS: After getting the ethical committee approval the study was conducted in 60 patients undergoing elective TURP surgeries. It was a double blinded study in which patients were randomly allocated into three groups A, B and C by using the computer based randomization. After getting informed consent and explaining the procedure details to the patients, the anaesthetic technique was performed. Inclusion Criteria: 1. Grade I prostatic hypertrophy with duration of surgery less than one hour, 2. Age 50 – 70 years, 3. ASA I and II. Exclusion Criteria : 1. Patient refusal, 2. ASA III & IV patients, 3. Known case of diabetics mellitus and hypertension, 4. Spinal deformity, 5. H/o drug allergy. Statistical Tools: The information collected from the study was documented in a Master Chart. Data analysis was done with the help of computer using Epidemiological Information Package (EPI 2008). Using this software range, frequencies, percentages, means, standard deviations and ‘p’ values were calculated. ANNOVA t test was used to test the significance of difference between quantitative variables. A 'p' value of less than 0.05 is taken to denote significant relationship. SUMMARY: This is a randomized double blinded study conducted in 60 patients of ASA I and II undergoing elective transurethral resection of prostate (TURP) surgeries. Patients were allocated in three groups. Group A (Bupivacaine + sterile normal saline as placibo), Group B (Bupivacaine + Clonindine 30Kg), Group C (Bupivacaine + Dexmedetomidine 5Kg). Parameters observed were time of onset of sensory block, time of onset of motor block, two segment regression time, duration of motor blockade, duration of sensory blockade, sedation score, duration of post operative analgesia, haemodynamic changes and side effects. 1. The post operative analgesia was significantly prolonged in Group C and was 364 minutes more than the Group A and 121.5 minutes more than Group B. 2. The systolic blood pressure dropped during the early anaesthetic period but the fall was within the 30 percentage of basal systolic blood pressure. 3. There was no significant fall in pulse rate in all Group A, Group B, and Group C. 4. No Sedation were observed in all three groups, but patient was comfortable, co-operative, oriented and calm. 5. Neither respiratory depression nor decrease in saturation was observed in any of the group. CONCLUSION: (i) Adding 30Kg Clonidine or 5Kg Dexmedetomidine to 10mg of Bupivacaine significantly prolongs the duration of post operative analgesia when compare to Bupivacaine alone in elective transurethral resection of prostate (TURP) surgeries. (ii) Bupivacaine with Dexmedetomidine prolongs significantly the duration of post operative analgesia when compared to Bupivacaine with Clonidine in spinal anaesthesia. (iii) Bupivacaine when used alone or with adjuants like Clonidine (30Kg) or Dexmedetomidine (5Kg) does not produce any appreciable side effects