Showing papers by "University of Rajasthan published in 2006"

ALICE: Physics Performance Report, Volume II

Abstract: ALICE is a general-purpose heavy-ion experiment designed to study the physics of strongly interacting matter and the quark–gluon plasma in nucleus–nucleus collisions at the LHC. It currently involves more than 900 physicists and senior engineers, from both the nuclear and high-energy physics sectors, from over 90 institutions in about 30 countries.The ALICE detector is designed to cope with the highest particle multiplicities above those anticipated for Pb–Pb collisions (dNch/dy up to 8000) and it will be operational at the start-up of the LHC. In addition to heavy systems, the ALICE Collaboration will study collisions of lower-mass ions, which are a means of varying the energy density, and protons (both pp and pA), which primarily provide reference data for the nucleus–nucleus collisions. In addition, the pp data will allow for a number of genuine pp physics studies.The detailed design of the different detector systems has been laid down in a number of Technical Design Reports issued between mid-1998 and the end of 2004. The experiment is currently under construction and will be ready for data taking with both proton and heavy-ion beams at the start-up of the LHC.Since the comprehensive information on detector and physics performance was last published in the ALICE Technical Proposal in 1996, the detector, as well as simulation, reconstruction and analysis software have undergone significant development. The Physics Performance Report (PPR) provides an updated and comprehensive summary of the performance of the various ALICE subsystems, including updates to the Technical Design Reports, as appropriate.The PPR is divided into two volumes. Volume I, published in 2004 (CERN/LHCC 2003-049, ALICE Collaboration 2004 J. Phys. G: Nucl. Part. Phys. 30 1517–1763), contains in four chapters a short theoretical overview and an extensive reference list concerning the physics topics of interest to ALICE, the experimental conditions at the LHC, a short summary and update of the subsystem designs, and a description of the offline framework and Monte Carlo event generators.The present volume, Volume II, contains the majority of the information relevant to the physics performance in proton–proton, proton–nucleus, and nucleus–nucleus collisions. Following an introductory overview, Chapter 5 describes the combined detector performance and the event reconstruction procedures, based on detailed simulations of the individual subsystems. Chapter 6 describes the analysis and physics reach for a representative sample of physics observables, from global event characteristics to hard processes.

Waist circumference cutoff points and action levels for Asian Indians for identification of abdominal obesity.

Abstract: To test the validity of internationally accepted waist circumference (WC) action levels for adult Asian Indians. Analysis of data from multisite cross-sectional epidemiological studies in north India. In all, 2050 adult subjects >18 years of age (883 male and 1167 female subjects). Body mass index (BMI), WC, waist-to-hip circumference ratio, blood pressure, and fasting samples for blood glucose, total cholesterol, serum triglycerides, and high-density lipoprotein cholesterol. In male subjects, a WC cutoff point of 78 cm (sensitivity 74.3%, specificity 68.0%), and in female subjects, a cutoff point of 72 cm (sensitivity 68.7%, specificity 71.8%) were appropriate in identifying those with at least one cardiovascular risk factor and for identifying those with a BMI >21 kg/m2. WC levels of ⩾90 and ⩾80 cm for men and women, respectively, identified high odds ratio for cardiovascular risk factor(s) and BMI level of ⩾25 kg/m2. The current internationally accepted WC cutoff points (102 cm in men and 88 cm in women) showed lower sensitivity and lower correct classification as compared to the WC cutoff points generated in the present study. We propose the following WC action levels for adult Asian Indians: action level 1: men, ⩾78 cm, women, ⩾72 cm; and action level 2: men, ⩾90 cm, women, ⩾80 cm.

Identified baryon and meson distributions at large transverse momenta from Au plus Au collisions at root(S)(NN)=200 GeV

Abstract: Transverse momentum spectra of pi(+/-), p, and (p) over bar p up to 12 GeV/c at midrapidity in centrality selected Au + Au collisions at root s(NN) = 200 GeV are presented. In central Au + Au collisions, both pi(+/-) and p((p) over bar) show significant suppression with respect to binary scaling at p(T) greater than or similar to 4 GeV/c. Protons and antiprotons are less suppressed than pi(+/-), in the range 1.5 less than or similar to p(T) less than or similar to 6 GeV/c. The pi(-)/pi(+) and (p) over bar /p ratios show at most a weak pT dependence and no significant centrality dependence. The p/pi ratios in central Au + Au collisions approach the values in p + p and d + Au collisions at p(T) greater than or similar to 5 GeV/c. The results at high p(T) indicate that the partonic sources of pi(+/-), p, and (p) over bar have similar energy loss when traversing the nuclear medium

Direct observation of dijets in central Au+Au collisions at sNN=200GeV

Abstract: The STAR Collaboration at the Relativistic Heavy Ion Collider reports measurements of azimuthal correlations of high transverse momentum (p(T)) charged hadrons in Au+Au collisions at higher p(T) than reported previously. As p(T) is increased, a narrow, back-to-back peak emerges above the decreasing background, providing a clear dijet signal for all collision centralities studied. Using these correlations, we perform a systematic study of dijet production and suppression in nuclear collisions, providing new constraints on the mechanisms underlying partonic energy loss in dense matter.

Minijet deformation and charge-independent angular correlations on momentum subspace (eta, phi) in Au-Au collisions at root S-NN=130 GeV

Abstract: Measurements of two-particle correlations on angular difference variables η1 − η2 (pseudorapidity) and φ1 − φ2 (azimuth) are presented for all primary charged hadrons with transverse momentum 0.15 ≤ p_t ≤ 2 GeV/c and |η| ≤ 1.3 from Au-Au collisions at √s_(NN) = 130 GeV. Large-amplitude correlations are observed over a broad range in relative angles where distinct structures appear on the same-side and away-side (i.e., relative azimuth less than π/2 or greater than π/2). The principal correlation structures include that associated with elliptic flow plus a strong, same-side peak. It is hypothesized that the latter results from correlated hadrons associated with semi-hard parton scattering in the early stage of the heavy-ion collision which produces a jet-like correlation peak at small relative angles. The width of the jet-like peak on η1 − η2 increases by a factor 2.3 from peripheral to central collisions, suggesting strong coupling of semi-hard scattered partons to a longitudinally-expanding medium. The new methods of jet analysis introduced here provide access to scattered partons at low transverse momentum well below the kinematic range where perturbative quantum chromodynamics and standard fragmentation models are applicable.

Forward neutral pion production in p+p and d+Au collisions at root(S)(NN)=200 GeV

Abstract: Measurements of the production of forward pi(0) mesons from p+p and d+Au collisions at root s(NN) = 200 GeV are reported. The p+p yield generally agrees with next-to-leading order perturbative QCD calculations. The d+Au yield per binary collision is suppressed as eta increases, decreasing to similar to 30% of the p+p yield at =4.00, well below shadowing expectations. Exploratory measurements of azimuthal correlations of the forward pi(0) with charged hadrons at eta approximate to 0 show a recoil peak in p+p that is suppressed in d+Au at low pion energy. These observations are qualitatively consistent with a saturation picture of the low-x gluon structure of heavy nuclei.

Longitudinal double-spin asymmetry and cross section for inclusive jet production in polarized proton collisions at s=200GeV

Abstract: We report a measurement of the longitudinal double-spin asymmetry A(LL) and the differential cross section for inclusive midrapidity jet production in polarized proton collisions at s=200 GeV. The cross section data cover transverse momenta 5 < p(T)< 50 GeV/c and agree with next-to-leading order perturbative QCD evaluations. The A(LL) data cover 5 < p(T)< 17 GeV/c and disfavor at 98% C.L. maximal positive gluon polarization in the polarized nucleon.

Discriminating four tectonic settings: Five new geochemical diagrams for basic and ultrabasic volcanic rocks based on log-ratio transformation of major-element data

Abstract: We present five new discriminant function diagrams based on an extensive database representative of basic and ultrabasic rocks from four tectonic settings of island arc, continental rift, ocean-island, and mid-ocean ridge. These diagrams were obtained after loge-transformation of concentration ratios of major-elements — a technique recommended for a correct statistical treatment of compositional data. Higher % success rates (overall values from ∼ 83 to 97%) were obtained for proposing these new diagrams as compared to those (∼82 to 94%) obtained from the discriminant analysis of the raw major-element concentration data (i.e., without the loge-transformation and without taking ratios of the compositional data, but using exactly the same database to provide an unbiased comparison), suggesting that such a data transformation constitutes a statistically correct and recommended technique. The new diagrams also resulted in less mis-classification of basic and ultrabasic rocks from known tectonic settings than the diagrams obtained from the raw data. The use of these highly successful new discriminant function diagrams is illustrated using Miocene to Recent basic and ultrabasic rocks from three areas of Mexico with complex or controversial tectonic settings (Mexican Volcanic Belt, Los Tuxtlas volcanic field, and Eastern Alkaline Province), as well as older rocks from three areas (Deccan, Malani, and Bastar) of India. Additionally, the major-element data from two ‘known’ continental arc settings are used to show that they are similar to those from the island arc setting. Continental rift setting is inferred for all Mexican cases and for one cratonic area of India (Malani) and an IAB setting for the Bastar craton. The Deccan flood basalt province of India is used to warn against an indiscriminate use of those discrimination diagrams that do not explicitly include the likely setting of the area under evaluation. An Excel template is also provided for an easy application of these new diagrams for discriminating the four settings considered in this work.

Some relationships between the generalized Apostol–Bernoulli polynomials and Hurwitz–Lerch Zeta functions

Abstract: The main object of this paper is to further investigate the generalized Apostol–Bernoulli polynomials of higher order, which were introduced and studied recently by Luo and Srivastava [2005, Journal of Mathematical Analysis and Applications, 308, 290–302; 2006, Computers and Mathematics with Applications, 51, 631–642]. Here, we first derive an explicit representation of these generalized Apostol–Bernoulli polynomials of higher order in terms of a generalization of the Hurwitz–Lerch Zeta function and then proceed to establish a functional relationship between the generalized Apostol–Bernoulli polynomials of rational arguments and the Hurwitz (or generalized) Zeta function. Our results would provide extensions of those given earlier by (for example) Apostol [1951, Pacific Journal of Mathematics, 1, 161–167] and Srivastava [2000, Mathematical Proceedings of the Cambridge Philosophical Society, 129, 77–84].

Strange baryon resonance production in sNN=200GeV p+p and Au+Au collisions

Abstract: We report the measurements of Σ(1385) and Λ(1520) production in p+p and Au+Au collisions at √sNN=200 GeV from the STAR Collaboration. The yields and the p_T spectra are presented and discussed in terms of chemical and thermal freeze-out conditions and compared to model predictions. Thermal and microscopic models do not adequately describe the yields of all the resonances produced in central Au+Au collisions. Our results indicate that there may be a time span between chemical and thermal freeze-out during which elastic hadronic interactions occur.

Animals and their products utilized as medicines by the inhabitants surrounding the Ranthambhore National Park, India.

Abstract: The present ethnozoological study describes the traditional knowledge related to the use of different animals and animal-derived products as medicines by the inhabitants of villages surrounding the Ranthambhore National Park of India (Bawaria, Mogya, Meena), which is well known for its very rich biodiversity. The field survey was conducted from May to July 2005 by performing interviews through structured questionnaires with 24 informants (16 men and 8 women), who provided information regarding therapeutic uses of animals. A total of 15 animals and animal products were recorded and they are used for different ethnomedical purposes, including tuberculosis, asthma, paralysis, jaundice, earache, constipation, weakness, snake poisoning. The zootherapeutic knowledge was mostly based on domestic animals, but some protected species like the collared dove (Streptopelia sp.), hard shelled turtle (Kachuga tentoria), sambhar (Cervus unicolor) were also mentioned as important medicinal resources. We would suggest that this kind of neglected traditional knowledge should be included into the strategies of conservation and management of faunistic resources in the investigated area.

Ion-acoustic dressed solitons in a dusty plasma

Abstract: Using the reductive perturbation method, equations for ion-acoustic waves governing the evolution of first- and second-order potentials in a dusty plasma including the dynamics of charged dust grains have been derived. The renormalization procedure of Kodama and Taniuti is used to obtain a steady state nonsecular solution of these equations. The variation of velocity and width of the Korteweg-de Vries (KdV) as well as dressed solitons with amplitude have been studied for different concentrations and charge multiplicity of dust grains. The higher-order perturbation corrections to the KdV soliton description significantly affect the characteristics of the solitons in dusty plasma. It is found that in the presence of positively charged dust grains the system supports only compressive solitons. However, the plasma with negatively charged dust grains can support compressive solitons only up to a certain concentration of dust. Above this critical concentration of negative charge, the dusty plasma can support rarefactive solitons. An expression for the critical concentration of negatively charged dust in terms of charge and mass ratio of dust grains with plasma ions is also derived.

Anticancer and antimutagenic properties of Acacia nilotica (Linn.) on 7,12-dimethylbenz(a)anthracene-induced skin papillomagenesis in Swiss albino mice.

Abstract: We report the chemopreventive activity of Acacia nilotica (Linn.) gum, flower and leaf aqueous extracts, on 7,12-dimethylbenz(a)anthracene (DMBA) induced skin papillomagenesis in male Swiss albino mice. Animals were divided into following groups: Group I (Controls) given DMBA and croton oil, with no extract ; Group II (treatment) animals treated with Acacia nilotica gum (Group II-a) (800 mg/kg body weight), flowers (Group II-b) (800 mg/kg body weight), or leaves (Group II-c) (800 mg/kg body weight) during the peri- and post initiation periods of DMBA and croton oil application. A significant reduction in the values of tumor burden, tumor incidence and cumulative number of papillomas was observed in mice treated by oral gavage with the Acacia nilotica gum, flower and leaf extracts as compared with the control group. The latency period in treatment Group-II (b) and Group-II (c) was significantly increased as compared with the control group. A significant reduction in the frequency of micronuclei was also observed in mice treated by oral gavage with the aqueous extracts, along with significant decrease in total chromosomal aberrations in the form of chromatid breaks, chromosome breaks, centric rings, dicentrics, acentric fragments and exchange. Treatment with Acacia nilotica flower (Group II-B) and leaf (Group II-C) aqueous extracts by oral gavage for 15 days resulted in a highly significant decrease in the lipid peroxidation (LPO) level in the liver, but this was less evident with the gum (Group II-A) . Conversely, reduced glutathione (GSH) content was observed to be significantly elevated as compared with the control group with leaves (Group II-C) and flowers (Group II-B). The chemopreventive and antimutagenic activity of the leaf extract of Acacia nilotica was most significant followed by the flower extract and then by gum.

Prophylactic Action of Linseed (Linum usitatissimum) Oil Against Cyclophosphamide-Induced Oxidative Stress in Mouse Brain

Abstract: The present study is a pilot study that explores the antioxidative properties of linseed (Linum usitatissimum) oil in its prophylactic action against oxidative stress induced by a radiomimetic drug, cyclophosphamide. Oral administration of linseed oil (0.1 mL/kg of body weight/day) for 20 days prior to an acute dose of cyclophosphamide (75 mg/kg) significantly inhibited the augmented level of malondialdehyde, conjugated dienes, and hydroperoxides in the mouse brain. The cyclophosphamide- induced decline in the levels of reduced glutathione, glutathione peroxidase, and alkaline phosphatase was also significantly prevented by linseed oil in mouse blood. Similarly, the increased activity of acid phosphatase and oxidized glutathione was significantly inhibited by linseed oil. Results clearly indicate the prophylactic action of linseed oil against cyclophosphamide- induced oxidative stress.

Bianchi Type I Magnetized String Cosmological Model in General Relativity

Abstract: Bianchi Type I magnetized string cosmological model following the techniques used by Letelier and Stachel, is investigated. To get a determinate model, we assume a condition ∊ = λ (geometric string) where ∊ is the rest energy density, λ the string tension density and expansion (θ) is proportional to eigen value σ11 of shear tensor (σ ji), which leads to A = l (BC)n where A, B, C are metric potentials and l and n are constants. The behaviour of the model in presence and absence of magnetic field is discussed. The physical and geometrical aspects of the model are also discussed.

Transverse-momentum p(t) correlations on (eta, phi) from mean-p(t) fluctuations in Au-Au collisions at root(s)(NN)=200 GeV

Abstract: We present first measurements of the pseudorapidity and azimuth (?, ) bin-size dependence of event-wise mean transverse-momentum pt fluctuations for Au?Au collisions at GeV. We invert that dependence to obtain pt autocorrelations on differences (??, ?) interpreted to represent velocity/temperature distributions on (?, ). The general form of the autocorrelations suggests that the basic correlation mechanism is parton fragmentation. The autocorrelations vary rapidly with collision centrality, which suggests that fragmentation is strongly modified by a dissipative medium in the more central Au?Au collisions relative to peripheral or p?p collisions.

Protective effects of Mentha piperita Linn on benzo[a]pyrene-induced lung carcinogenicity and mutagenicity in Swiss albino mice.

Abstract: The chemopreventive and antimutagenic effects of an aqueous extract of Mentha piperita leaves were evaluated by using 9 week medium term model of benzo[a]pyrene (BP)-induced lung tumors. Lung tumors were induced by a single subcutaneous injection in the scapular region with BP in newborn Swiss albino mice (<24 h old). The oral administration of Mentha extract (ME) showed a significant reduction in the number of lung tumors from an incidence of 67.92% in animals given only BP to 26.31%. The inhibition rate was 61.26% in ME treated group with respect to reference group (BP-alone). However, tumor multiplicity was reduced from 0.83 in the BP-alone group to 0.31 in the BP+ME group. Also, ME treatment reduced the frequency of BP-induced chromosomal aberrations and micronuclei in bone marrow cells and decreased the levels of lipoperoxides and increased sulfhydryl groups in liver as well as lung. In cell-free assays, ME showed strong scavenging activity for both the DPPH* and ABTS*+ radicals. ME had an IC50 value of 272 microg/ml in the DPPH* assay. The chemopreventive action and antimutagenic effects observed in the present study is attributed to the antioxidative and radical scavenging properties of ME.

Multiplicity dependence of inclusive pt spectra from p-p collisions at s=200GeV

Abstract: We report measurements of transverse momentum p(t) spectra for ten event multiplicity classes of p-p collisions at root s=200 GeV. By analyzing the multiplicity dependence we find that the spectrum shape can be decomposed into a part with amplitude proportional to multiplicity and described by a Levy distribution on transverse mass m(t), and a part with amplitude proportional to multiplicity squared and described by a Gaussian distribution on transverse rapidity y(t). The functional forms of the two parts are nearly independent of event multiplicity. The two parts can be identified with the soft and hard components of a two-component model of p-p collisions. This analysis then provides the first isolation of the hard component of the p(t) spectrum as a distribution of simple form on y(t).

Proton-Lambda correlations in central Au+Au collisions at root s(NN)=200 GeV

Abstract: We report on p-Lambda, p-(Lambda) over bar, (p) over bar-Lambda, and (p) over bar-(Lambda) over bar correlation functions constructed in central Au-Au collisions at root s(NN) = 200 GeV by the STAR experiment at RHIC. The proton and lambda source size is inferred from the p-Lambda and (p) over bar-(Lambda) over bar correlation functions. It is found to be smaller than the pion source size also measured by the STAR experiment at smaller transverse masses, in agreement with a scenario of a strong universal collective flow. The p-(Lambda) over bar and (p) over bar-Lambda correlation functions, which are measured for the first time, exhibit a large anticorrelation. Annihilation channels and/or a negative real part of the spin-averaged scattering length must be included in the final-state interactions calculation to reproduce the measured correlation function.

Optical properties of CdS sintered film

Abstract: Chemical method has been used to prepare cadmium sulphide by using cadmium, hydrochloric acid and H2S. The reflection spectra of covered and uncovered sintered films of CdS have been recorded by ‘Hitachi spectrophotometer’ over the wavelength range 300–700 nm. The energy band gaps of these films have been calculated from reflection spectra. It is found that the energy band gap of both films is same as 2.41 eV. It is indicated that energy band gap of these films does not change. This value of band gap is in good agreement with the value reported by other workers. The measurement of photocurrent has also been carried out using Keithley High Resistance meter/ Electrometer. This film shows the high photosensitivity and high photocurrent decay. Thus so obtained films are suitable for fabrication of photo detectors and solar cells.

Analytical study of heavy metals of industrial effluents at Jaipur, Rajasthan (India).

Abstract: Heavy metals contamination has been recognized as a major environmental concern due to their pervasiveness and persistence. These heavy metals are not biodegradable, hence there is a need to develop such a remediation technique, which should be efficient, economical and rapidly deployable in a wide range of physical settings. For the characterization of heavy metals of various industrial effluents, some heavy metals, like Arsenic, Cadmium, Chromium, Copper, Iron, Manganese, Nickel, Lead and Zinc were analyzed. The results exhibited that As, Cd, Cr and Pb were not found in any studied wastewater samples, while some of the following heavy metals ranged from: Cu (0.0 - 1.0 mg/L), Fe (0.1 - 0.4 mg/L), Mn (0.0 - 0.4 mg/L), Ni (0.01 - 0.07 mg/L) and Zn (0.68 - 60.84 mg/L). Copper, Iron, Manganese and Zinc were found above the standard limit recommended by IS: 3307 (1977). However, Nickel was found below the regulated safety values for all studied samples.

Multiplicity and pseudorapidity distributions of charged particles and photons at forward pseudorapidity in Au plus Au collisons at root s(NN)=62.4 GeV

Abstract: We present the centrality-dependent measurement of multiplicity and pseudorapidity distributions of charged particles and photons in Au+Au collisions at √s_(NN) = 62.4 GeV. The charged particles and photons are measured in the pseudorapidity region 2.9 ≤ η ≤ 3.9 and 2.3 ≤ η ≤ 3.7, respectively. We have studied the scaling of particle production with the number of participating nucleons and the number of binary collisions. The photon and charged particle production in the measured pseudorapidity range has been shown to be consistent with energy-independent limiting fragmentation behavior. Photons are observed to follow a centrality-independent limiting fragmentation behavior, while for charged particles it is centrality dependent. We have carried out a comparative study of the pseudorapidity distributions of positively charged hadrons, negatively charged hadrons, photons, pions, and net protons in nucleus-nucleus collisions and pseudorapidity distributions from p+p collisions. From these comparisons, we conclude that baryons in the inclusive charged particle distribution are responsible for the observed centrality dependence of limiting fragmentation. The mesons are found to follow an energy-independent behavior of limiting fragmentation, whereas the behavior of baryons is energy dependent.

Neutral kaon interferometry in Au+Au collisions at sNN=200 GeV

Abstract: We present the first statistically meaningful results fromtwo-K0s interferometry in heavy-ion collisions. A model that takes theeffect of the strong interaction into account has been used to fit themeasured correlation function. The effects of single and coupled channelwere explored. At the mean transverse mass m_T = 1.07 GeV, we obtain thevalues R = 4.09 +- 0.46 (stat.) +- 0.31 (sys) fm and lambda = 0.92 +-0.23 (stat) +- 0.13 (sys), where R and lambda are the invariant radiusand chaoticity parameters respectively. The results are qualitativelyconsistent with m_T systematics established with pions in a scenariocharacterized by a strong collective flow.