Study of the Λ–Λ interaction with femtoscopy correlations in p p and p–Pb collisions at the LHC

Acharya, S.,Adamová,, D.,Adhya, S.P.,Adler, A.,Adolfsson, J.,Aggarwal, M.M.,Aglieri Rinella, G.,Agnello, M.,Agrawal, N.,Ahammed, Z.,Ahmad, S.,Ahn, S.U.,Aiola, S.,Akindinov, A.,Al-Turany, M.,Alam North-Holland Pub. Co 2019 Physics letters. Section B Vol.797 No.-

<P><B>Abstract</B></P> <P>This work presents new constraints on the existence and the binding energy of a possible Λ–Λ bound state, the H-dibaryon, derived from Λ–Λ femtoscopic measurements by the ALICE collaboration. The results are obtained from a new measurement using the femtoscopy technique in ▪ collisions at s = 13 TeV and p – Pb collisions at <SUB> s NN </SUB> = 5.02 TeV, combined with previously published results from ▪ collisions at s = 7 TeV. The Λ–Λ scattering parameter space, spanned by the inverse scattering length f 0 − 1 and the effective range <SUB> d 0 </SUB> , is constrained by comparing the measured Λ–Λ correlation function with calculations obtained within the Lednický model. The data are compatible with hypernuclei results and lattice computations, both predicting a shallow attractive interaction, and permit to test different theoretical approaches describing the Λ–Λ interaction. The region in the ( f 0 − 1 , <SUB> d 0 </SUB> ) plane which would accommodate a Λ–Λ bound state is substantially restricted compared to previous studies. The binding energy of the possible Λ–Λ bound state is estimated within an effective-range expansion approach and is found to be <SUB> B Λ Λ </SUB> = 3.2 − 2.4 + 1.6 (stat) − 1.0 + 1.8 (syst) MeV.</P>

H Λ 3 and H ‾ Λ ‾ 3 lifetime measurement in Pb–Pb collisions at _{s NN} = 5.02 TeV via two-body decay

Acharya, S.,Adamová,, D.,Adhya, S.P.,Adler, A.,Adolfsson, J.,Aggarwal, M.M.,Aglieri Rinella, G.,Agnello, M.,Agrawal, N.,Ahammed, Z.,Ahmad, S.,Ahn, S.U.,Akindinov, A.,Al-Turany, M.,Alam, S.N.,Alb Elsevier 2019 Physics letters: B Vol.797 No.-

<P><B>Abstract</B></P> <P>An improved value for the lifetime of the (anti-)hypertriton has been obtained using the data sample of Pb–Pb collisions at <SUB> s NN </SUB> = 5.02 TeV collected by the ALICE experiment at the LHC. The (anti-)hypertriton has been reconstructed via its charged two-body mesonic decay channel and the lifetime has been determined from an exponential fit to the d<I>N</I>/d(<I>ct</I>) spectrum. The measured value, τ = 242 − 38 + 34 (stat.) ± 17 (syst.) ps, is compatible with representative theoretical predictions, thus contributing to the solution of the longstanding hypertriton lifetime puzzle.</P>

X-RAY ASTRONOMY EXPERIMENT ON THE INDIAN SATELLITE IRS-P3

AGRAWAL P. C.,PAUL B.,RAO A. R.,SHAH M. R.,MCKERJEE K.,VARIA M. N.,YADAV J. S.,DEDHIA D. K.,MALKAR J. P.,SHAH P.,DAMLE S. V.,MARAR T. M. K.,SEETHA S. The Korean Astronomical Society 1996 Journal of The Korean Astronomical Society Vol.29 No.suppl1

An x-ray astronomy experiment consisting of three collimated proportional counters and an X-ray Sky Monitor (XSM) was flown aboard the Indian Satellite IRS-P3 launched on March 21, 1996 from SHAR range in India. The Satellite is in a circular orbit of 830 km altitude with an orbital inclination of $98^{\circ}$ and has three axis stabilized pointing capability. Each pointed-mode Proportional Counter (PPC) is a multilayer, multianode unit filled with P-10 gas ($90\%$ Ar + $10\%\;CH_4$) at 800 torr and having an aluminized mylar window of 25 micron thickness. The three PPCs are identical and have a field of view of $2^{\circ}{\times}2^{\circ}$ defined by silver coated aluminium honeycomb collimators. The total effective area of the three PPCs is about 1200 $cm^2$. The PPCs are sensitive in 2-20 keV band. The XSM consists of a pin-hole of 1 $cm^2$ area placed 16 cm above the anode plane of a 32 cm$\times$32 cm position sensitive proportional counter sensitive in 3-8 keV interval. The position of the x-ray events is determined by charge division technique using nichrome wires as anodes. The principal objective of this experiment is to carry out timing studies of x-ray pulsars, x-ray binaries and other rapidly varying x-ray sources. The XSM will be used to detect transient x-ray sources and monitor intensity of bright x-ray binaries. Observations of black-hole binary Cyg X-1 and few other binary sources were carried out in early May and July-August 1996 period. Details of the x-ray detector characteristics are presented and preliminary results from the observations are discussed.

Measurement of jet radial profiles in Pb–Pb collisions at _{s NN} = 2.76 TeV

Acharya, S.,Adamová,, D.,Adhya, S.P.,Adler, A.,Adolfsson, J.,Aggarwal, M.M.,Aglieri Rinella, G.,Agnello, M.,Agrawal, N.,Ahammed, Z.,Ahmad, S.,Ahn, S.U.,Aiola, S.,Akindinov, A.,Al-Turany, M.,Alam North-Holland Pub. Co 2019 Physics letters. Section B Vol.796 No.-

<P><B>Abstract</B></P> <P>The jet radial structure and particle transverse momentum ( <SUB> p T </SUB> ) composition within jets are presented in centrality-selected Pb–Pb collisions at <SUB> s NN </SUB> = 2.76 TeV. Track-based jets, which are also called charged jets, were reconstructed with a resolution parameter of R = 0.3 at midrapidity | <SUB> η ch jet </SUB> | < 0.6 for transverse momenta <SUB> p T , ch jet </SUB> = 30 –120 GeV/<I>c</I>. Jet–hadron correlations in relative azimuth and pseudorapidity space ( Δ φ , Δ η ) are measured to study the distribution of the associated particles around the jet axis for different <SUB> p T , assoc </SUB> -ranges between 1 and 20 GeV/<I>c</I>. The data in Pb–Pb collisions are compared to reference distributions for pp collisions, obtained using embedded PYTHIA simulations. The number of high- <SUB> p T </SUB> associate particles ( 4 < <SUB> p T , assoc </SUB> < 20 GeV/<I>c</I>) in Pb–Pb collisions is found to be suppressed compared to the reference by 30 to 10%, depending on centrality. The radial particle distribution relative to the jet axis shows a moderate modification in Pb–Pb collisions with respect to PYTHIA. High- <SUB> p T </SUB> associate particles are slightly more collimated in Pb–Pb collisions compared to the reference, while low- <SUB> p T </SUB> associate particles tend to be broadened. The results, which are presented for the first time down to <SUB> p T , ch jet </SUB> = 30 GeV/<I>c</I> in Pb–Pb collisions, are compatible with both previous jet–hadron-related measurements from the CMS Collaboration and jet shape measurements from the ALICE Collaboration at higher <SUB> p T </SUB> , and add further support for the established picture of in-medium parton energy loss.</P>

Coherent J/<i>ψ</i> photoproduction at forward rapidity in ultra-peripheral Pb–Pb collisions at _{s NN} = 5.02 TeV

Acharya, S.,Adamová,, D.,Adhya, S.P.,Adler, A.,Adolfsson, J.,Aggarwal, M.M.,Aglieri Rinella, G.,Agnello, M.,Agrawal, N.,Ahammed, Z.,Ahmad, S.,Ahn, S.U.,Aiola, S.,Akindinov, A.,Al-Turany, M.,Alam North-Holland Pub. Co 2019 Physics letters. Section B Vol.798 No.-

<P><B>Abstract</B></P> <P>The ALICE collaboration performed the first rapidity-differential measurement of coherent J / ψ photoproduction in ultra-peripheral Pb–Pb collisions at a center-of-mass energy <SUB> s NN </SUB> = 5.02 TeV. The J / ψ is detected via its dimuon decay in the forward rapidity region ( − 4.0 < y < − 2.5 ) for events where the hadronic activity is required to be minimal. The analysis is based on an event sample corresponding to an integrated luminosity of about 750 μb<SUP>−1</SUP>. The cross section for coherent J / ψ production is presented in six rapidity bins. The results are compared with theoretical models for coherent J / ψ photoproduction. These comparisons indicate that gluon shadowing effects play a role in the photoproduction process. The ratio of <SUP> ψ ′ </SUP> to J / ψ coherent photoproduction cross sections was measured and found to be consistent with that measured for photoproduction off protons.</P>

The Kinetics and Mechanism for the Oxidation of Nicotinic Acid by Peroxomonosulfate in Acidic Aqueous Medium

Agrawal, Anju,Sailani, Riya,Gupta, Beena,Khandelwal, C.L.,Sharma, P.D. Korean Chemical Society 2012 대한화학회지 Vol.56 No.2

The kinetics of oxidation of nicotinic acid by peroxomonosulfate (PMS) has been studied in acetate buffers. Stoichiometry of the reaction corresponds to the reaction of one mole of the oxidant with a mole of nicotinic acid. N${\rightarrow}$O product has been confirmed both by UV visible and IR spectroscopy. The reaction is second order viz. first order with respect to each reactant. Activation parameters have also been evaluated. A plausible reaction mechanism is mentioned and the derived kinetic rate law accounts for experimental observations.

QUANTIFICATION OF β-GALACTOSIDASE TO MEASURE INTESTINAL DAMAGE IN ROTAVIRUS INFECTED CALVES

Agrawal, D.K.,Singh, N.P. Asian Australasian Association of Animal Productio 1993 Animal Bioscience Vol.6 No.3

Quantitative ${\beta}$-galactosidase estimation in the intestinal mucosal cells of calves with diarrhea under experimental conditions due to rotavirus were undertaken. A quantitative decrease of 40-70% in ${\beta}$-galactosidase activity was observed in proximal and middle segments of the small intestine of the infected calves, more so in the middle segments. The decrease in the distal part of the intestine, however, was lesser (5 to 30%). The decrease in the activity was more marked on the day 2 to 6 post infection indicating the degree of the damage of the villi of the small intestine.

Interaction analysis of a building frame supported on pile groups

Dode, P.A.,Chore, H.S.,Agrawal, D.K. Techno-Press 2014 Coupled systems mechanics Vol.3 No.3

The study deals with the physical modeling of a typical building frame resting on pile foundation and embedded in cohesive soil mass using complete three-dimensional finite element analysis. Two different pile groups comprising four piles ($2{\times}2$) and nine piles ($3{\times}3$) are considered. Further, three different pile diameters along with the various pile spacings are considered. The elements of the superstructure frame and those of the pile foundation are descretized using twenty-node isoparametric continuum elements. The interface between the pile and pile and soil is idealized using sixteen-node isoparametric surface elements. The current study is an improved version of finite element modeling for the soil elements compared to the one reported in the literature (Chore and Ingle 2008). The soil elements are discretized using eight-, nine- and twelve-node continuum elements. Both the elements of superstructure and substructure (i.e., foundation) including soil are assumed to remain in the elastic state at all the time. The interaction analysis is carried out using sub-structure approach in the parametric study. The total stress analysis is carried out considering the immediate behaviour of the soil. The effect of various parameters of the pile foundation such as spacing in a group and number piles in a group, along with pile diameter, is evaluated on the response of superstructure. The response includes the displacement at the top of the frame and bending moment in columns. The soil-structure interaction effect is found to increase displacement in the range of 58 -152% and increase the absolute maximum positive and negative moments in the column in the range of 14-15% and 26-28%, respectively. The effect of the soil- structure interaction is observed to be significant for the configuration of the pile groups and the soil considered in the present study.

Interaction analysis of a building frame suppoted on pile groups

Dode, P.A.,Chore, H.S.,Agrawal, D.K. Techno-Press 2014 Interaction and multiscale mechanics Vol.7 No.1

The study deals with the physical modeling of a typical building frame resting on pile foundation and embedded in cohesive soil mass using complete three-dimensional finite element analysis. Two different pile groups comprising four piles ($2{\times}2$) and nine piles ($3{\times}3$) are considered. Further, three different pile diameters along with the various pile spacings are considered. The elements of the superstructure frame and those of the pile foundation are descretized using twenty-node isoparametric continuum elements. The interface between the pile and pile cap is idealized using sixteen-node isoparametric surface elements. The current study is an improved version of finite element modeling for the soil elements compared to the one reported in the literature (Chore and Ingle 2008). The soil elements are discretized using eight-, nine- and twelve-node continuum elements. Both the elements of superstructure and substructure (i.e., foundation) including soil are assumed to remain in the elastic state at all the time. The interaction analysis is carried out using sub-structure approach in the parametric study. The total stress analysis is carried out considering the immediate behaviour of the soil. The effect of various parameters of the pile foundation such as spacing in a group and number piles in a group, along with pile diameter, is evaluated on the response of superstructure. The response includes the displacement at the top of the frame and bending moment in columns. The soil-structure interaction effect is found to increase displacement in the range of 58-152% and increase the absolute maximum positive and negative moments in the column in the range of 14-15% and 26-28%, respectively. The effect of the soil- structure interaction is observed to be significant for the configuration of the pile groups and the soil considered in the present study.

Structural and electrical properties of microwave -processed BaTiO3 ceramics

ChandraPrakash,O.P.Thakur,D.K.Agrawal 한양대학교 세라믹연구소 2002 Journal of Ceramic Processing Research Vol.3 No.2

Barium titanate (BaTiO3) was synthesized and sintered by microwave processing at 2.45 GHz. Appropriate amounts of BaCO3 and TiO2 were used as starting materials for the synthesis. BaTiO3 phase was obtained by heating the precursors in a multimode microwave cavity at 1450oC for just 25 minutes. The synthesis and sintering were carried out in air. A relative density of 97% was obtained. By contrast, it was found that to achieve the same densification, it required 4 hours of soaking at 1450oC in a conventional sintering process. The dielectric properties show the abrupt discontinuities in dielectric constant vs. temperature plots; typical properties of first order transitions. Above the Curie temperature the dielectric constant follows Curie-Weiss law with Curie constant C=1.3-1.4´105 oC.