Synthesis of Molecular Rulers to Study Distance and Orientation Dependent Förster Resonance Energy Transfer (FRET)

Sahoo D. Synthesis of Molecular Rulers to Study Distance and Orientation Dependent Förster Resonance Energy Transfer (FRET). Bielefeld: Universität Bielefeld; 2019

High-spin spectroscopy in 207^{207}At: Evidence of a 29/2+^{+} isomeric state

Yrast and near-yrast states above the known 25/2$^{+}$ isomer in $^{207}$At are established for the first time. The level scheme is extended up to 47/2$\hbar$ and 6.5 MeV with the addition of about 60 new $\gamma$-ray transitions. The half-life of the 25/2$^{+}$ isomer is revisited and a value of $T_{1/2}$ = 107.5(9) ns is deduced. Evidence of a hitherto unobserved 29/2$^{+}$ isomer in $^{207}$At is presented. A systematic study of $B(E3)$ values for the transitions de-exciting the 29/2$^{+}$ isomer in the neighboring odd-$A$ At isotopes suggests a half-life in the 2$-$4 $\mu$s range for this state in $^{207}$At. The experimental results are compared with large-scale shell-model calculations performed using the KHM3Y effective interaction in the $Z$ = 50$-$126, $N$ = 82$-$184 model space and an overall good agreement is noted between the theory and the experiment. A qualitative comparison of the excited states and the isomers with analogous states in neighboring nuclei provides further insight into the structure of $^{207}$At.Comment: 15 pages, 13 figure

Coexisting single-particle excitations and octupole correlations in transitional nucleus 217Ra\mathbf{^{217}Ra}

The level structure of the transitional nucleus $\mathrm{^{217}Ra}$ has been extended with the addition of around 20 new transitions. The discrepancies between the placements of several transitions reported in the earlier studies are resolved. The newly-established negative-parity sequence at low excitation energies hints at the expected parity-doublet structures in this nucleus. The properties of the observed simplex bands are compared with that of similar bands in neighboring nuclei. Since the presence of parity-doublet structures reflect octupole correlations, theoretical calculations using reflection-asymmetric triaxial particle rotor model (RAT-PRM) have been performed. A comparison of the observed features of the simplex bands with the predictions of the RAT-PRM calculations suggests that $\mathrm{^{217}Ra}$ exhibits an intermediate the behavior between the extremes of spherical and octupole-deformed nuclei. The termination of the simplex bands at intermediate energies and the structures lying above reflect the dominance of the single-particle excitations at higher excitation energies.Comment: 15 pages, 16 figure

Dynamics of Hot QCD Matter -- Current Status and Developments

The discovery and characterization of hot and dense QCD matter, known as Quark Gluon Plasma (QGP), remains the most international collaborative effort and synergy between theorists and experimentalists in modern nuclear physics to date. The experimentalists around the world not only collect an unprecedented amount of data in heavy-ion collisions, at Relativistic Heavy Ion Collider (RHIC), at Brookhaven National Laboratory (BNL) in New York, USA, and the Large Hadron Collider (LHC), at CERN in Geneva, Switzerland but also analyze these data to unravel the mystery of this new phase of matter that filled a few microseconds old universe, just after the Big Bang. In the meantime, advancements in theoretical works and computing capability extend our wisdom about the hot-dense QCD matter and its dynamics through mathematical equations. The exchange of ideas between experimentalists and theoreticians is crucial for the progress of our knowledge. The motivation of this first conference named "HOT QCD Matter 2022" is to bring the community together to have a discourse on this topic. In this article, there are 36 sections discussing various topics in the field of relativistic heavy-ion collisions and related phenomena that cover a snapshot of the current experimental observations and theoretical progress. This article begins with the theoretical overview of relativistic spin-hydrodynamics in the presence of the external magnetic field, followed by the Lattice QCD results on heavy quarks in QGP, and finally, it ends with an overview of experiment results.Comment: Compilation of the contributions (148 pages) as presented in the `Hot QCD Matter 2022 conference', held from May 12 to 14, 2022, jointly organized by IIT Goa & Goa University, Goa, Indi

Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

Multiplicity dependence of J/

In inelastic $$p+p$$ collisions, the interacting objects are quarks and gluons (partons). It is believed that there are multiple interactions between the partons in a single $$p+p$$ event. Recent studies of multiplicity dependence of particle production in $$p+p$$ collisions have gathered considerable interest in the scientific community. According to several theoretical calculations, multiple gluon participation in hadronic collisions is the cause of high-multiplicity events. If the interaction is hard enough (large $$p_{\mathrm{T}}$$ transfer), the semi-hard processes of multiple interactions of partons might also lead to the production of heavy particles like J/$$\psi$$. At the LHC, an approximately linear increase of the relative J/$$\psi$$ yield with charged particle multiplicity is observed in $$p+p$$ collisions. In the present work, we have studied the contribution of quarks and gluons to the multiplicity dependence of J/$$\psi$$ production using pQCD inspired event generator, PYTHIA8 tune 4C, in $$p+p$$ collisions at $$\sqrt{s} =$$13 TeV by investigating relative J/$$\psi$$ yield and relative $$\langle p_{\mathrm{T}} \rangle$$ of J/$$\psi$$ as a function of charged particle multiplicity for different hard-QCD processes. We have estimated a newly defined ratio, $$r_{pp} = {\langle p_{\mathrm{T}}^{2} \rangle }_{i}/{\langle p_{\mathrm{T}}^{2} \rangle }_{\mathrm{MB}}$$, to gain understanding of J/$$\psi$$ production in high-multiplicity $$p+p$$ collisions. For the first time we attempt to study the nuclear modification factor-like observables ($$R_{\mathrm{pp}}$$ and $$R_{\mathrm{cp}}$$) to describe the QCD medium formed in high-multiplicity $$p+p$$ collisions