We extract the proton charge radius from the elastic form factor (FF) data using a novel theoretical framework combining chiral effective field theory and dispersion analysis. Complex analyticity in the momentum transfer correlates the behavior of the spacelike FF at finite $Q^2$ with the derivative at $Q^2=0$. The FF calculated in the predictive theory contains the radius as a free parameter. We determine its value by comparing the predictions with a descriptive global fit of the spacelike FF data, taking into account the theoretical and experimental uncertainties. Our method allows us to use the finite-$Q^2$ FF data for constraining the radius (up to $Q^2\approx 0.5 {\mathrm{GeV}}^2$ and larger) and avoids the difficulties arising in methods relying on the $Q^2\to 0$ extrapolation. We obtain a radius of 0.844(7) fm, consistent with the high-precision muonic hydrogen results.

A new search for the decay modes of the fourfold forbidden nonunique decay of ${}^{50}\mathrm{V}$ has been performed at the Gran Sasso Underground Laboratory (LNGS). In total, an exposure of 197 kg d has been accumulated. The half-life for the electron capture into the first excited state of ${}^{50}\mathrm{Ti}$ has been measured with the highest precision to date as $2.{67}_{-0.18}^{+0.16}\times {10}^{17}$ yr (68% C.I.) in which systematics uncertainties dominate. The search for the $\beta$ decay into the first excited state of ${}^{50}\mathrm{Cr}$ resulted in a lower limit of $1.9\times {10}^{19}$ yr (90% C.I.), which is an improvement of almost one order of magnitude compared to existing results. The sensitivity of the new measurement is now in the region of theoretical predictions.

By using the valence quark exchange model, the up- and down-quark distribution functions as the distributions of three constituent quark inside the bound nucleons have been extracted and will be used in the context of the Altarelli, Cabibbo, Maiani, and Petronzio (ACMP) constituent quark model formalism to calculate the different pointlike parton distribution functions of the bound nucleons and the structure functions of ${}^3\mathrm{He}$ and ${}^3\mathrm{H}$ mirror nuclei at the energy scale of $Q^2=4$ ${\mathrm{GeV}}^2$. In the latter picture the constituent quarks are assumed to be complex objects, made of pointlike partons which can be pointlike valence quarks, pointlike sea quarks, and pointlike neutral gluons. The sea quark and the gluon contributions to the structure functions of the helium-3 and the tritium nuclei have been analyzed in this scale of energy by reparameterizing the ACMP constituent quark model formalism. Unlike our previous works, where the parton densities inside the nucleon have been computed at the hadronic scale of energy, i.e., $Q_0^2=0.34$ ${\mathrm{GeV}}^2$, and then those distributions have been evolved to the high-energy scales by using the Dokshitzer, Gribove, Lipatov, Altarelli, and Parisi evolution equations, in the present study the parton distribution functions have been calculated at the energy scale of $Q^2=4$ ${\mathrm{GeV}}^2$ directly by using the new parameters in the context of the dressed-quark scenario. Thus, at the first step, the extracted partonic distributions have been considered to calculate the nucleons and the nuclei structure functions and then the ratios of the neutron to the proton and ${}^3\mathrm{He}$ to ${}^3\mathrm{H}$ nuclei structure functions as well as the European Muon Collaboration ratios for the valence quark distributions, ${}^3\mathrm{He}$ and ${}^3\mathrm{H}$ nuclei, are calculated. The results are in a good agreement with both theoretical and available experimental data.

Relativistic heavy ion collisions produce nuclei-sized droplets of quark-gluon plasma whose expansion is well described by viscous hydrodynamic calculations. Over the past half decade, this formalism was also found to apply to smaller droplets closer to the size of individual nucleons, as produced in $p+p$ and $p+A$ collisions. The hydrodynamic paradigm was further tested with a variety of collision species, including $p+\mathrm{Au},d+\mathrm{Au}$, and ${}^3\mathrm{He}+\mathrm{Au}$ producing droplets with different geometries. Nevertheless, questions remain regarding the importance of pre-hydrodynamic evolution and the exact medium properties during the hydrodynamic evolution phase, as well as the applicability of alternative theories that argue the agreement with hydrodynamics is accidental. In this work we explore options for new collision geometries including $p+\mathrm{O}$ and $\mathrm{O}+\mathrm{O}$ proposed for running at the Large Hadron Collider, as well as ${}^4\mathrm{He}+\mathrm{Au},\mathrm{C}+\mathrm{Au},\mathrm{O}+\mathrm{Au}$, and ${}^{7,9}\mathrm{Be}+\mathrm{Au}$ at the Relativistic Heavy Ion Collider.

Isotopic yields and half-lives of ${}^{284}\mathrm{Cn}$ and ${}^{284}\mathrm{Fl}$ superheavy nuclei are calculated using nuclear proximity and Coulomb potentials. The energy released in fission, $Q$ value, driving potential $(V-Q)$, the penetrability through barrier, fission decay constant, and relative yield for each possible pair of fission fragments are obtained. According to the fragments mass and charge asymmetry, the most favored binary fragmentation is occurred for the highest $Q$ value and the lowest driving potential. For spontaneous binary fission of ${}^{284}\mathrm{Cn}$ superheavy nuclei, the higher relative yields are belong to production of ${}^{128}\mathrm{Sn}$ and ${}^{134}\mathrm{Te}$ fragments and for ${}^{284}\mathrm{Fl}$ superheavy isotope, the maximum yield were observed for ${}^{136}\mathrm{Xe}$ as one of the fission fragments. The comparison between the obtained isotopic relative yield shows the role of magic and near-magic closed-shell fragments in having the highest isotopic yield. Fission decay constant for each possible fragmentation is calculated and then by summation over them, the total decay constant and fission half-life for ${}^{284}\mathrm{Cn}$ and ${}^{284}\mathrm{Fl}$ superheavy nuclei are estimated. Finally, the calculated half-lives using direct method are compared with the results of semiempirical formulas as well as experimental data. Satisfactory agreement is achieved between the results of this approach and the experimental data than the results of semiempirical formulas.

We compare phenomenological results from $(3+1)$-dimensional quasiparticle anisotropic hydrodynamics (aHydroQP) with experimental data collected from RHIC 200 GeV Au-Au collisions. We compare identified particle spectra in different centrality classes, charged particle multiplicity versus pseudorapidity, identified particle multiplicity versus centrality across a wide range of particle species, identified particle elliptic flow versus transverse momentum, and charged particle elliptic flow as a function of transverse momentum and rapidity. We use the same aHydroQP and hadronic production codes that were used previously to describe LHC 2.76 TeV data. The aHydroQP hydrodynamic model includes the effects of both shear and bulk viscosities in addition to an infinite number of transport coefficients computed self-consistently in the relaxation-time approximation. To convert to the final-state hadrons, we use anisotropic Cooper–Frye freeze-out performed on a fixed-energy-density hypersurface and compute the production and feed-down by using a customized version of Therminator 2. We find good agreement with many heavy-ion collision observables using only smooth Glauber initial conditions parametrized by an initial central temperature of $T_0=455$ MeV, a constant shear-viscosity-to-entropy-density ratio $\eta /s=0.179$, and a switching (freeze-out) temperature of $T_{\mathrm{FO}}=130$ MeV.

The behavior of strange matter in the frame of the SU(3) Polyakov-loop extended Nambu–Jona-Lasinio (PNJL) model including the $U_A\left(1\right)$ anomaly is considered. We discuss the appearance of a peak in the ratio of the number of strange mesons to nonstrange mesons known as the “horn.” The PNJL model gives a schematic description of the chiral phase transition and meson properties at finite temperature and density. By using the model, we can show that the splitting of kaon and antikaon masses appears as a result of the introduction of density. This may explain the difference in the $K^{+}/{\pi }^{+}$ ratio and the $K^{-}/{\pi }^{-}$ ratio at low $\sqrt{s_{NN}}$ and their tendency to the same value at high $\sqrt{s_{NN}}$. We also show that the rise in the ratio $K^{+}/{\pi }^{+}$ appears near the critical endpoint when we build the $K^{+}/{\pi }^{+}$ ratio along the phase-transition diagram and it can be considered as a critical region signal.

We have obtained the Love number and corresponding tidal deformabilities $\left(\mathrm{\Lambda }\right)$ associated with the relativistic mean-field parametrizations shown to be consistent (CRMF) with the nuclear matter, pure neutron matter, symmetry energy, and its derivatives [Dutra et al., Phys. Rev. C 90, 055203 (2014)]. Our results show that CRMF models present very good agreement with the recent data from binary neutron star merger event GW170817. They also confirm the strong correlation between ${\mathrm{\Lambda }}_{1.4}$ and the radius of canonical stars $\left(R_{1.4}\right)$. When a recent GW170817 constraint on ${\mathrm{\Lambda }}_{1.4}$ and the corresponding radius $R_{1.4}$ is used, the majority of the models tested are shown to satisfy it.

A sequence of nine almost equidistant quadrupole transitions is observed in ${}^{137}\mathrm{Nd}$. The sequence represents an extremely regular rotational band that extends to a spin of about 75/2 and an excitation energy of $\approx 4.5\mathrm{MeV}$ above yrast. Cranked mean-field calculations of the Nilsson-Strutinsky type suggest an oblate shape for the band. They reproduce the observed $I(I+1)$ dependence of the rotational energy whereas predicting a pronounced decrease in the deformation, which is the hallmark of antimagnetic rotation.

The initial strong magnetic field produced in high-energy nuclear collisions will distort the distribution of the relative angle between oppositely charged particles within a pair. In this paper, two experimental observables are examined to quantify such effects: one based on the framework for detecting the hyperon global polarization, and the other based on the balance function. We also discuss the optimization of the signal, as well as the expected magnitude ranges for the two observables.

The global optical model potential for the ${}^9\mathrm{Be}$ projectile is developed by systematically studying the experimental data of elastic-scattering angular distributions and reaction cross sections from ${}^{24}\mathrm{Mg}$ to ${}^{209}\mathrm{Bi}$ below 100 MeV. The analysis is performed in terms of comparing the theoretical results with the available experimental data. A satisfactory agreement is observed in the whole energy and target mass regions. Moreover, the elastic-scattering angular distributions and reaction cross sections of ${}^9\mathrm{Be}$ on some lighter targets are also predicted using the global optical model potential and a reasonable description of the experimental data is obtained.

The isospin equilibration process in multinucleon transfer reactions is investigated by using the improved quantum molecular dynamics model. The collisions of ${}^{124}\mathrm{Xe}+{}^{208}\mathrm{Pb}$ at near-barrier energy are studied with different symmetry energy coefficients. We find that the neutron transfer is enhanced at the early stages of the collisions under the strong symmetry potential. The neutron's transfer takes place at an earlier stage than the proton's. The trajectory of neutron flow is along the low-density path from the target to projectile. The average $N/Z$ values of the primary products in the ${}^{58}\mathrm{Ni}+{}^{208}\mathrm{Pb}$ reaction are also investigated and compared with available experimental data. It shows that the average $N/Z$ values of the projectile-like products increase rapidly with increasing mass transfer. In the quasielastic collisions, the isospin equilibration process is incomplete due to a short contact time between the reaction partners. The complete isospin equilibration events take place in symmetric quasifission reactions.

A scheme to compute reactions is described that uses the Slater determinants constructed of oscillator orbitals. Simple linear equations are suggested for this purpose and shown to be efficient in model examples. A universal method to evaluate the required matrix elements is given.

We compare the mean-over-variance ratio of the net-kaon distribution calculated within the hadron resonance gas model to the latest experimental data from the Beam Energy Scan at the Relativistic Heavy Ion Collider by the STAR Collaboration. Our analysis indicates that it is not possible to reproduce the experimental results using the freeze-out parameters from the existing combined fit of net-proton and net-electric charge mean over variance. The strange mesons need about 15 MeV higher temperatures than the light hadrons at the highest collision energies. In view of the future $\mathrm{\Lambda }$ fluctuation measurements, we predict the $\mathrm{\Lambda }$ variance over mean and skewness times variance at the light and strange chemical freeze-out parameters. We observe that the $\mathrm{\Lambda }$ fluctuations are sensitive to the difference in the freeze-out temperatures established in this analysis. Our results have implications for other phenomenological models in the field of relativistic heavy ion collisions.

We study the surface tension of hot, highly magnetized three-flavor quark matter droplets, focusing specifically on the thermodynamic conditions prevailing in neutron stars, hot lepton-rich protoneutron stars, and neutron star mergers. We explore the role of temperature, baryon number density, trapped neutrinos, droplet size, and magnetic fields within the multiple reflection expansion formalism (MRE), assuming that astrophysical quark matter can be described as a mixture of free Fermi gases composed of quarks $u$, $d$, $s$, electrons, and neutrinos, in chemical equilibrium under weak interactions. We find that the total surface tension is rather unaffected by the size of the drop but is quite sensitive to the effect of baryon number density, temperature, trapped neutrinos, and magnetic fields (especially above $eB\sim 5\times {10}^{-3}{\mathrm{GeV}}^2$). Surface tensions parallel and transverse to the magnetic field span values up to $\approx 25\mathrm{MeV}/{\mathrm{fm}}^2$. For $T\lesssim 100$ MeV, the surface tension is a decreasing function of temperature but above 100 MeV it increases monotonically with $T$. Finally, we discuss some astrophysical consequences of our results.

The ${}^{15}\mathrm{O}(\alpha ,\gamma ){}^{19}\mathrm{Ne}$ reaction is responsible for breakout from the hot CNO cycle in type I x-ray bursts. Understanding the properties of resonances between $E_x=4$ and 5 MeV in ${}^{19}\mathrm{Ne}$ is crucial in the calculation of this reaction rate. The spins and parities of these states are well known, with the exception of the 4.14- and 4.20-MeV states, which have adopted spin-parities of $9/2^{-}$ and $7/2^{-}$, respectively. $\gamma$-ray transitions from these states were studied using triton-$\gamma -\gamma$ coincidences from the ${}^{19}\mathrm{F}({}^3\mathrm{He},t\gamma ){}^{19}\mathrm{Ne}$ reaction measured with the GODDESS (Gammasphere ORRUBA Dual Detectors for Experimental Structure Studies) at Argonne National Laboratory. The observed transitions from the 4.14- and 4.20-MeV states provide strong evidence that the $J^{\pi }$ values are actually $7/2^{-}$ and $9/2^{-}$, respectively. These assignments are consistent with the values in the ${}^{19}\mathrm{F}$ mirror nucleus and in contrast to previously accepted assignments.

We develop a macroscopic description of the space-time evolution of the energy-momentum tensor during the pre-equilibrium stage of a high-energy heavy-ion collision. Based on a weak coupling effective kinetic description of the microscopic equilibration process (à la “bottom-up”), we calculate the nonequilibrium evolution of the local background energy-momentum tensor as well as the nonequilibrium linear response to transverse energy and momentum perturbations for realistic boost-invariant initial conditions for heavy-ion collisions. We demonstrate how this framework can be used on an event-by-event basis to propagate the energy-momentum tensor from far-from-equilibrium initial-state models to the time ${\tau }_{\text{hydro}}$ when the system is well described by relativistic viscous hydrodynamics. The subsequent hydrodynamic evolution becomes essentially independent of the hydrodynamic initialization time ${\tau }_{\text{hydro}}$ as long as ${\tau }_{\text{hydro}}$ is chosen in an appropriate range where both kinetic and hydrodynamic descriptions overlap. We find that for $\sqrt{s_{NN}}=2.76\text{TeV}$ central Pb-Pb collisions, the typical timescale when viscous hydrodynamics with shear viscosity over entropy ratio $\eta /s=0.16$ becomes applicable is ${\tau }_{\text{hydro}}\sim 1\mathrm{fm}/\mathrm{c}$ after the collision.

In this paper we study the particle production at high transverse momentum $\left(p_T>8\mathrm{GeV}/c\right)$ in both $pp$ and Pb-Pb collisions at LHC energies. The characterization of the spectra is done using a power-law function and the resulting power-law exponent $\left(n\right)$ is studied as a function of $x_T$ for minimum-bias $pp$ collisions at different $\sqrt{s}$. The functional form of $n$ as a function of $x_T$ exhibits an approximate universal behavior. pythia 8.212 reproduces the scaling properties and therefore, it is used to study the multiplicity-dependent particle production. Going from low to high multiplicities, the power-law exponent decreases. A similar behavior is also observed in heavy-ion collisions when one studies the centrality-dependent particle production. The interpretation of heavy-ion results requires the quantification of the impact of this correlation (multiplicity and high $p_T)$ on jet-quenching observables.