Nuclear Theory·nucl-th

Tuesday·July 12, 2016

12 papers—8 primary·4 cross-listed

09
Parton Fragmentation Functions
Andreas Metz🇺🇸 · Anselm Vossen🇺🇸
The field of fragmentation functions of light quarks and gluons is reviewed. In addition to integrated fragmentation functions, attention is paid to the dependence of fragmentation functions on transverse momenta and on polarization degrees of freedom. Higher-twist and di-hadron fragmentation functions are considered as well. Moreover, the review covers both theoretical and experimental developments in single-inclusive hadron production in electron-positron annihilation, deep-inelastic lepton-nucleon scattering, and proton-proton collisions.
↳ hep-exhep-phnucl-exnucl-thPPNP(2016)·298 citations
10
Kaon fluctuations from lattice QCD
Jacquelyn Noronha-Hostler🇺🇸 · Rene Bellwied🇺🇸 · Jana Gunther🇩🇪 · Paolo Parotto🇺🇸 · Attila Pasztor🇩🇪 · Israel Portillo Vazquez🇺🇸 · Claudia Ratti🇺🇸
We show that it is possible to isolate a set of kaon fluctuations in lattice QCD. By means of the Hadron Resonance Gas (HRG) model, we calculate the actual kaon second-to-first fluctuation ratio, which receives contribution from primordial kaons and resonance decays, and show that it is very close to the one obtained for primordial kaons in the Boltzmann approximation. The latter only involves the strangeness and electric charge chemical potentials, which are functions of $T$ and $μ_{B}$ due to the experimental constraint on strangeness and electric charge, and can therefore be calculated on the lattice. This provides an unambiguous method to extract the kaon freeze-out temperature, by comparing the lattice results to the experimental values for the corresponding fluctuations.
↳ hep-phhep-latnucl-th47 citations
11
A Search for $0^{+}$ States in $^{50}$ Cr: Implications for the Superallowed $β$ -decay of $^{50}$ Mn
K.G. Leach · P.E. Garrett · G.C. Ball · P.C. Bender · V. Bildstein · B.A. Brown · C. Burbadge · T. Faestermann · B. Hadinia · J.D. Holt · A.T. Laffoley · D.S. Jamieson and 7 other authors
A $^{52}$ Cr $(p, t)$ $^{50}$ Cr two-neutron pickup reaction was performed using the Q3D magnetic spectrograph at the Maier-Leibnitz-Laboratorium in Garching, Germany. Excited states in $^{50}$ Cr were observed up to an excitation energy of 5.3 MeV. Despite significantly increased sensitivity and resolution over previous work, no evidence of the previously assigned first excited $0^{+}$ state was found. As a result, the $0_{2}^{+}$ state is reassigned at an excitation energy of $E_{x} = 3895.0 (5)$ keV in $^{50}$ Cr. This reassignment directly impacts direct searches for a non-analogue Fermi $β^{+}$ decay branch in $^{50}$ Mn. These results also show better systematic agreement with the theoretical predictions for the $0^{+}$ state spectrum in $^{50}$ Cr using the same formalism as the isospin-symmetry-breaking correction calculations for superallowed nuclei. The experimental data are also compared to $ab$ - $ini t i o$ shell-model predictions using the IM-SRG formalism based on $N N$ and $3 N$ forces from chiral-EFT in the $p f$ -shell for the first time.
↳ nucl-exnucl-thPRC(2016)·10 citations
12
Short Range Correlations and the EMC Effect in Effective Field Theory
Jiunn-Wei Chen🇹🇼 · William Detmold🇺🇸 · Joel E. Lynn🇩🇪 · Achim Schwenk🇩🇪
We show that the empirical linear relation between the magnitude of the EMC effect in deep inelastic scattering on nuclei and the short range correlation scaling factor $a_{2}$ extracted from high-energy quasi-elastic scattering at $x \geq 1$ is a natural consequence of scale separation and derive the relationship using effective field theory. While the scaling factor $a_{2}$ is a ratio of nuclear matrix elements that individually depend on the calculational scheme, we show that the ratio is independent of this choice. We perform Green's function Monte Carlo calculations with both chiral and Argonne-Urbana potentials to verify this and determine the scaling factors for light nuclei. The resulting values for $^{3}$ He and $^{4}$ He are in good agreement with experimental values. We also present results for $^{9}$ Be and $^{12}$ C extracted from variational Monte Carlo calculations.
↳ hep-phhep-latnucl-exnucl-thPRL(2017)·75 citations

Affiliations

first authorsco-authorsvia INSPIRE

Parton Fragmentation Functions

Kaon fluctuations from lattice QCD

A Search for 0+ States in 50Cr: Implications for the Superallowed β-decay of 50Mn

Short Range Correlations and the EMC Effect in Effective Field Theory

Affiliations

A Search for $0^{+}$ States in $^{50}$ Cr: Implications for the Superallowed $β$ -decay of $^{50}$ Mn