Nuclear Theory·nucl-th

Wednesday·January 7, 2015

8 papers—4 primary·4 cross-listed

01
Non-Perturbative Lepton Sea Fermions in the Nucleon and the Proton Radius Puzzle
Gerald A. Miller🇺🇸
A potential explanation [U.~D.~Jentschura, Phys.\ Rev.\ A {\bf 88}, 062514 (2013)] of the proton radius puzzle originating from the non-perturbative lepton-pair content of the proton is studied. Well-defined quantities that depend on this lepton-pair content are evaluated. Each is found to be of the order of $10 (\frac{α}{π})^{2}$ , so that we find such a lepton-pair content exists in the proton. However, we argue that this relatively large result and general features of loop diagrams rule out the possibility of lepton-pair content as an explanation of the proton radius puzzle. In addition, the contributions of a class of explanations of the proton radius puzzle (for which the dependence on the $μ p$ relative distance is as a contact interaction) is determined.
nucl-thhep-phnucl-exphysics.atom-phPRC(2015)·12 citations
02
New boson realization of the Lipkin model obeying the su(2)-algebra
Y.Tsue (Kochi Univ., Japan) · C.Providencia (Univ de Coimbra, Portugal) · J. da Providencia (Univ. de Coimbra, Portugal) · M.Yamamura (Kansai Univ., Japan)
New boson representation of the su(2)-algebra proposed by the present authors for describing the damped and amplified oscillator is examined in the Lipkin model as one of simple many-fermion models. This boson representation is expressed in terms of two kinds of bosons with a certain positive parameter. In order to describe the case of any fermion number, third boson is introduced. Through this examination, it is concluded that this representation is well workable for the boson realization of the Lipkin model in any fermion number.
nucl-thPTEP(2015)·2 citations
03
$^{1} S_{0}$ nucleon-nucleon scattering in the modified Weinberg approach
E. Epelbaum · A. M. Gasparyan · J. Gegelia · H. Krebs
Nucleon-nucleon scattering in the $^{1} S_{0}$ partial wave is considered in chiral effective field theory within the renormalizable formulation of Ref. [1] beyond the leading-order approximation. By applying subtractive renormalization, the subleading contact interaction in this channel is taken into account non-perturbatively. For a proper choice of renormalization conditions, the predicted energy dependence of the phase shift and the coefficients in the effective range expansion are found to be in a good agreement with the results of the Nijmegen partial wave analysis.
nucl-thEPJA(2015)·36 citations
04
Clusters in nuclear matter and Mott points
G. Röpke
Light clusters (mass number $A \leq 4$ ) in nuclear matter at subsaturation densities are described using a quantum statistical approach. In addition to self-energy and Pauli-blocking, effects of continuum correlations are taken into account to calculate the quasiparticle properties and abundances of light elements. Medium-modified quasiparticle properties are important ingredients to derive a nuclear matter equation of state applicable in the entire region of warm dense matter below saturation density. The influence of the nucleon-nucleon interaction on the quasiparticle shift is discussed.
nucl-thPhys.Part.Nucl.(2015)·8 citations
05
A non-abelian quasi-particle model for gluon plasma
E.P. Politis🇬🇷 · C.E. Tsagkarakis🇬🇷 · F.K. Diakonos🇬🇷 · X.N. Maintas🇬🇷 · A. Tsapalis🇬🇷
We propose a quasi-particle model for the thermodynamic description of the gluon plasma which takes into account non-abelian characteristics of the gluonic field. This is accomplished utilizing massive non-linear plane wave solutions of the classical equations of motion with a variable mass parameter, reflecting the scale invariance of the Yang-Mills Lagrangian. For the statistical description of the gluon plasma we interpret these non-linear waves as quasi-particles with a temperature dependent mass distribution. Quasi-Gaussian distributions with a common variance but different temperature dependent mean masses for the longitudinal and transverse modes are employed. We use recent Lattice results to fix the mean transverse and longitudinal masses while the variance is fitted to the equation of state of pure $S U (3)$ on the Lattice. Thus, our model succeeds to obtain both a consistent description of the gluon plasma energy density as well as a correct behaviour of the mass parameters near the critical point.
↳ hep-phhep-latnucl-thPLB(2016)·5 citations
06
Energy Dependent Growth of Nucleon and Inclusive Charged Hadron Distributions
Hongmin Wang · Zhao-Yu Hou🇨🇳 · Xian-Jing Sun🇨🇳
In the Color Glass Condensate formalism, charged hadron p_{T} distributions in p+p collisions are studied by considering an energy-dependent broadening of nucleon's density distribution. Then, in the Glasma flux tube picture, the n-particle multiplicity distributions at different pseudo-rapidity ranges are investigated. Both of the theoretical results show good agreement with the recent experimental data from ALICE and CMS at \sqrt{s}=0.9, 2.36, 7 TeV. The predictive results for p_{T} and multiplicity distributions in p+p and p+Pb collisions at the Large Hadron Collider are also given in this paper.
↳ hep-phmath.GMnucl-thCPC(2015)·0 citations
07
Nuclear structure studies of $^{24}$ F
L. Caceres (GANIL)🇫🇷 · A. Lepailleur (GANIL)🇫🇷 · O. Sorlin (GANIL)🇫🇷 · M. Stanoiu (GANIL)🇫🇷 · D. Sohler🇭🇺 · Zs. Dombradi🇭🇺 · S. K. Bogner🇺🇸 · B.A. Brown · H. Hergert · J.D. Holt · A. Schwenk · F. Azaiez (IPNO)🇫🇷 and 30 other authors
The structure of the $^{24}$ F nucleus has been studied at GANIL using the $β$ decay of $^{24}$ O and the in-beam $γ$ -ray spectroscopy from the fragmentation of projectile nuclei. Combining these complementary experimental techniques, the level scheme of $^{24}$ F has been constructed up to 3.6 Mev by means of particle- $γ$ and particle- $γ γ$ coincidence relations. Experimental results are compared to shell-model calculations using the standard USDA and USDB interactions as well as ab-initio valence-space Hamiltonians calculated from the in-medium similarity renormalization group based on chiral two- and three-nucleon forces. Both methods reproduce the measured level spacings well, and this close agreement allows unidentified spins and parities to be consistently assigned.
↳ nucl-exnucl-thPRC(2015)·21 citations
08
The RHIC SPIN Program: Achievements and Future Opportunities
Elke-Caroline Aschenauer (BNL)🇺🇸 · Alexander Bazilevsky (BNL)🇺🇸 · Markus Diehl (DESY)🇩🇪 · James Drachenberg (Valparaiso U.) · Kjeld Oleg Eyser (BNL)🇺🇸 · Renee Fatemi (Kentucky U.)🇺🇸 · Carl Gagliardi (Texas A&M)🇺🇸 · Zhongbo Kang (Los Alamos)🇺🇸 · Yuri V. Kovchegov (Ohio State U.)🇺🇸 · John Lajoie (Iowa State U.)🇺🇸 · Jeong-Hun Lee (BNL) · Emanuele-R. Nocera (Milano U. & INFN)🇮🇹 and 12 other authors
Time and again, spin has been a key element in the exploration of fundamental physics. Spin-dependent observables have often revealed deficits in the assumed theoretical framework and have led to novel developments and concepts. Spin is exploited in many parity-violating experiments searching for physics beyond the Standard Model or studying the nature of nucleon-nucleon forces. The RHIC spin program plays a special role in this grand scheme: it uses spin to study how a complex many-body system such as the proton arises from the dynamics of QCD. Many exciting results from RHIC spin have emerged to date, most of them from RHIC running after the 2007 Long Range Plan. In this document we present highlights from the RHIC program to date and lay out the roadmap for the significant advances that are possible with future RHIC running.
↳ nucl-exhep-phnucl-th144 citations

Affiliations

first authorsco-authorsvia INSPIRE