Nuclear Theory·nucl-th

Monday·January 2, 2017

10 papers—5 primary·5 cross-listed

06
Improved limits on the hadronic and semi-hadronic CP violating parameters and role of a dark force carrier in the electric dipole moment of $^{199}$ Hg
B. K. Sahoo🇮🇳
Combining the recently reported electric dipole moment (EDM) of $^{199}$ Hg atom due to breaking of parity and time-reversal symmetries with the improved relativistic atomic calculations, precise limits on the tensor-pseudotensor (T-PT) electron-nucleus (e-N) coupling coefficient and the nuclear Schiff moment (NSM) interactions are determined. Using these limits with the nuclear calculations, we infer limits on the EDMs of neutron and proton as $d_{n} < 2.2 \times 1 0^{- 26} ∣ e ∣ cm$ and $d_{p} < 2.1 \times 1 0^{- 25} ∣ e ∣ cm$ , respectively, and on the quantum chromodynamics (QCD) parameter and the combined up- and down- quark chromo-EDMs as $∣ θ ˉ ∣ < 1.1 \times 1 0^{- 10}$ and $∣ d ~_{u} - d ~_{d} ∣ < 5.5 \times 1 0^{- 27} ∣ e ∣ cm$ , respectively. These are the best limits till date to probe new sources of CP violation beyond the standard model (SM) from a diamagnetic atom. Role of considering a capable many-body method to account the electron correlation effects to all orders for inferring the above limits has been highlighted. From this analysis, constraints on the T-PT e-N coupling coefficient with a large range of mass of a possible dark matter carrier $χ$ between the atomic electrons and nucleus are given.
↳ hep-phnucl-thphysics.atom-phPRD(2017)·48 citations
07
Semirelativistic approximation to the $γ^{*} N \to N (1520)$ and $γ^{*} N \to N (1535)$ transition form factors
G. Ramalho🇧🇷
The representation of the wave functions of the nucleon resonances within a relativistic framework is a complex task. In a nonrelativistic framework the orthogonality between states can be imposed naturally. In a relativistic generalization, however, the derivation of the orthogonality condition between states can be problematic, particularly when the states have different masses. In this work we study the $N (1520)$ and $N (1535)$ states using a relativistic framework. We considered wave functions derived in previous works, but impose the orthogonality between the nucleon and resonance states using the properties of the nucleon, ignoring the difference of masses between the states (semirelativistic approximation). The $N (1520)$ and $N (1535)$ wave functions are then defined without any adjustable parameters and are used to make predictions for the valence quark contributions to the transition form factors. The predictions compare well with the data particularly for high momentum transfer, where the dominance of the quark degrees of freedom is expected.
↳ hep-phhep-exhep-latnucl-ex+1PRD(2017)·30 citations
08
Generalized Beth-Uhlenbeck approach to the equation of state for quark-hadron matter
D. Blaschke🇷🇺 · A. Dubinin🇵🇱 · L. Turko🇵🇱
A unified equation of state for quark-hadron matter is presented in the generalized Beth-Uhlenbeck form. It follows from a $Φ -$ derivable approach to the thermodynamic potential where the ansatz for the $Φ$ functional contains all 2PI diagrams at two-loop order formed with quark cluster Green's functions for quark, diquark, meson and baryon propagators. We present numerical results using an effective model for the generic behaviour of hadron masses and phase shifts at finite temperature which shares basic features with recent developments within the PNJL model for correlations in quark matter. We obtain the transition between a hadron resonance gas phase and the quark gluon plasma where the Mott dissociation of hadrons is encoded in the hadronic phase shifts. The resulting thermodynamics is in very good agreement with recent lattice QCD simulations.
↳ hep-phnucl-thActa Phys.Polon.Supp.(2017)·14 citations
09
Fine-tuning the Color-Glass Condensate with the nuclear configurational entropy
Gayane Karapetyan🇧🇷
The dipole-nucleus forward scattering amplitude rules the onset of the gluon anomalous dimension, in the Color-Glass Condensate regime. In this model, the onset of quantum regime is here derived as a critical stable point in the nuclear configurational entropy, matching the fitted experimental data in the literature with accuracy of 1%. It corroborates with the informational entropy paradigm in high energy nuclear physics.
↳ hep-phhep-thnucl-thEPL(2017)·38 citations
10
Liquid-Gas Phase Transitions and $C K$ Symmetry in Quantum Field Theories
Hiromichi Nishimura🇺🇸 · Michael C. Ogilvie🇺🇸 · Kamal Pangeni🇺🇸
A general field-theoretic framework for the treatment of liquid-gas phase transitions is developed. Starting from a fundamental four-dimensional field theory at nonzero temperature and density, an effective three-dimensional field theory with a sign problem is derived. Although charge conjugation $C$ is broken at finite density, there remains a symmetry under $C K$ , where $K$ is complex conjugation. We consider four models: relativistic fermions, nonrelativistic fermions, static fermions and classical particles. The thermodynamic behavior is extracted from $C K$ -symmetric complex saddle points of the effective field theory at tree level. The relativistic and static fermions show a liquid-gas transition, manifesting as a first-order line at low temperature and high density, terminated by a critical end point. In the cases of nonrelativistic fermions and classical particles, we find no first-order liquid-gas transitions at tree level. The mass matrix controlling the behavior of correlation functions is obtained from fluctuations around the saddle points. Due to the $C K$ symmetry of the models, the eigenvalues of the mass matrix can be complex. This leads to the existence of disorder lines, which mark the boundaries where the eigenvalues go from purely real to complex. The regions where the mass matrix eigenvalues are complex are associated with the critical line. In the case of static fermions, a powerful duality between particles and holes allows for the analytic determination of both the critical line and the disorder lines. Depending on the values of the parameters, either zero, one or two disorder lines are found. Numerical results for relativistic fermions give a very similar picture.
↳ hep-thhep-lathep-phnucl-thPRD(2017)·9 citations

Affiliations

first authorsco-authorsvia INSPIRE

Improved limits on the hadronic and semi-hadronic CP violating parameters and role of a dark force carrier in the electric dipole moment of 199Hg

Semirelativistic approximation to the γ∗N→N(1520) and γ∗N→N(1535) transition form factors

Generalized Beth-Uhlenbeck approach to the equation of state for quark-hadron matter

Fine-tuning the Color-Glass Condensate with the nuclear configurational entropy

Liquid-Gas Phase Transitions and CK Symmetry in Quantum Field Theories

Affiliations

Improved limits on the hadronic and semi-hadronic CP violating parameters and role of a dark force carrier in the electric dipole moment of $^{199}$ Hg

Semirelativistic approximation to the $γ^{} N \to N (1520)$ and $γ^{} N \to N (1535)$ transition form factors

Liquid-Gas Phase Transitions and $C K$ Symmetry in Quantum Field Theories