Nuclear Theory·nucl-th

Thursday·October 26, 2017

10 papers—5 primary·5 cross-listed

06
[Submitted on 23 Oct 2017] (cross-list from cond-mat.quant-gas)
Conformality Lost in Efimov Physics
Abhishek Mohapatra🇺🇸 · Eric Braaten🇺🇸
A general mechanism for the loss of conformal invariance is the merger and disappearance of an infrared fixed point and an ultraviolet fixed point of a renormalization group flow. We show explicitly how this mechanism works in the case of identical bosons at unitarity as the spatial dimension $d$ is varied. For $d$ between the critical dimensions $d_{1} = 2.30$ and $d_{2} = 3.76$ , there is loss of conformality as evidenced by the Efimov effect in the three-body sector. The beta function for an appropriate three-body coupling is a quadratic polynomial in that coupling. For $d < d_{1}$ and for $d > d_{2}$ , the beta function has two real roots that correspond to infrared and ultraviolet fixed points. As $d$ approaches $d_{1}$ from below and as $d$ approaches $d_{2}$ from above, the fixed points merge and disappear into the complex plane. For $d_{1} < d < d_{2}$ , the beta function has complex roots and the renormalization group flow for the three-body coupling is a limit cycle.
Comments:
11 pages, 3 figures
Subjects:
Quantum Gases (cond-mat.quant-gas); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1710.08447 [pdf]
PRA(2018)·13 citations
07
[Submitted on 24 Oct 2017] (cross-list from hep-th)
Circle compactification and 't Hooft anomaly
Yuya Tanizaki🇺🇸 · Tatsuhiro Misumi🇯🇵 · Norisuke Sakai🇯🇵
Anomaly matching constrains low-energy physics of strongly-coupled field theories, but it is not useful at finite temperature due to contamination from high-energy states. The known exception is an 't Hooft anomaly involving one-form symmetries as in pure $S U (N)$ Yang-Mills theory at $θ = π$ . Recent development about large- $N$ volume independence, however, gives us a circumstantial evidence that 't Hooft anomalies can also remain under circle compactifications in some theories without one-form symmetries. We develop a systematic procedure for deriving an 't Hooft anomaly of the circle-compactified theory starting from the anomaly of the original uncompactified theory without one-form symmetries, where the twisted boundary condition for the compactified direction plays a pivotal role. As an application, we consider $Z_{N}$ -twisted $C P^{N - 1}$ sigma model and massless $Z_{N}$ -QCD, and compute their anomalies explicitly.
Comments:
22 pages; (v2) references updated, minor changes
Subjects:
High Energy Physics — Theory (hep-th); Strongly Correlated Electrons (cond-mat.str-el); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
1710.08923 [pdf]
JHEP(2017)·98 citations
08
[Submitted on 24 Oct 2017] (cross-list from hep-ph)
QCD phase diagram from chiral symmetry restoration: analytic approach at high and low temperature using the Linear Sigma Model with Quarks
Alejandro Ayala🇿🇦 · Saul Hernandez-Ortiz🇲🇽 · Luis A. Hernandez🇲🇽
We use the linear sigma model with quarks to study the QCD phase diagram from the point of view of chiral symmetry restoration. We compute the leading order effective potential for high and low temperatures and finite quark chemical potential, up to the contribution of the ring diagrams to account for the plasma screening effects. We fix the values of the model couplings using physical values for the input parameters such as the vacuum pion and sigma masses, the critical temperature at vanishing quark chemical potential and the conjectured end point value of the baryon chemical potential of the transition line at vanishing temperature. We also make the analysis for the same input parameters but with vanishing pion mass. We find that the critical end point (CEP) is located at low temperatures and high quark chemical potentials $(315 < μ^{CEP} < 349 M e V, 18 < T^{CEP} < 45 M e V)$ .
Comments:
12 pages, 1 table and 9 figures. Expanded analysis including the chiral limit for the pion mass to estimate the coupling values. New discussion on the emergence of a boson chemical potential associated to density. Five references, one table and three figures added. To appear in Rev. Mex. Fis
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1710.09007 [pdf]
Rev.Mex.Fis.(2018)·28 citations
09
[Submitted on 24 Oct 2017] (cross-list from hep-lat)
Proton mass decomposition
Yi-Bo Yang🇺🇸 · Ying Chen🇨🇳 · Terrence Draper🇺🇸 · Jian Liang🇺🇸 · Keh-Fei Liu🇺🇸
We report the results on the proton mass decomposition and also on the related quark and glue momentum fractions. The results are based on overlap valence fermions on four ensembles of $N_{f} = 2 + 1$ DWF configurations with three lattice spacings and volumes, and several pion masses including the physical pion mass. With 1-loop perturbative calculation and proper normalization of the glue operator, we find that the $u, d,$ and $s$ quark masses contribute 9(2)\% to the proton mass. The quark energy and glue field energy contribute 31(5)\% and 37(5)\% respectively in the $M S$ scheme at $μ = 2$ GeV. The trace anomaly gives the remaining 23(1)\% contribution. The $u, d, s$ and glue momentum fractions in the $M S$ scheme are consistent with the global analysis at $μ = 2$ GeV.
Comments:
6 pages. Proceedings of the 35th International Symposium on Lattice Field Theory (Lattice2017), Granada, Spain
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1710.09011 [pdf]
EPJ Web Conf.(2018)·3 citations
10
[Submitted on 25 Oct 2017] (cross-list from hep-ph)
Mass hierarchy and energy scaling of the Tsallis--Pareto parameters in hadron productions at RHIC and LHC energies
Gábor Bíró🇭🇺 · Gergely Gábor Barnaföldi🇭🇺 · Tamás Sándor Biró🇭🇺 · Keming Shen🇨🇳
The latest, high-accuracy identified hadron spectra measurements in high-energy nuclear collisions led us to the investigation of the strongly interacting particles and collective effects in small systems. Since microscopical processes result in a statistical Tsallis-Pareto distribution, the fit parameters $q$ and $T$ are well suited for identifying system size scalings and initial conditions. Moreover, parameter values provide information on the deviation from the extensive, Boltzmann-Gibbs statistics in finite-volumes. We apply here the fit procedure developed in our earlier study for proton-proton collisions. The observed mass and $s$ energy trends in the hadron production are compared to RHIC dAu and LHC pPb data in different centrality/multiplicity classes. Here we present new results on mass hierarchy in pp and pA from light to heavy hadrons.
Comments:
Talk given by G.Bíró at SQM 2017, Utrecht, 4 pages
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1710.09062 [pdf]
EPJ Web Conf.(2018)·22 citations

Affiliations

first authorsco-authorsvia INSPIRE

Conformality Lost in Efimov Physics

Circle compactification and 't Hooft anomaly

QCD phase diagram from chiral symmetry restoration: analytic approach at high and low temperature using the Linear Sigma Model with Quarks

Proton mass decomposition

Mass hierarchy and energy scaling of the Tsallis--Pareto parameters in hadron productions at RHIC and LHC energies

Affiliations