Nuclear Theory·nucl-th

Thursday·August 10, 2017

5 papers—3 primary·2 cross-listed

04
[Submitted on 8 Aug 2017] (cross-list from hep-ph)
Extracting a Short Distance Top Mass with Light Grooming
Andre H. Hoang🇦🇹 · Sonny Mantry🇺🇸 · Aditya Pathak🇺🇸 · Iain W. Stewart🇺🇸
We propose a kinematic method based on a factorization formula for precisely measuring the top quark mass $m_{t}$ in $pp$ collisions using boosted top jets with light soft drop grooming. By using light grooming, which is an order of magnitude less aggressive than typical grooming, we retain a universal description of the top mass scheme and decay effects, while still effectively removing soft contamination from the top jet. We give field theory results for the hadronization corrections for jets induced by a heavy top quark, showing they are described by a universal hadronic parameter that also appears for groomed light quark jets. An important phenomenological application of our results is that one can obtain $m_{t}$ in a short distance scheme by fitting the hadron level jet mass distributions, predicted by our factorization formula, to data or by Monte-Carlo calibration. The peaked distributions for $pp$ and $e^{+} e^{-}$ collisions are similar, up to sensitivity to underlying event which is significantly reduced by soft drop. Since soft drop implies that the $t$ and $t ˉ$ jet masses each can be independently measured, the analysis enables the use of lepton+jet samples.
Comments:
v2: substantially extended text, now has 20 pages with 15 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
1708.02586 [pdf]
PRD(2019)·98 citations
05
[Submitted on 9 Aug 2017] (cross-list from hep-ph)
Repulsive baryonic interactions and lattice QCD observables at imaginary chemical potential
Volodymyr Vovchenko🇩🇪 · Attila Pasztor🇩🇪 · Zoltan Fodor🇭🇺 · Sandor D. Katz🇭🇺 · Horst Stoecker🇩🇪
The first principle lattice QCD methods allow to calculate the thermodynamic observables at finite temperature and imaginary chemical potential. These can be compared to the predictions of various phenomenological models. We argue that Fourier coefficients with respect to imaginary baryochemical potential are sensitive to modeling of baryonic interactions. As a first application of this sensitivity, we consider the hadron resonance gas (HRG) model with repulsive baryonic interactions, which are modeled by means of the excluded volume correction. The Fourier coefficients of the imaginary part of the net-baryon density at imaginary baryochemical potential -- corresponding to the fugacity or virial expansion at real chemical potential -- are calculated within this model, and compared with the $N_{t} = 12$ lattice data. The lattice QCD behavior of the first four Fourier coefficients up to $T ≃ 185$ MeV is described fairly well by an interacting HRG with a single baryon-baryon eigenvolume interaction parameter $b ≃ 1$ fm $^{3}$ , while the available lattice data on the difference $χ_{2}^{B} - χ_{4}^{B}$ of baryon number susceptibilities is reproduced up to $T ≃ 175$ MeV.
Comments:
11 pages, 4 figures, new Fig. 2 depicting $χ_{2}^{B} - χ_{4}^{B}$ , version accepted for publication in Physics Letters B
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
1708.02852 [pdf]
PLB(2017)·113 citations

Affiliations

first authorsco-authorsvia INSPIRE

Extracting a Short Distance Top Mass with Light Grooming

Repulsive baryonic interactions and lattice QCD observables at imaginary chemical potential

Affiliations