HEP Phenomenology·hep-ph
14 papers—7 primary·7 cross-listed·reconstructed*
Richard J. Hill🇺🇸 · Gil Paz🇺🇸
We reply to misleading claims made in a comment to our work by Birse and McGovern in arXiv:1708.09341.
K. Lapidus🇺🇸 · M.H. Oliver🇺🇸
Modification of the hard jet substructure in terms of the Soft Drop jet grooming algorithm observables is studied for three different scenarios of jet quenching in a quark-gluon plasma: i) an explicit enhancement of the parton splitting functions, ii) increased soft gluon emissions induced by an in-medium virtuality gain, and iii) energy loss due to a drag force. Despite the fact that first two scenarios both correspond to a radiative energy loss mechanism and lead to similar modifications of parton showers, they are shown to have very different impacts on the momentum balance of hard subjets. Simulations for heavy-ion collisions based on the second scenario are presented and found to be in a good agreement with the experimental data.
We perform an analysis of the influence of non-standard neutrino interactions (NSI) on neutrino signal from dark matter annihilations in the Sun. Taking experimentally allowed benchmark values for the matter NSI parameters we show that the evolution of such neutrinos with energies at GeV scale can be considerably modified. We simulate propagation of neutrinos from the Sun to the Earth for realistic dark matter annihilation channels and find that the matter NSI can result in at most 30% correction to the signal rate of muon track events at neutrino telescopes. Still present experimental bounds on dark matter from these searches are robust in the presence of NSI within considerable part of their allowed parameter space. At the same time electron neutrino flux from dark matter annihilation in the Sun can be changed by a factor of few.
S.M. Troshin🇷🇺 · N.E. Tyurin🇷🇺
Experimental observations at the LHC of the collective effects in small systems such as --scattering suggest introduction of the centrality variable to classify collision events similar to the case of nucleus--nucleus collisions. We discuss this issue with reference to the existing measurements at the LHC and the asymptotical energy region.
Tobias Hurth🇩🇪 · Michael Benzke🇩🇪 · Michael Fickinger🇩🇪 · Sascha Turczyk🇩🇪
We identify the correct power counting of all the variables in the low- window of the inclusive decay within the effective theory SCET if a hadronic mass cut is imposed. Furthermore we analyse the resolved power corrections at the order in a systematic way. As a special feature, the resolved contributions stay nonlocal when the hadronic mass cut is released. Therefore they represent an irreducible uncertainty independent of the hadronic mass cut.
Daniel de Florian (ICAS-UNSAM)🇦🇷
We present the first fully differential next-to-leading order QCD calculation for lepton production in transversely polarized hadronic collisions, pp -> l X , where the lepton arises from the decay of an electroweak gauge boson. The calculation is implemented in the Monte-Carlo like code `CHE' that already includes the unpolarized and longitudinally polarized cross sections and may be readily used to perform a comparison to experimental data and to extract information on the related parton distributions. We analyze the perturbative stability of the cross-section and double spin asymmetry A_TT at RHIC kinematics. We find that the QCD corrections are non-negligible even at the level of asymmetries and that they strongly depend on the lepton kinematics. Furthermore, we present two scenarios for transversely polarized parton distributions, based on the de Florian-Sassot-Stratmann-Vogelsang (DSSV) set of longitudinally parton densities and fully evolved to NLO accuracy, that can be used for the evaluation of different observables involving transverse polarization.
Volodymyr Vovchenko🇩🇪 · Jan Steinheimer🇩🇪 · Owe Philipsen🇩🇪 · Horst Stoecker🇩🇪
A Cluster Expansion Model (CEM), representing a relativistic extension of Mayer's cluster expansion, is constructed to study baryon number fluctuations in QCD. The temperature dependent first two coefficients, corresponding to the partial pressures in the baryon number and sectors, are the only model input, which we fix by recent lattice data at imaginary baryochemical potential. All other coefficients are constructed in terms of the first two and required to match the Stefan-Boltzmann limit at . The CEM allows calculations of the baryon number susceptibilities to arbitrary order. We obtain excellent agreement with available lattice data for the baryon fluctuation measures , , and predict higher order susceptibilities, that are not yet available from Lattice QCD. The calculated susceptibilities are then used to extract the radius of convergence of the Taylor expansion of the pressure. The commonly used ratio test fails due to the non-trivial asymptotic behavior of the Taylor coefficients. At the same time, a more elaborate estimator provides finite convergence radii at all temperatures and in agreement with the singularities of Padé approximants. The associated singularities lie in the complex -plane and appear smoothly connected to the Roberge-Weiss transition at high temperatures and imaginary chemical potential. No evidence for a phase transition at is found.
We give a detailed analysis of an abelianized gauge field model in which a Rarita-Schwinger spin- field is directly coupled to a spin- field. The model permits a perturbative expansion in powers of the gauge field coupling, and from the Feynman rules for the model we calculate the chiral anomaly.
Fuminori Hasegawa🇯🇵 · Masahiro Kawasaki🇯🇵
In this letter, we propose a novel scenario which simultaneously explains primordial black holes (PBHs) and dark matter in the minimally supersymmetric standard model. Gravitational waves (GWs) events detected by LIGO-Virgo collaboration suggest an existence of black holes as heavy as . In our scenario, as seeds of the PBHs, we make use of the baryon number perturbations which are induced by the special type of Affleck-Dine mechanism. Furthermore, the scenario does not suffer from the stringent constraints from CMB -distortion due to the Silk damping and pulsar timing. We find the scenario can explain not only the current GWs events consistently, but also dark matter abundance by the non-topological solitons formed after Affleck-Dine mechanism, called Q-balls.
Thomas A. Ryttov🇩🇰 · Robert Shrock🇺🇸
We study duality in supersymmetric QCD in the non-Abelian Coulomb phase, order-by-order in scheme-independent series expansions. Using exact results, we show how the dimensions of various fundamental and composite chiral superfields, and the quantities , , and at superconformal fixed points of the renormalization group emerge in scheme-independent series expansions in the electric and magnetic theories. We further demonstrate that truncations of these series expansions to modest order yield very accurate approximations to these quantities.
To understand mechanisms leading to inflation and late acceleration of the Universe it is important to see how one or a set of quantum fields may evolve such that the classical energy-momentum tensor behave similar to a cosmological constant. In this work we consider a toy model including 3 scalar fields with very different masses to study the formation of a light axion-like condensate, presumed to be responsible for inflation and/or late accelerating expansion of the Universe. Despite its simplicity, this model reflects hierarchy of masses and couplings of the Standard Model and its candidate extensions. The investigation is performed in the framework of non-equilibrium quantum field theory in a consistently evolved FLRW geometry. We discuss in details how the initial conditions for such a model must be defined in a fully quantum setup and show that in a multi-component model interactions reduce the number of independent initial degrees of freedom. Numerical simulation of this model shows that it can be fully consistent with present cosmological observations. For the chosen range of parameters we find that quantum interactions rather than effective potential of a condensate is the dominant contributor in the energy density of the Universe and triggers both inflation and late accelerating expansion. Nonetheless, despite its small contribution in the energy density, the light scalar field - in both condensate and quasi free particle forms - has a crucial role in controlling the trend of heavier fields. Furthermore, up to precision of our simulations we do not find any IR singularity during inflation. These findings highlight uncertainties in attempts to extract information about physics of the early Universe by naively comparing predictions of local effective classical models with cosmological observations, neglecting inherently non-local nature of quantum processes.
Takumi Doi🇯🇵 · Takumi Iritani🇯🇵 · Sinya Aoki🇯🇵 · Shinya Gongyo🇯🇵 · Tetsuo Hatsuda🇯🇵 · Yoichi Ikeda🇯🇵 · Takashi Inoue🇯🇵 · Noriyoshi Ishii🇯🇵 · Takaya Miyamoto🇯🇵 · Hidekatsu Nemura🇯🇵 · Kenji Sasaki🇯🇵
We present the latest lattice QCD results for baryon interactions obtained at nearly physical quark masses. nonperturbatively -improved Wilson quark action with stout smearing and Iwasaki gauge action are employed on the lattice of with GeV, where MeV and MeV. In this report, we study the two-nucleon systems and two- systems in channel and - coupled channel, and extract central and tensor interactions by the HAL QCD method. We also present the results for the interaction in channel which is relevant to the pair-momentum correlation in heavy-ion collision experiments.
Jing-Jing Liu🇨🇳 · Dong-Mei Liu
The electron screening strong effect on the electron energy and threshold energy of the beta decay reaction. in this paper, we study the decay rates of some iron isotopes. The electron screening beta decay rates increase by about two orders of magnitude. The strong screening beta decay rates due to Q-value correction are by more than one order of magnitude higher than those of without Q-value correction.
M.E. Carrington🇨🇦 · C.S. Fischer🇩🇪 · L. von Smekal🇩🇪 · M.H. Thoma🇩🇪
We study the frequency dependencies of the fermion and photon dressing functions in dynamical gap generation in graphene. We use a low energy effective QED-like description, but within this approximation, we include all frequency dependent effects including retardation. We obtain the critical coupling by calculating the gap using a non-perturbative Dyson-Schwinger approach. Compared to the results of our previous calculation [1] which used a Lindhard screening approximation instead of including a self-consistently calculated dynamical screening function, the critical coupling is substantially reduced.
* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.