HEP Phenomenology·hep-ph

Mon·Jun 7, 2021Monday·June 7, 2021

15 papers—6 primary·9 cross-listed·reconstructed*

01*
Automated EW corrections with isolated photons: $t t ˉ γ$ , $t t ˉ γ γ$ and $t γ j$ as case studies
Davide Pagani🇩🇪 · Hua-Sheng Shao🇫🇷 · Ioannis Tsinikos🇸🇪 · Marco Zaro🇮🇹
In this work we compute for the first time the so-called Complete-NLO predictions for top-quark pair hadroproduction in association with at least one isolated photon ( $t t ˉ γ$ ). We also compute NLO QCD+EW predictions for the similar case with at least two isolated photons ( $t t ˉ γ γ$ ) and for single-top hadroproduction in association with at least one isolated photon. In addition, we complement our results with NLO QCD+EW predictions of the hadronic and leptonic decays of top-quark including an isolated photon. All these results have been obtained in a completely automated approach, by extending the capabilities of the MadGraph5_aMC@NLO framework and enabling the Complete-NLO predictions for processes with isolated photons in the final state. We discuss the technical details of the implementation, which involves a mixed EW renormalisation scheme for such processes.
hep-phhep-exJHEP(2021)·43 citations
02*
Neutrino-antineutrino oscillations induced by strong magnetic fields in dense matter
Hirokazu Sasaki🇯🇵 · Tomoya Takiwaki🇯🇵
We simulate neutrino-antineutrino oscillations caused by strong magnetic fields in dense matter. With the strong magnetic fields and large neutrino magnetic moments, Majorana neutrinos can reach flavor equilibrium. We find that the flavor equilibration of neutrino-antineutrino oscillations is sensitive to the values of the baryon density and the electron fraction inside the matter. The neutrino-antineutrino oscillations are suppressed in the case of the large baryon density in neutron (proton)-rich matter. On the other hand, the flavor equilibration occurs when the electron fraction is close to $0.5$ even in the large baryon density. From the simulations, we propose a necessary condition for the equilibration of neutrino-antineutrino oscillations in dense matter. We also study whether such necessary condition is satisfied near the proto-neutron star by using results of neutrino hydrodynamic simulations of core-collapse supernovae. In our explosion model, the flavor equilibration would be possible if the magnetic field on the surface of the proto-neutron star is larger than $1 0^{14}$ G which is the typical value of the magnetic fields of magnetars.
hep-phastro-ph.HEPRD(2021)·18 citations
03*
Composite Model of Quarks and Leptons
Yoshio Koide🇯🇵
A compsite model of quarks and leptons is proposed. The quarks and leptons are given by three body states which are composed of constituents $(w_{1}, w_{2}, c_{1}, c_{2}, c_{3})$ of SU(5) $_{f l a v or}$ and $(f_{1}, f_{2}, f_{3})$ of SU(3) $_{f ami l y}$
hep-ph1 citation
04*
Primordial Black Hole Dark Matter evaporating on the Neutrino Floor
Roberta Calabrese🇮🇹 · Damiano F.G. Fiorillo🇮🇹 · Gennaro Miele🇮🇹 · Stefano Morisi🇮🇹 · Antonio Palazzo🇮🇹
Primordial black holes (PBHs) hypothetically generated in the first instants of life of the Universe are potential dark matter (DM) candidates. Focusing on PBHs masses in the range $[5 \times 1 0^{14} - 5 \times 1 0^{15}]$ g, we point out that the neutrinos emitted by PBHs evaporation can interact through the coherent elastic neutrino nucleus scattering (CE $ν$ NS) producing an observable signal in multi-ton DM direct detection experiments. We show that with the high exposures envisaged for the next-generation facilities, it will be possible to set bounds on the fraction of DM composed by PBHs improving the existing neutrino limits obtained with Super-Kamiokande. We also quantify to what extent a signal originating from a small fraction of DM in the form of PBHs would modify the so-called "neutrino floor", the well-known barrier towards detection of weakly interacting massive particles (WIMPs) as the dominant DM component.
hep-phastro-ph.COhep-exPLB(2022)·42 citations
05*
Multi-partonic medium induced cascades in expanding media
Souvik Priyam Adhya🇨🇿 · Carlos A. Salgado🇪🇸 · Martin Spousta🇨🇿 · Konrad Tywoniuk🇳🇴
Going beyond the simplified gluonic cascades, we introduce both gluon and quark degrees of freedom for partonic cascades inside the medium. We then solve the set of coupled evolution equations numerically with splitting kernels calculated for static, exponential, and Bjorken expanding media to arrive at medium-modified parton spectra for quark and gluon initiated jets. Using these, we calculate the inclusive jet $R_{AA}$ where the phenomenologically driven combinations of quark and gluon jet fractions are included. Then, the rapidity dependence of the jet $R_{AA}$ is examined. We also study the path-length dependence of jet quenching for different types of expanding media by calculating the jet $v_{2}$ . Additionally, we study the sensitivity of observables on effects from nuclear modification of parton distribution functions, vacuum-like emissions in the plasma, and the time of the onset of the quenching. All calculations are compared with recently measured data.
hep-phEPJC(2022)·26 citations
06*
QCD surprises: strong CP problem, neutrino mass, Dark Matter and Dark Energy
Andrea Addazi🇨🇳 · Antonino Marciano🇨🇳 · Roman Pasechnik🇸🇪 · Kaiqiang Alan Zeng🇨🇳
An unexpected explanation for neutrino mass, Dark Matter (DM) and Dark Energy (DE) from genuine Quantum Chromodynamics (QCD) of the Standard Model (SM) is proposed here, while the strong CP problem is resolved without any need to account for fundamental axions. We suggest that the neutrino sector can be in a double phase in the Universe: i) relativistic neutrinos, belonging to the SM; ii) non-relativistic condensate of Majorana neutrinos. The condensate of neutrinos can provide an attractive alternative candidate for the DM, being in a cold coherent state. We will explain how neutrinos, combining into Cooper pairs, can form collective low-energy degrees of freedom, hence providing a strongly motivated candidate for the QCD (composite) axion.
hep-phgr-qchep-thPhys.Dark Univ.(2022)·5 citations
07*
Measurement of high energy dark matter from the Sun at IceCube
Ye Xu🇨🇳
It is assumed that heavy dark matter particles (HDMs) with a mass of O(TeV) are captured by the Sun. HDMs can decay to relativistic light dark matter particles (LDMs), which could be measured by km $^{3}$ neutrino telescopes (like the IceCube detector). The numbers and fluxes of expected LDMs and neutrinos were evaluated at IceCube with the $Z^{'}$ portal dark matter model. Based on the assumption that no events are observed at IceCube in 6 years, the corresponding upper limits on LDM fluxes were calculated at 90\% C. L.. These results indicated that LDMs could be directly detected in the O(1TeV)-O(10TeV) energy range at IceCube with 100 GeV $≲ m_{Z^{'}} ≲$ 350 GeV and $τ_{ϕ} ≲ 5 \times 1 0^{22}$ s.
↳ astro-ph.HEhep-phJHEP(2021)·4 citations
08*
Measurements of Born Cross Sections of $e^{+} e^{-} \to D_{s}^{*+} D_{s J}^{-} + c . c .$
BESIII Collaboration: M. Ablikim · M. N. Achasov · P. Adlarson · S. Ahmed · M. Albrecht · R. Aliberti · A. Amoroso · M. R. An · Q. An · X. H. Bai · Y. Bai · O. Bakina and 501 other authors
The Born cross sections are measured for the first time for the processes $e^{+} e^{-} \to D_{s}^{*+} D_{s 0}^{*} (2317)^{-} + c . c .$ and $e^{+} e^{-} \to D_{s}^{*+} D_{s 1} (2460)^{-} + c . c .$ at the center-of-mass energy $s =$ 4.600~GeV, 4.612~GeV, 4.626~GeV, 4.640~GeV, 4.660~GeV, 4.68~GeV, and 4.700~GeV, and for $e^{+} e^{-} \to D_{s}^{*+} D_{s 1} (2536)^{-} + c . c .$ at $s =$ 4.660~GeV, 4.680~GeV, and 4.700~GeV, using data samples collected with the BESIII detector at the BEPCII collider. No structures are observed in cross-section distributions for any of the processes.
↳ hep-exhep-phPRD(2021)·8 citations
09*
Spectrum oscillations from features in the potential of single-field inflation
I. Dalianis🇬🇷 · G.P. Kodaxis🇬🇷 · I.D. Stamou🇬🇷 · N. Tetradis🇬🇷 · A. Tsigkas-Kouvelis🇬🇷
We study single-field inflationary models with steep step-like features in the potential that lead to the temporary violation of the slow-roll conditions during the evolution of the inflaton. These features enhance the power spectrum of the curvature perturbations by several orders of magnitude at certain scales and also produce prominent oscillatory patterns. We study analytically and numerically the inflationary dynamics. We describe quantitatively the size of the enhancement, as well as the profile of the oscillations, which are shaped by the number and position of the features in the potential. The induced tensor power spectrum inherits the distinctive oscillatory profile of the curvature spectrum and is potentially detectable by near-future space interferometers. The enhancement of the power specrtum by step-like features, though significant, may be insufficient to trigger the production of a sizeable number of primordial black holes if radiation dominates the energy density of the early universe. However, it can result in sufficient black hole production if the universe is dominated by non-relativistic matter. For the latter scenario, we find that deviations from the standard monochromatic profile of the mass spectrum of primordial black holes are possible because of the multiple-peak structure of the curvature power spectrum.
↳ astro-ph.COgr-qchep-phPRD(2021)·53 citations
10*
Impact of Multiplicity Fluctuations on Entropy Scaling Across System Size
Patrick Carzon🇺🇸 · Matthew D. Sievert🇺🇸 · Jacquelyn Noronha-Hostler🇺🇸
The initial state is one of the greatest uncertainties in heavy-ion collisions. A model-agnostic approach is taken in the phenomenological Trento framework which constrains parameters using Bayesian analysis. However, the color-glass condensate (CGC) effective theory predicts initial energy densities that lie outside the recent Bayesian analyses due, in part, to the assumption in Trento of event-by-event multiplicity fluctuations following a $Γ$ distribution. We compare the Trento-preferred $T_{A} T_{B}$ scaling to CGC-like $T_{A} T_{B}$ scaling coupled with log-normal fluctuations in $A u A u$ and $d A u$ collisions and find there is a significant impact on the multiplicity distributions and on the eccentricities, which may affect the extraction of viscosity in small systems.
↳ nucl-thhep-phnucl-exPRC(2022)·6 citations
11*
Hints of FLRW Breakdown from Supernovae
Chethan Krishnan🇮🇳 · Roya Mohayaee🇫🇷 · Eoin Ó Colgáin🇰🇷 · M. M. Sheikh-Jabbari🇮🇷 · Lu Yin🇰🇷
A 10\% difference in the scale for the Hubble parameter constitutes a clear problem for cosmology. Here, considering angular distribution of Type Ia supernovae (SN) within the Pantheon compilation and working within flat $Λ$ CDM cosmology, we observe a correlation between higher $H_{0}$ and the CMB dipole direction, confirming our previous results for strongly-lensed quasars \cite{Krishnan:2021dyb}. Concretely, we record a $\sim 1$ km/s/Mpc variation in $H_{0}$ at antipodal points on the sky within the Pantheon sample, which is evident in the Low $z$ subsample ( $z ≲ 0.075$ ) and gets enhanced by higher redshift SN. Our work raises the possibility that we may be at the precision required to probe anisotropic Hubble expansions, while providing a concrete prediction for future inferences of $H_{0}$ .
↳ astro-ph.COgr-qchep-phhep-thPRD(2022)·129 citations
12*
Towards charged hadron polarizabilities from four-point functions in lattice QCD
Walter Wilcox🇺🇸 · Frank X. Lee🇺🇸
We show how to compute electromagnetic polarizabilities of charged hadrons using four-point functions in lattice QCD. The low-energy behavior of Compton scattering amplitude is matched to matrix elements of current-current correlation functions on the lattice. Working in momentum space, formulas for electric polarizability ( $α_{E}$ ) and magnetic polarizability ( $β_{M}$ ) are derived for both charged pion and proton. Lattice four-point correlation functions are constructed from quark and gluon fields to be used in Monte-Carlo simulations. The content of the functions is assessed in detail and specific prescriptions are given to isolate the polarizabilities. The connected quark-line diagrams can be done today as a small lattice project. The disconnected diagrams are more challenging but are within reach of dedicated resources for medium to large lattice projects. We also draw attention to the potential of four-point functions as a multi-purpose tool for hadron structure.
↳ hep-lathep-phPRD(2021)·20 citations
13*
A simple description of holographic domain walls in confining theories -- extended hydrodynamics
Romuald A. Janik🇵🇱 · Matti Jarvinen🇰🇷 · Jacob Sonnenschein🇮🇱
In the context of theories with a first order phase transition, we propose a general covariant description of coexisting phases separated by domain walls using an additional order parameter-like degree of freedom. In the case of a holographic Witten model with a confining and deconfined phase, the resulting model extends hydrodynamics and has a simple formulation in terms of a spacetime action with corresponding expressions for the energy-momentum tensor. The proposed description leads to simple analytic profiles of domain walls, including expressions for surface tension density, which agree nicely with holographic numerical solutions, despite the apparent complexity of those gravitational backgrounds.
↳ hep-thhep-phJHEP(2021)·20 citations
14*
New method for detecting fast neutrino flavor conversions in core-collapse supernova models with two-moment neutrino transport
Hiroki Nagakura🇺🇸 · Lucas Johns🇺🇸
Fast-pairwise neutrino oscillations potentially affect many aspects of core-collapse supernova (CCSN): the explosion mechanism, neutrino signals, and nucleosynthesis in the ejecta. This particular mode of collective neutrino oscillations has a deep connection to the angular structure of neutrinos in momentum space; for instance, the appearance of electron neutrinos lepton number (ELN) angular crossings in momentum space is a good indicator of occurrences of the flavor conversions. However, many multi-dimensional (multi-D) CCSN simulations are carried out with approximate neutrino transport (such as two-moment methods), which limits the access to the angular distributions of neutrinos, i.e., inhibits ELN-crossing searches. In this paper, we develop a new method of ELN-crossing search in these CCSN simulations. The required data is the zero-th and first angular moments of neutrinos and matter profile, all of which are available in CCSN models with two-moment method. One of the novelties of our new method is to use a ray-tracing neutrino transport to determine ELNs in the direction of the stellar center. It is designed to compensate for shortcomings of the crossing searches only with the two angular moments. We assess the capability of the method by carrying out a detailed comparison to results of full Boltzmann neutrino transport in 1D and 2D CCSN models. We find that the ray-tracing neutrino transport improves the accuracy of crossing searches; indeed, the appearance/disappearance of the crossings is accurately detected even in the region of forward-peaked angular distributions. The new method is computationally cheap and has a benefit of efficient parallelization; hence, it will be useful for ELN-crossing searches in any CCSN models employed two-moment neutrino transport.
↳ astro-ph.HEhep-phPRD(2021)·34 citations
15*
Ladder resummation of spin 1/2 fermion many-body systems with arbitrary partial-wave content
J. M. Alarcón🇪🇸 · J. A. Oller🇪🇸
We resum the ladder diagrams for the calculation of the energy density $E$ of a spin 1/2 fermion many-body system in terms of arbitrary vacuum two-body scattering amplitudes. The partial-wave decomposition of the in-medium two-body scattering amplitudes is developed, and the expression for calculating $E$ in a partial-wave amplitude expansion is also given. The case of contact interactions is completely solved and is shown to provide renormalized results, expressed directly in terms of scattering data parameters, within cutoff regularization in a wide class of schemes. $S$ - and $P$ -wave interactions are considered up to including the first three-terms in the effective-range expansion, paying special attention to the parametric region around the unitary limit.
↳ nucl-thcond-mat.quant-gashep-phAnnals Phys.(2022)·10 citations

* 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.