Thu·Sep 2, 2021Thursday·September 2, 2021

1. 01*

   Black Hole Production of Monopoles in the Early Universe

   Saurav Das🇺🇸 · Anson Hook🇺🇸

   In the early universe, evaporating black holes heat up the surrounding plasma and create a temperature profile around the black hole that can be more important than the black hole itself. As an example, we demonstrate how the hot plasma surrounding evaporating black holes can efficiently produce monopoles via the Kibble-Zurek mechanism. In the case where black holes reheat the universe, reheat temperatures above $\sim 500$ GeV can already lead to monopoles overclosing the universe.

   hep-phJHEP(2021)·34 citations
2. 02*

   CP violation in mixing and oscillations for leptogenesis II: the highly degenerate case

   J. Racker🇦🇷

   We extend to the highly degenerate case a recent approach for analyzing the sources of CP violation in baryogenesis models with quasi-degenerate neutrinos. In this approach an expansion of the resummed propagator around the poles is plugged into a quantum field theory model of neutrino oscillations and a source term for the time evolution of the lepton asymmetry is built directly from the probabilities of lepton number violating processes involving only stable particles. This allows for a transparent consideration of unitarity requirements. The source term has contributions that can be identified with CP violation from mixing, oscillations and interference between both. For the highly degenerate case, i.e. when the mass difference between two neutrinos is similar or smaller than their decay widths, we find that in general the mixing and oscillation terms contribute with opposite signs to the generation of lepton asymmetry and the contribution of the interference term is typically very relevant and crucial to ensure unitarity is satisfied. Moreover, the expressions we obtain are finite in the double degenerate limit of equal masses and couplings. The calculations are done in a simple scalar toy model.

   hep-phJHEP(2021)·6 citations
3. 03*

   Simulations of Fast Neutrino Flavor Conversions with Interactions in Inhomogeneous Media

   Guenter Sigl🇩🇪

   We investigate toy models for spatial and temporal instabilities in collective neutrino oscillations induced by neutrino self-interactions, with special emphasis on inhomogeneous systems with densities following a profile. Simulations are based on a mathematica program that solves the Liouville equation with or without vacuum terms, refractive terms from a background medium, and neutrino-neutrino forward scattering, in one space dimension and in time. A discrete number of momentum modes are characterized by the neutrino velocity projection on the spatial direction. We also consider the effects of charged current interaction source terms and neutral current scattering contributions. We find that refractive effects from the medium, in particular for density distributions with a profile, and neutral current non-forward scattering off the background medium can strongly influence fast collective flavor transformations. Specifically we find that if both are present, fast flavor conversions can be strongly suppressed or at least delayed.

   hep-phastro-ph.HEPRD(2022)·63 citations
4. 04*

   Fluctuations and Selection Bias in 5 and 13 TeV p-p Collisions: Where are the jets?

   Thomas A. Trainor🇺🇸

   The ALICE collaboration recently reported high-statistics ${\mathbf{p}}_{\mathbf{t}}$ spectra from 5 TeV and 13 TeV p-p collisions with intent to determine the role of jets in high-multiplicity collisions. In the present study a two-component (soft + hard) model (TCM) of hadron production in p-p collisions is applied to ALICE ${\mathbf{p}}_{\mathbf{t}}$ spectra. As in previous TCM studies of A-B collision systems jet and nonjet contributions to ${\mathbf{p}}_{\mathbf{t}}$ spectra are accurately separated over the entire ${\mathbf{p}}_{\mathbf{t}}$ acceptance. The statistical significance of data-model differences is established leading to insights concerning selection bias and spectrum model validity.

   hep-phhep-exSciPost Phys.Proc.(2022)·0 citations
5. 05*

   Baryogenesis from ultra-slow-roll inflation

   Yi-Peng Wu🇫🇷 · Elena Pinetti🇫🇷 · Kalliopi Petraki🇫🇷 · Joseph Silk🇫🇷

   The ultra-slow-roll (USR) inflation represents a class of single-field models with sharp deceleration of the rolling dynamics on small scales, leading to a significantly enhanced power spectrum of the curvature perturbations and primordial black hole (PBH) formation. Such a sharp transition of the inflationary background can trigger the coherent motion of scalar condensates with effective potentials governed by the rolling rate of the inflaton field. We show that a scalar condensate carrying (a combination of) baryon or lepton number can achieve successful baryogenesis through the Affleck-Dine mechanism from unconventional initial conditions excited by the USR transition. Viable parameter space for creating the correct baryon asymmetry of the Universe naturally incorporates the specific limit for PBHs to contribute significantly to dark matter, shedding light on the cosmic coincidence problem between the baryon and dark matter densities today.

   hep-phastro-ph.COhep-thJHEP(2022)·15 citations
6. 06*

   Cross-correlation Power Spectra and Cosmic Birefringence of the CMB via Photon-neutrino Interaction

   Roohollah Mohammadi🇮🇷 · Jafar Khodagholizadeh🇮🇷 · Mahdi Sadegh🇮🇷 · Ali Vahedi🇮🇷 · She-sheng Xue🇮🇹

   In the context of the standard model of particles, the weak interaction of cosmic microwave background (CMB) and cosmic neutrino background (C$\nu$B), can generate non-vanishing TB and EB power spectra in the order of one loop forward scattering, in the presence of scalar perturbation, which is in contrast with the standard scenario cosmology. Comparing our results with the current experimental data may provide, significant information about the nature of C$\nu$B, including CMB-C$\nu$B forward scattering for TB, TE, and EB power spectra. To this end, different cases were studied, including Majorana C$\nu$B and Dirac C$\nu$B. On the other hand, it was shown that the mean opacity due to cosmic neutrino background could behave as an anisotropic birefringent medium and change the linear polarization rotation angle. Considering the contributions from neutrino and anti-neutrino forward scattering with CMB photons (in the case of Dirac neutrino), we introduce relative neutrino and anti-neutrino density asymmetry (${\delta }_{\nu }=\frac{\Delta n_{\nu }}{n_{\nu }}=\frac{n_{\nu }-n_{\bar{\nu }}}{n_{\nu }}$). Then, using the cosmic birefringence angle reported by the Planck data release $\beta =0.30^{\circ }\pm 0.11^{\circ }$ ($68\%C.L.$), some constraints can be put on ${\delta }_{\nu }$. Also, the value of cosmic birefringence due to Majorana C$\nu$B medium is estimated at about $\beta {|}_{\nu }\simeq 0.2$ rad. In this respect, since Majorana neutrino and anti-neutrino are exactly the same, both CB contributions will be added together. However, this value is at least two orders larger than the cosmic birefringence angle reported by the Planck data release, $\beta =0.30^{\circ }\pm 0.11^{\circ }$ ($68\%C.L.$).

   hep-phastro-ph.HEJCAP(2023)·9 citations
7. 07*

   Study of $D_s^{+}\to K^{+}{K}^{-}{\pi }^{+}$ decay

   Zhong-Yu Wang🇨🇳 · Jing-Yu Yi🇨🇳 · Zhi-Feng Sun🇨🇳 · C. W. Xiao🇨🇳

   We investigate the $D_s^{+}\to K^{+}{K}^{-}{\pi }^{+}$ decay theoretically with the final state interactions, which is based on the chiral unitary approach and takes into account the external and internal $W$-emission mechanisms at the quark level. Only considering three resonances contributions, the $f_0(980)$ in $S$-wave, the ${\bar{K}}^{\ast }(892{)}^0$ and $\varphi (1020)$ in $P$-wave, one can make a good description of the recent experimental data from BESIII Collaboration, where the contribution from $S$-wave is found to be small. Besides, we also make a calculation of the corresponding branching fractions, which are consistent with the results of BESIII Collaboration and Particle Data Group.

   hep-phhep-exPRD(2022)·19 citations
8. 08*

   Determination of parameters of a potential model for tetraquark study by studying all S-wave mesons

   Zheng Zhao🇹🇭 · Kai Xu🇹🇭 · Attaphon Kaewsnod🇹🇭 · Xuyang Liu🇨🇳 · Ayut Limphirat🇹🇭 · Yupeng Yan🇹🇭

   The masses of low-lying S-wave mesons are evaluated in a constituent quark model (CQM) where the Cornell-like potential and one-gluon exchange spin-spin interaction are employed. To make the model applicable to both the light and heavy quark sectors, we introduce mass-dependent coupling coefficients. There are four free parameters in the model, which are determined by comparing the theoretical results with experimental data. The established model with one set of parameters may be applied to study higher excited meson states as well as multiquark systems in both the light and heavy quark sectors.

   hep-phFew Body Syst.(2021)·5 citations
9. 09*

   Quantum Kinetic Theory for Quantum Electrodynamics

   Shu Lin🇨🇳

   We derive a quantum kinetic theory for QED based on Kadanoff-Baym equations for Wigner functions. By assuming parity invariance and considering a complete set of self-energy diagrams, we find the resulting kinetic theory expanded to lowest order in $\hslash$ generalizes the well-known classical kinetic theory to massive case. It contains elastic and inelastic collision terms and integrates screening effect naturally. For a given solution to the classical kinetic theory, we find at next order in $\hslash$ a non-dynamical quantum correction to Wigner functions for both fermions and photons, which gives rise to spin polarization for fermion and photon respectively. The approach allows us to study the non-dynamical part of collisional effect on spin polarization phenomenon.

   hep-phnucl-thPRD(2022)·44 citations
10. 10*

    Analysis of multiplicity dependencies of midrapidity pt distributions of identified charged particles in p+p collisions at (s)1/2=7 TeV at the LHC

    Khusniddin K. Olimov🇺🇿 · Fu-Hu Liu🇨🇳 · Kobil A. Musaev🇺🇿 · Maratbek Z. Shodmonov🇺🇿

    Multiplicity dependencies of midrapidity transverse momentum distributions of identified charged particles in inelastic proton-proton collisions at center-of-mass energy of 7 TeV at the Large Hadron Collider (LHC), measured by ALICE Collaboration, have been analyzed. The full abstract with important results on the established effective temperature versus energy density dependence, estimated critical energy densities for probable deconfinement phase transition in proton-proton collisions at center-of-mass energy of 7 and 13 TeV and other results is given in the manuscript file.

    hep-phhep-exUniverse(2022)·19 citations
11. 11*

    QCD sum rules analysis of weak decays of doubly heavy baryons: the $b\to c$ processes

    Zhi-Peng Xing🇨🇳 · Zhen-Xing Zhao🇨🇳

    A comprehensive study of $b\to c$ weak decays of doubly heavy baryons is presented in this paper. The transition form factors as well as the pole residues of the initial and final states are respectively obtained by investigating the three-point and two-point correlation functions in QCD sum rules. Contributions from up to dimension-6 operators are respectively considered for the two-point and three-point correlation functions. The obtained form factors are then applied to a phenomenological analysis of semi-leptonic decays.

    hep-phEPJC(2021)·21 citations
12. 12*

    Measuring $CP$ nature of $h\tau \bar{\tau }$ coupling at $e^{-}p$ collider

    Sukanta Dutta🇮🇳 · Ashok Goyal🇮🇳 · Mukesh Kumar🇿🇦 · Abhaya Kumar Swain🇮🇳

    The proposed future $e^{-}p$ collider provides sufficient energies to produce the Standard Model Higgs Boson ($h$) through $W^{\pm }$ and $Z$-Boson fusion in charged and neutral current modes, respectively and to measure its properties. We take this opportunity to investigate the prospect of measuring the $CP$ properties of $h$ through $h\to {\tau }^{+}{\tau }^{-}$, where ${\tau }^{-}\left({\tau }^{+}\right)$ decays to a charged pion ${\pi }^{-}\left({\pi }^{+}\right)$ and a neutral pion ${\pi }^0$ in association with neutrino (anti-neutrino). An interesting $CP$ sensitive angular observable ${\alpha }_{\mathrm{CP}}$ between the two $\tau$-leptons decay plane in the ${\pi }^{+}{\pi }^{-}$ centre of mass frame is proposed and investigated in this work. For fixed electron energy of 150 GeV along with 7 (50) TeV of proton energy, the $CP$ phase can be measured approximately to $25^{\circ }$ ($14^{\circ }$) at integrated luminosity of 1~ab${}^{-1}$ for $-$80\% polarised electron at 95\% confidence level.

    hep-phhep-exEPJC(2022)·4 citations
13. 13*

    Classifying Anomalies THrough Outer Density Estimation (CATHODE)

    Anna Hallin🇺🇸 · Joshua Isaacson🇺🇸 · Gregor Kasieczka🇩🇪 · Claudius Krause🇺🇸 · Benjamin Nachman🇺🇸 · Tobias Quadfasel🇩🇪 · Matthias Schlaffer🇺🇸 · David Shih🇺🇸 · Manuel Sommerhalder🇩🇪

    We propose a new model-agnostic search strategy for physics beyond the standard model (BSM) at the LHC, based on a novel application of neural density estimation to anomaly detection. Our approach, which we call Classifying Anomalies THrough Outer Density Estimation (CATHODE), assumes the BSM signal is localized in a signal region (defined e.g. using invariant mass). By training a conditional density estimator on a collection of additional features outside the signal region, interpolating it into the signal region, and sampling from it, we produce a collection of events that follow the background model. We can then train a classifier to distinguish the data from the events sampled from the background model, thereby approaching the optimal anomaly detector. Using the LHC Olympics R&D dataset, we demonstrate that CATHODE nearly saturates the best possible performance, and significantly outperforms other approaches that aim to enhance the bump hunt (CWoLa Hunting and ANODE). Finally, we demonstrate that CATHODE is very robust against correlations between the features and maintains nearly-optimal performance even in this more challenging setting.

    hep-phhep-exphysics.data-anPRD(2022)·174 citations
14. 14*

    The Breakdown of Resummed Perturbation Theory at High Energies

    Sebastian Schenk🇬🇧

    Calculations of high-energy processes involving the production of a large number of particles in weakly-coupled quantum field theories have previously signaled the need for novel non-perturbative behavior or even new physical phenomena. In some scenarios, already tree-level computations may enter the regime of large-order perturbation theory and therefore require a careful investigation. We demonstrate that in scalar quantum field theories with a unique global minimum, where suitably resummed perturbative expansions are expected to capture all relevant physical effects, perturbation theory may still suffer from severe shortcomings in the high-energy regime. As an example, we consider the computation of multiparticle threshold amplitudes of the form $1\to n$ in ${\phi }^6$ theory with a positive mass term, and show that they may violate unitarity of the quantum theory for large $n$, even after the resummation of all leading-$n$ quantum corrections. We further argue that this is a generic feature of scalar field theories with higher-order self-interactions beyond ${\phi }^4$, thereby rendering the latter unique with respect to its high-energy behavior.

    hep-phhep-thJHEP(2022)·9 citations
15. 15*

    Search for the Chiral Magnetic Effect with Isobar Collisions at $\sqrt{s_{NN}}$ = 200 GeV by the STAR Collaboration at RHIC

    STAR Collaboration: M. S. Abdallah · B. E. Aboona · J. Adam · L. Adamczyk · J. R. Adams · J. K. Adkins · G. Agakishiev · I. Aggarwal · M. M. Aggarwal · Z. Ahammed · I. Alekseev · D. M. Anderson and 385 other authors

    The chiral magnetic effect (CME) is predicted to occur as a consequence of a local violation of $\mathcal{P}$ and $\mathcal{C}\mathcal{P}$ symmetries of the strong interaction amidst a strong electro-magnetic field generated in relativistic heavy-ion collisions. Experimental manifestation of the CME involves a separation of positively and negatively charged hadrons along the direction of the magnetic field. Previous measurements of the CME-sensitive charge-separation observables remain inconclusive because of large background contributions. In order to better control the influence of signal and backgrounds, the STAR Collaboration performed a blind analysis of a large data sample of approximately 3.8 billion isobar collisions of ${}_{44}^{96}$Ru+${}_{44}^{96}$Ru and ${}_{40}^{96}$Zr+${}_{40}^{96}$Zr at $\sqrt{s_{\mathrm{NN}}}=200$ GeV. Prior to the blind analysis, the CME signatures are predefined as a significant excess of the CME-sensitive observables in Ru+Ru collisions over those in Zr+Zr collisions, owing to a larger magnetic field in the former. A precision down to 0.4% is achieved, as anticipated, in the relative magnitudes of the pertinent observables between the two isobar systems. Observed differences in the multiplicity and flow harmonics at the matching centrality indicate that the magnitude of the CME background is different between the two species. No CME signature that satisfies the predefined criteria has been observed in isobar collisions in this blind analysis.

    ↳ nucl-exhep-exhep-phnucl-thPRC(2022)·328 citations
16. 16*

    Ab initio structure factors for spin-dependent dark matter direct detection

    B. S. Hu🇨🇦 · J. Padua-Argüelles🇨🇦 · S. Leutheusser🇨🇦 · T. Miyagi🇨🇦 · S. R. Stroberg🇺🇸 · J. D. Holt🇨🇦

    We present converged ab initio calculations of structure factors for elastic spin-dependent WIMP scattering off all nuclei used in dark matter direct-detection searches: ${}^{19}$F, ${}^{23}$Na, ${}^{27}$Al, ${}^{29}$Si, ${}^{73}$Ge, ${}^{127}$I, and ${}^{129,131}$Xe. From a set of established two- and three-nucleon interactions derived within chiral effective field theory, we construct consistent WIMP-nucleon currents at the one-body level, including effects from axial-vector two-body currents. We then apply the in-medium similarity renormalization group to construct effective valence-space Hamiltonians and consistently transformed operators of nuclear responses. Combining the recent advances of natural orbitals with three-nucleon forces expressed in large spaces, we obtain basis-space converged structure factors even in heavy nuclei. Generally results are consistent with previous calculations, but large uncertainties in ${}^{127}$I highlight the need for further study.

    ↳ nucl-thastro-ph.COhep-exhep-ph+1PRL(2022)·47 citations
17. 17*

    Conserved charge fluctuations at vanishing net-baryon density from Lattice QCD

    Jishnu Goswami🇩🇪 · Frithjof Karsch🇩🇪 · Swagato Mukherjee🇺🇸 · Peter Petreczky🇺🇸 · Christian Schmidt🇩🇪

    We present here continuum extrapolated results for all 2nd order cumulants using the most recent results obtained by the HotQCD collaboration in (2+1)-flavor QCD. We constrain the applicability of various HRG models by presenting a detailed comparison of our results based on different sets of hadron spectra as well as with virial expansion based model calculations. A comparison with our lattice QCD results for 2nd order cumulants with models that parametrize repulsive interactions among baryons and anti-baryons in a hadron resonance gas through a single excluded volume parameter (EVHRG) is also shown.

    ↳ hep-lathep-phnucl-thEPJ Web Conf.(2022)·4 citations
18. 18*

    Searching for Isotropic Stochastic Gravitational-Wave Background in the International Pulsar Timing Array Second Data Release

    Zu-Cheng Chen🇨🇳 · Yu-Mei Wu🇨🇳 · Qing-Guo Huang🇨🇳

    We search for isotropic stochastic gravitational-wave background (SGWB) in the International Pulsar Timing Array second data release. By modeling the SGWB as a power-law, we find very strong Bayesian evidence for a common-spectrum process, and further this process has scalar transverse (ST) correlations allowed in general metric theory of gravity as the Bayes factor in favor of the ST-correlated process versus the spatially uncorrelated common-spectrum process is $30\pm 2$. The median and the $90\%$ equal-tail amplitudes of ST mode are ${\mathcal{A}}_{\mathrm{ST}}=1.29_{-0.44}^{+0.51}\times 10^{-15}$, or equivalently the energy density parameter per logarithm frequency is ${\Omega }_{\mathrm{GW}}^{\mathrm{ST}}=2.31_{-1.30}^{+2.19}\times 10^{-9}$, at frequency of 1/year. However, we do not find any statistically significant evidence for the tensor transverse (TT) mode and then place the $95\%$ upper limits as ${\mathcal{A}}_{\mathrm{TT}}<3.95\times 10^{-15}$, or equivalently ${\Omega }_{\mathrm{GW}}^{\mathrm{TT}}<2.16\times 10^{-9}$, at frequency of 1/year.

    ↳ astro-ph.COgr-qchep-phhep-thCommun.Theor.Phys.(2022)·52 citations
19. 19*

    Pulse envelope effects in nonlinear Breit-Wheeler pair-creation

    S. Tang🇨🇳 · B. King🇬🇧

    The effect of the pulse envelope on electron-positron pair creation in a circularly-polarised laser pulse is investigated. Interference on the length scale of the pulse envelope, and smoothness of the pulse edges are found to influence the pair spectrum. A toy model of a flat-top pulse is used to identify pulse envelope effects inaccessible to local approaches. Broadening of channel openings and a widening of the energy and transverse momentum distribution of the pair are found to receive contributions that are below the local harmonic threshold. By comparing pair yields in a flat-top, sine-squared and Gaussian pulse, a link between pulse shape and photon-polarised Breit-Wheeler is found. In the transverse momentum distribution, a signal of pulse envelope interference is found in an azimuthal asymmetry, which appears in intense fields and persists in long pulses.

    ↳ physics.opticshep-phPRD(2021)·30 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.