Mon·Nov 9, 2020Monday·November 9, 2020

1. 01*

   DAMA annual modulation is not due to electron recoils from Plasma/Mirror Dark Matter with Kinetic Mixing

   Douglas Q. Adams🇺🇸 · Sunniva Jacobsen🇸🇪 · Chris Kelso🇺🇸

   If dark matter is composed of new fundamental particles, Earth's orbital motion around the Sun may induce an annual modulation in the rate at which these particles interact in a terrestrial detector. The DAMA collaboration has identified at a 12$\sigma$ confidence level such an annual modulation in their event rate. One previously proposed explanation is `plasma dark matter' (e.g. mirror dark matter) which would have electron recoils in the detector from interactions via kinetic mixing. We perform a chi-squared goodness of fit test of this plasma dark matter model to DAMA/LIBRA modulation amplitude which rejects the hypothesis of plasma dark matter as an explanation of this data at greater than 7$\sigma$.

   hep-phJCAP(2021)·4 citations
2. 02*

   Search for U(1)${}_{L_{\mu }-L_{\tau }}$ charged Dark Matter with neutrino telescope

   Kento Asai🇯🇵 · Shohei Okawa🇨🇦 · Koji Tsumura🇯🇵

   We study a simple Dirac fermion dark matter model in U(1)${}_{L_{\mu }-L_{\tau }}$ theory. The new light gauge boson $X$ plays important roles in both dark matter physics and the explanation for the muon $g-2$ anomaly. The observed dark matter relic density is realized by a large U(1)${}_{L_{\mu }-L_{\tau }}$ charge without introducing a resonance effect of the $X$ boson. As a by-product of the model, characteristic neutrino signatures from sub-GeV dark matter $\psi$ are predicted depending on the mass spectrum. We formulate the analysis of $\psi \bar{\psi }\to \nu \bar{\nu }$, and of $\psi \bar{\psi }\to XX$ followed by $X\to \nu \bar{\nu }$, in a model independent way. The energy spectrum of neutrinos in the former process is monochromatic while in the latter process is bowl-shape. We also evaluate sensitivity at Super-Kamiokande and future Hyper-Kamiokande detectors. The analysis is finally applied to the U(1)${}_{L_{\mu }-L_{\tau }}$ dark matter model.

   hep-phastro-ph.HEhep-exJHEP(2021)·39 citations
3. 03*

   Forward Higgs production within high energy factorization in the heavy quark limit at next-to-leading order accuracy

   Martin Hentschinski🇲🇽 · Krzysztof Kutak🇵🇱 · Andreas van Hameren🇵🇱

   We use Lipatov's high energy effective action to determine the next-to-leading order corrections to Higgs production in the forward region within high energy factorization making use of the infinite top mass limit. Our result is based on an explicit calculation of real corrections combined with virtual corrections determined earlier by Nefedov. As a new element we provide a proper definition of the desired next-to-leading order coefficient within the high energy effective action framework, extending a previously proposed prescription. We further propose a subtraction mechanism to achieve for this coefficient a stable cancellation of real and virtual infra-red singularities in the presence of external off-shell legs. Apart from its relevance for direct phenomenological studies, such as high energy resummation of Higgs + jet configurations, our result will be further of use for the study of transverse momentum dependent factorization in the high energy limit.

   hep-phEPJC(2021)·71 citations
4. 04*

   Width effects in resonant three-body decays: $B$ decay as an example

   Hai-Yang Cheng🇹🇼 · Cheng-Wei Chiang🇹🇼 · Chun-Khiang Chua🇹🇼

   For three-body hadron decays mediated by intermediate resonances with large widths, we show how to properly extract the quasi-two-body decay rates for a meaningful comparison with the corresponding theoretical estimates, using several $B$ decays as explicit examples. We compute the correction factor from finite width effects in the QCD factorization approach, and make a comparison with that using the experimental parameterization in which the momentum dependence in the weak dynamics is absent. Although the difference is generally less than $10\%$ for tensor and vector resonances, it can be as large as $(25-40)\%$ for scalar resonances. Our finding can in fact be applied to general quasi-two-body decays.

   hep-phhep-exPLB(2021)·24 citations
5. 05*

   New searches at the reactor experiments based on the dark axion portal

   Patrick deNiverville🇺🇸 · Hye-Sung Lee🇰🇷 · Young-Min Lee🇰🇷

   A nuclear reactor is a powerful tool to study neutrinos and light dark sector particles. Some of the reactor experiments have proven to be extremely useful already. Considering the great interest in the power of intensity frontier to search for new light particles, it would be desirable to explore more possibilities to exploit the existing reactor power sources for particle physics research. We suggest a new reactor experiment searching for the dark sector. The dark photon can be produced in a reactor core and decay into a photon and an axion in the presence of the dark axion portal through an axion-photon-dark photon vertex. We investigate the potential to search for this new vertex with a monophoton signature and present the expected sensitivities at some of the existing reactor neutrino experiment detectors.

   hep-phPRD(2021)·32 citations
6. 06*

   Electroweak $SU(2{)}_L\times U(1{)}_Y$ model with strong spontaneously fermion-mass-generating gauge dynamics

   Petr Beneš🇨🇿 · Jiří Hošek🇨🇿 · Adam Smetana🇨🇿

   Higgs sector of the Standard model (SM) is replaced by quantum flavor dynamics (QFD), the gauged flavor $SU(3{)}_f$ symmetry with scale $\Lambda$. Anomaly freedom requires addition of three ${\nu }_R$. The approximate QFD Schwinger-Dyson equation for the Euclidean infrared fermion self-energies ${\Sigma }_f(p^2)$ has the spontaneous-chiral-symmetry-breaking solutions ideal for seesaw: (1) ${\Sigma }_f(p^2)=M_{fR}^2/p$ where three Majorana masses $M_{fR}$ of ${\nu }_{fR}$ are of order $\Lambda$. (2) ${\Sigma }_f(p^2)=m_f^2/p$ where three Dirac masses $m_f=m_{(0)}1+m_{(3)}{\lambda }_3+m_{(8)}{\lambda }_8$ of SM fermions are {\it exponentially suppressed w.r.t. $\Lambda$}, and {\it degenerate for all SM fermions in $f$}. (1) $M_{fR}$ break $SU(3{)}_f$ symmetry completely; $m_{(3)},m_{(8)}$ superimpose the tiny breaking to $U(1)\times U(1)$. All flavor gluons thus acquire self-consistently the masses $\sim \Lambda$. (2) All $m_f$ break the electroweak $SU(2{)}_L\times U(1{)}_Y$ to $U(1{)}_{em}$. Symmetry partners of the composite Nambu-Goldstone bosons are the genuine Higgs particles: (1) Three ${\nu }_R$-composed Higgses ${\chi }_i$ with masses $\sim \Lambda$. (2) Two new SM-fermion-composed Higgses $h_3,h_8$ with masses $\sim m_{(3)},m_{(8)}$, respectively. (3) The SM-like SM-fermion-composed Higgs $h$ with mass $\sim m_{(0)}$, the effective Fermi scale. ${\Sigma }_f(p^2)$-dependent vertices in the electroweak Ward-Takahashi identities imply: The axial-vector ones give rise to the $W$ and $Z$ masses at Fermi scale. The polar-vector ones give rise to the fermion mass splitting in $f$. At the present exploratory stage the splitting comes out unrealistic.

   hep-phJHEP(2021)·1 citation
7. 07*

   Covariant formulation of gluon self-energy in presence of ellipsoidal anisotropy

   Ritesh Ghosh🇮🇳 · Bithika Karmakar🇮🇳 · Arghya Mukherjee🇮🇳

   In this work, a covariant formulation of the gluon self-energy in presence of ellipsoidal anisotropy is considered. It is shown that the general structure of the gluon self-energy can be written in terms of six linearly independent projection tensors. Similar to the spheroidal anisotropy, mass scales can be introduced for each of the collective modes considering the static limits. With a simplified ellipsoidal generalization of the Romatschke-Strickland form, the angular dependencies of the mass scales are studied. It is observed that, compared to the spheroidal case, additional unstable mode may appear in presence of ellipsoidal anisotropy depending upon the choice of the parameters.

   hep-phnucl-thPRD(2020)·10 citations
8. 08*

   Partial decay widths of $\varphi (2170)$ to kaonic resonances

   Brenda B. Malabarba🇧🇷 · Xiu-Lei Ren🇩🇪 · K. P. Khemchandani🇧🇷 · A. Martinez Torres🇧🇷

   In this work we study the strong decays of $\varphi (2170)$ to final states involving the kaonic resonances $K(1460)$, $K_1(1270)$ and $K_1(1400)$, on which experimental data have recently been extracted by the BESIII Collaboration. The formalism developed here is based on interpreting $\varphi (2170)$ and $K(1460)$ as states arising from three-hadron dynamics, which is inspired by our earlier works. For $K_1(1270)$ and $K_1(1400)$ we investigate different descriptions, such as a mixture of states belonging to the nonet of axial resonances, or the former one as a state originating from the vector-pseudoscalar dynamics. The ratios among the partial widths of $K^{+}(1460)K^{-}$, $K_1^{+}(1400)K^{-}$ and $K_1^{+}(1270)K^{-}$ obtained are compatible with the experimental results, reinforcing the three-body nature of $\varphi (2170)$. Within our formalism, we can also explain the suppressed decay of $\varphi (2170)$ to $K^{\ast }(892){\bar{K}}^{\ast }(892)$, as found by the BESIII Collaboration. Furthermore, our results can be useful in clarifying the properties of $K(1460)$, $K_1(1270)$ and $K_1(1400)$ when higher statistics data would be available.

   hep-phnucl-thPRD(2021)·16 citations
9. 09*

   Fermion Masses and Mixing from Double Cover and Metaplectic Cover of $A_5$ Modular Group

   Chang-Yuan Yao🇨🇳 · Xiang-Gan Liu🇨🇳 · Gui-Jun Ding🇨🇳

   We perform a comprehensive study of the homogeneous finite modular group $A_5^{\prime }$ which is the double covering of $A_5$. The integral weight and level 5 modular forms have been constructed up to weight 6 and they are decomposed into the irreducible representations of $A_5^{\prime }$. Then we perform a systematical analysis of the $A_5^{\prime }$ modular models for lepton masses and mixing. The phenomenologically viable models with minimal number of free parameters and the results of fit are presented. We find out 15 models with 9 real free parameters which can accommodate the experimental data of lepton sector. After including generalized CP symmetry, 9 viable models with 7 free parameters are found out. We apply $A_5^{\prime }$ modular symmetry to the quark sector, and a quark-lepton unification model is given. The framework of modular invariance is extended to include the rational weight modular forms of level 5. The ring of modular forms at level 5 can be generated by two algebraically independent weight $1/5$ modular forms denoted by $F_1(\tau )$ and $F_2(\tau )$. We give the expressions of the rational weight modular forms of level 5 up to weight $3$ and arrange them into the irreducible multiplets of finite metaplectic group ${\tilde{\Gamma }}_5\cong A_5^{\prime }\times Z_5$. A neutrino mass model with ${\tilde{\Gamma }}_5$ modular symmetry is presented, and the phenomenological predictions of the model are analyzed numerically.

   hep-phPRD(2021)·94 citations
10. 10*

    Building Kinetic Mixing From Scalar Portal Matter

    Thomas D. Rueter🇺🇸 · Thomas G. Rizzo🇺🇸

    The nature of dark matter (DM) and how it might interact with the particles of the Standard Model (SM) is an ever-growing mystery. It is possible that the existence of new `dark sector' forces, yet undiscovered, are the key to solving this fundamental problem. In this paper, we construct a model in which a dark photon mediates interactions with the SM via kinetic mixing. Unlike traditional models, in which the dark photon, which couples to a dark charge, $Q_D$, mixes with the hypercharge boson, our model effectively mixes the dark photon directly with the photon after electroweak symmetry is broken, but remains unmixed until the symmetry breaks. The kinetic mixing is generated at one loop by fields which satisfy $\sum Q_D{Q}_{em}=0$, a condition which guarantees a finite result at one loop. In the literature, this has been traditionally obtained via heavy fermions, which may lie out of the reach of current accelerators. In this model, by contrast, this process is mediated by scalar `portal matter' fields, which are charged under the $SU(2{)}_L\times U(1{)}_Y$ of the standard model as well as the dark gauge group $U(1{)}_D$ and acquire GeV-scale vevs which give mass to the dark Higgs and dark photon. The additional scalar fields are relatively light, at or below the weak scale, yet may remain undetected by current experiments since their couplings to SM fermions come only through percent level mixing with the SM Higgs. At colliders, these models are typified by relatively low MET due the BSM states decaying into MET and SM bosons, with MET which is balanced by the decay of the associated production object. Nevertheless, the higher statistics of HL-LHC may be able to probe the entirety of the model space.

    hep-ph24 citations
11. 11*

    Quasi Anomalous Knowledge: Searching for new physics with embedded knowledge

    Sang Eon Park🇺🇸 · Dylan Rankin🇺🇸 · Silviu-Marian Udrescu🇺🇸 · Mikaeel Yunus🇺🇸 · Philip Harris🇺🇸

    Discoveries of new phenomena often involve a dedicated search for a hypothetical physics signature. Recently, novel deep learning techniques have emerged for anomaly detection in the absence of a signal prior. However, by ignoring signal priors, the sensitivity of these approaches is significantly reduced. We present a new strategy dubbed Quasi Anomalous Knowledge (QUAK), whereby we introduce alternative signal priors that capture some of the salient features of new physics signatures, allowing for the recovery of sensitivity even when the alternative signal is incorrect. This approach can be applied to a broad range of physics models and neural network architectures. In this paper, we apply QUAK to anomaly detection of new physics events at the CERN Large Hadron Collider utilizing variational autoencoders with normalizing flow.

    hep-phhep-exJHEP(2020)·58 citations
12. 12*

    Shining light through the Higgs portal with $\gamma \gamma$ colliders

    Adrian Garcia-Abenza🇪🇸 · Jose Miguel No🇪🇸

    High-energy $\gamma \gamma$ colliders constitute a potential running mode of future $e^{+}{e}^{-}$ colliders such as the ILC and CLIC. We study the sensitivity of a high-energy $\gamma \gamma$ collider to the Higgs portal scenario to a hidden sector above the invisible Higgs decay threshold. We show that such $\gamma \gamma$ collisions could allow to probe the existence of dark sectors through the Higgs portal comparatively more precisely than any other planned collider facility, from the unique combination of sizable cross-section with clean final state and collider environment. In addition, this search could cover the singlet Higgs portal parameter space yielding a first-order electroweak phase transition in the early Universe.

    hep-phEPJC(2022)·7 citations
13. 13*

    Low-Energy Probes of No-Scale SU(5) Super-GUTs

    John Ellis🇬🇧 · Jason L. Evans🇨🇳 · Natsumi Nagata🇯🇵 · Keith A. Olive🇺🇸 · Liliana Velasco-Sevilla🇳🇴

    We explore the possible values of the $\mu \to e\gamma$ branching ratio, $\text{BR}(\mu \to e\gamma )$, and the electron dipole moment (eEDM), $d_e$, in no-scale SU(5) super-GUT models with the boundary conditions that soft supersymmetry-breaking matter scalar masses vanish at some high input scale, $M_{\mathrm{in}}$, above the GUT scale, $M_{\mathrm{GUT}}$. We take into account the constraints from the cosmological cold dark matter density, ${\Omega }_{CDM}{h}^2$, the Higgs mass, $M_h$, and the experimental lower limit on the lifetime for $p\to K^{+}\bar{\nu }$, the dominant proton decay mode in these super-GUT models. Reconciling this limit with ${\Omega }_{CDM}{h}^2$ and $M_h$ requires the Higgs field responsible for the charge-2/3 quark masses to be twisted, and possibly also that responsible for the charge-1/3 and charged-lepton masses, with model-dependent soft supersymmetry-breaking masses. We consider six possible models for the super-GUT initial conditions, and two possible choices for quark flavor mixing, contrasting their predictions for proton decay with versions of the models in which mixing effects are neglected. We find that $\tau \left(p\to K^{+}\bar{\nu }\right)$ may be accessible to the upcoming Hyper-Kamiokande experiment, whereas all the models predict $\text{BR}(\mu \to e\gamma )$ and $d_e$ below the current and prospective future experimental sensitivities or both flavor choices, when the dark matter density, Higgs mass and current proton decay constraints are taken into account. However, there are limited regions with one of the flavor choices in two of the models where $\mu \to e$ conversion on a heavy nucleus may be observable in the future. Our results indicate that there is no supersymmetric flavor problem in the class of no-scale models we consider.

    hep-phEPJC(2021)·9 citations
14. 14*

    Precision SMEFT bounds from the VBF Higgs at high transverse momentum

    Jack Y. Araz🇬🇧 · Shankha Banerjee🇨🇭 · Rick S. Gupta🇬🇧 · Michael Spannowsky🇬🇧

    We study the production of Higgs bosons at high transverse momenta via vector-boson fusion (VBF) in the Standard Model Effective Field Theory (SMEFT). We find that contributions from four independent operator combinations dominate in this limit. These are the same `high energy primaries' that control high energy diboson processes, including Higgs-strahlung. We perform detailed collider simulations for the diphoton decay mode of the Higgs boson as well as the three final states arising from the ditau channel. Using the quadratic growth of the SMEFT contributions relative to the Standard Model (SM) contribution, we project very stringent bounds on these operators that far surpass the corresponding bounds from the LEP experiment.

    hep-phhep-exJHEP(2021)·33 citations
15. 15*

    125 GeV Higgs boson decay to a pair of muons in the $\mu \nu$SSM

    Hai-Bin Zhang🇨🇳 · Zhi-Min Niu🇨🇳 · Ke-Sheng Sun🇨🇳 · Shu-Min Zhao🇨🇳 · Ying-Long Wang🇨🇳 · Tai-Fu Feng🇨🇳

    Recently, the ATLAS and CMS Collaborations measured the 125 GeV Higgs boson decay to a pair of muons $h\to \mu \bar{\mu }$, which reported the signal strength relative to the standard model (SM) prediction is $1.2\pm 0.6$ and $1.19_{-0.39-0.14}^{+0.40+0.15}$, respectively. In this work, we investigate the 125 GeV Higgs boson decay $h\to \mu \bar{\mu }$ at one-loop level in the $\mu$ from $\nu$ Supersymmetric Standard Model ($\mu \nu$SSM). Compared to the SM prediction, the decay width of $h\to \mu \bar{\mu }$ in the $\mu \nu$SSM can boost up about 10\%, considering the constraint from the muon anomalous magnetic dipole moment.

    hep-ph2 citations
16. 16*

    Cosmological Trans-Planckian Conjectures are not Effective

    C.P. Burgess🇨🇦 · S. P. de Alwis🇺🇸 · F. Quevedo🇬🇧

    It is remarkable that the primordial fluctuations as revealed by the CMB coincide with what quantum fluctuations would look like if they were stretched across the sky by accelerated cosmic expansion. It has been observed that this same stretching also brings very small -- even trans-Planckian -- length scales up to observable sizes if extrapolated far enough into the past. This potentially jeopardizes later descriptions of late-time cosmology by introducing uncontrolled trans-Planckian theoretical errors into all calculations. Recent speculations, such as the Trans-Planckian Censorship Conjecture (TCC), have been developed to avoid this problem. We revisit old arguments why the consistency of (and control over) the Effective Field Theory (EFT) governing late-time cosmology is not necessarily threatened by the descent of modes due to universal expansion, even if EFT methods may break down at much earlier times. Failure of EFT methods only poses a problem if late-time predictions rely on non-adiabatic behaviour at these early times (such as is often true for bouncing cosmologies, for example). We illustrate our arguments using simple non-gravitational examples such as slowly rolling scalar fields and the spacing between Landau levels for charged particles in slowly varying magnetic fields, for which similar issues arise and are easier to understand. We comment on issues associated with UV completions. Our arguments need not invalidate speculative ideas like the TCC but suggest they are not required by the present evidence.

    ↳ hep-thgr-qchep-phJCAP(2021)·31 citations
17. 17*

    Blue-tilted inflationary tensor spectrum and reheating in the light of NANOGrav results

    Sachiko Kuroyanagi🇪🇸 · Tomo Takahashi🇯🇵 · Shuichiro Yokoyama🇯🇵

    We discuss the possibility of explaining the recent NANOGrav results by inflationary gravitational waves (IGWs) with a blue-tilted primordial spectrum. Although such IGWs can account for the NANOGrav signal without contradicting the upper bound on the tensor-to-scalar ratio at the cosmic microwave background scale, the predicted spectrum is in strong tension with the upper bound on the amplitude of the stochastic gravitational wave background by big-bang nucleosynthesis (BBN) and the second LIGO-Virgo observation run. However, the thermal history of the Universe, such as reheating and late-time entropy production, affects the spectral shape of IGWs at high frequencies and permits evading the upper bounds. We show that, for the standard reheating scenario, when the reheating temperature is relatively low, a blue tensor spectrum can explain the recent NANOGrav signal without contradicting the BBN and the LIGO-Virgo constraints. We further find that, when one considers a late-time entropy production, the NANOGrav signal can be explained even for an instant reheating scenario.

    ↳ astro-ph.COgr-qchep-phJCAP(2021)·101 citations
18. 18*

    BICEP / Keck XII: Constraints on axion-like polarization oscillations in the cosmic microwave background

    BICEP/Keck Collaboration: P. A. R. Ade🇬🇧 · Z. Ahmed🇺🇸 · M. Amiri🇨🇦 · D. Barkats🇺🇸 · R. Basu Thakur🇺🇸 · C. A. Bischoff🇺🇸 · J. J. Bock🇺🇸 · H. Boenish🇺🇸 · E. Bullock🇺🇸 · V. Buza🇺🇸 · J. R. Cheshire IV🇺🇸 · J. Connors🇺🇸 and 69 other authors

    We present a search for axion-like polarization oscillations in the cosmic microwave background (CMB) with observations from the Keck Array. A local axion field induces an all-sky, temporally sinusoidal rotation of CMB polarization. A CMB polarimeter can thus function as a direct-detection experiment for axion-like dark matter. We develop techniques to extract an oscillation signal. Many elements of the method are generic to CMB polarimetry experiments and can be adapted for other datasets. As a first demonstration, we process data from the 2012 observing season to set upper limits on the axion-photon coupling constant in the mass range $10^{-21}$-$10^{-18}\mathrm{eV}$, which corresponds to oscillation periods on the order of hours to months. We find no statistically significant deviations from the background model. For periods larger than $24\mathrm{hr}$ (mass $m<4.8\times 10^{-20}\mathrm{eV}$), the median 95%-confidence upper limit is equivalent to a rotation amplitude of $0.68^{\circ }$, which constrains the axion-photon coupling constant to $g_{\varphi \gamma }<\left(1.1\times 10^{-11}{\mathrm{GeV}}^{-1}\right)m/\left(10^{-21}\mathrm{eV}\right)$, if axion-like particles constitute all of the dark matter. The constraints can be improved substantially with data already collected by the BICEP series of experiments. Current and future CMB polarimetry experiments are expected to achieve sufficient sensitivity to rule out unexplored regions of the axion parameter space.

    ↳ astro-ph.COhep-exhep-phPRD(2021)·25 citations
19. 19*

    Shear viscosity and electric conductivity of a hot and dense QGP with a chiral phase transition

    Olga Soloveva🇩🇪 · David Fuseau🇫🇷 · Jörg Aichelin🇫🇷 · Elena Bratkovskaya🇩🇪

    We calculate two transport coefficients -- the shear viscosity over entropy ratio $\eta /s$ and the ratio of the electric conductivity to the temperature ${\sigma }_0/T$ -- of strongly interacting quark matter within the extended $N_f=3$ Polyakov Nambu-Jona-Lasinio (PNJL) model along the crossover transition line for moderate values of baryon chemical potential $0\le {\mu }_B\le 0.9$ GeV as well as in the vicinity of the critical endpoint (CEP) and at large baryon chemical potential ${\mu }_B=1.2$ GeV, where the first-order phase transition takes place. The evaluation of the transport coefficients is performed on the basis of the effective Boltzmann equation in the relaxation time approximation. We employ two different methods for the calculation of the quark relaxation times: i) using the averaged transition rate defined via thermal averaged quark-quark and quark-antiquark PNJL cross sections and ii) using the 'weighted' thermal averaged quark-quark and quark-antiquark PNJL cross sections. The $\eta /s$ and ${\sigma }_0/T$ transport coefficients have a similar temperature and chemical potential behavior when approaching the chiral phase transition for the both methods for the quark relaxation time, however, the differences grow with increasing temperature. We demonstrate the effect of the first-order phase transition and of the CEP on the transport coefficients in the deconfined QCD medium.

    ↳ nucl-thhep-phPRC(2021)·42 citations
20. 20*

    The IceCube high-energy starting event sample: Description and flux characterization with 7.5 years of data

    R. Abbasi🇺🇸 · M. Ackermann🇩🇪 · J. Adams🇳🇿 · J. A. Aguilar🇧🇪 · M. Ahlers🇩🇰 · M. Ahrens🇸🇪 · C. Alispach🇨🇭 · A. A. Alves Jr.🇩🇪 · N. M. Amin🇺🇸 · K. Andeen🇺🇸 · T. Anderson🇺🇸 · I. Ansseau🇧🇪 and 354 other authors

    The IceCube Neutrino Observatory has established the existence of a high-energy all-sky neutrino flux of astrophysical origin. This discovery was made using events interacting within a fiducial region of the detector surrounded by an active veto and with reconstructed energy above 60 TeV, commonly known as the high-energy starting event sample, or HESE. We revisit the analysis of the HESE sample with an additional 4.5 years of data, newer glacial ice models, and improved systematics treatment. This paper describes the sample in detail, reports on the latest astrophysical neutrino flux measurements, and presents a source search for astrophysical neutrinos. We give the compatibility of these observations with specific isotropic flux models proposed in the literature as well as generic power-law-like scenarios. Assuming ${\nu }_e:{\nu }_{\mu }:{\nu }_{\tau }=1:1:1$, and an equal flux of neutrinos and antineutrinos, we find that the astrophysical neutrino spectrum is compatible with an unbroken power law, with a preferred spectral index of ${2.87}_{-0.19}^{+0.20}$ for the $68.3\%$ confidence interval.

    ↳ astro-ph.HEhep-exhep-phPRD(2021)·541 citations
21. 21*

    Measurement of the high-energy all-flavor neutrino-nucleon cross section with IceCube

    R. Abbasi🇺🇸 · M. Ackermann🇩🇪 · J. Adams🇳🇿 · J. A. Aguilar🇧🇪 · M. Ahlers🇩🇰 · M. Ahrens🇸🇪 · C. Alispach🇨🇭 · A. A. Alves Jr.🇩🇪 · N. M. Amin🇺🇸 · K. Andeen🇺🇸 · T. Anderson🇺🇸 · I. Ansseau🇧🇪 and 353 other authors

    The flux of high-energy neutrinos passing through the Earth is attenuated due to their interactions with matter. The interaction rate is modulated by the neutrino interaction cross section and affects the flux arriving at the IceCube Neutrino Observatory, a cubic-kilometer neutrino detector embedded in the Antarctic ice sheet. We present a measurement of the neutrino cross section between 60 TeV and 10 PeV using the high-energy starting events (HESE) sample from IceCube with 7.5 years of data. The result is binned in neutrino energy and obtained using both Bayesian and frequentist statistics. We find it compatible with predictions from the Standard Model. Flavor information is explicitly included through updated morphology classifiers, proxies for the the three neutrino flavors. This is the first such measurement to use the three morphologies as observables and the first to account for neutrinos from tau decay.

    ↳ hep-exastro-ph.HEhep-phPRD(2021)·94 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.