Fri·Nov 22, 2019Friday·November 22, 2019

1. 01*

   New constraints on Heavy Neutral Leptons from Super-Kamiokande data

   Pilar Coloma🇪🇸 · Pilar Hernández🇪🇸 · Víctor Muñoz🇪🇸 · Ian. M. Shoemaker🇺🇸

   Heavy neutral leptons are predicted in many extensions of the Standard Model with massive neutrinos. If kinematically accessible, they can be copiously produced from kaon and pion decays in atmospheric showers, and subsequently decay inside large neutrino detectors. We perform a search for these long-lived particles using Super-Kamiokande multi-GeV neutrino data and derive stringent limits on the mixing with electron, muon and tau neutrinos as a function of the long-lived particle mass. We also present the limits on the branching ratio versus lifetime plane, which are helpful in determining the constraints in non-minimal models where the heavy neutral leptons have new interactions with the Standard Model.

   hep-phhep-exEPJC(2020)·55 citations
2. 02*

   Theory challenges at future lepton colliders

   Stanisław Jadach🇵🇱 · Maciej Skrzypek🇵🇱

   High energy, high luminosity, future lepton colliders, circular or linear, may possibly give us hint about fundamental laws of Nature governing at very short distances and very short time intervals, the same which have brought our Universe to live. Currently considered projects are on one hand linear electron-positron colliders, which offer higher energy and lower beam intensities and on the other hand circular electron-positron colliders, limited in energy but offering tremendous interaction rates. On the far future horizon, muon circular colliders are the only viable projects which can explore $>10$TeV teritory of the lepton colliders. Experiments in all these future colliders will require theoretical calculations, mainly of Standard Model processes (including QED), at the precision level one or even two orders better than available today. After briefly characterization of theory puzzles in the fundamental interactions we shall overview main challenges in the precision calculations of the Standard Model effects, which have to be removed from data, in order to reveal traces of new unexpected phenomena.

   hep-phActa Phys.Polon.B(2019)·4 citations
3. 03*

   Search for hidden particles in intensity frontier experiment SHiP

   Volodymyr M. Gorkavenko🇺🇦

   Despite the undeniable success of the Standard Model of particle physics (SM) there are some phenomena (neutrino oscillations, baryon asymmetry of the Universe, dark matter, etc.) that SM cannot explain. These phenomena indicate that the SM has to be modified. Most likely there are new particles beyond the SM. There are many experiments to search for new physics that can be divided into two types: energy and intensity frontier. In experiments of the first type, one tries to directly produce and detect new heavy particles. In experiments of the second type, one tries to directly produce and detect new light particles that feebly interact with SM particles. Future intensity frontier SHiP experiment (\textbf{S}earch for \textbf{Hi}dden \textbf{P}articles) at the CERN SPS is discussed. Its advantages and technical characteristics are given.

   hep-phhep-exUkr.J.Phys.(2019)·4 citations
4. 04*

   Convolutional Neural Networks for Direct Detection of Dark Matter

   Charanjit K. Khosa (1)🇬🇧 · Lucy Mars (1)🇬🇧 · Joel Richards (1)🇬🇧 · Veronica Sanz (1, 2 and 3) ((1) Department of Physics and Astronomy, University of Sussex, Brighton, UK, (2) Alan Turing Institute, British Library, London, UK and (3) Instituto de Física Corpuscular (IFIC), Universidad de Valencia-CSIC, Valencia, Spain)🇬🇧

   The XENON1T experiment uses a time projection chamber (TPC) with liquid Xenon to search for Weakly Interacting Massive Particles (WIMPs), a proposed Dark Matter particle, via direct detection. As this experiment relies on capturing rare events, the focus is on achieving a high recall of WIMP events. Hence the ability to distinguish between WIMP and the background is extremely important. To accomplish this, we suggest using Convolutional Neural Networks (CNNs); a Machine Learning procedure mainly used in image recognition tasks. To explore this technique we use XENON collaboration open-source software to simulate the TPC graphical output of Dark Matter signals and main backgrounds. A CNN turns out to be a suitable tool for this purpose, as it can identify features in the images that differentiate the two types of events without the need to manipulate or remove data in order to focus on a particular region of the detector. We find that the CNN can distinguish between the dominant background events (ER) and 500 GeV WIMP events with a recall of 93.4\%, precision of 81.2\% and an accuracy of 87.2\%.

   hep-phastro-ph.IMJ.Phys.G(2020)·32 citations
5. 05*

   Hidden charm pentaquark states and ${\Sigma }_c^{(\ast )}{\bar{D}}^{(\ast )}$ interaction in chiral perturbation theory

   Lu Meng🇨🇳 · Bo Wang🇨🇳 · Guang-Juan Wang🇨🇳 · Shi-Lin Zhu🇨🇳

   We adopt the chiral perturbation theory to calculate the ${\Sigma }_c^{(\ast )}{\bar{D}}^{(\ast )}$ interaction to the next-to-leading order (NLO) and include the couple-channel effect in the loop diagrams. We reproduce the three $P_c$ states in the molecular picture after including the ${\Lambda }_c{\bar{D}}^{(\ast )}$ intermediate states. We also discuss some novel observations arising from the loop diagrams.

   hep-ph4 citations
6. 06*

   A study of Higgs $\mathbf{CP}$ properties using the Higgs Characterization Model and top associated production

   Martin Mosny

   This study utilises the Higgs Characterization model to investigate the $CP$ properties of the Higgs coupling to the top quark using the $tH$ and $t\bar{t}H$ generation processes. This is done via simulations of proton-proton collisions with ATLAS detector conditions, which are calculated for seven different $CP$ eigenstates using MadGraph5_aMC@NLO. Three orthogonal categories of cuts are subsequently implemented to find the cut efficiencies, which are used in conjunction with the cross-section to find the signal strength. Comparing the signal strength with experimental results shows that one cannot yet conclusively rule out any Higgs $CP$ eigenstates. Analysing histograms showed that the most $CP$ sensitive variables were the transverse momenta of the Higgs, leptons and photons, which showed a hardening as the Higgs coupling became $CP$ odd.

   hep-ph0 citations
7. 07*

   Photon pair production in gluon fusion: Top quark effects at NLO with threshold matching

   Long Chen🇩🇪 · Gudrun Heinrich🇩🇪 · Stephan Jahn🇩🇪 · Stephen P. Jones🇨🇭 · Matthias Kerner🇨🇭 · Johannes Schlenk🇨🇭 · Hiroshi Yokoya🇰🇷

   We present a calculation of the NLO QCD corrections to the loop-induced production of a photon pair through gluon fusion, including massive top quarks at two loops, where the two-loop integrals are calculated numerically. Matching the fixed-order NLO results to a threshold expansion, we obtain accurate results around the top quark pair production threshold. We analyse how the top quark threshold corrections affect distributions of the photon pair invariant mass and comment on the possibility of determining the top quark mass from precision measurements of the diphoton invariant mass spectrum.

   hep-phJHEP(2020)·27 citations
8. 08*

   $S$, $P$ and $D$-wave resonance contributions to $B_{(s)}\to {\eta }_c(1S,2S)K\pi$ decays in the perturbative QCD approach

   Ya Li🇨🇳 · Da-Cheng Yan🇨🇳 · Zhou Rui🇨🇳 · Zhen-Jun Xiao🇨🇳

   In this work, we analyze the three-body $B_{(s)}\to {\eta }_c(1S,2S)K\pi$ decays within the framework of the perturbative QCD approach (PQCD) under the quasi-two-body approximation, where the kaon-pion invariant mass spectra are dominated by the $K_0^{\ast }(1430{)}^0,K_0^{\ast }(1950{)}^0,K^{\ast }(892{)}^0,K^{\ast }(1410{)}^0,K^{\ast }(1680{)}^0$ and $K_2^{\ast }(1430{)}^0$ resonances. The time-like form factors are adopted to parametrize the corresponding $S$, $P$, $D$-wave kaon-pion distribution amplitudes for the concerned decay modes, which describe the final-state interactions between the kaon and pion in the resonant region. The $K\pi$ $S$-wave component at low $K\pi$ mass is described by the LASS line shape, while the time-like form factors of other resonances are modeled by the relativistic Breit-Wigner function. We find the following main points: (a) the PQCD predictions of the branching ratios for most considered $B\to {\eta }_c(1S)(K^{\ast 0}\to )K^{+}{\pi }^{-}$ decays agree well with the currently available data within errors; (b) for $\mathcal{B}(B^0\to {\eta }_c(K_0^{\ast }(1430)\to )K^{+}{\pi }^{-})$ and $\mathcal{B}(B^0\to {\eta }_c{K}^{+}{\pi }^{-}(\mathrm{NR}))$ (here NR means nonresonant), our predictions of the branching ratios are a bit smaller than the measured ones; and (c) the PQCD results for the $D$-wave contributions considered in this work can be tested once the precise data from the future LHCb and Belle-II experiments are available.

   hep-phhep-exPRD(2020)·19 citations
9. 09*

   A Holographic Perspective on the Axion Quality Problem

   Peter Cox🇦🇺 · Tony Gherghetta🇺🇸 · Minh D. Nguyen🇺🇸

   The axion provides a compelling solution to the strong CP problem as well as a candidate for the dark matter of the universe. However, the axion solution relies on the spontaneous breaking of a global $U(1{)}_{PQ}$ symmetry, which is also explicitly violated by quantum gravity. To preserve the axion solution, gravitational violations of the $U(1{)}_{PQ}$ symmetry must be suppressed to sufficiently high order. We present a simple, geometric solution of the axion quality problem by modelling the axion with a bulk complex scalar field in a slice of AdS${}_5$, where the $U(1{)}_{PQ}$ symmetry is spontaneously broken in the bulk but explicitly broken on the UV brane. By localising the axion field towards the IR brane, gravitational violations of the PQ symmetry on the UV brane are sufficiently sequestered. This geometric solution is holographically dual to 4D strong dynamics where the global $U(1{)}_{PQ}$ is an accidental symmetry to sufficiently high order.

   hep-phJHEP(2020)·67 citations
10. 10*

    Searching for non-unitary neutrino oscillations in the present T2K and NO$\nu$A data

    Luis Salvador Miranda🇿🇦 · Pedro Pasquini🇧🇷 · Ushak Rahaman🇿🇦 · Soebur Razzaque🇿🇦

    The mixing of three active neutrino flavors is parameterized by the unitary PMNS matrix. If there are more than three neutrino flavors and if the extra generations are heavy isosinglets, the effective $3\times 3$ mixing matrix for the three active neutrinos will be non-unitary. We have analyzed the latest T2K and \nova data with the hypothesis of non-unitary mixing of the active neutrinos. We found that the 2019 NO$\nu$A data slightly (at $\sim 1\sigma$ C.L.) prefer the non-unitary mixing over unitary mixing. In fact, allowing the non-unitary mixing brings the \nova best-fit point in the ${\sin }^2{\theta }_{23}-{\delta }_{CP}$ plane closer to the T2K best-fit point. The 2019 T2K data, on the other hand, cannot rule out any of the two mixing schemes. A combined analysis of the NO$\nu$A and T2K 2019 data prefers the non-unitary mixing at $1\sigma$ C.L.. We derive constraints on the non-unitary mixing parameters using the best-fit to the combined NO$\nu$A and T2K data. These constraints are weaker than previously found. The latest 2020 data from both the experiments prefer non-unitarity over unitary mixing at $1\sigma$ C.L. The combined analysis preferes non-unitarity at $2\sigma$ C.L. The stronger tension, which exists between the latest 2020 data of the two experiments, also gets reduced with non-unitary analysis.

    hep-phhep-exEPJC(2021)·38 citations
11. 11*

    Are Charged Leptons in the Simultaneous Eigenstates of Mass and Family?

    Yoshio Koide🇯🇵

    Conventionally, the observed charged leptons are regarded the simultaneous eigenstates of "mass" and "family". Against this view, we discuss a possibility that the observed charged leptons $e_i=(e,\mu ,\tau )$ are not identical with the eigenstates of family $e_{\alpha }^0=(e_1^0,e_2^0,e_3^0)$. Here, we define the eigenstates of family, $e_{\alpha }^0$, as the states which interact with family gauge bosons in the mass eigenstates of the broken U(3)${}_{family}$ gauge symmetry. Although there is at present not any experimental evidence for $e_1^0$-$e_2^0$ mixing, and we have only an upper limit for the mixing from the present experimental data. We will conclude that the $e$-$\mu$ mixing angle $\theta$ must be $\theta \lesssim 10^{-3}$. Thus, we can not exclude a possibility $\theta \ne 0$. If we want more small upper limit of $\theta$, a rare decay search $\mu \to e+\gamma$ will be useful.

    hep-ph0 citations
12. 12*

    Three body open flavor decays of higher vector charmonium and bottomonium

    Xin-Zhen Weng🇨🇳 · Li-Ye Xiao🇨🇳 · Wei-Zhen Deng🇨🇳 · Xiao-Lin Chen🇨🇳 · Shi-Lin Zhu🇨🇳

    With an extended quark pair creation model we systematically study the OZI-allowed three body open flavor decays of higher vector charmonium and bottomonium states. We obtain that the $B{B}^{\ast }\pi$ and $B^{\ast }{B}^{\ast }\pi$ partial decay widths of ${\rm Y}(10860)$ are consistent with experiment, and the corresponding partial decay widths of ${\rm Y}(11020)$ can reach up to 2$\sim$3 MeV. Meanwhile the partial widths of $D{D}^{\ast }\pi$ and $D^{\ast }{D}^{\ast }\pi$ modes for most higher vector charmonium states can reach up to several MeV.

    hep-ph0 citations
13. 13*

    Kaon CP violation and neutron EDM in the minimal left-right symmetric model

    Stefano Bertolini🇮🇹 · Alessio Maiezza🇭🇷 · Fabrizio Nesti🇮🇹

    Within the minimal Left-Right (LR) symmetric model we revisit the predictions for the kaon CP violating observables $\epsilon$ and ${\epsilon }^{\prime }$ in correlation with the neutron electric dipole moment. We perform a complete study of the cross constraints on the model parameters, phases and the $M_{W_R}$ scale, considering the two cases of extended parity or charge conjugation as LR discrete symmetries, together with the possible presence of a Peccei-Quinn symmetry. We discuss in particular two scenarios: whether the Standard Model saturates the experimental value of ${\epsilon }^{\prime }/\epsilon$ or whether new physics is needed, still an open issue after the recent lattice results on the QCD penguin matrix elements. Within the first scenario, we find no constraints on the LR scale in the charge-conjugation case while in the parity case we show that $M_{W_R}$ can be as low as 13 TeV. On the other side, the request that new physics contributes dominantly to ${\epsilon }^{\prime }$ implies strong correlations among the model parameters, with an upper bound of $M_{W_R}<8-100$ TeV depending on $\tan \beta$ in the case of charge conjugation and a range of $M_{W_R}\simeq 7-45$ TeV in the parity setup. Both scenarios may be probed directly at future colliders and only indirectly at the LHC.

    hep-phPRD(2020)·49 citations
14. 14*

    Kinematic surprises in twisted particle collisions

    Igor P. Ivanov🇵🇹 · Nikolai Korchagin🇨🇳 · Alexandr Pimikov🇨🇳 · Pengming Zhang🇨🇳

    "Twisted particles" refer to non-plane-wave states of photons, electrons, hadrons, or any other particle which carry non-zero, adjustable orbital angular momentum with respect to their average propagation direction. Twisted photons and electrons have already been experimentally demonstrated, and one can expect creation of twisted states of other particles in future. Such states can be brought in collisions, offering a completely new degree of freedom in collider experiments and, especially, a novel tool for hadronic physics. We recently showed that $2\to 1$ processes with two twisted particles such as resonance production in twisted $e^{+}{e}^{-}$ annihilation give access to observables which are difficult or impossible to probe in the usual plane-wave collisions. In this paper, we discuss in detail surprising kinematic features of this process, focusing on spinless particle annihilation. They include (1) a new dimension in the final momentum space available in twisted annihilation, (2) interference fringes emerging in the cross section as a function of the total energy, and (3) the built-in mass spectrometric capability of this process, that is, simultaneous production and automatic angular separation of several resonances with different masses in monochromatic twisted particle annihilation experiment running at fixed energy. All these features cannot be obtained in the usual plane wave collision setting.

    hep-phquant-phPRD(2020)·24 citations
15. 15*

    Wilson-line geometries and the relation between IR singularities of form factors and the large-x limit of DGLAP splitting functions

    Calum Milloy🇬🇧 · Giulio Falcioni🇬🇧 · Einan Gardi🇬🇧

    We discuss the relation between the infrared singularities of on-shell partonic form factors and parton distribution functions (PDFs) near the elastic limit, through their factorisation in terms of Wilson-line correlators. Ultimately we identify the difference between the anomalous dimensions controlling single poles of these two quantities to all loops in terms of the closed parallelogram Wilson loop. To arrive at this result we first use the common hard-collinear behaviour of the two to derive a relation between their respective soft singularities, and then show that the latter is manifested in terms of differing Wilson-line geometries. We perform explicit diagrammatic calculations in configuration space through two loops to verify the relation. More generally, the emerging picture allows us to classify collinear singularities in eikonal quantities depending on whether they are associated with finite (closed) Wilson-line segments or infinite (open) ones.

    hep-ph0 citations
16. 16*

    $SU(3{)}_C\times SU(3{)}_L\times U(1{)}_X$ model from $SU(6)$

    Tianjun Li🇨🇳 · Junle Pei🇨🇳 · Fangzhou Xu🇨🇳 · Wenxing Zhang🇨🇳

    We propose the $SU(3{)}_C\times SU(3{)}_L\times U(1{)}_X$ model arising from $SU(6)$ breaking. One family of the Standard Model (SM) fermions arises from two $\bar{6}$ representations and one $15$ representation of $SU(6)$ gauge symmetry. To break the $SU(3{)}_C\times SU(3{)}_L\times U(1{)}_X$ gauge symmetry down to the SM, we introduce three $SU(3{)}_L$ triplet Higgs fields, where two of them come from the $\bar{6}$ representation while the other one from the $15$ representation. We study the gauge boson masses and Higgs boson mass in detail, and find that the vacuum expectation value (VEV) of the Higgs field for $SU(3{)}_L\times U(1{)}_X$ gauge symmetry breaking is around 10 TeV. The neutrino masses and mixing can be generated via the littlest inverse seesaw mechanism. In particular, we have normal hierarchy for neutrino masses and the lightest active neutrino is massless. Also, we consider constraints from the charged lepton flavor changing decays as well. Furthermore, introducing two $SU(3{)}_L$ adjoint fermions, one $SU(3{)}_C$ adjoint scalar, and one $SU(3{)}_L$ triplet scalar, we can achieve gauge coupling unification within 1\%. These extra particles can provide a dark matter candidate as well.

    hep-phPRD(2020)·11 citations
17. 17*

    Gluon evolution for the Berger-Block-Tan form of the structure function F2

    A.V. Kotikov🇷🇺

    We present a nonlinear modification of the evolution of the gluon density, obtained at small x from the Berger-Block-Tan form of the deep inelastic structure function F2 in the leading order of perturbation theory.

    hep-phJETP Lett.(2020)·4 citations
18. 18*

    A new formulation of the loop-tree duality at higher loops

    Robert Runkel🇩🇪 · Zoltán Szőr🇩🇪 · Juan Pablo Vesga🇩🇪 · Stefan Weinzierl🇩🇪

    We present a new formulation of the loop-tree duality theorem for higher loop diagrams valid both for massless and massive cases. $l$-loop integrals are expressed as weighted sum of trees obtained from cutting $l$ internal propagators of the loop graph. In addition, the uncut propagators gain a modified $i\delta$-prescription, named dual-propagators. In this new framework one can go beyond graphs and calculate the integrand of loop amplitudes as a weighted sum of tree graphs, which form a tree-like object. These objects can be computed efficiently via recurrence relations.

    hep-phhep-th2 citations
19. 19*

    Probing hidden-charm decay properties of $P_c$ states in a molecular scenario

    Guang-Juan Wang🇨🇳 · Li-Ye Xiao🇨🇳 · Rui Chen🇨🇳 · Xiao-Hai Liu🇨🇳 · Xiang Liu🇨🇳 · Shi-Lin Zhu🇨🇳

    The $P_c(4312)$, $P_c(4440)$, and $P_c(4457)$ observed by the LHCb Collaboration are very likely to be $S$-wave ${\Sigma }_c{\bar{D}}^{(\ast )}$ molecular candidates due to their near-threshold character. In this work, we study the hidden-charm decay modes of these $P_c$ states, $P_c\to J/\psi p({\eta }_{c}p)$, using a quark interchange model. The decay mechanism for the $P_c\to J/\psi p({\eta }_{c}p)$ processes arises from the quark-quark interactions, where all parameters are determined by the mass spectra of mesons. We present our results in two scenarios. In scenario I, we perform the dynamical calculations and treat the $P_c$ states as pure ${\Sigma }_c{\bar{D}}^{(\ast )}$ molecules. In scenario II, after considering the coupled channel effect between different flavor configurations ${\Sigma }_c^{(\ast )}{\bar{D}}^{(\ast )}$, we calculate these partial decay widths again. The decay patterns in these two scenarios can help us to explore the molecular assignment and the inner flavor configurations for the $P_c$ states. In particular, the decay widths of $\Gamma (P_c(4312)\to {\eta }_{c}p)$ are comparable to the $J/\psi p$ decay widths in both of these two scenarios. Future experiments like LHCb may confirm the existence of the $P_c(4312)$ in the ${\eta }_{c}p$ channel.

    hep-phhep-exPRD(2020)·78 citations
20. 20*

    The Swampland and Screened Modified Gravity

    Philippe Brax🇫🇷 · Carsten van de Bruck🇬🇧 · Anne-Christine Davis🇬🇧

    We consider the implications of the swampland conjectures on scalar-tensor theories defined in the Einstein frame in which the scalar interaction is screened. We show that chameleon models are not in the swampland provided the coupling to matter is larger than unity and the mass of the scalar field is much larger than the Hubble rate. We apply these conditions to the inverse power law chameleon and the symmetron. We then focus on the dilaton of string theory in the strong coupling limit, as defined in the string frame. We show that solar system tests of gravity imply that viable dilaton models are not in the swampland. In the future of the Universe, if the low energy description with a single scalar is still valid and the coupling to matter remains finite, we find that the scalar field energy density must vanish for models with the chameleon and symmetron mechanisms. Hence in these models dark energy is only a transient phenomenon. This is not the case for the strongly coupled dilaton, which keeps evolving slowly, leading to a quasi de Sitter space-time.

    ↳ hep-thastro-ph.COgr-qchep-phPRD(2020)·14 citations
21. 21*

    Masses of Light and Heavy Mesons and Baryons: A Unified Picture

    L. X. Gutiérrez-Guerrero🇲🇽 · Adnan Bashir🇲🇽 · Marco A. Bedolla🇲🇽 · E. Santopinto🇮🇹

    We compute masses of positive parity spin-$1/2$ and $3/2$ baryons composed of $u$, $d$, $s$, $c$ and $b$ quarks in a quark-diaquark picture. The mathematical foundation for this analysis is implemented through a symmetry-preserving Schwinger-Dyson equations treatment of a vector-vector contact interaction, which preserves key features of quantum chromodynamics, such as confinement, chiral symmetry breaking and low energy Goldberger-Treiman relations. This study requires a computation of diquark correlations containing these quarks which in turn are readily inferred from solving the Bethe-Salpeter equations of the corresponding mesons. Therefore, it serves as a unified formalism for a multitude of mesons and baryons. It builds on our previous works on the study of masses, decay constants and form factors of quarkonia and light mesons, employing the same model. We use two sets of parameters, one which remains exactly the same for both the light and heavy sector hadrons, and another where the coupling strength is allowed to evolve according to the available mass scales of quarks. Our results are in very good agreement with the existing experimental data as well as predictions of other theoretical approaches whenever comparison is possible.

    ↳ nucl-thhep-phPRD(2019)·78 citations
22. 22*

    Axion-like particles and high energy astrophysics

    Giorgio Galanti🇮🇹

    Axion-like particles (ALPs) are light, neutral, pseudo-scalar bosons predicted by several extensions of the Standard Model of particle physics -- such as the String Theory -- and are supposed to interact primarily only with two photons. In the presence of an external magnetic field, photon-ALP oscillations occur and can produce sizable astrophysical effects in the very-high energy (VHE) band ($100\mathrm{GeV}-100\mathrm{TeV}$). Photon-ALP oscillations increase the transparency of the Universe to VHE photons partially preventing the gamma-gamma absorption caused by the Extragalactic Background Light (EBL). Moreover, they have important implications for active galactic nuclei (AGN) by modifying their observed spectra both for flat spectrum radio quasars (FSRQs) and BL Lacs. Many attempts have been made in order to constrain the ALP parameter space by studying irregularities in spectra due to photon-ALP conversion in galaxy clusters and the consequences of ALP emission by stars. Upcoming new VHE photon detectors like CTA, HAWC, GAMMA-400, LHAASO, TAIGA-HiSCORE, HERD and ASTRI will settle the issue.

    ↳ astro-ph.HEhep-phFrascati Phys.Ser.(2019)·9 citations
23. 23*

    On the origin of the LIGO "mystery" noise and the high energy particle physics desert

    Niayesh Afshordi (U-Waterloo and Perimeter)🇨🇦

    One of the most ubiquitous features of quantum theories is the existence of zero-point fluctuations in their ground states. For massive quantum fields, these fluctuations decouple from infrared observables in ordinary field theories. However, there is no "decoupling theorem" in Quantum Gravity, and we recently showed that the vacuum stress fluctuations of massive quantum fields source a red spectrum of metric fluctuations given by $\sim$ mass${}^5$/frequency in Planck units. I show that this signal is consistent with the reported unattributed persistent noise, or "mystery" noise, in the Laser Interferometer Gravitational-Wave Observatory (LIGO), for the Standard Model of Particle Physics. If this interpretation is correct, then it implies that: 1) This will be a fundamental irreducible noise for all gravitational wave interferometers, and 2) There is no fundamental weakly-coupled massive particle heavier than those in the Standard Model.

    ↳ gr-qcastro-ph.COastro-ph.IMhep-ph+11 citation
24. 24*

    Relic neutrino clustering in the Milky Way

    Pablo F. de Salas🇸🇪

    The Standard Cosmological Model predicts the existence of relic neutrinos, which are indirectly probed through the effective number of relativistic species in the early Universe. In addition, from neutrino flavour oscillations we know that at least two of the neutrino mass states have a non-zero mass. Since the expansion of the Universe has diluted the energy of relic neutrinos, those that are massive are also non relativistic today. This means that they can be trapped in strong gravitational potentials, such as the one of the Milky Way. We review the calculation of the local overdensity of relic neutrinos produced from the gravitational attraction of our Galaxy, Andromeda and the Virgo cluster, commenting on the implications for an experiment aiming at relic neutrino detection, such as the PTOLEMY project.

    ↳ astro-ph.COhep-phJ.Phys.Conf.Ser.(2020)·4 citations
25. 25*

    NN scattering and nuclear uncertainties

    Enrique Ruiz Arriola🇪🇸 · Jose Enrique Amaro🇪🇸 · Rodrigo Navarro Perez🇺🇸

    Ab initio calculations in Nuclear physics for atomic nuclei require a specific knowledge of the interactions among their constituents, protons and neutrons. In particular, NN interactions can be constrained down to scale resolutions of $\Delta r\sim 0.6\mathrm{fm}$ from the study of phase shifts below the pion production threshold. However, this allows for ambiguities and uncertainties which have an impact on finite nuclei, nuclear- and neutron-matter properties. On the other hand the nuclear many body problem is intrinsically difficult and the computational cost increases with numerical precision and number of nucleons. However, it is unclear what the physical precision should be for these calculations. In this contribution we review much of the work done in Granada to encompass both the uncertainties stemming from the NN scattering database in light nuclei such as triton and alpha particle and the numerical precision required by the solution method.

    ↳ nucl-thhep-phFront.in Phys.(2020)·17 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.