Wed·Mar 14, 2018Wednesday·March 14, 2018

1. 01*

   Flavourful $Z^{\prime }$ portal for vector-like neutrino Dark Matter and $R_{K^{(\ast )}}$

   Adam Falkowski🇫🇷 · Stephen F. King🇬🇧 · Elena Perdomo🇬🇧 · Mathias Pierre🇫🇷

   We discuss a flavourful $Z^{\prime }$ portal model with a coupling to fourth-family singlet Dirac neutrino dark matter. In the absence of mixing, the $Z^{\prime }$ is fermiophobic, having no couplings to the three chiral families, but does couple to a fourth vector-like family. Due to mixing effects, the $Z^{\prime }$ gets induced couplings to second family left-handed lepton doublets and third family left-handed quark doublets. This model can simultaneously account for the measured $B$-decay ratios $R_K$ and $R_{K^{\ast }}$ and for the observed relic abundance of dark matter. We identify the parameter space where this explanation is consistent with existing experimental constraints from dark matter direct and indirect detection, LHC searches, and precision measurements of flavour mixing and neutrino processes.

   hep-phJHEP(2018)·87 citations
2. 02*

   Decoherence in neutrino propagation through matter, and bounds from IceCube/DeepCore

   Pilar Coloma🇺🇸 · Jacobo Lopez-Pavon🇨🇭 · Ivan Martinez-Soler🇪🇸 · Hiroshi Nunokawa🇧🇷

   We revisit neutrino oscillations in matter considering the open quantum system framework which allows to introduce possible decoherence effects generated by New Physics in a phenomenological manner. We assume that the decoherence parameters ${\gamma }_{ij}$ may depend on the neutrino energy, as ${\gamma }_{ij}={\gamma }_{ij}^0(E/\text{GeV}{)}^n$ $(n=0,\pm 1,\pm 2)$. The case of non-uniform matter is studied in detail, both within the adiabatic approximation and in the more general non-adiabatic case. In particular, we develop a consistent formalism to study the non-adiabatic case dividing the matter profile into an arbitrary number of layers of constant densities. This formalism is then applied to explore the sensitivity of IceCube and DeepCore to this type of effects. Our study is the first atmospheric neutrino analysis where a consistent treatment of the matter effects in the three-neutrino case is performed in presence of decoherence. We show that matter effects are indeed extremely relevant in this context. We find that IceCube is able to considerably improve over current bounds in the solar sector (${\gamma }_{21}$) and in the atmospheric sector (${\gamma }_{31}$ and ${\gamma }_{32}$) for $n=0,1,2$ and, in particular, by several orders of magnitude (between 3 and 9) for the $n=1,2$ cases. For $n=0$ we find ${\gamma }_{32},{\gamma }_{31}<4.0\cdot 10^{-24}(1.3\cdot 10^{-24})$ GeV and ${\gamma }_{21}<1.3\cdot 10^{-24}(4.1\cdot 10^{-24})$ GeV, for normal (inverted) mass ordering.

   hep-phhep-exEPJC(2018)·74 citations
3. 03*

   Constraints on light Dark Matter fermions from relic density consideration and Tsallis statistics

   Atanu Guha🇮🇳 · Prasanta Kumar Das🇮🇳

   The cold dark matter fermions with mass MeV scale, pair produced inside the supernova SN1987A core, can freely stream away from the supernovae and hence contributes to its energy loss rate. Similar type of DM fermions(having similar kind of coupling to the standard model photon), produced from some other sources earlier, could have contributed to the relic density of the Universe. Working in a theory with an effective dark matter-photon coupling (inversely proportional to the scale $\Lambda$) in the formalism of Tsallis statistics, we find the dark matter contribution to the relic density and obtain a upper bound on $\Lambda$ using the experimental bound on the relic density for cold non-baryonic matter i.e. $\Omega h^2=0.1186\pm 0.0020$. The upper bound obtained from the relic density is shown with the lower bound obtained from the Raffelt's criterion on the emissibity rate of the supernovae SN1987A energy loss $\dot{\epsilon }(e^{+}{e}^{-}\to \chi \overline{\chi })\le 10^{19}\mathrm{erg}{\mathrm{g}}^{-1}{\mathrm{s}}^{-1}$ and the optical depth criteria on the free streaming of the dark matter fermion (produced inside the supernovae core). As the deformation parameter $q$ changes from $1.0$ (undeformed scenario) to $1.1$(deformed scenario), the relic density bound on $\Lambda$ is found to vary from $\sim 4.9\times 10^7$ TeV to $1.6\times 10^8$ TeV for a fermion dark matter($\chi$) of mass $m_{\chi }=30\mathrm{MeV}$, which is almost $10$ times more than the lower bound obtained from the SN1987A energy loss rate and the optical depth criteria. \noindent {{\bf Keywords}: Dark matter, Relic density, Supernova cooling, Tsallis statistics, free-streaming, } }

   hep-phastro-ph.HEJHEP(2018)·1 citation
4. 04*

   Probing secret interactions of eV-scale sterile neutrinos with the diffuse supernova neutrino background

   Yu Seon Jeong (1)🇺🇸 · Sergio Palomares-Ruiz (2)🇪🇸 · Mary Hall Reno (3)🇺🇸 · Ina Sarcevic (1) ((1) University of Arizona, (2) Valencia U. IFIC, (3) University of Iowa)🇺🇸

   Sterile neutrinos with mass in the eV-scale and large mixings of order ${\theta }_0\simeq 0.1$ could explain some anomalies found in short-baseline neutrino oscillation data. Here, we revisit a neutrino portal scenario in which eV-scale sterile neutrinos have self-interactions via a new gauge vector boson $\varphi$. Their production in the early Universe via mixing with active neutrinos can be suppressed by the induced effective potential in the sterile sector. We study how different cosmological observations can constrain this model, in terms of the mass of the new gauge boson, $M_{\varphi }$, and its coupling to sterile neutrinos, $g_s$. Then, we explore how to probe part of the allowed parameter space of this particular model with future observations of the diffuse supernova neutrino background by the Hyper-Kamiokande and DUNE detectors. For $M_{\varphi }\sim 5-10$~keV and $g_s\sim 10^{-4}-10^{-2}$, as allowed by cosmological constraints, we find that interactions of diffuse supernova neutrinos with relic sterile neutrinos on their way to the Earth would result in significant dips in the neutrino spectrum which would produce unique features in the event spectra observed in these detectors.

   hep-phastro-ph.HEJCAP(2018)·53 citations
5. 05*

   Neutrino masses in the minimal gauged $(B-L)$ supersymmetry

   Yu-Li Yan🇨🇳 · Tai-Fu Feng🇨🇳 · Jin-Lei Yang🇨🇳 · Hai-Bin Zhang🇨🇳 · Shu-Min Zhao🇨🇳 · Rong-Fei Zhu🇨🇳

   We present the radiative corrections to neutrino masses in a minimal supersymmetric extension of the standard model with local $U(1{)}_{B-L}$ symmetry. At tree level, three tiny active neutrinos and two nearly massless sterile neutrinos can be obtained through the seesaw mechanism. Considering the one-loop corrections to the neutrino masses, the numerical results indicate that two sterile neutrinos obtain $\mathrm{KeV}$ masses and the small active-sterile neutrino mixing angles. The lighter sterile neutrino is a very interesting dark matter candidate in cosmology. Meanwhile the active neutrinos mixing angles and mass squared differences agree with present experimental data.

   hep-phPRD(2018)·5 citations
6. 06*

   Modifications to the neutrino mixing from the mu-tau reflection symmetry

   Zhen-hua Zhao🇨🇳

   The $\mu$-$\tau$ reflection symmetry serves as a unique basis for understanding the observed neutrino mixing as it can lead us to the interesting results ${\theta }_{23}^{}=\pi /4$ and $\delta =-\pi /2$ which stand close to the current experimental results. But a precise measurement for ${\theta }_{23}^{}$ and $\delta$ will probably force us to modify the neutrino mixing $U^{(0)}$ from such a symmetry. Here we perform a study for modifications to $U^{(0)}$ in the forms of $U^{(1)†}{U}^{(0)}$ and $U^{(0)}{U}^{(1)}$ where $U^{(1)}=R_{ij}^{(1)}$ (for $ij=12,23$ and 13) with $R_{ij}^{(1)}$ denoting a real orthogonal rotation on the $ij$ plane.

   hep-phNPB(2018)·21 citations
7. 07*

   Constraints on two Higgs doublet models from domain walls

   Minoru Eto🇯🇵 · Masafumi Kurachi🇯🇵 · Muneto Nitta🇯🇵

   We show that there is a constraint on the parameter space of two Higgs doublet models that comes from the existence of the stable vortex-domain wall systems. The constraint is quite universal in the sense that it depends on only two combinations of Lagrangian parameters and does not depend on how fermions couple to two Higgs fields. Numerical solutions of field configurations of domain wall-vortex system are obtained, which provide a basis for further quantitative study of cosmology which involve such topological objects.

   hep-phhep-thPLB(2018)·43 citations
8. 08*

   Liouville term for neutrinos: Flavor structure and wave interpretation

   Tobias Stirner🇩🇪 · Günter Sigl🇩🇪 · Georg Raffelt🇩🇪

   Neutrino production, absorption, transport, and flavor evolution in astrophysical environments is described by a kinetic equation $D\varrho =-i[\mathsf{H},\varrho ]+\mathcal{C}[\varrho ]$. Its basic elements are generalized occupation numbers $\varrho$, matrices in flavor space, that depend on time $t$, space $\mathbf{x}$, and momentum $\mathbf{p}$. The commutator expression encodes flavor conversion in terms of a matrix $\mathsf{H}$ of oscillation frequencies, whereas $\mathcal{C}[\varrho ]$ represents source and sink terms as well as collisions. The Liouville operator on the left hand side involves linear derivatives in $t$, $\mathbf{x}$ and $\mathbf{p}$. The simplified expression $D={\partial }_t+\hat{\mathbf{p}}\cdot {\partial }_{\mathbf{x}}$ for ultra-relativistic neutrinos was recently questioned in that flavor-dependent velocities should appear instead of the unit vector $\hat{\mathbf{p}}$. Moreover, a new damping term was postulated as a result. We here derive the full flavor-dependent velocity structure of the Liouville term although it appears to cause only higher-order corrections. Moreover, we argue that on the scale of the neutrino oscillation length, the kinetic equation can be seen as a first-order wave equation.

   hep-phastro-ph.HEJCAP(2018)·30 citations
9. 09*

   Anomalies in $b\to s$ transitions and dark matter

   Avelino Vicente🇪🇸

   Since 2013, the LHCb collaboration has reported on the measurement of several observables associated to $b\to s$ transitions, finding various deviations from their predicted values in the Standard Model. These include a set of deviations in branching ratios and angular observables, as well as in the observables $R_K$ and $R_{K^{\ast }}$, specially built to test the possible violation of Lepton Flavor Universality. Even though these tantalizing hints are not conclusive yet, the $b\to s$ anomalies have gained considerable attention in the flavor community. Here we review New Physics models that address these anomalies and explore their possible connection to the dark matter of the Universe. After discussing some of the ideas introduced in these works and classifying the proposed models, two selected examples are presented in detail in order to illustrate the potential interplay between these two areas of current particle physics.

   hep-phAdv.High Energy Phys.(2018)·25 citations
10. 10*

    Soft-Drop Thrust

    Jeremy Baron🇺🇸 · Simone Marzani🇮🇹 · Vincent Theeuwes🇩🇪

    Soft drop, a technique originally developed in the context of jet physics in proton-proton collisions in order to reduce the contamination from non-perturbative effects, is applied to event shapes in electron-positron annihilation. In particular, we study the thrust distribution at the $Z$ pole and show that the region where non-perturbative corrections due to the hadronisation process are small is considerably extended if soft drop is applied. Therefore, we argue that the use of soft drop to reduce hadronisation effects is potentially of great benefit in the context of strong coupling determination using event shapes, which would be otherwise characterised by a strong correlation between ${\alpha }_s$ and non-perturbative parameters. However, reduced sensitivity to hadronisation corrections is only one of the aspects that need to be considered. In this context, we show that perturbative calculability, especially away from the soft and collinear region of the event-shape spectrum, has a nontrivial interplay with the soft-drop observable of choice. To this purpose, besides thrust, we investigate the behaviour of the hemisphere mass as well as the jet mass. We find that the latter shows the most promising behaviour in the intermediate region of the spectrum, especially if small jet radii are considered.

    hep-phJHEP(2018)·54 citations
11. 11*

    Zee-Babu type model with $U(1{)}_{L_{\mu }-L_{\tau }}$ gauge symmetry

    Takaaki Nomura🇰🇷 · Hiroshi Okada🇹🇼

    We extend the Zee-Babu model introducing local $U(1{)}_{L_{\mu }-L_{\tau }}$ symmetry with several singly-charged bosons. We find a predictive neutrino mass texture in a simple hypothesis that mixings among singly-charged bosons are negligible. Also lepton flavor violations are less constrained compared with the original model. Then we explore testability of the model focussing on a doubly-charged boson physics at the LHC and the ILC.

    hep-phhep-exPRD(2018)·34 citations
12. 12*

    Post-recombination Dark Matter for the 21-cm Signal

    Zhaofeng Kang🇨🇳

    We have no certain knowledge of the early history of dark matter (DM). In this paper we propose a scenario where DM is produced post-recombination but prior to the cosmic dawn. It helps to relax the bounds on DM interactions, in particular with baryons, from the CMB. It may be of interest in some circumstances, for example, to understand the recent cosmic dawn 21-cm signal anomaly. We argue that the cosmic gas cooling mechanism via the minicharged DM-baryon scattering may be viable even if it takes up the total DM budget. We also investigate the possibility of a gluon-philic mediator of a few 10 keV, to find that the most reliable exclusion is from the neutron scattering.

    hep-ph13 citations
13. 13*

    Dark decay of the neutron

    James M. Cline🇨🇦 · Jonathan M. Cornell🇨🇦

    New decay channels for the neutron into dark matter plus other particles have been suggested for explaining a long-standing discrepancy between the neutron lifetime measured from trapped neutrons versus those decaying in flight. Many such scenarios are already ruled out by their effects on neutron stars, and the decay into dark matter plus photon has been experimentally excluded. Here we explore the decay into a dark Dirac fermion $\chi$ and a dark photon $A^{\prime }$, which can be consistent with all constraints if $\chi$ is a subdominant component of the dark matter. Neutron star constraints are evaded if the dark photon mass to coupling ratio is $m_{A^{\prime }}/g^{\prime }\lesssim (45-60)$MeV, depending upon the nuclear equation of state. $g^{\prime }$ and the kinetic mixing between U(1)${}^{\prime }$ and electromagnetism are tightly constrained by direct and indirect dark matter detection, supernova constraints, and cosmological limits.

    hep-phastro-ph.COastro-ph.HEnucl-thJHEP(2018)·81 citations
14. 14*

    An $S_4\times SU(5)$ SUSY GUT of flavour in 6d

    Francisco J. de Anda🇲🇽 · Stephen F. King🇬🇧

    We propose a 6d model with a SUSY $SU(5)$ gauge symmetry. After compactification, it explains the origin of the $S_4$ Family Symmetry with CSD3 vacuum alignment, as well as $SU(5)$ breaking with doublet-triplet splitting. The model naturally accounts for all quark and lepton (including neutrino) masses and mixings, incorporating the highly predictive Littlest Seesaw structure. It spontaneously breaks CP symmetry, resulting in successful CP violation in the quark and lepton sectors, while solving the Strong CP problem. It also explains the Baryon Asymmetry of the Universe (BAU) through leptogenesis, with the leptogenesis phase directly linked to the Dirac and Majorana phases.

    hep-phJHEP(2018)·43 citations
15. 15*

    Extreme walking behavior and SDE boundary conditions in a 331-TC model

    A. Doff🇧🇷

    The solution of the phenomenological problems of technicolor (TC) models may reside in the different dynamical behavior of the technifermions self-energy appearing in walking (or quasi-conformal) theories. Motivated by recent results where it is shown how the boundary conditions (bc) of the anharmonic oscillator representation of the Schwinger-Dyson gap equation (SDE) to $SU(N)$ are directly related with the mass anomalous dimensions, and different bc cause a change in the ultraviolet asymptotic behavior of the self-energies, in this work we verify that it is possible to have a hard technifermion self-energy in TC models originated through radiative corrections coming from the interactions mediated by the new massive neutral and charged gauge bosons, $Z^{\prime }$ and $U^{\pm \pm }$ in the context of a 331-TC model.

    hep-ph0 citations
16. 16*

    Phenomenology of fermion production during axion inflation

    Peter Adshead🇺🇸 · Lauren Pearce🇺🇸 · Marco Peloso🇺🇸 · Michael A. Roberts🇺🇸 · Lorenzo Sorbo🇺🇸

    We study the production of fermions through a derivative coupling with a pseudoscalar inflaton and the effects of the produced fermions on the scalar primordial perturbations. We present analytic results for the modification of the scalar power spectrum due to the produced fermions, and we estimate the amplitude of the non-Gaussianities in the equilateral regime. Remarkably, we find a regime where the effect of the fermions gives the dominant contribution to the scalar spectrum while the amplitude of the bispectrum is small and in agreement with observation. We also note the existence of a regime in which the backreaction of the fermions on the evolution of the zero-mode of the inflaton can lead to inflation even if the potential of the inflaton is steep and does not satisfy the slow-roll conditions.

    ↳ astro-ph.COhep-phJCAP(2018)·79 citations
17. 17*

    Neutrino flavor transformations in supernovae as a probe for nonstandard neutrino-scalar interactions

    Yue Yang🇺🇸 · James P. Kneller🇺🇸

    We explore the possibility of probing the nonstandard interactions between the neutrino and a hypothetical massive scalar or pseudoscalar via neutrino flavor transformation in supernovae. We find that in the ultrarelativistic limit, the effective interaction between the neutrinos vanishes if neutrinos are Dirac fermions but not if they are Majorana fermions. The impact of the new neutrino interaction upon the flavor transformation above the neutrinosphere is calculated in the context of the multi-angle "neutrino bulb model". We find that the addition of the nonstandard neutrino self-interaction (NSSI) to the ordinary V-A self-interaction between neutrinos is capable of dramatically altering the collective oscillations when its strength is comparable to the standard, V-A, interaction. The effect of flavor-preserving (FP) NSSI is generally to suppress flavor transformation, while the flavor-violating (FV) interactions are found to promote flavor transformations. If the neutrino signal from a Galactic supernova can be sufficiently well understood, supernova neutrinos can provide complimentary constraints on scalar/pseudoscalar interactions of neutrinos as well as distinguishing whether the neutrino is a Majorana or Dirac fermion.

    ↳ astro-ph.HEhep-phPRD(2018)·22 citations
18. 18*

    Identifying Universality in Warm Inflation

    Arjun Berera🇬🇧 · Joel Mabillard🇬🇧 · Mauro Pieroni🇪🇸 · Rudnei O. Ramos🇧🇷

    Ideas borrowed from renormalization group are applied to warm inflation to characterize the inflationary epoch in terms of flows away from the de Sitter regime. In this framework different models of inflation fall into universality classes. Furthermore, for warm inflation this approach also helps to characterise when inflation can smoothly end into the radiation dominated regime. Warm inflation has a second functional dependence compared to cold inflation due to dissipation, yet despite this feature, it is shown that the universality classes defined for cold inflation can be consistently extended to warm inflation.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2018)·29 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.