Baryon and dark matter genesis from strongly coupled strings

Measurements of cosmic microwave background (CMB) anisotropies constrain isocurvature fluctuations between photons and nonrelativistic particles to be subdominant to adiabatic fluctuations. Perturbations in the relative number densities of baryons and dark matter, however, are surprisingly poorly constrained. In fact, baryon-density perturbations of fairly large amplitude may exist if they are compensated by darkmatter perturbations, so that the total density remains unchanged. These compensated isocurvature perturbations (CIPs) leave no imprint on the CMB at observable scales, at linear order. B modes in the CMB polarization are generated at reionization through the modulation of the optical depth by CIPs, but this induced polarization is small. The strongest known constraint & 10% to the CIP amplitude comes from galaxy-cluster baryon fractions. Here, it is shown that modulation of the baryon density by CIPs at and before the decoupling of Thomson scattering at z $ 1100 gives rise to CMB effects several orders of magnitude larger than those considered before. Polarization B modes are induced, as are correlations between temperature/polarization spherical-harmonic coefficients of different lm. It is shown that the CIP field at the surface of last scatter can be measured with these off-diagonal correlations. The sensitivity of ongoing and future experiments to these fluctuations is estimated. Data from the WMAP, ACT, SPT, and Spider experiments will be sensitive to fluctuations with amplitude $5-10%. The Planck satellite and Polarbear experiment will be sensitive to fluctuations with amplitude $3%. SPTPol, ACTPol, and future space-based polarization methods will probe amplitudes as low as $0:4%-0:6%. In the cosmic-variance limit, the smallest CIPs that could be detected with the CMB are of amplitude $0:05%.

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“…(57) is applied to the extension of Eqs. (53) and (54) that includes gravitational lensing, a bias will be induced in the measurement of Á LM .…”

Section: Discussionmentioning

confidence: 99%

Compensated isocurvature perturbations and the cosmic microwave background

2011

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“…The DM in this class of models carries opposite charge baryon/lepton numbers as the left-over SM particles. Such scenario is recently studied by [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42].…”

Section: Jhep02(2014)077mentioning

confidence: 99%

Dark matter induced nucleon decay: model and signatures

Huang

Zhao

2014

J. High Energ. Phys.

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If dark matter (DM) carries anti-baryon number, a DM particle may annihilate with a nucleon by flipping to anti-DM. Inspired by Hylogenesis models, we introduce a single component DM model where DM is asymmetric and carries B and L as -1/2. It can annihilate with a nucleon to an anti-lepton and an anti-DM at leading order or with an additional meson at sub-leading order. Such signals may be observed in proton decay experiments. If DM is captured in the Sun, the DM induced nucleon decay can generate a large flux of anti-neutrinos, which could be observed in neutrino experiments. Furthermore, the anti-DM particle in the final state obtains a relatively large momentum (few hundred MeV), and escapes the Sun. These fast-moving anti-DM particles could also induce interesting signals in various underground experiments.

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“…Then we study the case that 100 GeV m X 10 TeV. We emphasize that this latter case, while motivated by models of ADM, may arise in many GUT-inspired models, such as those explored in [34,35,45].…”

Section: Jhep07(2014)017mentioning

confidence: 99%

Indirect detection signatures for the origin of asymmetric dark matter

Zhao

Zurek

2014

J. High Energ. Phys.

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Abstract:We study the decay signatures of Asymmetric Dark Matter (ADM) via higher dimension operators which are responsible for generating the primordial dark matter (DM) asymmetry. Since the signatures are sensitive both to the nature of the higher dimension operator generating the DM asymmetry and to the sign of the baryon or lepton number that the DM carries, indirect detection may provide a window into the nature of the mechanism which generates the DM asymmetry. We consider in particular dimension-6 fermionic operators of the form(or operators related through a Hermitian conjugate) with the scale M around or just below the GUT scale. We derive constraints on ADM particles both in the natural mass range (around a few GeV), as well as in the range between 100 GeV to 10 TeV. For light ADM, we focus on constraints from both the low energy gamma ray data and proton/antiproton fluxes. For heavy ADM, we consider γ-rays and proton/anti-proton fluxes, and we fit e + /e − data from AMS-02 and H.E.S.S. (neglecting the Fermi charged particle fluxes which disagree with AMS-02 below 100 GeV). We show that, although the best fit regions from electron/positron measurement are still in tension with other channels on account of the H.E.S.S. measurement at high energies, compared to an ordinary symmetric dark matter scenario, the decay of DM with a primordial asymmetry reduces the tension. Better measurement of the flux at high energy will be necessary to draw a definite conclusion about the viability of decaying DM as source for the signals.

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Baryon and dark matter genesis from strongly coupled strings

Cited by 54 publications

References 120 publications

Compensated isocurvature perturbations and the cosmic microwave background

Compensated isocurvature perturbations and the cosmic microwave background

Dark matter induced nucleon decay: model and signatures

Indirect detection signatures for the origin of asymmetric dark matter

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