Forbidden Channels and SIMP Dark Matter

In this review, we focus on dark matter production from thermal freeze-out with forbidden channels and SIMP processes. We show that forbidden channels can be dominant to produce dark matter depending on the dark photon and / or dark Higgs mass compared to SIMP.Comment: 5 pages, Prepared for the proceedings of the 13th International Conference on Gravitation, 3-7 July 201

On thermal production of self-interacting dark matter

We consider thermal production mechanisms of self-interacting dark matter in models with gauged $Z_3$ symmetry. A complex scalar dark matter is stabilized by the $Z_3$, that is the remnant of a local dark $U(1)_d$. Light dark matter with large self-interaction can be produced from thermal freeze-out in the presence of SM-annihilation, SIMP and/or forbidden channels. We show that dark photon and/or dark Higgs should be relatively light for unitarity and then assist the thermal freeze-out. We identify the constraints on the parameter space of dark matter self-interaction and mass in cases that one or some of the channels are important in determining the relic density.Comment: 26 pages, 11 figures, Version to appear in Journal of High Energy Physic

Unitary inflaton as decaying dark matter

We consider the inflation model of a singlet scalar field (sigma field) with both quadratic and linear non-minimal couplings where unitarity is ensured up to the Planck scale. We assume that a $Z_2$ symmetry for the sigma field is respected by the scalar potential in Jordan frame but it is broken explicitly by the linear non-minimal coupling due to quantum gravity. We discuss the impacts of the linear non-minimal coupling on various dynamics from inflation to low energy, such as a sizable tensor-to-scalar ratio, a novel reheating process with quartic potential dominance, and suppressed physical parameters in the low energy, etc. In particular, the linear non-minimal coupling leads to the linear couplings of the sigma field to the Standard Model through the trace of the energy-momentum tensor in Einstein frame. Thus, regarding the sigma field as a decaying dark matter, we consider the non-thermal production mechanisms for dark matter from the decays of Higgs and inflaton condensate and show the parameter space that is compatible with the correct relic density and cosmological constraints.Comment: 36 pages, 7 figures, v2: minor corrections made and references added, v3: discussion on preheating added, accepted for Journal of High Energy Physics, v4: Lyman-alpha bound included and inflationary predictions refined for perturbative reheatin

A minimal flavored U(1)′U(1)' for BB-meson anomalies

We consider an anomaly-free $U(1)'$ model with favorable couplings to heavy flavors in the Standard Model(SM), as motivated by $B$-meson anomalies at LHCb. Taking the $U(1)'$ charge to be $Q'=y(L_\mu-L_\tau)+ x(B_3-L_3)$, we can explain the $B$-meson anomalies without invoking extra charged fermions or flavor violation beyond the SM. We show that there is a viable parameter space with a small $x$ that is compatible with other meson decays, tau lepton and neutrino experiments as well as the LHC dimuon searches. We briefly discuss the prospects of discovering the $Z'$ gauge boson at the LHC in the proposed model.Comment: 20 pages, 4 figures, v2: references and discussion on electroweak precision test added, v3: Version to appear in Physical Review

EFFECT OF AEROBIC EXERCISE INTERVENTION ON PAINFUL DIABETIC NEUROPATHY

Background: Painful diabetic peripheral neuropathy (DPN) is a common complication of diabetes. While the beneficial effect of exercise on diabetes has been well established, its effect specifically on painful DPN has not been thoroughly explored. The objective of this pilot study is to examine the effect of aerobic exercise on pain in DPN. Methods: Twelve Sedentary individuals with type 2 diabetes mellitus between ages 40-70 with clinical diagnosis of DPN were enrolled in a 16-week, 3X week supervised aerobic exercise program. Brief Pain Inventory-Diabetic Peripheral Neuropathy (BPI-DPN) was used to assess pain intensity (worst, least, average, now) and pain interference with daily life (activity, mood, walk, normal work, relationship, sleep, enjoyment of life) pre and post the intervention. BMI, maximum oxygen uptake (VO2max), hemoglobin A1c (HbA1c), and blood pressure were also measured pre and post the intervention as secondary outcomes of interest. Results: 10 of 12 (83.3%) (5 males/5 females; age 57 ± 4.59 years; duration of diabetes 12.2 ± 5.94 years) participants reported pain due to DPN on the BPI-DPN and were included in the analysis. In these participants, significant reductions in pain interference on walking (4.95±2.83pre/2.8±2.74post, 0.0073), normal work (5.3±3.16pre/3.5±3.06post, P=0.0478), relationship with others (3.55±3.62pre/1±1.15post, P=0.0264), and sleep (5.05±2.77pre/3.2±3.12post, P=0.0407) were observed following the intervention. The overall pain interference was also reduced (4.50±2.48pre/2.56±2.01post, P=0.0267). However, there was no change in pain intensity scores. VO2max showed a significant increase post-intervention, while BMI, HbA1c, and blood pressure remained unchanged. Conclusion: These preliminary results show reductions in perceived pain interference in people with painful DPN following an aerobic exercise intervention, without a change in pain intensity. Further validation by a randomized controlled trial is needed