Effect of Prolonged Non-Traumatic Noise Exposure on Unvoiced Speech Recognition

Animal models in the past decade have shown that noise exposure may affect temporal envelope processing at supra-threshold levels while the absolute hearing threshold remains in the normal range. However, human studies have failed to consistently find such issue due to poor control of the participants’ noise exposure history and the measure sensitivity. The current study operationally defined non-traumatic noise exposure (NTNE) to be noise exposure at dental schools because of its distinctive high-pass spectral feature, non-traumatic nature, and systematic exposure schedule across dental students of different years. Temporal envelope processing was examined through unvoiced speech recognition interrupted by noise or by silence. The results showed that people who had systematic exposure to dental noise performed more poorly on tasks of temporal envelope processing than the exposed people. The effect of high-frequency NTNE on temporal envelope processing was more robust inside than outside the spectral band of dental noise and was more obvious in conditions that required finer temporal resolution (e.g faster noise modulation rate) than in those requiring less fine temporal resolution (e.g. slower noise modulation rate). Furthermore, there was a significant performance difference between the exposed and the unexposed groups on tasks of spectral envelope processing at low frequency. Meanwhile, the two groups performed similarly in tasks near threshold. Additional analyses showed that factors such as age, years of musical training, non-dental noise exposure history and peripheral auditory function were not able to explain the variance of the performance in tasks of temporal or spectral envelope processing. The findings from the current study support the general assumptions from animal models of NTNE that temporal and spectral envelope processing issues related to NTNE likely occur in retro-cochlear sites, at supra-threshold levels, and could be easily overlooked by clinically routine audiologic screening

Uncover Compressed Supersymmetry via Boosted Bosons from the Heavier Stop/Sbottom

A light stop around the weak scale is a hopeful messenger of natural supersymmetry (SUSY), but it has not shown up at the current stage of LHC. Such a situation raises the question of the fate of natural SUSY. Actually, a relatively light stop can easily be hidden in a compressed spectra such as mild mass degeneracy between stop and neutralino plus top quark. Searching for such a stop at the LHC is a challenge. On the other hand, in terms of the argument of natural SUSY, other members in the stop sector, including a heavier stop $\tilde{t}_2$ and lighter sbottom $\tilde{b}_1$ (both assumed to be left-handed-like), are also supposed to be relatively light and therefore searching for them would provide an alternative method to probe natural SUSY with a compressed spectrum. In this paper we consider quasi-natural SUSY which tolerates relatively heavy colored partners near the TeV scale, with a moderately large mass gap between the heavier members and the lightest stop. Then $W/Z/h$ as companions of $\tilde{t}_2$ and $\tilde{b}_1$ decaying into $\tilde{t}_1$ generically are well boosted, and they, along with other visible particles from $\tilde{t}_1$ decay, are a good probe to study compressed SUSY. We find that the resulting search strategy with boosted bosons can have better sensitivity than those utilizing multi-leptons.Comment: 19 pages, 6 figures, to appear in EPJ

Revisiting lepton-specific 2HDM in light of muon g-2 anomaly

We examine the lepton-specific 2HDM as a solution of muon $g-2$ anomaly under various theoretical and experimental constraints, especially the direct search limits from the LHC and the requirement of a strong first-order phase transition in the early universe. We find that the muon g-2 anomaly can be explained in the region of 32 $<\tan\beta<$ 80, 10 GeV $<m_A<$ 65 GeV, 260 GeV $<m_H<$ 620 GeV and 180 GeV $<m_{H^\pm}<$ 620 GeV after imposing the joint constraints from the theory, the precision electroweak data, the 125 GeV Higgs data, the leptonic/semi-hadronic $\tau$ decays, the leptonic $Z$ decays and Br$(B_s \to \mu^+ \mu^-)$. The direct searches from the $h\to AA$ channels can impose stringent upper limits on Br$(h\to AA)$ and the multi-lepton event searches can sizably reduce the allowed region of $m_A$ and $\tan\beta$ (10 GeV $<m_A<$ 44 GeV and 32 $<\tan\beta<$ 60). Finally, we find that the model can produce a strong first-order phase transition in the region of 14 GeV $<m_A<$ 25 GeV, 310 GeV $<m_H<$ 355 GeV and 250 GeV $<m_{H^\pm}<$ 295 GeV, allowed by the explanation of the muon $g-2$ anomaly.Comment: 24 pages, 8 figures, 3 Tables, matches published versio

Lepton-portal Dark Matter in Hidden Valley model and the DAMPE recent results

We study the recent $e^\pm$ cosmic ray excess reported by DAMPE in a Hidden Valley Model with lepton-portal dark matter. We find the electron-portal can account for the excess well and satisfy the DM relic density and direct detection bounds, while electron+muon/electron+muon+tau-portal suffers from strong constraints from lepton flavor violating observables, such as $\mu \to 3 e$. We also discuss possible collider signatures of our model, both at the LHC and a future 100 TeV hadron collider.Comment: invited by Science China, accepted versio

Single top partner production in the Higgs to diphoton channel in the Littlest Higgs Model with TT-parity

The top partner as a hallmark of the Littlest Higgs model with $T$-parity (LHT model) has been extensively searched for during the Large Hadron Collider (LHC) Run-1. With the increasing mass limits on the top partner, the single production of the top partner will be dominant over the pair production. Under the constraints from the Higgs data, the electroweak precision observables and $R_b$, we find that the mass of $T$-even top partner ($T_+$) has to be heavier than 730 GeV. Then, we investigate the observability of the single $T$-even top partner production through the process $pp \to T_+ j$ with the sequent decay $T_+ \to th$ in the di-photon channel in the LHT model at the LHC. We find that the mass of $T_+$ can be excluded up to 800 GeV at $2\sigma$ level at 14 TeV LHC with the integrated luminosity ${\cal L}=3$ ab$^{-1}$