arXiv subjects

Ethan T. Neil

Publications and source records attributed to Ethan T. Neil.

76 records · Page 5Linked to original sources

arXiv2010

Toward TeV Conformality

We study the chiral condensate $<\barψ ψ>$ for an SU(3) gauge theory with $N_f$ massless Dirac fermions in the fundamental representation when $N_f$ is increased from 2 to 6. For $N_f=2$, our lattice simulations of $<\barψ ψ>/F^3$, where $F$ is the Nambu-Goldstone-boson decay constant, agree with the measured QCD value. For $N_f = 6$, this ratio shows significant enhancement, presaging an even larger enhancement anticipated as $N_f$ increases further, toward the critical value for transition from confinement to infrared conformality.

hep-ph↗

arXiv2009

Lattice Study of Conformal Behavior in SU(3) Yang-Mills Theories

Using lattice simulations, we study the extent of the conformal window for an SU(3) gauge theory with N_f Dirac fermions in the fundamental representation. We extend our recently reported work, describing the general framework and the lattice simulations in more detail. We find that the theory is conformal in the infrared for N_f = 12, governed by an infrared fixed point, whereas the N_f = 8 theory exhibits confinement and chiral symmetry breaking. We therefore conclude that the low end of the conformal window N_f^c lies in the range 8 <= N_f^c <= 12. We discuss open questions and the potential relevance of the present work to physics beyond the standard model.

hep-ph↗

arXiv2008

Lattice Study of the Conformal Window in QCD-like Theories

Using lattice simulations, we study the extent of the conformal window for an $\text{SU}(3)$ gauge theory with $N_f$ Dirac fermions in the fundamental representation. We present evidence that the infrared behavior is conformal for $12 \leq N_f \leq 16$, governed by an infrared fixed point, while confinement and chiral symmetry breaking are present for $N_f \leq 8$.

hep-ph↗

arXiv2007

IR Monitoring of the Microquasar GRS 1915+105: Detection of Orbital and Superhump Signatures

We present the results of seven years of K-band monitoring of the low-mass X-ray binary GRS 1915+105. Positive correlations between the infrared flux and the X-ray flux and X-ray hardness are demonstrated. Analysis of the frequency spectrum shows that the orbital period of the system is $P_{orb}= 30.8 \pm 0.2$ days. The phase and amplitude of the orbital modulation suggests that the modulation is due to the heating of the face of the secondary star. We also report another periodic signature between 31.2 and 31.6 days, most likely due to a superhump resonance. From the superhump period we then obtain a range on the mass ratio of the system, $0.05 < q < 0.12$.

astro-ph↗