119395913
Proof of principle for a high sensitivity search for the electric dipole moment of the electron using the metastable a(1)[^3\Sigma^+] state of PbO
The metastable a(1)[^3\Sigma^+] state of PbO has been suggested as a suitable system in which to search for the electric dipole moment (EDM) of the electron. We report here the development of experimental techniques allowing high-sensitivity measurements of Zeeman and Stark effects in this system, similar to those required for an EDM search. We observe Zeeman quantum beats in fluorescence from a vapor cell, with shot-noise limited extraction of the quantum beat frequencies, high counting rates, and long coherence times. We argue that improvement in sensitvity to the electron EDM by at least two orders of magnitude appears possible using these techniques.
55339745
Multi-Harmonic Cavity for RF Breakdown Studies
An axially-asymmetric cavity to support several modes at harmonically-related frequencies is predicted to sustain higher RF breakdown thresholds than a conventional pillbox cavity, when driven by two or more external RF phase-locked harmonic sources. Experimental efforts are underway at Yale Beam Physics Lab to study RF breakdown in a bimodal asymmetric cavity. Such a cavity could be a basic building-block for a future high-gradient warm accelerator structure.
119738846
Two-beam detuned-cavity electron accelerator structure
Progress has been made in the theory, development, cavity design and optimization, beam dynamics study, beam transport design, and hardware construction for studies of a detuned two-beam electron accelerator structure.
119484972
Multi-harmonic test setup for RF breakdown studies
A multi-harmonic asymmetric cavity is predicted to obtain lower RF breakdown probability than a conventional pillbox cavity, when driven by two or more external RF harmonic sources. Experimental efforts are underway to study RF breakdown in a bimodal asymmetric cavity powered by dual frequency test stand. Details of design of the test stand are described.
119300428
Why X(3915) is so narrow as a $\chi_{c0}(2P)$ state
New resonance X(3915) was identified as the charmonium $\chi_{c0}(2P)$ by BABAR Collaboration, but there seems still open question of this assignment: why its full width is so narrow? To answer this question, we calculate the Okubo-Zweig-Iizuka (OZI) allowed strong decays $X(3915)\to D \bar D$, where X(3915) is assigned as a $\chi_{c0}(2P)$ state, and estimate its full width in the cooperating framework of $^3/!P_0^{}$ model and the Bethe-Salpeter (BS) method using the Mandelstam Formalism, during which non-perturbative QCD effects of the hadronic matrix elements are well considered by overlapping integral over the relativistic Salpeter wave functions of the initial and finial states. We find the node structure of $\chi_{c0}(2P)$ wave function resulting in the narrow width of X(3915) and show the dependence of the decay width on the variation of the initial mass of X(3915). We point out that the rate of $\frac{\Gamma(X(3915)\to D^+ D^-)}{\Gamma(X(3915)\to D^0 \bar D^0)}$ is crucial to confirm whether X(3915) is the $\chi_{c0}(2P)$ state or not.
56216722
Could two NMSSM Higgs bosons be present near 125 GeV
We examine next-to-minimal supersymmetric model scenarios with partial parameter unification at the grand unification scale in which both ${h}_{1}$ and ${h}_{2}$ lie in the 123\char21{}128 GeV mass range. Very substantially enhanced $\ensuremath{\gamma}\ensuremath{\gamma}$ and other rates are possible. Broadened mass peaks are natural.
122208724
The calculation of quark number susceptibility at finite chemical potential and temperature
Abstract In this paper, we calculate the quark number susceptibility (QNS) at finite chemical potential μ and finite temperature T in the framework of the Dyson-Schwinger approach using the meromorphic quark propagator proposed in [Phys. Rev. D 70 , 014014 (2004)]. Analysis and discussions of the calculated result of the QNS is given.
120455304
A DYNAMICAL, CONFINING MODEL AND BULK VISCOSITY OF QCD MATTER AT FINITE TEMPERATURE
In this paper we calculate the thermodynamic quantities and bulk viscosity in a simple confining Dyson–Schwinger equation model of two-flavor QCD. Our results show that the velocity of sound shows a sharp increase around and at the phase transition temperature the derivative of the velocity with respect to T has a distinct change. It is also found that the trace anomaly increases sharply below the phase transition point and the bulk viscosity has a peak located at which is almost the same as the peak of the trace anomaly. A comparison of our results with those in the previous literature is given.
118135921
Two Higgs Bosons at the Tevatron and the LHC
The best fit to the Tevatron results in the bb channel and the mild excesses at CMS in the gamma-gamma channel at 136 GeV and in the tau-tau channel above 132 GeV can be explained by a second Higgs state in this mass range, in addition to the one at 125 GeV recently discovered at the LHC. We show that a scenario with two Higgs bosons at 125 GeV and 136 GeV can be consistent with practically all available signal rates, including a reduced rate in the tau-tau channel around 125 GeV as reported by CMS. An example in the parameter space of the general NMSSM is given where, moreover, the signal rates of the 125 GeV Higgs boson in the gamma-gamma channels are enhanced relative to the expectation for a SM Higgs boson of this mass.