17 research outputs found
Three-loop HTL gluon thermodynamics at intermediate coupling
We calculate the thermodynamic functions of pure-glue QCD to three-loop order
using the hard-thermal-loop perturbation theory (HTLpt) reorganization of
finite temperature quantum field theory. We show that at three-loop order
hard-thermal-loop perturbation theory is compatible with lattice results for
the pressure, energy density, and entropy down to temperatures .
Our results suggest that HTLpt provides a systematic framework that can used to
calculate static and dynamic quantities for temperatures relevant at LHC.Comment: 24 pages, 13 figs. 2nd version: improved discussion and fixing typos.
Published in JHE
On the Strength of First Order Phase Transitions
Electroweak baryogenesis may solve one of the most fundamental questions we
can ask about the universe, that of the origin of matter. It has become clear
in the past few years that it also poses a multi-faceted challenge. In order to
compute the tiny primordial baryonic excess, we probably must invoke physics
beyond the standard model (an exciting prospect for most people), we must push
perturbation theory to its ``limits'' (or beyond), and we must deal with
nonequilibrium aspects of the phase transition. In this talk, I focus mainly on
the latter issue, that of nonequilibrium aspects of first order transitions. In
particular, I discuss the elusive question of ``weakness''. What does it mean
to have a weak first order transition, and how can we distinguish between weak
and strong? I argue that weak and strong transitions have very different
dynamics; while strong transitions proceed by the usual bubble nucleation
mechanism, weak transitions are characterized by a mixing of phases as the
system reaches the critical temperature from above. I show that it is possible
to clearly distinguish between the two, and discuss consequences for studies of
first order transitions in general. (Invited talk given at the ``Electroweak
Physics and the Early Universe'' workshop, Sintra, March 23-25, 1994.)Comment: 16 pages, 4 figures not included (can be obtained from
hep-ph/9403310, or by request) RevTeX, DART-HEP-94/0
IBP methods at finite temperature
We demonstrate the applicability of integration-by-parts (IBP) identities in
finite-temperature field theory. As a concrete example, we perform 3-loop
computations for the thermodynamic pressure of QCD in general covariant gauges,
and confirm earlier Feynman-gauge results.Comment: 16 pages, 4 Axodraw figure
Electroweak Baryogenesis in Two Higgs Doublet Models and B meson anomalies
Motivated by 3.9 sigma evidence of a CP-violating phase beyond the standard
model in the like-sign dimuon asymmetry reported by DO, we examine the
potential for two Higgs doublet models (2HDMs) to achieve successful
electroweak baryogenesis (EWBG) while explaining the dimuon anomaly. Our
emphasis is on the minimal flavour violating 2HDM, but our numerical scans of
model parameter space include type I and type II models as special cases. We
incorporate relevant particle physics constraints, including electroweak
precision data, b to s gamma, the neutron electric dipole moment, R_b, and
perturbative coupling bounds to constrain the model. Surprisingly, we find that
a large enough baryon asymmetry is only consistently achieved in a small subset
of parameter space in 2HDMs, regardless of trying to simultaneously account for
any B physics anomaly. There is some tension between simultaneous explanation
of the dimuon anomaly and baryogenesis, but using a Markov chain Monte Carlo we
find several models within 1 sigma of the central values. We point out
shortcomings with previous studies that reached different conclusions. The
restricted parameter space that allows for EWBG makes this scenario highly
predictive for collider searches. We discuss the most promising signatures to
pursue at the LHC for EWBG-compatible models.Comment: 58 pages, 16 figures, 6 tables; v2 added references; v3 minor
corrections and improvements, published versio
p63 Immunohistochemistry Differentiates Salivary Gland Oncocytoma and Oncocytic Carcinoma from Metastatic Renal Cell Carcinoma
Metastatic renal cell carcinoma (RCC) can pose diagnostic challenges in the head and neck often resembling benign and malignant oncocytic lesions. Immunohistochemical panels have been reported to help with this differential but are not entirely specific or sensitive. We have noticed that p63 routinely stains salivary gland oncocytomas but not metastatic RCC. Nineteen oncocytomas, 9 cases of oncocytosis, 9 oncocytic carcinomas and 16 head and neck metastatic RCC were studied. Morphologic features evaluated were cytoplasmic character (clear versus oncocytic), Fuhrman nuclear grade, mitotic rate, growth pattern, presence of lumens/blood lakes and stromal characteristics. Tumors were stained with antibodies to p63, renal cell carcinoma marker (RCCm), CD10, and vimentin. Eight benign oncocytic tumors (29%) had clear cell features while 6 metastatic RCC (37%) had oncocytic features. Median Fuhrman nuclear grade was 2 in oncocytoma and oncocytosis and 3 both oncocytic carcinoma and metastatic RCC. Mitotic rates were only significantly different between benign oncocytic tumors and metastatic RCC. All oncocytomas had lumina compared to half of metastatic RCC, all of which also demonstrated blood lakes. Seven benign oncocytic tumors (25%) and 5 oncocytic carcinomas (56%) had RCC-like vascular stroma. All primary salivary gland tumors were positive for p63, predominately in basal cell-type distribution. None of the metastatic RCC was positive. RCCm was entirely specific but lacked sensitivity for metastatic RCC while CD10 and vimentin showed variable sensitivity and specificity. While clinical history and morphology usually are adequate, demonstration of p63 staining can definitively exclude metastatic RCC from the differential diagnosis of similar appearing tumors in salivary glands, namely oncocytoma and oncocytic carcinoma, with 100% specificity and sensitivity. While RCCm, CD10, and vimentin performed adequately, they were significantly less reliable than p63 with both false positives and false negatives