Order alpha_s^2 beta_0 Correction to the Charged Lepton Spectrum in b \to c \ell \bar\nu_\ell decays

We compute the \alpha_s^2\beta_0 part of the two-loop QCD corrections to the charged lepton spectrum in b \to c \ell \bar\nu_\ell decays and find them to be about 50\% of the first order corrections at all lepton energies, except those close to the end point. Including these corrections we extract the central values \bar\Lambda=0.33 GeV and \lambda_1=-0.17 GeV^2 for the HQET matrix elements and use them to determine the $\overline{\rm MS}$ b and c quark masses, and |V_{cb}|.Comment: 15 pages, 1 Postscript figur

Renormalization schemes and the range of two-nucleon effective field theory

The OS and PDS renormalization schemes for the effective field theory with nucleons and pions are investigated. We explain in detail how the renormalization is implemented using local counterterms. Fits to the NN scattering data are performed in the 1S0 and 3S1 channels for different values of mu_R. An error analysis indicates that the range of the theory with perturbative pions is consistent with 500 MeV.Comment: 40 pages, typos corrected, journal version. Discussion of the range in section VII clarified, conclusions unchange

Running of the heavy quark production current and 1/k potential in QCD

The 1/k contribution to the heavy quark potential is first generated at one loop order in QCD. We compute the two loop anomalous dimension for this potential, and find that the renormalization group running is significant. The next-to-leading-log coefficient for the heavy quark production current near threshold is determined. The velocity renormalization group result includes the alpha_s^3 ln^2(alpha_s) ``non-renormalization group logarithms'' of Kniehl and Penin.Comment: 30 pages, journal versio

Doing Biopolitics Differently? Radical Potential in the Post-2015 MDG and SDG Debates

Post print On institutional repository or subject-based repository after a 18 months embargo, withdraw

The QCD heavy-quark potential to order v^2: one loop matching conditions

The one-loop QCD heavy quark potential is computed to order v^2 in the color singlet and octet channels. Several errors in the previous literature are corrected. To be consistent with the velocity power counting, the full dependence on |p' + p|/|p' - p| is kept. The matching conditions for the NRQCD one-loop potential are computed by comparing the QCD calculation with that in the effective theory. The graphs in the effective theory are also compared to terms from the hard, soft, potential, and ultrasoft regimes in the threshold expansion. The issue of off-shell versus on-shell matching and gauge dependence is discussed in detail for the 1/(m k) term in the potential. Matching on-shell gives a 1/(m k) potential that is gauge independent and does not vanish for QED.Comment: 28 pages, References added and minor changes to section III, results unchange

2D Kagome Ordering in the 3D Frustrated Spinel Li2Mn2O4

muSR experiments on the geometrically frustrated spinel oxide, Li2Mn2O4, show the development of spin correlations over a range of length scales with decreasing temperature. Increased relaxation below 150 K is consistent with the onset of spin correlations. Below 50 K, spin order on a length scale, which is long range for the muSR probe, appears abruptly in temperature, consistent with prior neutron diffraction results. The oscillations in the zero field asymmetry are analyzed using a three frequency model. By locating the muon site this is shown to be consistent with the unexpected 2D q = root 3 x root 3 structure on the Kagome planes proposed originally from neutron data. Longitudinal field data demonstrate that some spin dynamics persist even at 2 K. Thus, a very complex magnetic ground state, featuring the co-existence of long length scale 2D ordering and significant spin dynamics, is proposed. This is unusual considering the 3D topology of the Mn3+ spins in this material.Comment: 9 pages, 9 figures, to be submitted to J. Phys. Cond. Mat

Possible Pairing Symmetry of Three-dimensional Superconductor UPt3_3 -- Analysis Based on a Microscopic Calculation --

Stimulated by the anomalous superconducting properties of UPt$_3$, we investigate the pairing symmetry and the transition temperature in the two-dimensional(2D) and three-dimensional(3D) hexagonal Hubbard model. We solve the Eliashberg equation using the third order perturbation theory with respect to the on-site repulsion $U$. As results of the 2D calculation, we obtain distinct two types of stable spin-triplet pairing states. One is the $f$-wave(B$_1$) pairing around $n = 1.2$ and in a small $U$ region, which is caused by the ferromagnetic fluctuation. Then, the other is the $p_x$(or $p_y$)-wave(E$_1$) pairing in large $U$ region far from the half-filling ($n = 1$) which is caused by the vertex corrections only. However, we find that the former $f$-wave pairing is destroyed by introduced 3D dispersion. This is because the 3D dispersion breaks the favorable structures for the $f$-wave pairing such as the van Hove singularities and the small pocket structures. Thus, we conclude that the ferromagnetic fluctuation mediated spin-triplet state can not explain the superconductivity of UPt$_3$. We also study the case of the pairing symmetry with a polar gap. This $p_z$-wave(A$_1$) is stabilized by the large hopping integral along c-axis $t_z$. It is nearly degenerate with the suppressed $p_x$(or $p_y$)-wave(E$_1$) in the best fitting parameter region to UPt$_3$ ($1.3 \le t_z \le 1.5$). These two p-wave pairing states exist in the region far from the half-filling, in which the vertex correction terms play crucial roles like the case in Sr$_2$RuO$_4$.Comment: 15 pages, 12 figure

Loss of tumor suppressor NF1 activates HSF1 to promote carcinogenesis

Intrinsic stress response pathways are frequently mobilized within tumor cells. The mediators of these adaptive mechanisms and how they contribute to carcinogenesis remain poorly understood. A striking example is heat shock factor 1 (HSF1), master transcriptional regulator of the heat shock response. Surprisingly, we found that loss of the tumor suppressor gene neurofibromatosis type 1 (Nf1) increased HSF1 levels and triggered its activation in mouse embryonic fibroblasts. As a consequence, Nf1[superscript –/–] cells acquired tolerance to proteotoxic stress. This activation of HSF1 depended on dysregulated MAPK signaling. HSF1, in turn, supported MAPK signaling. In mice, Hsf1 deficiency impeded NF1-associated carcinogenesis by attenuating oncogenic RAS/MAPK signaling. In cell lines from human malignant peripheral nerve sheath tumors (MPNSTs) driven by NF1 loss, HSF1 was overexpressed and activated, which was required for tumor cell viability. In surgical resections of human MPNSTs, HSF1 was overexpressed, translocated to the nucleus, and phosphorylated. These findings reveal a surprising biological consequence of NF1 deficiency: activation of HSF1 and ensuing addiction to this master regulator of the heat shock response. The loss of NF1 function engages an evolutionarily conserved cellular survival mechanism that ultimately impairs survival of the whole organism by facilitating carcinogenesis.United States. Army Medical Research and Materiel Command (Neurofibromatosis Research Program)Kathy and Curt Marble Cancer Research Fun

Linear Field Dependence of the Normal-State In-Plane Magnetoresistance of Sr2RuO4

The transverse and longitudinal in-plane magnetoresistances in the normal state of superconducting Sr2RuO4 single crystals have been measured. At low temperatures, both of them were found to be positive with a linear magnetic-field dependence above a threshold field, a result not expected from electronic band theory. We argue that such behavior is a manifestation of a novel coherent state characterized by a spin pseudo gap in the quasi-particle excitation spectrum in Sr2RuO4.Comment: 4 pages + 5 figure

Model independent results for B→D1(2420)ℓνˉB\to D_1(2420)\ell\bar\nu and B→D2∗(2460)ℓνˉB\to D_2^*(2460)\ell\bar\nu at order ΛQCD/mc,b\Lambda_{QCD}/m_{c,b}

Exclusive semileptonic B decays into $D_1$ and $D_2^*$ mesons are investigated including order $\Lambda_{QCD}/m_{c,b}$ corrections using the heavy quark effective theory. At zero recoil, the $\Lambda_{QCD}/m_{c,b}$ corrections can be written in terms of the leading Isgur-Wise function for these transitions, $\tau$, and known meson mass splittings. We obtain an almost model independent prediction for the shape of the spectrum near zero recoil, including order $\Lambda_{QCD}/m_{c,b}$ corrections. We determine $\tau(1)$ from the measured $B\to D_1\ell\bar\nu$ branching ratio. Implications for B decay sum rules are discussed.Comment: 11 pages, revte