Charged Higgs bosons in the transition region M{sub H{sup {+-}}} {approx} m{sub t} at the LHC (open access)

Charged Higgs bosons in the transition region M{sub H{sup {+-}}} {approx} m{sub t} at the LHC

We illustrate preliminary results obtained through Monte Carlo (HERWIG) and detector (ATLFAST) simulations of the H{sup {+-}} {yields} {tau}{sup {+-}}{nu}{sub {tau}} signature of charged Higgs bosons with masses comparable to that of the top quark.
Date: May 25, 2003
Creator: ASSAMAGAN,K. A. GUCHAIT,M. MORETTI,S.
System: The UNT Digital Library
V-1 TRANSITION AND N-VALUE OF MULTIFILAMENTARY LTS AND HTS WIRES AND CABLES. (open access)

V-1 TRANSITION AND N-VALUE OF MULTIFILAMENTARY LTS AND HTS WIRES AND CABLES.

For low T, multifilamentary conductors like NbTi and Nb{sub 3}Sn, the V-I transition to the normal state is typically quantified by the parameter, n, defined by ({rho}/{rho}{sub c})= (I/I{sub c}){sup n}. For NbTi, this parameterization has been very useful in the development of high Jc wires, where the n-value is regarded as an index of the filament quality. In copper-matrix wires with undistorted filaments, the n-value at 5T is {approx} 40-60, and drops monotonically with increasing field. However, n can vary significantly in conductors with higher resistivity matrices and those with a low copper fraction. Usually high n-values are associated with unstable resistive behavior and premature quenching. The n-value in NbTi Rutherford cables, when compared to that in the wires is useful in evaluating cabling degradation of the critical current due to compaction at the edges of the cable. In Nb{sub 3}Sn wires, n-value has been a less useful tool, since often the resistive transition shows small voltages {approx} a few {mu}V prior to quenching. However, in ''well behaved'' wires, n is {approx} 30-40 at 12T and also shows a monotonic behavior with field. Strain induced I{sub c} degradation in these wires is usually associated with lower n-values. For high …
Date: May 25, 2003
Creator: GHOSH,A. K.
System: The UNT Digital Library
IN PLANE OPTICAL RESPONSE OF UNDERDOPED La{sub 2-x}(Ca,Sr){sub x}CaCu{sub 2}O{sub 6+D} SINGLE CRYSTALS : EVIDENCE FOR INTRINSIC INHOMOGENEITY. (open access)

IN PLANE OPTICAL RESPONSE OF UNDERDOPED La{sub 2-x}(Ca,Sr){sub x}CaCu{sub 2}O{sub 6+D} SINGLE CRYSTALS : EVIDENCE FOR INTRINSIC INHOMOGENEITY.

The in-plane optical properties of two crystals of the bilayer cuprate La{sub 2-x}(Ca,Sr){sub x}Ca,Sr){sub x}CaCu{sub 2}O{sub 6+{delta}}, one with excess Ca and x = 0.10 and the other with Sr and x = 0.15, were investigated over the frequency range of 45-25000 cm{sup -1}. A metallic response both in frequency and temperature was observed for Sr = 0.15 superconducting sample at low frequencies. Meanwhile, the sample also exhibits a prominent charge-transfer excitation at around 15000 cm{sup -1}. This observation, together with neutron experiments performed on the same sample showing diffuse, elastic antiferromagnetic scattering, indicate that the quasi-mobile carriers coexist at low temperature with static antiferromagnetic clusters. This coexistence indicates intrinsic spatial inhomogeneity.
Date: May 25, 2003
Creator: WANG,N. L. ZHENG,P. FENG,T. GU,G. D. HOMES,C. C. TRANQUADA,J. M. GAULIN,B. D. TIMUSK,T.
System: The UNT Digital Library