125324833
The effects of the geometry of fireball expansion on the particle spectra in relativistic heavy-ion collisions
121511469
The ϱ-peak in the dimuon spectrum as a clock for fireball lifetimes in relativistic nuclear collisions
Abstract We discuss the modification of the dipleton yield from vector mesons inside a nuclear fireball. We argue that the relative magnitude of the ϱ peak in the dilepton spectrum determines the lifetime of the hadron gas phase in nuclear collisions with an accuracy of about 1 fm/ c . We also find that the φ (ω + ϱ) ratio measured in the dimuon channel in 200 A GeV O + U and S + U collisions points towards a rather short-lived hadronic phase in these collisions.
45880759
Strange matter lumps in the early Universe.
We study the stability of hot strange matter lumps formed in the early Universe. As the Universe cools below the hadronization temperature, these lumps normally become unstable against boiling. They can stabilize themselves against this process if their mass is sufficiently large to hold a hadronic crust by gravitational attraction. Our analysis improves on previous studies of the internal structure of such stable hot quark matter lumps with hadronic crust by correctly treating the constraints from chemical equilibrium of baryonic and electric charge between crust and core. Since the expansion rate of the early Universe is much faster than the cooling rate of the strange matter lumps, their internal structure is characterized by constant entropy per baryon. Our improved analysis confirms the earlier finding that such stable quark matter lumps require a mass well above the total mass inside the horizon.
124365920
A statistical model analysis of the rapidity distribution of hadrons
122366381
Collective flow model for the pion transverse momentum spectra from relativistic nuclear collisions at CERN
The transverse momentum spectra for pions observed by WA80 and NA35 collaborations are analysed within a fireball model with collective isentropic expansion and a realistic freeze-out criterion. By varing the initial state of the fireball, an excellent fit to the data is achieved for the whole measured range ofPT. Slight differences in the data for the spectral slopes from central and pheripheral collisions originate in our model from the difference in the size of the fireball and in the number of participating nucleons in central and peripheral collisions. Using additional information from two-pion correlations, we can extrapolate our model back from the freeze-out point (determined from the spectra) to the initial state; we find that an initial energy density of 1.5–2GGeV/fm3 is sufficient to explain the data from central O+Au collisions at 200A GeV.
122648978
Strangeness and hadronization from a quark-gluon plasma☆
Abstract From a phenomenological equation of state, the role of strangeness in the hadronizing QGP is studied. Even though strangeness abundance of the QGP is similar to that of an equilibrium hadron gas, the characteristic change in the slope of energy spectra of K + and K − mesons can serve as a signature of QGP.
119117503
Emergent Schrödinger geometries from mass-deformed CFT
We study an M-theory solution for the holographic flow of AdS4 times Sasaki-Einstein 7-manifolds with skew-whiffing, perturbed by a mass operator. The infrared solution contains the5dimensional Schrödinger geometry after considering the gravity dual of the standard non-relativistic limit of relativistic field theories. The mass deformation of the field theory is discussed in detail for the case with 7 manifold being a round sphere.
111303184
A MODULAR CAVITY FOR MUON IONIZATION COOLING R&D ∗
A goal of the Muon Accelerator Program (MAP) is the development of an ionization cooling channel for muon beams. Ionization cooling channel designs call for the operation of high-gradient, normal-conducting RF cavities in multi-Tesla solenoidal magnetic fields. However, strong magnetic fields have been shown in some cases to limit the maximum achievable gradient in RF cavities. This gradient limit is characterized by RF breakdown and damage to the cavity surface. To study this issue, we have developed an experimental program based on a modular pillbox cavity operating at 805 MHz. The modular cavity design allows for the evaluation of different cavity geometries and materials ‐ such as beryllium ‐ which may ameliorate or circumvent RF breakdown triggers. Modular cavity componentsmayfurthermorebe preparedwith differentsurface treatments, suchas high-temperatureannealingor chemical polishing. This poster presents the design and fabrication status of the modular cavity, as well as plans for the experimental program.
11647076
MASSLESS MONOPOLES AND MULTI-PRONGED STRINGS
We investigate the role of massless magnetic monopoles in the N=4 supersymmetric Yang-Mills Higgs theories. They can appear naturally in the 1/4-BPS dyonic configurations associated with multi-pronged string configurations. Massless magnetic monopoles can carry nonabelian electric charge when their associated gauge symmetry is unbroken. Surprisingly, massless monopoles can also appear even when the gauge symmetry is broken to abelian subgroups.
119250832
New BPS configurations of BMN matrix theory
We explore the 1/2 BPS configurations in BMN matrix theory with SO(3) angular momentum of SO(3) × SO(6) symmetry. The fluctuation analysis of the BPS configurations near the abelian solutions and also the fuzzy two sphere vacua reveals how nonabelian BPS configurations emerge. Especially the irreducible nonabelian configurations seem to have the maximal angular momentum of order N3, beyond which they collapse to abelian ones. We also find some new BPS configurations explicitly.
14552682
Probing large extra dimensions with spin configuration of top quark pair production at the JLC
We explore signatures of large extra dimensions with a polarized electron/positrn beam at the Joint Linear Collider (JLC). We point out that spin informations can be useful to study indirect signals for large extra dimensions due to spin-2 nature of Kaluza-Klein gravitons. The spin configurations of the top quark pair production at e + e and γγ collisions provide an unique testing ground to search for effects of the large extra dimensions. Especially we show the forward-backward ~