Beam instrumentation for the Tevatron Collider

The Tevatron in Collider Run II (2001-present) is operating with six times more bunches and many times higher beam intensities and luminosities than in Run I (1992-1995). Beam diagnostics were crucial for the machine start-up and the never-ending luminosity upgrade campaign. We present the overall picture of the Tevatron diagnostics development for Run II, outline machine needs for new instrumentation, present several notable examples that led to Tevatron performance improvements, and discuss the lessons for future colliders

Language of Lullabies: The Russification and De-Russification of the Baltic States

This article argues that the laws for promotion of the national languages are a legitimate means for the Baltic states to establish their cultural independence from Russia and the former Soviet Union

Supersymmetry discovery potential of the LHC at s=\sqrt{s}=10 and 14 TeV without and with missing ETE_T

We examine the supersymmetry (SUSY) reach of the CERN LHC operating at $\sqrt{s}=10$ and 14 TeV within the framework of the minimal supergravity model. We improve upon previous reach projections by incorporating updated background calculations including a variety of $2\to n$ Standard Model (SM) processes. We show that SUSY discovery is possible even before the detectors are understood well enough to utilize either $E_T^{\rm miss}$ or electrons in the signal. We evaluate the early SUSY reach of the LHC at $\sqrt{s}=10$ TeV by examining multi-muon plus $\ge4$ jets and also dijet events with {\it no} missing $E_T$ cuts and show that the greatest reach in terms of $m_{1/2}$ occurs in the dijet channel. The reach in multi-muons is slightly smaller in $m_{1/2}$, but extends to higher values of $m_0$. We find that an observable multi-muon signal will first appear in the opposite-sign dimuon channel, but as the integrated luminosity increases the relatively background-free but rate-limited same-sign dimuon, and ultimately the trimuon channel yield the highest reach. We show characteristic distributions in these channels that serve to distinguish the signal from the SM background, and also help to corroborate its SUSY origin. We then evaluate the LHC reach in various no-lepton and multi-lepton plus jets channels {\it including} missing $E_T$ cuts for $\sqrt{s}=10$ and 14 TeV, and plot the reach for integrated luminosities ranging up to 3000 fb$^{-1}$ at the SLHC. For $\sqrt{s}=10$ TeV, the LHC reach extends to $m_{gluino}=1.9, 2.3, 2.8$ and 2.9 TeV for $m_{squark}\sim m_{gluino}$ and integrated luminosities of 10, 100, 1000 and 3000 fb$^{-1}$, respectively. For $\sqrt{s}=14$ TeV, the LHC reach for the same integrated luminosities is to m_{gluino}=2.4,\3.1, 3.7 and 4.0 TeV.Comment: 34 pages, 25 figures. Revised projections for the SUSY reach for ab^-1 integrated luminosities, with minor corrections of references and text. 2 figures added. To appear in JHE

The pole structure of the unitary, crossing symmetric low energy ππ\pi\pi scattering amplitudes

The pole structure of the low energy $\pi\pi$ scattering amplitudes is studied using a proper chiral unitarization method combined with crossing symmetry and the low energy phase shift data. It is found that the $\sigma$ pole position is at $M_\sigma=470\pm 50MeV$, $\Gamma_\sigma=570\pm 50MeV$. The existence of the virtual state pole in the IJ=20 channel is reconfirmed. Various threshold parameters are estimated and are found in general in good agreement with the results obtained from the Roy equation analyses.Comment: Minor corrections made and references added. Final version accepted for publication as JHEP02(2005)04

Dirty black holes: Quasinormal modes

In this paper, we investigate the asymptotic nature of the quasinormal modes for "dirty" black holes -- generic static and spherically symmetric spacetimes for which a central black hole is surrounded by arbitrary "matter" fields. We demonstrate that, to the leading asymptotic order, the [imaginary] spacing between modes is precisely equal to the surface gravity, independent of the specifics of the black hole system. Our analytical method is based on locating the complex poles in the first Born approximation for the scattering amplitude. We first verify that our formalism agrees, asymptotically, with previous studies on the Schwarzschild black hole. The analysis is then generalized to more exotic black hole geometries. We also extend considerations to spacetimes with two horizons and briefly discuss the degenerate-horizon scenario.Comment: 15 pages; uses iopart.cls setstack.sty; V2: one additional reference added, no physics changes; V3: two extra references, minor changes in response to referee comment

Implications for the Constrained MSSM from a new prediction for b to s gamma

We re-examine the properties of the Constrained MSSM in light of updated constraints, paying particular attention to the impact of the recent substantial shift in the Standard Model prediction for BR(B to X_s gamma). With the help of a Markov Chain Monte Carlo scanning technique, we vary all relevant parameters simultaneously and derive Bayesian posterior probability maps. We find that the case of \mu>0 remains favored, and that for \mu<0 it is considerably more difficult to find a good global fit to current constraints. In both cases we find a strong preference for a focus point region. This leads to improved prospects for detecting neutralino dark matter in direct searches, while superpartner searches at the LHC become more problematic, especially when \mu<0. In contrast, prospects for exploring the whole mass range of the lightest Higgs boson at the Tevatron and the LHC remain very good, which should, along with dark matter searches, allow one to gain access to the otherwise experimentally challenging focus point region. An alternative measure of the mean quality-of-fit which we also employ implies that present data are not yet constraining enough to draw more definite conclusions. We also comment on the dependence of our results on the choice of priors and on some other assumptions.Comment: JHEP versio

Yukawa Unified Supersymmetric SO(10) Model: Cosmology, Rare Decays and Collider Searches

It has recently been pointed out that viable sparticle mass spectra can be generated in Yukawa unified SO(10) supersymmetric grand unified models consistent with radiative breaking of electroweak symmetry. Model solutions are obtained only if $\tan\beta \sim 50$, $\mu <0$ and positive $D$-term contributions to scalar masses from SO(10) gauge symmetry breaking are used. In this paper, we attempt to systematize the parameter space regions where solutions are obtained. We go on to calculate the relic density of neutralinos as a function of parameter space. No regions of the parameter space explored were actually cosmologically excluded, and very reasonable relic densities were found in much of parameter space. Direct neutralino detection rates could exceed 1 event/kg/day for a $^{73}$Ge detector, for low values of GUT scale gaugino mass $m_{1/2}$. We also calculate the branching fraction for $b\to s \gamma$ decays, and find that it is beyond the 95% CL experimental limits in much, but not all, of the parameter space regions explored. However, recent claims have been made that NLO effects can reverse the signs of certain amplitudes in the $b\to s\gamma$ calculation, leading to agreement between theory and experiment in Yukawa unified SUSY models. For the Fermilab Tevatron collider, significant regions of parameter space can be explored via $b\bar{b}A$ and $b\bar{b}H$ searches. There also exist some limited regions of parameter space where a trilepton signal can be seen at TeV33. Finally, there exist significant regions of parameter space where direct detection of bottom squark pair production can be made, especially for large negative values of the GUT parameter $A_0$.Comment: Added comparison to Blazek/Raby results and added Comments on de Boer et al. b->s gamma result

Prospects for e+e- physics at Frascati between the phi and the psi

We present a detailed study, done in the framework of the INFN 2006 Roadmap, of the prospects for e+e- physics at the Frascati National Laboratories. The physics case for an e+e- collider running at high luminosity at the phi resonance energy and also reaching a maximum center of mass energy of 2.5 GeV is discussed, together with the specific aspects of a very high luminosity tau-charm factory. Subjects connected to Kaon decay physics are not discussed here, being part of another INFN Roadmap working group. The significance of the project and the impact on INFN are also discussed. All the documentation related to the activities of the working group can be found in http://www.roma1.infn.it/people/bini/roadmap.html.Comment: INFN Roadmap Report: 86 pages, 25 figures, 9 table