Story of a journey: Rutherford to the Large Hadron Collider and onwards

In this article, I set out arguments why the Large Hadron Collider (LHC) : the machine and the experiments with it, are a watershed for particle physics. I give a historical perspective of the essential link between development of particle accelerators and that in our knowledge of the laws governing interactions among the fundamental particles, showing how this journey has reached destination LHC. I explain how the decisions for the LHC design; the energy and number of particles in the beam, were arrived at. I will end by discussing the LHC physics agenda and the time line in which the particle physicists hope to achieve it.Comment: 30 pages, 6 figures, LaTe

Physics potential of the LHC

The basic aim of physics studies at the LHC is to unravel the mechanism responsible for the spontaneous symmetry breaking in the Standard Model (SM). In the currently accepted theoretical picture, this translates into finding `direct' experimental evidence for the Higgs sector. TeV scale supersymmetry (SUSY) provides a very attractive solution to the `naturalness' problem that theories with elementary scalar fields have. Hence in this talk I will summarise the physics potential of the LHC for searching for Higgs and Supersymmetry as well as for measurement of the parameters of the Higgs sector and the SUSY model. Theories with localised gravity (and large extra dimensions) give a credible option to have Standard Model without the attendant `naturalness' problems. I will therefore also summarise the potential of LHC to probe these `large' extra dimensions.Comment: Invited talk at the Asia Pacific Physics Conference 2000 and III ACFA Linear Collider Workshop, 19 pages, 11 figures, LaTe

LHC-ILC synergy

I will begin by making a few general comments on the synergy between the Large Hadron Collider (LHC) which will go in action in 2007 and the International Linear Collider (ILC) which is under planning. I will then focus on the synergy between the LHC and the PLC option at the ILC, which is expected to be realised in the later stages of the ILC program. In this I will cover the possible synergy in the Higgs sector (with and without CP violation), in the determination of the anomalous vector boson couplings and last but not the least, in the search for extra dimensions and radions.Comment: 12 pages,8 figures, uses appolb.cls, talk presented at the PLC2005 workshop, Kazimierz, Poland, 5-8 September, to appear in Acta Physics Polonic

SUSY and SUSY Breaking Scale at the Linear Collider

After summarising very briefly the key features of different model predictions for sparticle masses and their relation with the supersymmetry (SUSY) breaking scales and parameters, I discuss the capabilities of an $e^+ e^-$ Linear Collider (LC) with $\sqrt{s} \geq$ 500 GeV for precision measurements of sparticle properties. Then I focus on the lessons one can learn about the scale and mechanism of SUSY breaking from these measurements and point out how LC can crucially complement and extend the achievements of the LHC. I end by mentioning what would be the desired extensions in the type/energy of the colliding particles and their luminosity from the point of view of SUSY investigations.Comment: 28 pages, 17 figures, LaTeX, uses aipproc.cls and aipproc.sty. Plenary talk given at the International Linear Collider Workshop (LCWS) 2000, October 26-30, 2000, Fermila

Physics Potential of the Next Generation Colliders

In this article I summarize some aspects of the current status of the field of high energy physics and discuss how the next generation of high energy colliders will aid in furthering our basic understanding of elementary particles and interactions among them, by shedding light on the mechanism for the spontaneous breakdown of the Electroweak Symmetry.Comment: 42 pages, 27 figures, LaTeX, Invited article for the special issue on High Energy Physics of the Indian Journal of Physics on the occasion of its Platinum Jubile

Supersymmetry at the PLC

In this talk I will begin with a very brief discussion as to why TeV scale Supersymmetry forms an important subject of the studies at all the current and future Colliders. Then, I will give different examples where the Photon Linear Collider, PLC, will be able to make unique contributions. PlC's most important role is in the context of Higgs Physics, due to its ability of accurate determination of $\Gamma_{\gamma \gamma}$ as well as the possibilities it offers for the determination of the CP property of the Higgs boson and of possible CP mixing in the Higgs sector. Further, the PLC can provide probes of SUSY in the regions of the SUSY parameter space, which are either difficult or inaccessible at the LHC and also in the $e^+e^-$ mode of the International Linear Collider (ILC).Comment: 14 pages, LaTeX, 8 figures, uses appolb.cls, included in the submission, talk presented at the PLC2005 workshop, Kazimierz Sept. 5-8, 2005, To appear in Acta Physica Polonic

Photon Structure Function

After briefly explaining the idea of photon structure functions (\f2gam\ , \flgam) I review the current theoretical and experimental developements in the subject of extraction of \qvph\ from a study of the Deep Inelastic Scattering (DIS). I then end by pointing out recent progress in getting information about the parton content of the photon from hard processes other than DIS.Comment: 14 pages, 6 postscript figures, latex, uses equation.sty and epsfig.sty .sty files not adde

SUSY at the Linear Colliders: Working Group Summary

I summarise the activities of the different members of the SUSY working group. There have been two major areas of activity: 1) precision measurement of the SUSY particle masses/couplings and hence those of the SUSY model parameters, 2) investigations into SUSY searches at \eplem, \gamgam, \game and \emem colliders, in the nonstandard scenarios such as explicit CP violation, R-parity violation and Anomaly Mediated Supersymmtery Breaking. In addition there have been studies which looked at the effect of `large' extra dimensions at the various colliders mentioned above.Comment: Presented at the III ACFA Linear Collider Workshop, 16 pages, 8 figures, LaTe