Group Leader    Prof.  V. K. Gupta


Group Members  

         The main aim of our research is to study the properties of nuclear matter under conditions of intense high temperature and density, as it may have existed, a few moment after the creation of Universe through ‘Big Bang’.  In Interaction between nuclei at high energies, extremely dense nuclear matter can be produced and probably be melted into its constituents of quarks and gluons.  A phase transition from ordinary nuclear matter to a new type of matter, the quark gluon plasma is searched for.    The experiments are performed in large International collaborations at CERN in Switzerland and at Brookhaven National Laboratory  in United States.  These collaborations involve several hundred physists from 10-15 different countries.


            The group has focused the experimental activity on development of measurement systems, software for analysis of the data,  simulation studies as well as the fabrication of the detectors.


Participation in Various Collaborative projects:






> ALICE Project ^


P.V.K.S. Baba, S. K. Badyal,  A. Bhasin,  A. Gupta,  V. K. Gupta,  S. Mahajan, N. K. Rao,  S. K.  Nayak,   L. K. Mangotra,   S. S.  Sambyal

 ALICE ( A large Ion Collider Experiment) is a general purpose heavy ion detector designed to study the physics of strongly interacting matter and the Quark Gluon Plasma in Nucleus – Nucleus Collisions at the Large Hadron Collider (LHC)  (centre of mass energy-5.5 TeV/nucleon) at CERN, Geneva, Switzerland.  It currently includes more than 750 physicists and ~ 70 institutions in 27 countries.  The detector is designed to cope with the highest particle multiplicities anticipated for Pb-Pb reactions (~8000 particles per unit rapidity) and will be operational at start of LHC (2007).   In addition to heavy systems, the ALICE collaboration will study collisions of lower mass ions,  which are means of varying energy density, and also collision of protons (both pp and p-nucleus), which provide reference data for nucleus-nucleus collisions.

  The aim of ALICE Collaboration is to build a dedicated heavy Ion detector to exploit the unique physics Potential of Nucleus Nucleus Interactions at LHC energies to study physics at extreme densities where a formation of a new phase of matter, the QGP is expected. The existence of such a phase of matter and the study of its properties is crucial for understanding Qantum Chromodynamics (QCD) and in particular chiral symmetry restoration. For this we propose to perform a comprehensive study of Hadrons, Electrons, Muons and photons in the collisions of Heavy Ion nuclei.


            The main Challenge of Heavy ion Experiments is recording the enormous number of particles which emerge from the collisions. A large fraction of these must be tracked and identified. Only then can a clear picture emerge and key Signals be found pointing to different stages in evolution from ordinary matter to a QGP and back again.

 The Jammu group, which is a part of this International Collaboration, is presently involved in simulation and fabrication of one of the detectors which will form parts of ALICE; the Central Photon Multiplicity Detector (PMD) to detect and study photons.

PMD is a preshower gaseous detector and is an exclusively Indian effort.  PMD has a full azimuthal coverage in pseudo rapidity region 1.8 ≤ η ≤ 2.6.  The material, technology and tools employed are all Indian.  PMD consists of hexagonal shaped 8mm long cells arranged in the shape of a rhombus, with each cell diameter being 5 mm.  For this detector we have employed gas mixtures which consist of Argon and CO2 in the ratio 70:30.  From the GEANT simulation results we got 60% purity at 65% efficiency for detection of Photons in PMD.  In addition to the fabrication and testing of the detector prototype, Jammu group is also associated in the PCB designing for mounting the readout chips to be used in Front End Electronics of the PMD.





Fig : Principle of operation of PMD


Fig: Layout of the PMD showing four supermodules in one plane. There are two types of supermodules and two types of unit modules and the detector separates into two vertical halves for ease of installation and maintenance


Fig :  Cross sectional view of PMD



The Group has also taken the responsibility for fabricating and commissioning of ALICE Detector Control System (DCS) for the PMD.


        For the ALICE data acquisition and for its analysis the group is also involved in setting up of the GRID facility at Jammu which is going to be a part of ALICE Data GRID. In our endevour to set up this GRID facility we aim at developing the High Energy Physics Lab at Jammu University to be a viable centre for data analysis of large experiments.



For further information about ALICE


<!--[if !supportLists]--> ·        <!--[endif]-->The ALICE home page at   http://aliceinfo.cern.ch/




> STAR Project ^


P.V.K.S. Baba, S. K. Badyal,  A. Bhasin, Sunil Dogra, Neeraj Gupta,  A. Gupta, S.  Mahajan,   L. K.Mangotra, S. Nayak,  


            Solenodial Tracker at RHIC (STAR) experiment is an International collaborative experiment at BNL (Brookhaven National Laboratory), USA. The collaboration includes more than 45 Institutes in 9 Countries (USA, S. America, France, Poland, Germany, Russia, U. K., China and India).  STAR is designed to search for signatures of Quark Gluon Plasma (QGP) formation and investigate strongly interacting matter at high energy density.  STAR is one of the two large-scale experiments at Relativistic Heavy Ion Collider (RHIC) at BNL on Long Island (New York, USA) that become operational in 1999.  RHIC is the first machine in the world colliding heavy ion.  RHIC is primarily using gold ions at energy of 200 GeV.




            The effort of Indian team (VECC, Kolkata; Punjab University, Chandigarh; Jammu University, Jammu; Rajasthan University; Jaipur, IOP, Bhubaneshwar) at STAR is presently focused in designing and fabrication of PMD for detecting photons.  This is a preshower detector which is in an exclusive Indian effort.  The PMD has full azimuthal coverage in pseudo-rapidity region  2.3 ≤η≤ 3.5.  The individual cells of hexagonal shape with 1cm diameter are arranged in the shape of a rhombus for construction of one super module.  Satisfactory results have been obtained, when employed a gas mixture of Argon and CO2  in the ratio 70:30 in the prototype testing, the efficiency 65% for a purity of  60% was found for detection of photons in PMD.  The detector is fabricated in India and installed at BNL, USA during 2002 and data taking is in progress.




The photograph shows a 96 cell prototype of honeycomb proportional Counter of PMD to be installed at RHIC.


Picture below shows the first Au-Au Collision at STAR at full RHIC Energy.




For further information refer to the website:





> WA-98/WA93 Project ^

S. K. Badyal,  P.V.K.S. Baba, S. Dutt,  S. K. Nayak,  N. K. Rao,  S. S. Sambyal,        T. H. Shah, Md. F. Mir,  Devanand,  S.  Kachroo


These are International Collaborative projects consisting of hybrid experimental setup exposed at CERN,  SPS at Geneva for various heavy ion beams over a wide range of projectile mass, i.e; from S 32 to Pb 208.  In each of these setups one of the detectors was preshower Photon Multiplicity Detector (PMD) and was designed and fabricated exclusively by the Indian team consisting of members of High energy physics groups of VECC (Variable Energy Cyclotron Centre), Kolkata; Institute of Physics, Bhubaneshwar; Punjab University, Chandigarh; Rajasthan University, Jaipur; Jammu University, Jammu. For the preshower PMD, the scintillating plastic pads were used as a radiation sensitive material and the WLS, thermally bonded with clear optical fibers were used as light transport mechanism.  The UA2 Image Intensifier-II coupled with the CCD camera were used as read out device.  The WA 98 set-up consisting of 22 cameras coupled to 41,800 readout pads was fabricated in India and then transported and installed at CERN, Geneva at Accelerator Site. 


For the preshower PMD, the scintillating plastic pads were used as a radiation sensitive material and the WLS, thermally bonded with clear optical fibers were used as light transport mechanism.  The UA2 Image Intensifier-II coupled with the CCD camera were used as read out device.  The WA 98 set-up consisting of 22 cameras coupled to 41,800 readout pads was fabricated in India and then transported and installed at CERN, Geneva at Accelerator Site.  The PMD has been successfully used for data taking during 1994-96.  The data so collected is currently being used extensively for physics analysis.  The project has played a significant role in developing the necessary technological  know-how and generated the expertise pertaining to detector simulation, design, physics simulation and analysis that is acting as input for the future High Energy Physics Experiments in which the group at Jammu is participating (STAR, ALICE). 


For further information about ALICE


<!--[if !supportLists]--> ·        <!--[endif]-->The ALICE home page at   http://wa98.web.cern.ch/






> The EMU01 Project ^



 Almaty – Beijing – Bucharest -                     

 Chandigarh    –     Changsha    –    Dubna -

 Gatchina  –  Jaipur  –   Jammu  –  Kosice -

 Linfen   -   Lund   -  Marburg  – Moskow -

 St.Petersburg – Seattle – Seoul –    Sydney

  -Tashkent  –  Wuhan   -  Yerevan



S. K. Badyal, A. Bhasin, V. K. Gupta, L. K. Mangotra, S. Kitroo.  S. Kachroo,G. L. Kaul, I. Manhas,  N. K. Rao

      The EMU01 project is a world wide collaboration using Nuclear Emulsions to study High Energy heavy ion interactions.  The collaboration was established in 1985.  The data collected by the collaboration so far as well as the different experiments within the project are summarized in the table below.


Collected Data :



(S=stack, C=Chamber)


Two different experimental methods are used by the collaboration.  The conventional technique with emulsion stacks are used for studies of target     break-up and other specific topics.  A new technique with emulsion chambers, equipped with thin target foils, exposed perpendicular to the emulsion surface, is developed by the collaboration, a technique which has been shown to work well for semi-automatic measurements.  Several measuring systems for these chambers are in use by the collaboration, including the HEP Laboratory at Jammu.


            56 publications in the international journals have appeared as a result of this collaborative effort.


The figure shows a view, projected onto a plane parallel to the beam, of the first fully reconstructed EMU12 lead-on-lead interaction at 158 AGeV/c.  As can be seen the projectile, coming in from the left, collides with a lead nucleus and essentially all produced particles continue in a narrow forward cone seen in the right part of the figure.  The 1510 observed charged particles cannot be resolved in this view but in reality they are all resolved in the emulsion plates downstream in the detector.