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M. Kaur

Publications and source records attributed to M. Kaur.

At least 19 recordsLinked to original sources

Comparative analysis of C-moments using different phenomenological models

Analysis of normalised C-moments of multiplicity distribution calculated from the different phenomenological models, the Bialas-Praszalowics~(BP) model, modified negative binomial and the superposed SGD at different center of mass~(cms) energies is presented.~The analysis covers a range of energies~(200-900 GeV) of $\bar{p}p$ collisions in restricted phase space slices.~A comparison of different models to the experimental data on charged particle multiplicity spectra from the $\bar{p}p$ annihilation in five pseudorapidity windows is reported.~The comparison shows that the two approaches other than the BP model are in better agreement to the data.~Results on variation of moments with pseudorapidity window size and with center of mass energy and observations from such a study in $\bar{p}p$ annihilation and $pp$ interactions at the same cms energy are also presented.

hep-ph

Design of a Thomson scattering diagnostic for the SMART tokamak

We describe the design of a Thomson scattering (TS) diagnostic to be used on the SMall Aspect Ratio Tokamak (SMART). SMART is a spherical tokamak being commissioned in Spain that aims to explore positive triangularity (PT) and negative triangularity (NT) plasma scenarios at a low aspect ratio. The SMART TS diagnostic is designed to enable a wide range of electron temperature (1 eV to 1 keV) and density (0.5 - 10 $\times 10^{19} ~\rm{m^{ - 3}}$) measurements. A 2Joule laser operating at 1064 nm will be used to probe the electron temperature and density of the plasma. The laser is capable of operating in the burst mode at 1kHz, 2kHz, and 4kHz to investigate fast phenomena or at $30$ Hz to study 1 sec (or more) long discharges. The scattered light will be collected over an angular range of 60-120 degrees at 28 spatial points in the midplane covering the core region and edge plasma on both the low-field side (LFS) and the high-field side (HFS). Simulation data is used to determine the optimum location of Thomson scattering measurement points to effectively resolve the edge pedestal in the LFS and HFS regions under different triangularity conditions. Each scattering signal will be spectrally resolved on five wavelength channels of a polychromator to obtain the electron temperature measurement. We will also present a method to monitor in-situ laser alignment in the core during calibrations and plasma operations.

physics.plasm-ph

Search for nonextensivity in electron-proton interactions at $\sqrt{s}$ = 300 GeV

Study of canonical entropy in electron-proton interactions at $\sqrt{s}$ = 300 GeV is presented. The precision data collected by the H1 experiment at the HERA in different ranges of invariant hadronic mass $W$ and the squared four-momentum exchange $Q^{2}$ in $ep$ interactions have been analyzed in the ensemble theory approach. The canonical partition function relates to the multiplicity distribution which is often studied in collider experiments. We use the canonical ensemble partition function to explore the dynamics of hadron production in $ep$ interactions by devising different methods to find the entropic parameter and the collision temperature. The inverse slope of the transverse momentum spectrum of produced hadrons also relates to the temperature. In the recent past, the CMS, ATLAS and ALICE experiments at the LHC have studied the charged hadron transverse momentum and particle distributions in proton-proton and proton-nucleus interactions by using the Tsallis function within this approach. A detailed investigation into the role of the system volume and relation amongst different dynamical parameters reveals interesting results.

hep-ph

Updated Trends in Neutrino-induced hadron production

With four different type of neutrino-induced interactions, we considered to investigate and reanalyse the KNO scaling in modified multiplicity distributions from a different perspective. In an attempt of first of its kind, we propose alternate fitting function to parameterise the distribution than the most widely adopted Slattery's function and compare it with yet another form. We propose the shifted Gompertz and Weibull functions as the fitting functions and compare their potency for the most conventional form of Slattery's function. In addition the analysis of the data by evaluating the central moments and factorial moments, we show the dependence of moments on the target size.

hep-ph

Jet substructure in neutral current deep inelastic e+p scattering at upcoming Electron-Ion Collider

Predictions are made for the jet substructure of one-jet events produced in electron-proton neutral current deep inelastic scattering at the future Electron-Ion Collider for exchanged four-momentum squared, $Q^2 > 125$ GeV$^2$. Data are simulated using Monte Carlo event generators PYTHIA 8.304 and RAPGAP 3.308 at the center of mass energies $\sqrt{s}$ = 63.2, 104.9 and 141 GeV. Jets and subjets are produced by longitudinally invariant $k_T$ cluster algorithm. The subjet multiplicity distributions and differential jet shapes are measured for different jet sizes and varying jet-resolution parameter. A comparison is presented between the $k_T$ and anti-$k_T$ cluster algorithms for the study of jets and subjets using the simulated data and the HERA data.

hep-ph

Muon Collider Forum Report

A multi-TeV muon collider offers a spectacular opportunity in the direct exploration of the energy frontier. Offering a combination of unprecedented energy collisions in a comparatively clean leptonic environment, a high energy muon collider has the unique potential to provide both precision measurements and the highest energy reach in one machine that cannot be paralleled by any currently available technology. The topic generated a lot of excitement in Snowmass meetings and continues to attract a large number of supporters, including many from the early career community. In light of this very strong interest within the US particle physics community, Snowmass Energy, Theory and Accelerator Frontiers created a cross-frontier Muon Collider Forum in November of 2020. The Forum has been meeting on a monthly basis and organized several topical workshops dedicated to physics, accelerator technology, and detector R&D. Findings of the Forum are summarized in this report.

hep-ex

Dual Parton Model for the Charged Multiplicity in pp Collisions at 13, 13.6 TeV and for future LHC energy of 27 TeV

Analysis of the charged multiplicity in proton-proton inelastic interactions at the LHC energies in the setting of Dual Parton Model is presented. Data from the CMS experiment and the data simulated at different energies in various pseudo-rapidity windows using the event generator PYTHIA8are analysed and compared with the calculations from the model. Each inelastic scattering is assumed to follow the Poisson distribution. The theoretical Koba-Nielsen-Olesen (KNO) scaling of the multiplicity distributions is studied and compared with previously published experimental results at $\sqrt{s}$ = 0.9, 2.36, 7 TeV. Predictions from the model for the KNO distributions at $\sqrt{s}$ = 13, 13.6 TeV and for the future LHC energy of 27 TeV are computed and compared with the simulated data.

hep-ph

Charged particle production in $pp$ collisions at $\sqrt{s}$=8, 7 and 2.76 TeV at the LHC -- a case study

We analyse the charged${\text -}$particle multiplicity distributions measured by the ALICE experiment, over a wide pseudorapidity range, for $pp$ collisions at $\sqrt{s}$=8,\,7\,and\, 2.76~TeV at the LHC.~The analysis offers an understanding of particle production in high energy collisions in the purview of a new distribution, the shifted Gompertz distribution.~Data are compared with the distribution and moments of the distributions are calculated.~A modified version of the distribution is also proposed and used to improve the description of the data consisting of two different event classes; the inelastic and the non${\text -}$single${\text -}$diffractive and their subsets in different windows of pseudorapidity, $\eta$.~The distribution used to analyse the data has a wide range of applicability to processes in different fields and complements the analysis done by the ALICE collaboration in terms of various LHC event generators and IP-Glasma calculations.

hep-ex

Investigation of particle production in $h{\text -}A$ collisions using statistical distributions

Study of the characteristic properties of charged particle production in hadron-nucleus collisions at high energies, by utilising the approaches from different statistical models is performed.~Predictions from different approaches using the Negative Binomial distribution, shifted Gompertz distribution, Weibull distribution and the Krasznovszky-Wagner distribution are utilised for a comparative study of the relative successes of these models.~These distributions derived from a variety of functional forms are based on either phenomenological parameterizations or some model of the underlying dynamics.~Some of these have have also been used to study the data at the LHC for both proton-proton and nucleus-nucleus collisions.~Various physical and derived observables have been used for the analysis.

hep-ph

Multiplicity Moments using Tsallis Statistics in High-Energy Hadron-Nucleus Interactions

The study of higher-order moments of a distribution and its cumulants constitute a sensitive tool to investigate the correlations between the particle produced in high energy interactions. In our previous work we have used the Tsallis $q$ statistics, NBD, Gamma and shifted Gamma distributions to describe the multiplicity distributions in $\pi ^-$ -nucleus and $p$ -nucleus fixed target interactions at various energies ranging from P$_{Lab}$ = 27 GeV to 800 GeV. In the present study we have extended our analysis by calculating the moments using the Tsallis model at these fixed target experiment data. By using the Tsallis model we have also calculated the average charged multiplicity and its dependence on energy. It is found that the average charged multiplicity and moments predicted by the Tsallis statistics are in much agreement with the experimental values and indicates the success of the Tsallis model on data from visual detectors. The study of moments also illustrates that KNO scaling hypothesis holds good at these energies.

hep-ph

Comparative study of charged multiplicities and moments in $pp$ collisions at $\sqrt{s}$=7 TeV in the forward region at the LHC

Charged particle multiplicities in proton-proton collisions measured in the LHCb detector at a centre-of-mass energy of $\sqrt s$=7 TeV in different windows of pseudorapidity $\eta$, in the forward region of the vertex detector are studied by using different statistical distributions. Three distributions are compared with the data and the moments of the distributions are calculated. The data constituting two sets, one of minimum bias events and another of hard QCD events are analysed. The distributions considered derive from different functional forms based on underlying interaction dynamics. The analysis complements the multiplicity analysis done by LHCb in terms of Monte Carlo event generators. The present analysis is from a different perspective, using statistical distributions.

hep-ex

Compelling evidence of oscillatory behaviour of hadronic multiplicities in the shifted Gompertz distribution

Study of charged particle multiplicity distribution in high energy interactions of particles helps in revealing the dynamics of particle production and the underlying statistical patterns, which these distributions follow. Several distributions derived from statistics have been employed to understand its behaviour. In one of our earlier papers, we introduced the shifted Gompertz distribution to investigate this variable and showed that the multiplicity distributions in a variety of processes at different energies can be very well described by this distribution. The fact that the shifted Gompertz distribution, which has been extensively used in diffusion theory, social networks and forecasting has been used for the first time in high energy physics collisions, remains interesting. In this paper we investigate the phenomenon of oscillatory behaviour of the counting statistics observed in the experimental data, resulting from different types of recurrence relations defining the probability distributions. We search for such oscillations in the multiplicity distributions well described by the shifted Gompertz distribution and compare our results with the analysis proposed by G. Wilk et al.

hep-ph

Moments of multiplicity distributions using Tsallis statistics in leptonic and hadronic collisions

Moments play a crucial role in investigating the characteristics of charged particle multiplicities in high energy interactions. The success of any model which describes the multiplicity data can be understood well by studying the normalised and factorial moments of that distribution.~The Tsallis model is one of the most successful models which describes the multiplicity spectra, transverse momentum ($p_T$) spectra very precisely in high energy interactions.~In our previous work we have used the Tsallis $q$-statistics to describe the multiplicity distributions in leptonic and hadronic collisions at various energies ranging from 14 GeV to 7 TeV.~In the present study we have extended our analysis for calculating the moments using the Tsallis model for $e^+e^-$ interactions at $\sqrt{s}$ = 91 to 206 GeV from the LEP data and for $pp$ interactions at $\sqrt{s}$ = 0.9 to 7 TeV in various pseudo-rapidity intervals from the CMS data at LHC. By using the Tsallis model we have also calculated the average charged multiplicity and its dependence on energy.~It is found that the moments and the mean multiplicities predicted by the Tsallis model are in good agreement with the experimental values.~We have also predicted the mean multiplicity at $\sqrt{s}$ = 500 GeV for $e^+e^-$ collisions and at $\sqrt{s}$ = 14 TeV for $pp$ collisions in extreme pseudo-rapidity interval, $|\eta|$ $<$ 2.4

hep-ph

Multiplicity moments of shifted Gompertz distribution in $e^{+}e^{-}$, $p\bar{p}$ and $pp$ collisions at high energies

In continuation of our earlier work, in which we analysed the charged particle multiplicities in leptonic and hadronic interactions at different center of mass energies in full phase space as well as in restricted phase space with the shifted Gompertz distribution, a detailed analysis of the normalized and factorial moments is reported here. A two-component model in which probability distribution function is obtained from the superposition of two shifted Gompertz distributions introduced in our earlier work has also been used for the analysis. This is the first analysis of the moments with the shifted Gompertz distribution. Analysis has also been done to predict the moments of multiplicity distribution for the electron-positron collisions at c.m. energy of 500 GeV at a future Collider.

hep-ph

Multiplicity spectra in $e^{+}e^{-}$ and $\overline{p}p$ collisions in terms of Tsallis and Weibull distributions

Charged hadron production in the $e^{+}e^{-}$ annihilations at 91 to 206 GeV in full phase space and in $\overline{p}p$ collisions at 200 to 900~GeV collision energies are studied using non-extensive Tsallis and stochastic Weibull probability distributions.~The Tsallis distribution shows better description of the data than the Weibull distribution. The 2-jet modification of the statistical distribution is applied to describe $e^{+}e^{-}$ data.~The main features of these distributions can be described by a two-component model with soft, collective interactions at low transverse energy and hard, constituent interactions dominating at high transverse energy.~This modification is found to give much better description than a full-sample fit, and again Tsallis function is found to better describe the data than the Weibull one pointing at the non-extensive character of the multiparticle production process.

hep-ph

Magnetothermodynamics: measuring the equations of state of a compressible magnetized plasma

Magnetothermodynamics (MTD) is the study of compression and expansion of magnetized plasma with an eye towards identifying equations of state for magneto-inertial fusion experiments. We present recent results from SSX experiments on the thermodynamics of compressed magnetized plasmas. In these experiments, we generate twisted flux ropes of magnetized, relaxed plasma accelerated from one end of a $1.5~m$ long copper flux conserver, and observe their compression in a closed conducting boundary installed at the other end. Plasma parameters are measured during compression. The instances of ion heating during compression are identified by constructing a PV diagram using measured density, temperature, and volume of the magnetized plasma. The theoretically predicted MHD and double adiabatic (CGL) equations of state are compared to experimental measurements to estimate the adiabatic nature of the compressed plasma. Since our magnetized plasmas relax to an equilibrium described by magnetohydrodynamics, one might expect their thermodynamics to be governed by the corresponding equation of state. However, we find that the magnetohydrodynamic equation of state is not supported by our data. Our results are more consistent with the parallel CGL equation of state suggesting that these weakly collisional plasmas have most of their proton energy in the direction parallel to the magnetic field.

physics.plasm-ph

Temperature and lifetime measurements in the SSX wind tunnel

We describe electron temperature measurements in the SSX MHD wind tunnel using two different methods. First, we estimate $T_e$ along a chord by measuring the ratio of the $C_{III}~97.7~nm$ to $C_{IV}~155~nm$ line intensities using a vacuum ultraviolet monochrometer. Second, we record a biasing scan to a double Langmuir probe to obtain a local measurement of $T_e$. The aim of these studies is to increase the Taylor state lifetime, primarily by increasing the electron temperature. Also, a model is proposed to predict magnetic lifetime of relaxed states and is found of predict the lifetime satisfactorily. Furthermore, we find that proton cooling can be explained by equilibration with the electrons.

physics.plasm-ph

Multiplicity spectra in pp collisions at LHC energies in terms of Gamma and Tsallis distributions

In recent years the Tsallis statistics is gaining popularity in describing charged particle produc- tion and their properties, in particular pT spectra and the multiplicities in high energy particle collisions. Motivated by its success, an analysis of the LHC data of proton-proton collisions at ener- gies ranging from 0.9 TeV to 7 TeV in different rapidity windows for charged particle multiplicities has been done. A comparative analysis is performed in terms of the Tsallis distribution, the Gamma distribution and the shifted-Gamma distribution. An interesting observation on the inapplicability of these distributions at sqrt{s}=7 TeV in the lower rapidity windows is intriguing. The non-extensive nature of the Tsallis statistics is studied by determining the entropic index and its energy depen- dence. The analysis is extrapolated to predict the multiplicity distribution at sqrt{s}=14 TeV for one rapidity window, |y| < 1.5 with the Tsallis function.

hep-ph