119203692
B decay anomalies in an effective theory
We investigate how far a new physics scenario affecting primarily the third-generation fermions can ameliorate the tension between $B$ decay observables and Standard Model expectations. Adopting a model-independent approach, we find that among the three observables that show signs of such a tension, viz., the branching fractions for ${B}^{+}\ensuremath{\rightarrow}\ensuremath{\tau}\ensuremath{\nu}$, ${B}_{d}\ensuremath{\rightarrow}D({D}^{*})\ensuremath{\tau}\ensuremath{\nu}$, and the like-sign dimuon anomaly in neutral $B$ decays, the first two can be explained adequately, while there is only a marginal improvement for the third. As a spin-off, it is shown that one can also accommodate a change in the branching fraction of the Higgs boson to a $\ensuremath{\tau}$ lepton pair from the Standard Model expectation, if such a change is established in future data.
6337992
Constraining anomaly mediated supersymmetry breaking framework via ongoing muon g − 2 experiment at Brookhaven
The ongoing high precision E821 Brookhaven National Laboratory experiment on muon $g\ensuremath{-}2$ is promising to probe a theory involving supersymmetry. We have studied the constraints on the minimal anomaly mediated supersymmetry breaking (AMSB) model using the current data of muon $g\ensuremath{-}2$ from Brookhaven. A scenario of seeing no deviation from the standard model is also considered, within a $2\ensuremath{\sigma}$ limit of the combined error from the standard model result and the Brookhaven predicted uncertainty level. The resulting constraint is found to be complementary to what one obtains from $\stackrel{\ensuremath{\rightarrow}}{b}s+\ensuremath{\gamma}$ bounds within the AMSB scenario, since only a definite sign of $\ensuremath{\mu}$ is effectively probed via $\stackrel{\ensuremath{\rightarrow}}{b}s+\ensuremath{\gamma}.$ A few relevant generic features of the model are also described for disallowed regions of parameter space.
121486698
Working group report: Physics at the Large Hadron Collider
Abstract.This is a summary of the activities of the Physics at the LHC working group in the XIth Workshop on High Energy Physics Phenomenology (WHEPP-XI) held at the Physical Research Laboratory, Ahmedabad, India in January 2010. We discuss the activities of each sub-working group on physics issues at colliders such as Tevatron and Large Hadron Collider (LHC). The main issues discussed involve (1) results on W mass measurement and associated QCD uncertainties, (2) an attempt to understand the asymmetry measured at Tevatron in the top quark production, and (3) phenomenology of warped space dimension model.
17801288
Signals for gauge mediated supersymmetry breaking model at an e−e− collider
We study the pair-production and decay of right handed selectrons within a Gauge Mediated Supersymmetry Breaking Model in polarised e−e− interaction. Detailed analyses of the possible signals and backgrounds are performed for a few selected points in the parameter space. A judicious choice for polarisation of the initial electron beam helps eliminate almost the entire Standard Model background. We also show that phase space distributions can be used to distinguish such a supersummetry breaking scheme from the supergravity inspired models.
15752198
Invisible decays of Higgs and other mesons in models with singlet neutrinos in large extra dimensions
Abstract In light of current atmospheric neutrino oscillation data, we revisit the invisible decay of the standard model Higgs boson and other pseudoscalar mesons which can be enhanced because of large number of KK modes in models with right-handed singlet neutrinos in large extra dimensions. We find that the invisible decay rate of Higgs can be as large as H→b b decay rate only for a very restricted region of parameter space. This parameter space is even further restricted if one demands that the dimensionless neutrino Yukawa coupling λ is O (1). We have also studied the scenarios where singlet neutrino propagate in a sub-space, which lowers the string scale M ∗ and keeps neutrino Yukawa coupling O (1). We have also considered decays of other spin-0 mesons to ν ν and found the rates to be too small for measurement.
17303620
Study of single sneutrino production in association with fermion pairs at polarized photon colliders
We investigate single sneutrino production in the context of R-parity-violating supersymmetry at future ?? linear colliders. The sneutrino is produced in association with fermion pairs and it is shown that its decays into two further fermions will lead to a clean signal. We also discuss possible standard model backgrounds and the effects of beam polarization.
122068137
MULTIPLICITY DISTRIBUTION AND MULTIPLICITY MOMENT OF BLACK AND GREY PARTICLES IN HIGH ENERGY NUCLEUS–NUCLEUS INTERACTIONS
In this paper we have studied the multiplicity distribution of black and grey particles emitted from 16O–AgBr interactions at 2.1 AGeV and 60 AGeV. We have also calculated the multiplicity moment up to the fifth order for both the interactions and for both kinds of emitted particles. The variation of multiplicity moment with the order number has been investigated. It is seen that in the case of black particles multiplicity moment up to fourth order remains almost constant as energy increases from 2.1 AGeV to 60 AGeV. Fifth order multiplicity moment increases insignificantly with energy. However in the case of grey particles no such constancy of multiplicity moment with energy of the projectile beam is obtained. Later we have extended our study on the basis of Regge–Mueller approach to find the existence of second order correlation during the emission of black as well as the grey particles. The second Mueller moment is found to be positive and it increases as energy increases in the case of black particles. On the contrary in the case of grey particles the second Mueller moment decreases with energy. It can be concluded that as energy increases correlation among the black particles increases. On the other hand with the increase of energy correlation among the grey particles is found to diminish.
121661899
Multifractal behavior of nuclear fragments in high-energy leptonic interactions
The multifractal analysis of nuclear fragmentation data obtained from muon-nucleus interactions at 420{+-}45 GeV is performed using G-moment and Takagi-moment methods. The generalized fractal dimensions D{sub q} are determined from these methods and also are compared with those obtained from intermittency exponents. The analysis reveals the multifractal behavior of target fragments in lepton-nucleus interactions.
123078551
Ring and jet study on the azimuthal substructure of pions at CERN SPS energy
We have presented an investigation on the ring- and jet-like azimuthal angle substructures in the emission of secondary charged hadrons coming from 32S–Ag/Br interactions at 200 A GeV/c. Nuclear photographic emulsion technique has been employed to collect the experimental data. The presence of such substructures, their average behaviour, their size, and their position of occurrence have been examined. The experimental results have also been compared with the results simulated by Monte-Carlo method. The analysis strongly indicates the presence of ring- and jet-like structures in the experimental distributions of particles beyond statistical noise. The experimental results are in good agreement with I M Dremin idea, that the phenomenon is similar to the emission of Cherenkov electromagnetic radiation.
123163498
Multifractality in charged pion production at a few GeV/n
The multifractal analysis of charged pion produced in 16O–AgBr interactions at 2.1 AGeV and 24Mg–AgBr interactions at 4.5 AGeV has been investigated using the Takagi moment method in pseudo-rapidity space. The generalized fractal dimensions Dq are determined for these two interactions for different orders of moment. Experimental data reflects multifractal geometry in the multipion production process. From the knowledge of the generalized fractal dimensions Dq, the multifractal specific heat has also been evaluated for these data. A detailed comparison is presented with the results obtained from 12C–AgBr and 28Si–AgBr interactions at 4.5 AGeV/c, 28Si–AgBr interactions at 14.5 A GeV/c, 16O–AgBr interactions 60 AGeV and 32S–AgBr interactions 200 AGeV from the recent literatures.
120905653
NON-STATISTICAL FLUCTUATIONS OF PIONS FOR RING- AND JET-LIKE EVENTS AT CERN SPS ENERGY — AN IN-DEPTH ANALYSIS WITH FACTORIAL CORRELATOR
This study reveals the analysis of ring-like and jet-like events in terms of factorial correlations of 16O–Ag/Br interactions at 60A GeV. The investigation revealed that the correlated moments are found to increase with decreasing bin–bin separation D and follows a power-law which suggests the presence of an intermittent nature of self-similar dynamical fluctuations pattern for ring-like and jet-like events. From the analysis we find that for jet-like events the strength of non-statistical fluctuation is greater than the ring-like and total event set. Jet-like events follow the bin size independence according to α model of intermittency as like total events, whereas ring-like events are not consistent with the prediction of α model of intermittency.