In this paper, we study the fine Selmer groups attached to a Galois module defined over a commuta... more In this paper, we study the fine Selmer groups attached to a Galois module defined over a commutative complete Noetherian ring with finite residue field of characteristic p. Namely, we are interested in its properties upon taking residual representation and within field extensions. In particular, we will show that the variation of the fine Selmer group in a cyclotomic Zp-extension is intimately related to the variation of the class groups in the cyclotomic tower.
Bolometer is a thermal infrared sensor used for measuring the intensity of radiation via the heat... more Bolometer is a thermal infrared sensor used for measuring the intensity of radiation via the heating of a material due to the radiations. A bolometer consists of an absorptive element, a thin layered material, connected to a thermal reservoir. The result is that any radiation received on the absorptive element raises its temperature above that of the reservoir: the greater the absorbed radiation, the higher the temperature. The element is thus deformed proportional to the temperature of radiation and thus the temperature is measured. This paper presents a design of the said bolometer with absorptive element as a biologically sensitive material namely a Piezo-Protein which can be employed for biosensing applications.
I would like to dedicate this thesis to my parents who have always supported me in all my decisio... more I would like to dedicate this thesis to my parents who have always supported me in all my decisions and encouraged me to follow my heart. Without their love, support and unfailing belief in me, I could not have been able to pursue my interests. I would also like to dedicate this thesis to my fiancée Sneha Aman Singh, who inspired me to take on this journey. It would have been hard to keep focus on work so far away from home without her constant help and encouragement.
SummaryThe interactions of 720 MeV negative pions with protons were investigated using pictures f... more SummaryThe interactions of 720 MeV negative pions with protons were investigated using pictures from the 35 cm Saclay hydrogen bubble chamber. Partial cross-sections were determined with the following results: σ(elastic)=13.2±0.5) mb, σ(π−pπ0)=(5.25±0.30) mb, σ(π−π+n)=()7.17±0.35) mb σ (neutrals)=(9.9±0.7) mb, σ (2π production)=(1.03±0.13) mb. The elastic-scattering angular distribution was fitted with a fifth-order polynomial in cos θ*π which shows the effect of a significantF5/2-D5/2 interference contribution and predicts a value for (dσ/dΩ) (0°) in agreement with dispersion theory. For both single-π production channels, the two-body effective mass plots and c.m. angular distributions are presented, discussed and compared with the predictions from phase-space, the Olsson-Yodh isobar model and the pole model of isobar production. TheN*(3/2, 3/2) isobar is seen to play an important role in the ππN final states, but the agreement of the data with the existing isobar models and their assumptions is not satisfactory. A comparison of the different two-pion production cross-sections π−pπ−π+, π−pπ0π0 and π−π+nπ0 suggests a strong contribution of π−p→η0n to the π−π+nπ0 final state. An upper limit for σ(π−p→η0n) of (3.0±0.4) mb was obtained.RiassuntoSi sono studiate le interazioni di pioni negativi di 720 MeV con protoni usando fotografie ottenute dalla camera a bolle ad idrogeno da 35 cm di Saclay. Si sono determinate le sezioni d’urto parziali con i seguenti risultati: σ (elastiche)-(13.2±0.5) mb, σ(π−pπ0)=(5.25±0.30) mb, σ(π−π+n)=(7.17±0.35) mb σ (neutre)=(9.9±0.7) mb. σ (produzione di 2π)=(1.03±0.13) mb. La distribuzione angolare per mostra l’effetto di un importante contributo dell’interferenzaF5/2−-D5/2 e predice un valore per dσ/dΩ(0°) in accordo con la teoria della dispersione. Per entrambi i canali di produzione di singoli π, si presentano e discutono i grafici della massa effettiva di due corpi e le distribuzioni angolari nel centro di massa e inoltre si confrontano con le previsioni dello spazio delle fasi, del modello degli isobari di Olsson-Yodh e del modello dei poli della produzione di isobari. Si vede che l’isobaroN*(3/2), 3/2) svolge un ruolo importante negli stati finali ππN ma l’accordo dei dati con i modelli isobarici esistenti e le loro ipotesi non è soddisfacente. Un confronto delle differenti sezioni d’urto di produzione di due pioni π−pπ−π+, π−pπ0π0 e π−π+nπ0 suggerisce un notevole contributo di π−p→η0n allo stato finale π−π+nπ0. È stato ottenuto un limite superiore di (3.0±0.4) mb per σ (π−p→η0n).РеяюмеИзучались взаимодействия отрицательных пионов 720 МэВ/с протонами, используя снимки с 35 см водородной пузырьковой камеры Саклэ. Получены следующие результаты для парциальных поперечных сечений: σ(упругое)=(13.2±0.5) мб, σ(π−pπ0)=(5.25±0.30) мб, σ(π−π+n)=(7.17±0.35) мб, σ(нейтралые)=(9.9±0.7) мб, с(рождение 2π)=(1.03±0.13) мб. Угловое распределение упругого рассеяния соответствует полиномам пятого порядка по cos θ*π, который показывает влияние значителщного интерференционного вкладаF3/2−D3/2 и предсказывает знагение для (dс/dЩ) (0°) в соответствии с дисперсионой теорией. Для обоих каналов рождения одного π, приводятся эффективные двух-частичные массовые кривые и угловые распределения в системе центра масс, которые обсуждаются и сравниваются с предсказаниями из фазового пространства, изобарной модели Олсона-Иодха и полюсной модели изобарного рожения. Кажется, изобараN*(3/2, 3/2) играет важную роль в конегных состояниях ππN, но согласие результатов с данными сушествуюших изобарных моделей и их предположениями неудовлетворительное. Сравнение различных поперечных сечений двух-пионного рождения π−pπ−π+, π−pπ0π0 и π−π+nπ0 предполагает силъный вклад π−p→η0n в канечное состояние π−π+nπ0. Получен верхний предел для σ(π−p→η0n)∼(3.0±0.4) мб.
1999 IEEE Nuclear Science Symposium. Conference Record. 1999 Nuclear Science Symposium and Medical Imaging Conference (Cat. No.99CH37019)
This work presents an evaluation of a gamma camera operating in coincidence mode. The major limit... more This work presents an evaluation of a gamma camera operating in coincidence mode. The major limitations of these cameras compared to full-ring PET are the limited count rate and sensitivity. The authors evaluate the progress in count rate which was made by upgrading the system with new electronics. At the moment most gamma cameras use septa to limit the axial
The 26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Monte Carlo simulations are widely used to study the behavior and detection of gamma photons in m... more Monte Carlo simulations are widely used to study the behavior and detection of gamma photons in medical imaging devices. Such simulations are computationally expensive. This is why geometrical importance sampling, a variance reduction technique, was recently incorporated into the GEANT4 Monte Carlo code. In order to use this technique for single photon emission computed tomography (SPECT) imaging, it needed to be made compatible with pulse height tallies. These tallies correspond to the number of detected pulses in distinct energy bins, covering an energy spectrum relevant to SPECT. Since each pulse is the combination of different detector hits, the tally bin is not known until the end of an event. In an analog simulation (without variance reduction) this poses no problems as each detected hit can be stored and the pulse can be calculated at the end of each event. Geometrical importance sampling combined with Russian Roulette however introduces branches into the particle history, which results in a much more complicated pulse calculation. This work describes how pulse height tallies are adjusted to geometrical importance sampling and Russian Roulette within GATE, a medical imaging and simulation application based on GEANT4. The validation of this technique is done through SPECT simulations comparing the analog result with the new method.
The inclusive production of neutral kaons in 70 GeV/c K+p interactions is studied with the CERN B... more The inclusive production of neutral kaons in 70 GeV/c K+p interactions is studied with the CERN BEBC bubble chamber. The (semi-)inclusive cross sections are interpreted in terms of the various strangeness channels leading to neutral kaon production. The invariant inclusive cross section for kaon production is studied as a function of pt2 and the Feynman variable x. The latter distributions
The characteristics of the neutral kaons produced in the reaction 4.2 GeV/c K-+ p K o + anything ... more The characteristics of the neutral kaons produced in the reaction 4.2 GeV/c K-+ p K o + anything are compared with data at other momenta. A survey is made of mediumenergy inclusive cross sections obtained by postulating aT(K-p) = o_(K-) + o_(K o) + o(Y). The inclusive cross sections o(K-) and o_(K o) are found to be constant as functions of the incoming kaon momentum. Moreover, a comparison with inclusive K * production in the reaction K ÷+ p shows o (K-) ~o÷(K ÷) ~ 11.7 mb.
The scaling properties of tile reaction K + p ~ A + anything are studied at 4.2 and 10.1 GeV/c. I... more The scaling properties of tile reaction K + p ~ A + anything are studied at 4.2 and 10.1 GeV/c. In this energy range, this reaction is peculiar, as it practically coincides with the hypercharge annihilation reaction K-+ p-+ ,\ + pions and has a cross section rapidly decreasing with increasing energy. It is found that while the Feynman function E* do * dx 7rPmax and the function do/dr do not scale in the energy range studied, the distributions at 4.2 and 10.1 GeV/c of the function 1 do o(A) 4-c' where o(A) is the cross section for A-production. coincide over the entire x-range. Comments are made on the facts that this inclusive reaction is undeveloped and that the hypercharge annihilation reaction is neither inclusive nor exclusive.
We present a study of the structure of hadronic events recorded by the L3 detector at center-of-m... more We present a study of the structure of hadronic events recorded by the L3 detector at center-of-mass energies of 130 and 136 GeV. The data sample corresponds to an integrated luminosity o f 5 p b 1 collected during the high energy run of 1995. The shapes of the event shape distributions and the energy dependence of their mean values are well reproduced by QCD models. From a comparison of the data with resummed O(2 s) QCD calculations, we determine the strong coupling constant t o be s (133 GeV) = 0.107 0.005 (exp) 0.006 (theor).
A search for exclusive decays of B 0 d and B 0 s mesons has been performed in the channels B 0 d ... more A search for exclusive decays of B 0 d and B 0 s mesons has been performed in the channels B 0 d ! J; B 0 s !J; B 0 d !J 0 and B 0 s ! J 0. The data sample consisted of more than three and half million hadronic Z decays collected by the L3 experiment at LEP from 1991 through 1995. No candidate events have been observed for any of the modes thus determining upper limits at 90% condence level: 3:2 10 4 on Br(B 0 d ! J 0) and the rst experimental limits: Br(B 0 d ! J) < 1:2 10 3 ; Br(B 0 s ! J) < 3:8 10 3 ; Br(B 0 s ! J 0
Final results of the search for the Standard Model Higgs boson are presented for the data collect... more Final results of the search for the Standard Model Higgs boson are presented for the data collected by the L3 detector at LEP at centre-of-mass energies up to about 209 GeV. These data are compared with the expectations of Standard Model processes for Higgs boson masses up to 120 GeV. A lower limit on the mass of the Standard Model Higgs boson of 112.0 GeV is set at the 95% confidence level. The most significant high mass candidate is a Hνν event. It has a reconstructed Higgs mass of 115 GeV and it was recorded at √ s = 206.4 GeV.
We h a v e studied the process e + e ! n (n 2) at an average center-of-mass energy of 133 GeV usi... more We h a v e studied the process e + e ! n (n 2) at an average center-of-mass energy of 133 GeV using the L3 detector at LEP. F or an integrated luminosity o f 4 : 95 pb 1 we nd one () nal state with only hard photons. The rates of both and events are consistent with QED expectations. The cross section of the reaction e + e ! () in the polar range 16 < < 164 is measured to be 22:6 2:2 pb. Decays into photons of narrow scalar resonances with masses between 90 and 130 GeV are not observed. The observation of the event with four energetic photons is consistent with QED although the kinematic conguration of the photons is atypical.
Using the Crystal Ball detector at the e+e-storage ring DORIS II, we have measured the energy spe... more Using the Crystal Ball detector at the e+e-storage ring DORIS II, we have measured the energy spectrum of direct photons from "f(IS) decays. According to QCD, these photons result from the decays of the "f(IS) resonance into one photon and two gluons, T (1 S)-'l'gg-* T + hadrons. The shape of our spectrum does not agree with that calculated in lowest order QCD, but can be described well by a prediction incorporating gluon self-interaction. Using this fit, the ratio Rv=F('f-,'tgg)/F(F~ggg) is determined to be (2.7+0.2+0.4)%. From this ratio we deduce the strong coupling constant in the MS scheme at Q2=2.2 GeV 2 and find cq= 0.25 + 0.02 + 0.04.
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
We report on the measurement of W-boson pair-production with the L3 detector at LEP. In a data sa... more We report on the measurement of W-boson pair-production with the L3 detector at LEP. In a data sample corresponding to a total luminosity of 55.47 pb 1 collected at an average centre-of-mass energy of 182:68 GeV, we select 824 four-fermion events with pairs of hadronic jets or pairs of leptons with high invariant masses. Branching fractions of W decays into dierent fermion-antifermion pairs are determined. Assuming charged-current lepton universality, the branching fraction for hadronic W decays is measured to be: B(W ! hadrons) = 70:1 1:3 (stat:) 0:4 (syst:) % .
Using a sample of e + e annihilation events collected with the L3 detector at the Z resonance cor... more Using a sample of e + e annihilation events collected with the L3 detector at the Z resonance corresponding to an integrated luminosity of 137 pb 1 , we have searched for anomalous production of X nal states where X represents stable, weakly interacting particles and the photon energy is greater than 15 GeV. The sample of events found is consistent with Standard Model expectations. Upper limits are set on Z couplings, the neutrino magnetic moment, and the branching ratio for Z ! X.
A study of resonance formation is presented in the + 0 nal state in twophoton collisions at LEP. ... more A study of resonance formation is presented in the + 0 nal state in twophoton collisions at LEP. The a 2 (1320) radiative width is measured to be = 0:98 0:05 0:09 keV. The helicity 2 production is dominant. Exclusive + 0 production has also been studied in the mass region above the a 2 in the and f 2 channels. This region is dominated by a J P =2 + helicity 2 w a v e.
Bose-Einstein correlations of both neutral and like-sign charged pion pairs are measured in a sam... more Bose-Einstein correlations of both neutral and like-sign charged pion pairs are measured in a sample of 2 million hadronic Z decays collected with the L3 detector at LEP. The analysis is performed in the four-momentum difference range 300 MeV < Q < 2 GeV. The radius of the neutral pion source is found to be smaller than that of charged pions. This result is in qualitative agreement with the string fragmentation model.
In this paper, we study the fine Selmer groups attached to a Galois module defined over a commuta... more In this paper, we study the fine Selmer groups attached to a Galois module defined over a commutative complete Noetherian ring with finite residue field of characteristic p. Namely, we are interested in its properties upon taking residual representation and within field extensions. In particular, we will show that the variation of the fine Selmer group in a cyclotomic Zp-extension is intimately related to the variation of the class groups in the cyclotomic tower.
Bolometer is a thermal infrared sensor used for measuring the intensity of radiation via the heat... more Bolometer is a thermal infrared sensor used for measuring the intensity of radiation via the heating of a material due to the radiations. A bolometer consists of an absorptive element, a thin layered material, connected to a thermal reservoir. The result is that any radiation received on the absorptive element raises its temperature above that of the reservoir: the greater the absorbed radiation, the higher the temperature. The element is thus deformed proportional to the temperature of radiation and thus the temperature is measured. This paper presents a design of the said bolometer with absorptive element as a biologically sensitive material namely a Piezo-Protein which can be employed for biosensing applications.
I would like to dedicate this thesis to my parents who have always supported me in all my decisio... more I would like to dedicate this thesis to my parents who have always supported me in all my decisions and encouraged me to follow my heart. Without their love, support and unfailing belief in me, I could not have been able to pursue my interests. I would also like to dedicate this thesis to my fiancée Sneha Aman Singh, who inspired me to take on this journey. It would have been hard to keep focus on work so far away from home without her constant help and encouragement.
SummaryThe interactions of 720 MeV negative pions with protons were investigated using pictures f... more SummaryThe interactions of 720 MeV negative pions with protons were investigated using pictures from the 35 cm Saclay hydrogen bubble chamber. Partial cross-sections were determined with the following results: σ(elastic)=13.2±0.5) mb, σ(π−pπ0)=(5.25±0.30) mb, σ(π−π+n)=()7.17±0.35) mb σ (neutrals)=(9.9±0.7) mb, σ (2π production)=(1.03±0.13) mb. The elastic-scattering angular distribution was fitted with a fifth-order polynomial in cos θ*π which shows the effect of a significantF5/2-D5/2 interference contribution and predicts a value for (dσ/dΩ) (0°) in agreement with dispersion theory. For both single-π production channels, the two-body effective mass plots and c.m. angular distributions are presented, discussed and compared with the predictions from phase-space, the Olsson-Yodh isobar model and the pole model of isobar production. TheN*(3/2, 3/2) isobar is seen to play an important role in the ππN final states, but the agreement of the data with the existing isobar models and their assumptions is not satisfactory. A comparison of the different two-pion production cross-sections π−pπ−π+, π−pπ0π0 and π−π+nπ0 suggests a strong contribution of π−p→η0n to the π−π+nπ0 final state. An upper limit for σ(π−p→η0n) of (3.0±0.4) mb was obtained.RiassuntoSi sono studiate le interazioni di pioni negativi di 720 MeV con protoni usando fotografie ottenute dalla camera a bolle ad idrogeno da 35 cm di Saclay. Si sono determinate le sezioni d’urto parziali con i seguenti risultati: σ (elastiche)-(13.2±0.5) mb, σ(π−pπ0)=(5.25±0.30) mb, σ(π−π+n)=(7.17±0.35) mb σ (neutre)=(9.9±0.7) mb. σ (produzione di 2π)=(1.03±0.13) mb. La distribuzione angolare per mostra l’effetto di un importante contributo dell’interferenzaF5/2−-D5/2 e predice un valore per dσ/dΩ(0°) in accordo con la teoria della dispersione. Per entrambi i canali di produzione di singoli π, si presentano e discutono i grafici della massa effettiva di due corpi e le distribuzioni angolari nel centro di massa e inoltre si confrontano con le previsioni dello spazio delle fasi, del modello degli isobari di Olsson-Yodh e del modello dei poli della produzione di isobari. Si vede che l’isobaroN*(3/2), 3/2) svolge un ruolo importante negli stati finali ππN ma l’accordo dei dati con i modelli isobarici esistenti e le loro ipotesi non è soddisfacente. Un confronto delle differenti sezioni d’urto di produzione di due pioni π−pπ−π+, π−pπ0π0 e π−π+nπ0 suggerisce un notevole contributo di π−p→η0n allo stato finale π−π+nπ0. È stato ottenuto un limite superiore di (3.0±0.4) mb per σ (π−p→η0n).РеяюмеИзучались взаимодействия отрицательных пионов 720 МэВ/с протонами, используя снимки с 35 см водородной пузырьковой камеры Саклэ. Получены следующие результаты для парциальных поперечных сечений: σ(упругое)=(13.2±0.5) мб, σ(π−pπ0)=(5.25±0.30) мб, σ(π−π+n)=(7.17±0.35) мб, σ(нейтралые)=(9.9±0.7) мб, с(рождение 2π)=(1.03±0.13) мб. Угловое распределение упругого рассеяния соответствует полиномам пятого порядка по cos θ*π, который показывает влияние значителщного интерференционного вкладаF3/2−D3/2 и предсказывает знагение для (dс/dЩ) (0°) в соответствии с дисперсионой теорией. Для обоих каналов рождения одного π, приводятся эффективные двух-частичные массовые кривые и угловые распределения в системе центра масс, которые обсуждаются и сравниваются с предсказаниями из фазового пространства, изобарной модели Олсона-Иодха и полюсной модели изобарного рожения. Кажется, изобараN*(3/2, 3/2) играет важную роль в конегных состояниях ππN, но согласие результатов с данными сушествуюших изобарных моделей и их предположениями неудовлетворительное. Сравнение различных поперечных сечений двух-пионного рождения π−pπ−π+, π−pπ0π0 и π−π+nπ0 предполагает силъный вклад π−p→η0n в канечное состояние π−π+nπ0. Получен верхний предел для σ(π−p→η0n)∼(3.0±0.4) мб.
1999 IEEE Nuclear Science Symposium. Conference Record. 1999 Nuclear Science Symposium and Medical Imaging Conference (Cat. No.99CH37019)
This work presents an evaluation of a gamma camera operating in coincidence mode. The major limit... more This work presents an evaluation of a gamma camera operating in coincidence mode. The major limitations of these cameras compared to full-ring PET are the limited count rate and sensitivity. The authors evaluate the progress in count rate which was made by upgrading the system with new electronics. At the moment most gamma cameras use septa to limit the axial
The 26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Monte Carlo simulations are widely used to study the behavior and detection of gamma photons in m... more Monte Carlo simulations are widely used to study the behavior and detection of gamma photons in medical imaging devices. Such simulations are computationally expensive. This is why geometrical importance sampling, a variance reduction technique, was recently incorporated into the GEANT4 Monte Carlo code. In order to use this technique for single photon emission computed tomography (SPECT) imaging, it needed to be made compatible with pulse height tallies. These tallies correspond to the number of detected pulses in distinct energy bins, covering an energy spectrum relevant to SPECT. Since each pulse is the combination of different detector hits, the tally bin is not known until the end of an event. In an analog simulation (without variance reduction) this poses no problems as each detected hit can be stored and the pulse can be calculated at the end of each event. Geometrical importance sampling combined with Russian Roulette however introduces branches into the particle history, which results in a much more complicated pulse calculation. This work describes how pulse height tallies are adjusted to geometrical importance sampling and Russian Roulette within GATE, a medical imaging and simulation application based on GEANT4. The validation of this technique is done through SPECT simulations comparing the analog result with the new method.
The inclusive production of neutral kaons in 70 GeV/c K+p interactions is studied with the CERN B... more The inclusive production of neutral kaons in 70 GeV/c K+p interactions is studied with the CERN BEBC bubble chamber. The (semi-)inclusive cross sections are interpreted in terms of the various strangeness channels leading to neutral kaon production. The invariant inclusive cross section for kaon production is studied as a function of pt2 and the Feynman variable x. The latter distributions
The characteristics of the neutral kaons produced in the reaction 4.2 GeV/c K-+ p K o + anything ... more The characteristics of the neutral kaons produced in the reaction 4.2 GeV/c K-+ p K o + anything are compared with data at other momenta. A survey is made of mediumenergy inclusive cross sections obtained by postulating aT(K-p) = o_(K-) + o_(K o) + o(Y). The inclusive cross sections o(K-) and o_(K o) are found to be constant as functions of the incoming kaon momentum. Moreover, a comparison with inclusive K * production in the reaction K ÷+ p shows o (K-) ~o÷(K ÷) ~ 11.7 mb.
The scaling properties of tile reaction K + p ~ A + anything are studied at 4.2 and 10.1 GeV/c. I... more The scaling properties of tile reaction K + p ~ A + anything are studied at 4.2 and 10.1 GeV/c. In this energy range, this reaction is peculiar, as it practically coincides with the hypercharge annihilation reaction K-+ p-+ ,\ + pions and has a cross section rapidly decreasing with increasing energy. It is found that while the Feynman function E* do * dx 7rPmax and the function do/dr do not scale in the energy range studied, the distributions at 4.2 and 10.1 GeV/c of the function 1 do o(A) 4-c' where o(A) is the cross section for A-production. coincide over the entire x-range. Comments are made on the facts that this inclusive reaction is undeveloped and that the hypercharge annihilation reaction is neither inclusive nor exclusive.
We present a study of the structure of hadronic events recorded by the L3 detector at center-of-m... more We present a study of the structure of hadronic events recorded by the L3 detector at center-of-mass energies of 130 and 136 GeV. The data sample corresponds to an integrated luminosity o f 5 p b 1 collected during the high energy run of 1995. The shapes of the event shape distributions and the energy dependence of their mean values are well reproduced by QCD models. From a comparison of the data with resummed O(2 s) QCD calculations, we determine the strong coupling constant t o be s (133 GeV) = 0.107 0.005 (exp) 0.006 (theor).
A search for exclusive decays of B 0 d and B 0 s mesons has been performed in the channels B 0 d ... more A search for exclusive decays of B 0 d and B 0 s mesons has been performed in the channels B 0 d ! J; B 0 s !J; B 0 d !J 0 and B 0 s ! J 0. The data sample consisted of more than three and half million hadronic Z decays collected by the L3 experiment at LEP from 1991 through 1995. No candidate events have been observed for any of the modes thus determining upper limits at 90% condence level: 3:2 10 4 on Br(B 0 d ! J 0) and the rst experimental limits: Br(B 0 d ! J) < 1:2 10 3 ; Br(B 0 s ! J) < 3:8 10 3 ; Br(B 0 s ! J 0
Final results of the search for the Standard Model Higgs boson are presented for the data collect... more Final results of the search for the Standard Model Higgs boson are presented for the data collected by the L3 detector at LEP at centre-of-mass energies up to about 209 GeV. These data are compared with the expectations of Standard Model processes for Higgs boson masses up to 120 GeV. A lower limit on the mass of the Standard Model Higgs boson of 112.0 GeV is set at the 95% confidence level. The most significant high mass candidate is a Hνν event. It has a reconstructed Higgs mass of 115 GeV and it was recorded at √ s = 206.4 GeV.
We h a v e studied the process e + e ! n (n 2) at an average center-of-mass energy of 133 GeV usi... more We h a v e studied the process e + e ! n (n 2) at an average center-of-mass energy of 133 GeV using the L3 detector at LEP. F or an integrated luminosity o f 4 : 95 pb 1 we nd one () nal state with only hard photons. The rates of both and events are consistent with QED expectations. The cross section of the reaction e + e ! () in the polar range 16 < < 164 is measured to be 22:6 2:2 pb. Decays into photons of narrow scalar resonances with masses between 90 and 130 GeV are not observed. The observation of the event with four energetic photons is consistent with QED although the kinematic conguration of the photons is atypical.
Using the Crystal Ball detector at the e+e-storage ring DORIS II, we have measured the energy spe... more Using the Crystal Ball detector at the e+e-storage ring DORIS II, we have measured the energy spectrum of direct photons from "f(IS) decays. According to QCD, these photons result from the decays of the "f(IS) resonance into one photon and two gluons, T (1 S)-'l'gg-* T + hadrons. The shape of our spectrum does not agree with that calculated in lowest order QCD, but can be described well by a prediction incorporating gluon self-interaction. Using this fit, the ratio Rv=F('f-,'tgg)/F(F~ggg) is determined to be (2.7+0.2+0.4)%. From this ratio we deduce the strong coupling constant in the MS scheme at Q2=2.2 GeV 2 and find cq= 0.25 + 0.02 + 0.04.
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
We report on the measurement of W-boson pair-production with the L3 detector at LEP. In a data sa... more We report on the measurement of W-boson pair-production with the L3 detector at LEP. In a data sample corresponding to a total luminosity of 55.47 pb 1 collected at an average centre-of-mass energy of 182:68 GeV, we select 824 four-fermion events with pairs of hadronic jets or pairs of leptons with high invariant masses. Branching fractions of W decays into dierent fermion-antifermion pairs are determined. Assuming charged-current lepton universality, the branching fraction for hadronic W decays is measured to be: B(W ! hadrons) = 70:1 1:3 (stat:) 0:4 (syst:) % .
Using a sample of e + e annihilation events collected with the L3 detector at the Z resonance cor... more Using a sample of e + e annihilation events collected with the L3 detector at the Z resonance corresponding to an integrated luminosity of 137 pb 1 , we have searched for anomalous production of X nal states where X represents stable, weakly interacting particles and the photon energy is greater than 15 GeV. The sample of events found is consistent with Standard Model expectations. Upper limits are set on Z couplings, the neutrino magnetic moment, and the branching ratio for Z ! X.
A study of resonance formation is presented in the + 0 nal state in twophoton collisions at LEP. ... more A study of resonance formation is presented in the + 0 nal state in twophoton collisions at LEP. The a 2 (1320) radiative width is measured to be = 0:98 0:05 0:09 keV. The helicity 2 production is dominant. Exclusive + 0 production has also been studied in the mass region above the a 2 in the and f 2 channels. This region is dominated by a J P =2 + helicity 2 w a v e.
Bose-Einstein correlations of both neutral and like-sign charged pion pairs are measured in a sam... more Bose-Einstein correlations of both neutral and like-sign charged pion pairs are measured in a sample of 2 million hadronic Z decays collected with the L3 detector at LEP. The analysis is performed in the four-momentum difference range 300 MeV < Q < 2 GeV. The radius of the neutral pion source is found to be smaller than that of charged pions. This result is in qualitative agreement with the string fragmentation model.
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Papers by Arko Mukherjee