Proton

The quark structure of the proton. (The color assignment of individual quarks is not important, only that all three colors are present.)
Classification	Baryon
Composition	2 up quarks, 1 down quark
Statistics	Fermionic
Interactions	Gravity, Electromagnetic, Weak, Strong
Symbol	p, p+ , N+
Antiparticle	Antiproton
Theorized	William Prout (1815)
Discovered	Ernest Rutherford (1917-1919, named by him, 1920)
Mass	1.672621777(74)×10−27 kg[1] 938.272046(21) MeV/c2[1] 1.007276466812(90) u[1]
Mean lifetime	>2.1×1029 yr (stable)
Electric charge	+1 e 1.602176565(35)×10−19 C[1]
Charge radius	0.8775(51) fm[1]
Electric dipole moment	<5.4×10−24 e·cm
Electric polarizability	1.20(6)×10−3 fm3
Magnetic moment	1.410606743(33)×10−26 J·T−1[1] 1.521032210(12)×10−3 μB[1] 2.792847356(23) μN[1]
Magnetic polarizability	1.9(5)×10−4 fm3
Spin	1⁄2
Isospin	1⁄2
Parity	+1
Condensed	I(JP) = 1⁄2(1⁄2+)

The proton is a subatomic particle with the symbol p or p+
and a positive electric charge of 1 elementary charge. One or more protons are present in the nucleus of each atom, along with neutrons. The number of protons in each atom is its atomic number. The name proton was given to the hydrogen nucleus by Ernest Rutherford in 1920, because in previous years he had discovered that the hydrogen nucleus (known to be the lightest nucleus) could be extracted from the nuclei of nitrogen, and was thus a candidate to be a fundamental particle and building block of all complex atomic nuclei.

In the standard model of particle physics, the proton is a hadron, composed of quarks. Prior to that model becoming a consensus in the physics community, the proton was considered a fundamental particle. A proton is composed of two up quarks and one down quark, with the rest mass of the quarks thought to contribute only about 1% of the proton's mass. The remainder of the proton mass is due to the kinetic energy of the quarks and to the energy of the gluon fields that bind them together.

Because the proton is not a fundamental particle, it possesses a physical size—although this is not perfectly well-defined since the surface of a proton is defined by forces that do not come to an abrupt end, and is therefore somewhat fuzzy. The proton is about 1.6–1.7 fm in diameter.^[2]

The free proton (a proton not bound to nucleons or electrons) is stable and is found naturally in a number of situations. Free protons exist in plasmas in which temperatures are too high to allow them to combine with electrons. Free protons of high energy and velocity make up 90% of cosmic rays, which propagate in vacuum for interstellar distances. Free protons are emitted directly from atomic nuclei in some rare types of radioactive decay, and also result from the decay of free neutrons, which are unstable.

In all such cases, protons must lose sufficient velocity (and kinetic energy) to allow them to become associated with electrons, since this is a relatively low-energy interaction. However, in such an association, the character of the bound proton is not changed, and it remains a proton. The attraction of low-energy free protons to electrons in normal matter causes such protons to soon stop and to form a new chemical bond. Such a bond happens at any sufficiently "cold" temperature (i.e., comparable to temperatures at the surface of the Sun) and with any type of atom. In interaction with normal (non-plasma) matter, low-velocity free protons are attracted to electrons in any atom or molecule with which they come in contact, causing the proton and molecule to combine. Such molecules are then said to be "protonated," and chemically they often as a result become so-called Bronsted acids.

In vacuum, when free electrons are present, a sufficiently slow proton may pick up a single free electron, becoming a neutral hydrogen atom, which is chemically a free radical. Such "free hydrogen atoms" tends to react chemically with many other types of atoms, if the two come into contact and are moving sufficiently slowly.

Description[link]

Protons are spin-½ fermions and are composed of three quarks,^[3] making them baryons (a sub-type of hadrons). The two up quarks and one down quark of the proton are held together by the strong force, mediated by gluons.^[2] A modern perspective has the proton composed of the valence quarks (up, up, down), the gluons, and transitory pairs of sea quarks. The proton has an approximately exponentially decaying positive charge distribution with a mean square radius of about 0.8 fm.^[4]

Protons and neutrons are both nucleons, which may be bound by the nuclear force into atomic nuclei. The nucleus of the most common isotope of the hydrogen atom (with the chemical symbol "H") is a lone proton. The nuclei of the heavy hydrogen isotopes deuterium and tritium contain one proton bound to one and two neutrons, respectively. All other types of atoms are composed of two or more protons and various numbers of neutrons.

Stability[link]

The spontaneous decay of free protons has never been observed, and the proton is therefore considered a stable particle. However, some grand unified theories of particle physics predict that proton decay should take place with lifetimes of the order of 10³⁶ yr, and experimental searches have established lower bounds on the mean lifetime of the proton for various assumed decay products.

Experiments at the Super-Kamiokande detector in Japan gave lower limits for proton mean lifetime of 6.6×10³³ yr for decay to an antimuon and a neutral pion, and 8.2×10³³ yr for decay to a positron and a neutral pion.^[5] Another experiment at the Sudbury Neutrino Observatory in Canada searched for gamma rays resulting from residual nuclei resulting from the decay of a proton from oxygen-16. This experiment was designed to detect decay to any product, and established a lower limit to the proton lifetime of 2.1×10²⁹ yr.^[6]

However, protons are known to transform into neutrons through the process of electron capture (also called inverse beta decay). For free protons, this process does not occur spontaneously but only when energy is supplied. The equation is:

p+
+ e−
→ n + ν
e

The process is reversible; neutrons can convert back to protons through beta decay, a common form of radioactive decay. In fact, a free neutron decays this way, with a mean lifetime of about 15 minutes.

Quarks and the mass of the proton[link]

In quantum chromodynamics, the modern theory of the nuclear force, most of the mass of the proton and the neutron is explained by special relativity. The mass of the proton is about eighty times greater than the sum of the rest masses of the quarks that make it up, while the gluons have zero rest mass. The extra energy of the quarks and gluons in a region within a proton, as compared to the rest energy of the quarks alone in the QCD vacuum, accounts for almost 99% of the mass. The rest mass of the proton is, thus, the invariant mass of the system of moving quarks and gluons that make up the particle, and, in such systems, even the energy of massless particles is still measured as part of the rest mass of the system.

Two terms are used in referring to the mass of the quarks that make up protons: Current quark mass refers to the mass of a quark by itself, while constituent quark mass refers to the current quark mass plus the mass of the gluon particle field surrounding the quark.^[7] These masses typically have very different values. As noted, most of a proton's mass comes from the gluons that bind the constituent quarks together, rather than from the quarks themselves. While gluons are inherently massless, they possess energy— to be more specific, quantum chromodynamics binding energy (QCBE)—and it is this that contributes so greatly to the overall mass of the proton (see mass in special relativity). A proton has a mass of approximately 938 MeV/c², of which the rest mass of its three valence quarks contributes only about 11 MeV/c²; much of the remainder can be attributed to the gluons' QCBE.^[8]

The internal dynamics of the proton are complicated, because they are determined by the quarks' exchanging gluons, and interacting with various vacuum condensates. Lattice QCD provides a way of calculating the mass of the proton directly from the theory to any accuracy, in principle. The most recent calculations^[9][10] claim that the mass is determined to better than 4% accuracy, even to 1% accuracy (see Figure S5 in Dürr et al.^[10]). These claims are still controversial, because the calculations cannot yet be done with quarks as light as they are in the real world. This means that the predictions are found by a process of extrapolation, which can introduce systematic errors.^[11] It is hard to tell whether these errors are controlled properly, because the quantities that are compared to experiment are the masses of the hadrons, which are known in advance.

These recent calculations are performed by massive supercomputers, and, as noted by Boffi and Pasquini: “a detailed description of the nucleon structure is still missing because ... long-distance behavior requires a nonperturbative and/or numerical treatment..."^[12] More conceptual approaches to the structure of the proton are: the topological soliton approach originally due to Tony Skyrme and the more accurate AdS/QCD approach that extends it to include a string theory of gluons, various QCD-inspired models like the bag model and the constituent quark model, which were popular in the 1980s, and the SVZ sum rules, which allow for rough approximate mass calculations. These methods do not have the same accuracy as the more brute-force lattice QCD methods, at least not yet.

Charge radius[link]

The internationally-accepted value of the proton's charge radius is 0.8768 fm (see orders of magnitude for comparison to other sizes). This value is based on measurements involving a proton and an electron.

However, since July 5, 2010, an international research team has been able to make measurements involving a proton and a negatively-charged muon. After a long and careful analysis of those measurements, the team concluded that the root-mean-square charge radius of a proton is "0.84184(67) fm, which differs by 5.0 standard deviations from the CODATA value of 0.8768(69) fm."^[13]

The international research team that obtained this result at the Paul Scherrer Institut (PSI) in Villigen (Switzerland) includes scientists from the Max Planck Institute of Quantum Optics (MPQ) in Garching, the Ludwig-Maximilians-Universität (LMU) Munich and the Institut für Strahlwerkzeuge (IFWS) of the Universität Stuttgart (both from Germany), and the University of Coimbra, Portugal.^[14][15] They are now attempting to explain the discrepancy, and re-examining the results of both previous high-precision measurements and complicated calculations. If no errors are found in the measurements or calculations, it could be necessary to re-examine the world’s most precise and best-tested fundamental theory: quantum electrodynamics.^[16]

Proton in chemistry[link]

Atomic number[link]

In chemistry, the number of protons in the nucleus of an atom is known as the atomic number, which determines the chemical element to which the atom belongs. For example, the atomic number of chlorine is 17; this means that each chlorine atom has 17 protons and that all atoms with 17 protons are chlorine atoms. The chemical properties of each atom are determined by the number of (negatively charged) electrons, which for neutral atoms is equal to the number of (positive) protons so that the total charge is zero. For example, a neutral chlorine atom has 17 protons and 17 electrons, whereas a negative Cl⁻ ion has 17 protons and 18 electrons for a total charge of −1.

All atoms of a given element are not necessarily identical, however, as the number of neutrons may vary to form different isotopes, and energy levels may differ forming different nuclear isomers. For example, there are two stable isotopes of chlorine: 35
17Cl with 35 - 17 = 18 neutrons and 37
17Cl with 37 - 17 = 20 neutrons.

Hydrogen ion[link]

In chemistry, the term proton refers to the hydrogen ion, H⁺. Since the atomic number of hydrogen is 1, a hydrogen ion has no electrons and corresponds to a bare nucleus, consisting of a proton (and 0 neutrons for the most abundant isotope protium 1
1H). The proton is a "bare charge" with only about 1/64,000^th of the radius of a hydrogen atom, and so is extremely reactive chemically. The free proton, thus, has an extremely short lifetime in chemical systems such as liquids and it reacts immediately with the electron cloud of any available molecule. In aqueous solution, it forms the hydronium ion, H₃O⁺, which in turn is further solvated by water molecules in clusters such as [H₅O₂]⁺ and [H₉O₄]⁺.^[17]

The transfer of H⁺ in an acid–base reaction is usually referred to as "proton transfer". The acid is referred to as a proton donor and the base as a proton acceptor. Likewise, biochemical terms such as proton pump and proton channel refer to the movement of hydrated H⁺ ions.

The ion produced by removing the electron from a deuterium atom is known as a deuteron, not a proton. Likewise, removing an electron from a tritium atom produces a triton.

Proton nuclear magnetic resonance (NMR)[link]

Also in chemistry, the term "proton NMR" refers to the observation of hydrogen-1 nuclei in (mostly organic) molecules by nuclear magnetic resonance. This method uses the spin of the proton, which has the value one-half. The name refers to examination of protons as they occur in protium (hydrogen-1 atoms) in compounds, and does not imply that free protons exist in the compound being studied.

History[link]

The concept of a hydrogen-like particle as a constituent of other atoms was developed over a long period. As early as 1815, William Prout proposed that all atoms are composed of hydrogen atoms, based on a simplistic interpretation of early values of atomic weights (see Prout's hypothesis), which was disproved when more accurate values were measured.

Ernest Rutherford at the first Solvay Conference, 1911

In 1886, Eugen Goldstein discovered canal rays (also known as anode rays) and showed that they were positively charged particles (ions) produced from gases. However, since particles from different gases had different values of charge-to-mass ratio (e/m), they could not be identified with a single particle, unlike the negative electrons discovered by J. J. Thomson.

Following the discovery of the atomic nucleus by Ernest Rutherford in 1911, Antonius van den Broek proposed that the place of each element in the periodic table (its atomic number) is equal to its nuclear charge. This was confirmed experimentally by Henry Moseley in 1913 using X-ray spectra.

In 1917, (in experiments reported in 1919) Rutherford proved that the hydrogen nucleus is present in other nuclei, a result usually described as the discovery of the proton.^[18] Rutherford had earlier learned to produce hydrogen nuclei as a type of radiation produced as a product of the impact of alpha particles on hydrogen gas, and recognize them by their unique penetration signature in air and their appearance in scintillation detectors.

Later, Rutherford noticed that, when alpha particles were shot into air (mostly nitrogen), and (after experimentation) when alphas were produced into pure nitrogen gas, his scintillation detectors showed the signatures of typical hydrogen nuclei as a product. Rutherford determined that this hydrogen could have come only from the nitrogen, and therefore nitrogen must contain hydrogen nuclei. One hydrogen nucleus was being knocked off by the impact of the alpha particle, producing oxygen-17 in the process. This was the first reported nuclear reaction, ¹⁴N + α → ¹⁷O + p.

Rutherford knew hydrogen to be the simplest and lightest element and was influenced by Prout's hypothesis that hydrogen was the building block of all elements. Discovery that the hydrogen nucleus is present in all other nuclei as an elementary particle, led Rutherford to give the hydrogen nucleus a special name as a particle, since he suspected that hydrogen, the lightest element, contained only one of these particles. He named this new fundamental building block of the nucleus the proton, after the neuter singular of the Greek word for "first", πρῶτον. The first use of the word "proton" in the scientific literature appears in 1920. ^[19]

Exposure[link]

The Apollo Lunar Surface Experiments Packages (ALSEP) determined that more than 95% of the particles in the solar wind are electrons and protons, in approximately equal numbers.^[20][21]

Because the Solar Wind Spectrometer made continuous measurements, it was possible to measure how the Earth's magnetic field affects arriving solar wind particles. For about two-thirds of each orbit, the Moon is outside of the Earth's magnetic field. At these times, a typical proton density was 10 to 20 per cubic centimeter, with most protons having velocities between 400 and 650 kilometers per second. For about five days of each month, the Moon is inside the Earth's geomagnetic tail, and typically no solar wind particles were detectable. For the remainder of each lunar orbit, the Moon is in a transitional region known as the magnetosheath, where the Earth's magnetic field affects the solar wind but does not completely exclude it. In this region, the particle flux is reduced, with typical proton velocities of 250 to 450 kilometers per second. During the lunar night, the spectrometer was shielded from the solar wind by the Moon and no solar wind particles were measured.^[20]

Protons also occur in from extrasolar origin in space, from galactic cosmic rays, where they make up about 90% of the total particle flux. These protons often have higher energy than solar wind protons, but their intensity is far more uniform and less variable than protons coming from the Sun, the production of which is heavily affected by solar proton events such as coronal mass ejections.

Research has been performed on the dose-rate effects of protons, as typically found in space travel, on human health.^[21][22] To be more specific, there are hopes to identify what specific chromosomes are damaged, and to define the damage, during cancer development from proton exposure.^[21] Another study looks into determining "the effects of exposure to proton irradiation on neurochemical and behavioral endpoints, including dopaminergic functioning, amphetamine-induced conditioned taste aversion learning, and spatial learning and memory as measured by the Morris water maze."^[22] Electrical charging of a spacecraft due to interplanetary proton bombardment has also been proposed for study.^[23] There are many more studies that pertain to space travel, including galactic cosmic rays and their possible health effects, and solar proton event exposure.

The American Biostack and Soviet Biorack space travel experiments have demonstrated the severity of molecular damage induced by heavy ions on micro organisms including Artemia cysts.^[24]

Antiproton[link]

CPT-symmetry puts strong constraints on the relative properties of particles and antiparticles and, therefore, is open to stringent tests. For example, the charges of the proton and antiproton must sum to exactly zero. This equality has been tested to one part in 10⁸. The equality of their masses has also been tested to better than one part in 10⁸. By holding antiprotons in a Penning trap, the equality of the charge to mass ratio of the proton and the antiproton has been tested to one part in 6×10⁹.^[25] The magnetic moment of the antiproton has been measured with error of 8×10⁻³ nuclear Bohr magnetons, and is found to be equal and opposite to that of the proton.

See also[link]

References[link]

External links[link]

Wikimedia Commons has media related to: Proton

• Particle Data Group
• Large Hadron Collider

Jean Alesi Born (1964-06-11) 11 June 1964 (age 48) Formula One World Championship career Nationality French Active years 1989–2001 Teams Tyrrell, Ferrari, Benetton, Sauber, Prost, Jordan Races 202 (201 starts) Championships 0 Wins 1 Podiums 32 Career points 241 Pole positions 2 Fastest laps 4 First race 1989 French Grand Prix First win 1995 Canadian Grand Prix Last win 1995 Canadian Grand Prix Last race 2001 Japanese Grand Prix 24 Hours of Le Mans career Participating years 1989, 2010 Teams Team Schuppan AF Corse Best finish 4th in LMGT2 (2010) Class wins 0 IndyCar Series career 1 race(s) run over 1 year(s) Team(s) No. 64 (Fan Force United) First race 2012 Indianapolis 500 (Indy) Wins Podiums Poles 0 0 0

Jean Alesi (born Giovanni Alesi; June 11, 1964) is a French racing driver of Italian origin. His Formula One career included spells at Tyrrell, Benetton, Sauber, Prost, Jordan and most notably Ferrari where he proved very popular among the tifosi. In 2006 Alesi was awarded Chevalier de la Legion d’honneur.^[1]

Early career[link]

Alesi was born to Sicilian parents in Avignon, Vaucluse. Starting his career with a passion for rallying rather than racing, he graduated to single seaters through the French Renault 5 championship. In the late 1980s he was very much a coming man in motor racing, winning the 1987 French Formula 3 title before moving up to International Formula 3000 in 1988. In 1989, his second season in International F3000, he won the championship. Both crowns were after duels with his rival Érik Comas. In 1989 Alesi tied on points for the F3000 title with Comas but won the titled based on the fact Alesi had three wins to Comas' two.

Formula One[link]

Alesi at the 1991 US GP, driving for Ferrari

Alesi debuted in the 1989 French Grand Prix at Paul Ricard in a Tyrrell-Cosworth, replacing Michele Alboreto, finishing fourth. He drove most of the rest of the season for Tyrrell while continuing his successful Formula 3000 campaign, (occasionally giving the car up in favour of Johnny Herbert when Formula 3000 clashed), scoring points again at the Italian and Spanish Grands Prix.

1990 was his first full year in Grand Prix racing, with the underfunded Tyrrell team. At the first event, the United States Grand Prix at Phoenix, he was a sensation, leading for 25 laps in front of Ayrton Senna with a car considered as inferior, and also re-passing Senna after the Brazilian had first overtaken for the lead. Second place in the Monaco Grand Prix followed the second place gained in Phoenix, and by mid-season, top teams were clamouring for his services in 1991. A very confused situation erupted, with Tyrrell, Williams, and Ferrari all claiming to have signed the driver within a very short period.

Jean Alesi took his only Grand Prix win at the 1995 Canadian Grand Prix in Montreal.

Ferrari were championship contenders at the time, and there he would be driving with fellow countryman Alain Prost, at that time the most successful driver in Formula One history. Alesi signed with Ferrari, making the choice that not only appeared to maximize his chances for winning the championship and for learning from an experienced and successful teammate, but that fulfilled his childhood dream of driving for the Italian team.

Alesi driving for Sauber at the 1999 Canadian Grand Prix.

Alesi driving for Prost at the 2001 French Grand Prix.

Ferrari, however, experienced a disastrous downturn in form in 1991, while the Williams team experienced a resurgence which would lead them to win five constructor's titles between 1992 and 1997, thus becoming the most successful team of the 1990s. Alesi's choice of Ferrari over Williams seemed the most logical at the time, but turned out to be very unfortunate. One of the reasons for this failure was because Ferrari's famous V12 engine was no longer competitive against the smaller, lighter and more fuel efficient V10s of their competitors. Having a dismal 1991 season, Prost left the team describing the car as a "truck" and took a sabbatical.

Alesi was partnered by Ivan Capelli the following year, before being joined by Austrian Gerhard Berger in 1993. Alesi injured his back after the first race of the 1994 season (Brazil) and was replaced in the Pacific Grand Prix and the infamous San Marino Grand Prix (round 3) by Nicola Larini. In five years at the Italian marque Alesi gained little, except the passionate devotion of the tifosi, who loved his aggressive style. That style, and his use of the number 27 on his car, led many to associate him with Gilles Villeneuve, a beloved and still-popular Ferrari driver from 1977–1982. Alesi and Berger won only one race each during this period at Ferrari. Following Alesi's first and only GP win in the 1995 Canadian Grand Prix (on his 31st birthday), his Ferrari ran out of fuel as he waved to fans on the backstraight and he was given a lift back to the pits by Michael Schumacher.

When Benetton's Michael Schumacher joined Ferrari in 1996, Alesi and teammate Gerhard Berger swapped places with him. Though Benetton was the defending constructors' champions, they were about to experience a lull in form like Ferrari in 1991. Schumacher went on to rejuvenate Ferrari, while Alesi and Berger spent two seasons at a declining Benetton riddled with bad luck and internal politics. While Berger had a reasonable run at Benetton, winning the 1997 German Grand Prix after having come two laps from victory at the same race the previous year when his engine blew while he was leading within sight of the flag, Alesi's Benetton career proved more turbulent, not helped by an embarrassing retirement in the season-opening Australian Grand Prix in 1997 when he ignored several radio messages from the pit mechanics to come in for his pit stop, and continued for five laps until running out of fuel. His form became increasingly erratic that season, including incidents at the French Grand Prix when he needlessly pushed David Coulthard off the track, and the Austrian Grand Prix, where his attempt to outbrake Eddie Irvine from nearly eight lengths behind caused a spectacular collision that saw Alesi placed under investigation for dangerous driving after the race. A pole position and eventual second place at the Italian Grand Prix were not enough to salvage his drive at Benetton, and the team released Alesi at the end of the 1997 season.

Alesi at the 2001 United States Grand Prix at Indianapolis.

Alesi moved on, initially to Sauber and later Prost, the latter which was owned by his former Ferrari teammate Alain Prost. With Prost, Alesi was consistent, finishing every race, occasionally in points scoring positions, his best finish being at Canada. A fallout after the British Grand Prix, however saw Alesi walk out after the German Grand Prix, where he scored a point. The reason was because of the German driver Heinz-Harald Frentzen was suddenly sacked by Jordan after the British Grand Prix and he needed a drive, he was interested in joining the Prost team. Alesi finally decided to leave Prost after the German Grand Prix in order give way to Frentzen. Then, Alesi joined Jordan and eventually swapped teams.

Alesi ended his open-wheel career in 2001 with Jordan, bookending his career nicely: Alesi had driven for Jordan in Formula 3000 when he won the championship in 1989.

Legacy[link]

Alesi was often regarded as flamboyant, emotional and aggressive, but after his spectacular performance at Phoenix in 1990, his career was notable more for its "bad luck" and longevity than for its final results. In 2001, he became only the fifth driver to start 200 Grand Prix races, and he achieved thirty-two podiums, yet he only gained one victory. It could be suggested that Alesi's potential was unfulfilled – some say he spent his peak years during the uncompetitive period at Ferrari – retiring while in the lead or in 2nd place in no less than 9 races (1991: Spain (10 seconds stop penalty and still finishing 23 seconds behind the winner) and Belgium (1st), 1994: Belgium (2nd) and Italy (1st), 1995: Spain, Monaco, Japan (all in 2nd place), Belgium and Italy (both in 1st) – but somehow he was unlucky when driving for Benetton too, losing the lead of the Italian GP both in 1996 and 1997 after relatively slow pitstops and Monaco 1996 retiring with suspension failure.

His sole win was an emotional triumph at the 1995 Canadian Grand Prix in Montreal on his 31st birthday. Although he had inherited the lead when Michael Schumacher pitted with electrical problems and Damon Hill's hydraulics prevented a challenge, the victory was a popular one, particularly after several excellent but ultimately unrewarded drives for years at Ferrari, notably in Italy. Alesi's win at Montreal was voted the most popular race victory of the season by many, as it was the scarlet red number 27 Ferrari – once belonging to the famous Gilles Villeneuve at his much loved home Grand Prix. Memorably, Schumacher gave Alesi a lift back to the pits after Alesi's car ran out of fuel just before the Pits Hairpin.

Alesi would never win another Formula One Grand Prix, although later in 1995 at Monza his right-rear wheel bearing failed while he was leading with 9 laps to go, then at the Nürburgring severely worn tyres broke his defence of the lead with two laps remaining and he was passed by Michael Schumacher. In 1996 suspension failure with ten laps left prevented him from taking victory at Monaco (although he had led this race only after Damon Hill, who had held a commanding lead for the first half of the race, was forced to retire on lap 40 when his Renault engine blew up in the Tunnel) while in 1997 he led the Italian Grand Prix from pole before relinquishing the lead to David Coulthard courtesy of a slow pit stop in the middle stages of the race.

Post-Formula One career[link]

Alesi driving for Mercedes-Benz (Persson Motorsport) in the 2006 DTM season.

Jean Alesi in his 2006 DTM-Mercedes racecar

DTM 2002-2006[link]

After Formula One, Alesi was a popular and successful driver in the DTM (German Touring Car Championship), where he placed fifth in the 2002 championship for Mercedes with one victory. He repeated this in 2003 but this time scoring two victories. In 2004 he finished seventh in the championship scoring no victories. In 2005 he won the opening race and went on to take seventh place in the standings once more. He retired from the DTM after finishing the 2006 season in 9th place.

• 2002 – 5th in the championship, 1 victory,
• 2003 – 5th, 2 victories,
• 2004 – 7th,
• 2005 – 7th, 1 victory,
• 2006 – 9th

Direxiv[link]

Alesi was an active spokesman for the Direxiv team in their bid for entry to the 2008 Formula 1 series. It was planned as a McLaren B Team with backing and engines from Mercedes. However, the proposal was beaten to the final grid place by Prodrive.

Speedcar Series 2008-2009[link]

Alesi joined a number of other ex-Formula One drivers (Christian Danner, Johnny Herbert, Stefan Johansson, Ukyo Katayama, JJ Lehto, Gianni Morbidelli, Jacques Villeneuve and Alex Yoong) in the inaugural season of the Far & Middle Eastern Speedcar Series. He won two races and finished 4th in the championship. He finished fifth in the second and last season of Speedcar Series after taking two wins in 2009.

• 2008 - 4th, 2 victories
• 2009 - 5th, 2 victories

Le Mans Series 2010-[link]

On October 13, 2009, Alesi tested an AF Corse Ferrari F430 GT2 at Maranello, on the same day that Felipe Massa drove an F1 car for the first time after his accident in Hungary earlier in the year. After the test, which lasted just 65 laps, Alesi was enthusiastic and Amato Ferrari talked about Alesi's possible involvement in the 2010 programme.

Early in 2010 it was announced that Alesi would be the team-mate of another ex-F1 Ferrari driver, Giancarlo Fisichella, in the Le Mans Series GT2 class in Ferrari's AF Corse team.^[2] In the first two races Alesi and his team-mates Fisichella and Finn Toni Vilander finished on the podium. Alesi, Fisichella and Vilander raced in the Le Mans 24 h race for AF Corse and finished 4th in their class.^[3] In the third race of the season in Algarve the trio finished in second position^[4] and at the Hungaroring they finished in fourth place. They finished second in the championship.

Lotus 2011–[link]

In January 2011, along with the launch of their new car, Lotus Renault GP announced that they had hired Alesi as an ambassador for the team and test driver for the T125 single-seater project. In September, Alesi announced that he will attempt to qualify for the 2012 Indianapolis 500, in a car powered by a Lotus-badged engine.^[5]

On Series Seventeen, Episode 5 of BBC TV show Top Gear, Alesi helped current host Jeremy Clarkson to test drive one of the T125 single seaters.

i1 Super Series[link]

In the last quarter of 2011, Alesi joined the inaugural i1 Super Series as an International class driver, however this series was later postponed.

Indianapolis 500[link]

In April 2012, Alesi announced his intent to race in the 2012 Indianapolis 500 with a Lotus engine. Deals with former IZOD Indycar Series team Newman/Haas Racing fell through, and HVM Racing owner Keith Wiggins said that his team didn't have the funding to run Alesi in the 500.^[6] However, Firestone Indy Lights team Fan Force United agreed to field Alesi in the 500^[7] where he qualified 33rd. Unfortunately, his Lotus powered car, along with that of fellow Lotus driver Simona de Silvestro, were unable to maintain sufficient pace in the race and were forced to park their cars after less than a dozen laps.

Helmet[link]

His helmet is white with black and red lines going down on the front side of the helmet with his name written, being an homage to Elio de Angelis, in addition to a deep blue top section(sometimes shaped after a raindrop which contains smaller, light blue "raindrops". From 2000 his helmet has changed from white to silver (owing to one of Sauber's sponsors being Red Bull).

Personal life[link]

Alesi is a wine connoisseur and has a vineyard near his hometown of Avignon, where he resides with his wife, Japanese model, actress, and pop singer Kumiko Goto (後藤久美子), and their four children.

Racing record[link]

Complete International Formula 3000 results[link]

(key) (Races in bold indicate pole position) (Races in italics indicate fastest lap)

* – Alesi won the 1989 title on countback, winning three races to Érik Comas' two.

Complete Formula One results[link]

(key) (Races in bold indicate pole position; races in italics indicate fastest lap)

Complete DTM results[link]

(key) (Races in bold indicate pole position) (Races in italics indicate fastest lap)

¹ - Shanghai was a non-championship round.

24 Hours of Le Mans results[link]

Year	Class	No	Tyres	Car	Team	Co-Drivers	Laps	Pos.	Class Pos.
1989	C1	33	D	Porsche 962C Porsche Type-935 3.0L Turbo Flat-6	Team Schuppan	Will Hoy Dominic Dobson	69	DNF	DNF
2010	GT2	95	M	Ferrari F430 GT2 Ferrari 4.0L V8	AF Corse SRL	Giancarlo Fisichella Toni Vilander	323	16th	4th

Complete American open–wheel racing results[link]

(key)

IndyCar Series[link]

* Season in progress

Indianapolis 500[link]